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authorRich Geldreich <richgel99@gmail.com>2014-02-07 16:48:08 +0900
committerCedric BAIL <cedric.bail@free.fr>2014-04-01 22:00:13 +0900
commit03b29127f1bf27ab38147308c5615c35c4ee5b65 (patch)
treebc8b2e19c8fdee830ae5cbdca8b97c066216a433 /src/static_libs
parent9f5ea9cdae92128e586f49778ce99db7a7214689 (diff)
rg_etc: add original code from rg-etc1 project.
Code come from https://code.google.com/p/rg-etc1/ and is under Zlib license. The content of this directory will remain under that said license.
Diffstat (limited to 'src/static_libs')
-rw-r--r--src/static_libs/rg_etc/rg_etc1.cpp2446
-rw-r--r--src/static_libs/rg_etc/rg_etc1.h76
2 files changed, 2522 insertions, 0 deletions
diff --git a/src/static_libs/rg_etc/rg_etc1.cpp b/src/static_libs/rg_etc/rg_etc1.cpp
new file mode 100644
index 0000000..a1cd73f
--- /dev/null
+++ b/src/static_libs/rg_etc/rg_etc1.cpp
@@ -0,0 +1,2446 @@
1// File: rg_etc1.cpp - Fast, high quality ETC1 block packer/unpacker - Rich Geldreich <richgel99@gmail.com>
2// Please see ZLIB license at the end of rg_etc1.h.
3//
4// For more information Ericsson Texture Compression (ETC/ETC1), see:
5// http://www.khronos.org/registry/gles/extensions/OES/OES_compressed_ETC1_RGB8_texture.txt
6//
7// v1.04 - 5/15/14 - Fix signed vs. unsigned subtraction problem (noticed when compiled with gcc) in pack_etc1_block_init().
8// This issue would cause an assert when this func. was called in debug. (Note this module was developed/testing with MSVC,
9// I still need to test it throughly when compiled with gcc.)
10//
11// v1.03 - 5/12/13 - Initial public release
12#include "rg_etc1.h"
13
14#include <stdlib.h>
15#include <memory.h>
16#include <assert.h>
17//#include <stdio.h>
18#include <math.h>
19
20#pragma warning (disable: 4201) // nonstandard extension used : nameless struct/union
21
22#if defined(_DEBUG) || defined(DEBUG)
23#define RG_ETC1_BUILD_DEBUG
24#endif
25
26#define RG_ETC1_ASSERT assert
27
28namespace rg_etc1
29{
30 typedef unsigned char uint8;
31 typedef unsigned short uint16;
32 typedef unsigned int uint;
33 typedef unsigned int uint32;
34 typedef long long int64;
35 typedef unsigned long long uint64;
36
37 const uint32 cUINT32_MAX = 0xFFFFFFFFU;
38 const uint64 cUINT64_MAX = 0xFFFFFFFFFFFFFFFFULL; //0xFFFFFFFFFFFFFFFFui64;
39
40 template<typename T> inline T minimum(T a, T b) { return (a < b) ? a : b; }
41 template<typename T> inline T minimum(T a, T b, T c) { return minimum(minimum(a, b), c); }
42 template<typename T> inline T maximum(T a, T b) { return (a > b) ? a : b; }
43 template<typename T> inline T maximum(T a, T b, T c) { return maximum(maximum(a, b), c); }
44 template<typename T> inline T clamp(T value, T low, T high) { return (value < low) ? low : ((value > high) ? high : value); }
45 template<typename T> inline T square(T value) { return value * value; }
46 template<typename T> inline void zero_object(T& obj) { memset((void*)&obj, 0, sizeof(obj)); }
47 template<typename T> inline void zero_this(T* pObj) { memset((void*)pObj, 0, sizeof(*pObj)); }
48
49 template<class T, size_t N> T decay_array_to_subtype(T (&a)[N]);
50
51#define RG_ETC1_ARRAY_SIZE(X) (sizeof(X) / sizeof(decay_array_to_subtype(X)))
52
53 enum eNoClamp { cNoClamp };
54
55 struct color_quad_u8
56 {
57 static inline int clamp(int v) { if (v & 0xFFFFFF00U) v = (~(static_cast<int>(v) >> 31)) & 0xFF; return v; }
58
59 struct component_traits { enum { cSigned = false, cFloat = false, cMin = 0U, cMax = 255U }; };
60
61 public:
62 typedef unsigned char component_t;
63 typedef int parameter_t;
64
65 enum { cNumComps = 4 };
66
67 union
68 {
69 struct
70 {
71 component_t r;
72 component_t g;
73 component_t b;
74 component_t a;
75 };
76
77 component_t c[cNumComps];
78
79 uint32 m_u32;
80 };
81
82 inline color_quad_u8()
83 {
84 }
85
86 inline color_quad_u8(const color_quad_u8& other) : m_u32(other.m_u32)
87 {
88 }
89
90 explicit inline color_quad_u8(parameter_t y, parameter_t alpha = component_traits::cMax)
91 {
92 set(y, alpha);
93 }
94
95 inline color_quad_u8(parameter_t red, parameter_t green, parameter_t blue, parameter_t alpha = component_traits::cMax)
96 {
97 set(red, green, blue, alpha);
98 }
99
100 explicit inline color_quad_u8(eNoClamp, parameter_t y, parameter_t alpha = component_traits::cMax)
101 {
102 set_noclamp_y_alpha(y, alpha);
103 }
104
105 inline color_quad_u8(eNoClamp, parameter_t red, parameter_t green, parameter_t blue, parameter_t alpha = component_traits::cMax)
106 {
107 set_noclamp_rgba(red, green, blue, alpha);
108 }
109
110 inline void clear()
111 {
112 m_u32 = 0;
113 }
114
115 inline color_quad_u8& operator= (const color_quad_u8& other)
116 {
117 m_u32 = other.m_u32;
118 return *this;
119 }
120
121 inline color_quad_u8& set_rgb(const color_quad_u8& other)
122 {
123 r = other.r;
124 g = other.g;
125 b = other.b;
126 return *this;
127 }
128
129 inline color_quad_u8& operator= (parameter_t y)
130 {
131 set(y, component_traits::cMax);
132 return *this;
133 }
134
135 inline color_quad_u8& set(parameter_t y, parameter_t alpha = component_traits::cMax)
136 {
137 y = clamp(y);
138 alpha = clamp(alpha);
139 r = static_cast<component_t>(y);
140 g = static_cast<component_t>(y);
141 b = static_cast<component_t>(y);
142 a = static_cast<component_t>(alpha);
143 return *this;
144 }
145
146 inline color_quad_u8& set_noclamp_y_alpha(parameter_t y, parameter_t alpha = component_traits::cMax)
147 {
148 RG_ETC1_ASSERT( (y >= component_traits::cMin) && (y <= component_traits::cMax) );
149 RG_ETC1_ASSERT( (alpha >= component_traits::cMin) && (alpha <= component_traits::cMax) );
150
151 r = static_cast<component_t>(y);
152 g = static_cast<component_t>(y);
153 b = static_cast<component_t>(y);
154 a = static_cast<component_t>(alpha);
155 return *this;
156 }
157
158 inline color_quad_u8& set(parameter_t red, parameter_t green, parameter_t blue, parameter_t alpha = component_traits::cMax)
159 {
160 r = static_cast<component_t>(clamp(red));
161 g = static_cast<component_t>(clamp(green));
162 b = static_cast<component_t>(clamp(blue));
163 a = static_cast<component_t>(clamp(alpha));
164 return *this;
165 }
166
167 inline color_quad_u8& set_noclamp_rgba(parameter_t red, parameter_t green, parameter_t blue, parameter_t alpha)
168 {
169 RG_ETC1_ASSERT( (red >= component_traits::cMin) && (red <= component_traits::cMax) );
170 RG_ETC1_ASSERT( (green >= component_traits::cMin) && (green <= component_traits::cMax) );
171 RG_ETC1_ASSERT( (blue >= component_traits::cMin) && (blue <= component_traits::cMax) );
172 RG_ETC1_ASSERT( (alpha >= component_traits::cMin) && (alpha <= component_traits::cMax) );
173
174 r = static_cast<component_t>(red);
175 g = static_cast<component_t>(green);
176 b = static_cast<component_t>(blue);
177 a = static_cast<component_t>(alpha);
178 return *this;
179 }
180
181 inline color_quad_u8& set_noclamp_rgb(parameter_t red, parameter_t green, parameter_t blue)
182 {
183 RG_ETC1_ASSERT( (red >= component_traits::cMin) && (red <= component_traits::cMax) );
184 RG_ETC1_ASSERT( (green >= component_traits::cMin) && (green <= component_traits::cMax) );
185 RG_ETC1_ASSERT( (blue >= component_traits::cMin) && (blue <= component_traits::cMax) );
186
187 r = static_cast<component_t>(red);
188 g = static_cast<component_t>(green);
189 b = static_cast<component_t>(blue);
190 return *this;
191 }
192
193 static inline parameter_t get_min_comp() { return component_traits::cMin; }
194 static inline parameter_t get_max_comp() { return component_traits::cMax; }
195 static inline bool get_comps_are_signed() { return component_traits::cSigned; }
196
197 inline component_t operator[] (uint i) const { RG_ETC1_ASSERT(i < cNumComps); return c[i]; }
198 inline component_t& operator[] (uint i) { RG_ETC1_ASSERT(i < cNumComps); return c[i]; }
199
200 inline color_quad_u8& set_component(uint i, parameter_t f)
201 {
202 RG_ETC1_ASSERT(i < cNumComps);
203
204 c[i] = static_cast<component_t>(clamp(f));
205
206 return *this;
207 }
208
209 inline color_quad_u8& set_grayscale(parameter_t l)
210 {
211 component_t x = static_cast<component_t>(clamp(l));
212 c[0] = x;
213 c[1] = x;
214 c[2] = x;
215 return *this;
216 }
217
218 inline color_quad_u8& clamp(const color_quad_u8& l, const color_quad_u8& h)
219 {
220 for (uint i = 0; i < cNumComps; i++)
221 c[i] = static_cast<component_t>(rg_etc1::clamp<parameter_t>(c[i], l[i], h[i]));
222 return *this;
223 }
224
225 inline color_quad_u8& clamp(parameter_t l, parameter_t h)
226 {
227 for (uint i = 0; i < cNumComps; i++)
228 c[i] = static_cast<component_t>(rg_etc1::clamp<parameter_t>(c[i], l, h));
229 return *this;
230 }
231
232 // Returns CCIR 601 luma (consistent with color_utils::RGB_To_Y).
233 inline parameter_t get_luma() const
234 {
235 return static_cast<parameter_t>((19595U * r + 38470U * g + 7471U * b + 32768U) >> 16U);
236 }
237
238 // Returns REC 709 luma.
239 inline parameter_t get_luma_rec709() const
240 {
241 return static_cast<parameter_t>((13938U * r + 46869U * g + 4729U * b + 32768U) >> 16U);
242 }
243
244 inline uint squared_distance_rgb(const color_quad_u8& c) const
245 {
246 return rg_etc1::square(r - c.r) + rg_etc1::square(g - c.g) + rg_etc1::square(b - c.b);
247 }
248
249 inline uint squared_distance_rgba(const color_quad_u8& c) const
250 {
251 return rg_etc1::square(r - c.r) + rg_etc1::square(g - c.g) + rg_etc1::square(b - c.b) + rg_etc1::square(a - c.a);
252 }
253
254 inline bool rgb_equals(const color_quad_u8& rhs) const
255 {
256 return (r == rhs.r) && (g == rhs.g) && (b == rhs.b);
257 }
258
259 inline bool operator== (const color_quad_u8& rhs) const
260 {
261 return m_u32 == rhs.m_u32;
262 }
263
264 color_quad_u8& operator+= (const color_quad_u8& other)
265 {
266 for (uint i = 0; i < 4; i++)
267 c[i] = static_cast<component_t>(clamp(c[i] + other.c[i]));
268 return *this;
269 }
270
271 color_quad_u8& operator-= (const color_quad_u8& other)
272 {
273 for (uint i = 0; i < 4; i++)
274 c[i] = static_cast<component_t>(clamp(c[i] - other.c[i]));
275 return *this;
276 }
277
278 friend color_quad_u8 operator+ (const color_quad_u8& lhs, const color_quad_u8& rhs)
279 {
280 color_quad_u8 result(lhs);
281 result += rhs;
282 return result;
283 }
284
285 friend color_quad_u8 operator- (const color_quad_u8& lhs, const color_quad_u8& rhs)
286 {
287 color_quad_u8 result(lhs);
288 result -= rhs;
289 return result;
290 }
291 }; // class color_quad_u8
292
293 struct vec3F
294 {
295 float m_s[3];
296
297 inline vec3F() { }
298 inline vec3F(float s) { m_s[0] = s; m_s[1] = s; m_s[2] = s; }
299 inline vec3F(float x, float y, float z) { m_s[0] = x; m_s[1] = y; m_s[2] = z; }
300
301 inline float operator[] (uint i) const { RG_ETC1_ASSERT(i < 3); return m_s[i]; }
302
303 inline vec3F& operator += (const vec3F& other) { for (uint i = 0; i < 3; i++) m_s[i] += other.m_s[i]; return *this; }
304
305 inline vec3F& operator *= (float s) { for (uint i = 0; i < 3; i++) m_s[i] *= s; return *this; }
306 };
307
308 enum etc_constants
309 {
310 cETC1BytesPerBlock = 8U,
311
312 cETC1SelectorBits = 2U,
313 cETC1SelectorValues = 1U << cETC1SelectorBits,
314 cETC1SelectorMask = cETC1SelectorValues - 1U,
315
316 cETC1BlockShift = 2U,
317 cETC1BlockSize = 1U << cETC1BlockShift,
318
319 cETC1LSBSelectorIndicesBitOffset = 0,
320 cETC1MSBSelectorIndicesBitOffset = 16,
321
322 cETC1FlipBitOffset = 32,
323 cETC1DiffBitOffset = 33,
324
325 cETC1IntenModifierNumBits = 3,
326 cETC1IntenModifierValues = 1 << cETC1IntenModifierNumBits,
327 cETC1RightIntenModifierTableBitOffset = 34,
328 cETC1LeftIntenModifierTableBitOffset = 37,
329
330 // Base+Delta encoding (5 bit bases, 3 bit delta)
331 cETC1BaseColorCompNumBits = 5,
332 cETC1BaseColorCompMax = 1 << cETC1BaseColorCompNumBits,
333
334 cETC1DeltaColorCompNumBits = 3,
335 cETC1DeltaColorComp = 1 << cETC1DeltaColorCompNumBits,
336 cETC1DeltaColorCompMax = 1 << cETC1DeltaColorCompNumBits,
337
338 cETC1BaseColor5RBitOffset = 59,
339 cETC1BaseColor5GBitOffset = 51,
340 cETC1BaseColor5BBitOffset = 43,
341
342 cETC1DeltaColor3RBitOffset = 56,
343 cETC1DeltaColor3GBitOffset = 48,
344 cETC1DeltaColor3BBitOffset = 40,
345
346 // Absolute (non-delta) encoding (two 4-bit per component bases)
347 cETC1AbsColorCompNumBits = 4,
348 cETC1AbsColorCompMax = 1 << cETC1AbsColorCompNumBits,
349
350 cETC1AbsColor4R1BitOffset = 60,
351 cETC1AbsColor4G1BitOffset = 52,
352 cETC1AbsColor4B1BitOffset = 44,
353
354 cETC1AbsColor4R2BitOffset = 56,
355 cETC1AbsColor4G2BitOffset = 48,
356 cETC1AbsColor4B2BitOffset = 40,
357
358 cETC1ColorDeltaMin = -4,
359 cETC1ColorDeltaMax = 3,
360
361 // Delta3:
362 // 0 1 2 3 4 5 6 7
363 // 000 001 010 011 100 101 110 111
364 // 0 1 2 3 -4 -3 -2 -1
365 };
366
367 static uint8 g_quant5_tab[256+16];
368
369 static const int g_etc1_inten_tables[cETC1IntenModifierValues][cETC1SelectorValues] =
370 {
371 { -8, -2, 2, 8 }, { -17, -5, 5, 17 }, { -29, -9, 9, 29 }, { -42, -13, 13, 42 },
372 { -60, -18, 18, 60 }, { -80, -24, 24, 80 }, { -106, -33, 33, 106 }, { -183, -47, 47, 183 }
373 };
374
375 static const uint8 g_etc1_to_selector_index[cETC1SelectorValues] = { 2, 3, 1, 0 };
376 static const uint8 g_selector_index_to_etc1[cETC1SelectorValues] = { 3, 2, 0, 1 };
377
378 // Given an ETC1 diff/inten_table/selector, and an 8-bit desired color, this table encodes the best packed_color in the low byte, and the abs error in the high byte.
379 static uint16 g_etc1_inverse_lookup[2*8*4][256]; // [diff/inten_table/selector][desired_color]
380
381 // g_color8_to_etc_block_config[color][table_index] = Supplies for each 8-bit color value a list of packed ETC1 diff/intensity table/selectors/packed_colors that map to that color.
382 // To pack: diff | (inten << 1) | (selector << 4) | (packed_c << 8)
383 static const uint16 g_color8_to_etc_block_config_0_255[2][33] =
384 {
385 { 0x0000, 0x0010, 0x0002, 0x0012, 0x0004, 0x0014, 0x0006, 0x0016, 0x0008, 0x0018, 0x000A, 0x001A, 0x000C, 0x001C, 0x000E, 0x001E,
386 0x0001, 0x0011, 0x0003, 0x0013, 0x0005, 0x0015, 0x0007, 0x0017, 0x0009, 0x0019, 0x000B, 0x001B, 0x000D, 0x001D, 0x000F, 0x001F, 0xFFFF },
387 { 0x0F20, 0x0F30, 0x0E32, 0x0F22, 0x0E34, 0x0F24, 0x0D36, 0x0F26, 0x0C38, 0x0E28, 0x0B3A, 0x0E2A, 0x093C, 0x0E2C, 0x053E, 0x0D2E,
388 0x1E31, 0x1F21, 0x1D33, 0x1F23, 0x1C35, 0x1E25, 0x1A37, 0x1E27, 0x1839, 0x1D29, 0x163B, 0x1C2B, 0x133D, 0x1B2D, 0x093F, 0x1A2F, 0xFFFF },
389 };
390
391 // Really only [254][11].
392 static const uint16 g_color8_to_etc_block_config_1_to_254[254][12] =
393 {
394 { 0x021C, 0x0D0D, 0xFFFF }, { 0x0020, 0x0021, 0x0A0B, 0x061F, 0xFFFF }, { 0x0113, 0x0217, 0xFFFF }, { 0x0116, 0x031E,
395 0x0B0E, 0x0405, 0xFFFF }, { 0x0022, 0x0204, 0x050A, 0x0023, 0xFFFF }, { 0x0111, 0x0319, 0x0809, 0x170F, 0xFFFF }, {
396 0x0303, 0x0215, 0x0607, 0xFFFF }, { 0x0030, 0x0114, 0x0408, 0x0031, 0x0201, 0x051D, 0xFFFF }, { 0x0100, 0x0024, 0x0306,
397 0x0025, 0x041B, 0x0E0D, 0xFFFF }, { 0x021A, 0x0121, 0x0B0B, 0x071F, 0xFFFF }, { 0x0213, 0x0317, 0xFFFF }, { 0x0112,
398 0x0505, 0xFFFF }, { 0x0026, 0x070C, 0x0123, 0x0027, 0xFFFF }, { 0x0211, 0x0909, 0xFFFF }, { 0x0110, 0x0315, 0x0707,
399 0x0419, 0x180F, 0xFFFF }, { 0x0218, 0x0131, 0x0301, 0x0403, 0x061D, 0xFFFF }, { 0x0032, 0x0202, 0x0033, 0x0125, 0x051B,
400 0x0F0D, 0xFFFF }, { 0x0028, 0x031C, 0x0221, 0x0029, 0xFFFF }, { 0x0120, 0x0313, 0x0C0B, 0x081F, 0xFFFF }, { 0x0605,
401 0x0417, 0xFFFF }, { 0x0216, 0x041E, 0x0C0E, 0x0223, 0x0127, 0xFFFF }, { 0x0122, 0x0304, 0x060A, 0x0311, 0x0A09, 0xFFFF
402 }, { 0x0519, 0x190F, 0xFFFF }, { 0x002A, 0x0231, 0x0503, 0x0415, 0x0807, 0x002B, 0x071D, 0xFFFF }, { 0x0130, 0x0214,
403 0x0508, 0x0401, 0x0133, 0x0225, 0x061B, 0xFFFF }, { 0x0200, 0x0124, 0x0406, 0x0321, 0x0129, 0x100D, 0xFFFF }, { 0x031A,
404 0x0D0B, 0x091F, 0xFFFF }, { 0x0413, 0x0705, 0x0517, 0xFFFF }, { 0x0212, 0x0034, 0x0323, 0x0035, 0x0227, 0xFFFF }, {
405 0x0126, 0x080C, 0x0B09, 0xFFFF }, { 0x0411, 0x0619, 0x1A0F, 0xFFFF }, { 0x0210, 0x0331, 0x0603, 0x0515, 0x0907, 0x012B,
406 0xFFFF }, { 0x0318, 0x002C, 0x0501, 0x0233, 0x0325, 0x071B, 0x002D, 0x081D, 0xFFFF }, { 0x0132, 0x0302, 0x0229, 0x110D,
407 0xFFFF }, { 0x0128, 0x041C, 0x0421, 0x0E0B, 0x0A1F, 0xFFFF }, { 0x0220, 0x0513, 0x0617, 0xFFFF }, { 0x0135, 0x0805,
408 0x0327, 0xFFFF }, { 0x0316, 0x051E, 0x0D0E, 0x0423, 0xFFFF }, { 0x0222, 0x0404, 0x070A, 0x0511, 0x0719, 0x0C09, 0x1B0F,
409 0xFFFF }, { 0x0703, 0x0615, 0x0A07, 0x022B, 0xFFFF }, { 0x012A, 0x0431, 0x0601, 0x0333, 0x012D, 0x091D, 0xFFFF }, {
410 0x0230, 0x0314, 0x0036, 0x0608, 0x0425, 0x0037, 0x0329, 0x081B, 0x120D, 0xFFFF }, { 0x0300, 0x0224, 0x0506, 0x0521,
411 0x0F0B, 0x0B1F, 0xFFFF }, { 0x041A, 0x0613, 0x0717, 0xFFFF }, { 0x0235, 0x0905, 0xFFFF }, { 0x0312, 0x0134, 0x0523,
412 0x0427, 0xFFFF }, { 0x0226, 0x090C, 0x002E, 0x0611, 0x0D09, 0x002F, 0xFFFF }, { 0x0715, 0x0B07, 0x0819, 0x032B, 0x1C0F,
413 0xFFFF }, { 0x0310, 0x0531, 0x0701, 0x0803, 0x022D, 0x0A1D, 0xFFFF }, { 0x0418, 0x012C, 0x0433, 0x0525, 0x0137, 0x091B,
414 0x130D, 0xFFFF }, { 0x0232, 0x0402, 0x0621, 0x0429, 0xFFFF }, { 0x0228, 0x051C, 0x0713, 0x100B, 0x0C1F, 0xFFFF }, {
415 0x0320, 0x0335, 0x0A05, 0x0817, 0xFFFF }, { 0x0623, 0x0527, 0xFFFF }, { 0x0416, 0x061E, 0x0E0E, 0x0711, 0x0E09, 0x012F,
416 0xFFFF }, { 0x0322, 0x0504, 0x080A, 0x0919, 0x1D0F, 0xFFFF }, { 0x0631, 0x0903, 0x0815, 0x0C07, 0x042B, 0x032D, 0x0B1D,
417 0xFFFF }, { 0x022A, 0x0801, 0x0533, 0x0625, 0x0237, 0x0A1B, 0xFFFF }, { 0x0330, 0x0414, 0x0136, 0x0708, 0x0721, 0x0529,
418 0x140D, 0xFFFF }, { 0x0400, 0x0324, 0x0606, 0x0038, 0x0039, 0x110B, 0x0D1F, 0xFFFF }, { 0x051A, 0x0813, 0x0B05, 0x0917,
419 0xFFFF }, { 0x0723, 0x0435, 0x0627, 0xFFFF }, { 0x0412, 0x0234, 0x0F09, 0x022F, 0xFFFF }, { 0x0326, 0x0A0C, 0x012E,
420 0x0811, 0x0A19, 0x1E0F, 0xFFFF }, { 0x0731, 0x0A03, 0x0915, 0x0D07, 0x052B, 0xFFFF }, { 0x0410, 0x0901, 0x0633, 0x0725,
421 0x0337, 0x0B1B, 0x042D, 0x0C1D, 0xFFFF }, { 0x0518, 0x022C, 0x0629, 0x150D, 0xFFFF }, { 0x0332, 0x0502, 0x0821, 0x0139,
422 0x120B, 0x0E1F, 0xFFFF }, { 0x0328, 0x061C, 0x0913, 0x0A17, 0xFFFF }, { 0x0420, 0x0535, 0x0C05, 0x0727, 0xFFFF }, {
423 0x0823, 0x032F, 0xFFFF }, { 0x0516, 0x071E, 0x0F0E, 0x0911, 0x0B19, 0x1009, 0x1F0F, 0xFFFF }, { 0x0422, 0x0604, 0x090A,
424 0x0B03, 0x0A15, 0x0E07, 0x062B, 0xFFFF }, { 0x0831, 0x0A01, 0x0733, 0x052D, 0x0D1D, 0xFFFF }, { 0x032A, 0x0825, 0x0437,
425 0x0729, 0x0C1B, 0x160D, 0xFFFF }, { 0x0430, 0x0514, 0x0236, 0x0808, 0x0921, 0x0239, 0x130B, 0x0F1F, 0xFFFF }, { 0x0500,
426 0x0424, 0x0706, 0x0138, 0x0A13, 0x0B17, 0xFFFF }, { 0x061A, 0x0635, 0x0D05, 0xFFFF }, { 0x0923, 0x0827, 0xFFFF }, {
427 0x0512, 0x0334, 0x003A, 0x0A11, 0x1109, 0x003B, 0x042F, 0xFFFF }, { 0x0426, 0x0B0C, 0x022E, 0x0B15, 0x0F07, 0x0C19,
428 0x072B, 0xFFFF }, { 0x0931, 0x0B01, 0x0C03, 0x062D, 0x0E1D, 0xFFFF }, { 0x0510, 0x0833, 0x0925, 0x0537, 0x0D1B, 0x170D,
429 0xFFFF }, { 0x0618, 0x032C, 0x0A21, 0x0339, 0x0829, 0xFFFF }, { 0x0432, 0x0602, 0x0B13, 0x140B, 0x101F, 0xFFFF }, {
430 0x0428, 0x071C, 0x0735, 0x0E05, 0x0C17, 0xFFFF }, { 0x0520, 0x0A23, 0x0927, 0xFFFF }, { 0x0B11, 0x1209, 0x013B, 0x052F,
431 0xFFFF }, { 0x0616, 0x081E, 0x0D19, 0xFFFF }, { 0x0522, 0x0704, 0x0A0A, 0x0A31, 0x0D03, 0x0C15, 0x1007, 0x082B, 0x072D,
432 0x0F1D, 0xFFFF }, { 0x0C01, 0x0933, 0x0A25, 0x0637, 0x0E1B, 0xFFFF }, { 0x042A, 0x0B21, 0x0929, 0x180D, 0xFFFF }, {
433 0x0530, 0x0614, 0x0336, 0x0908, 0x0439, 0x150B, 0x111F, 0xFFFF }, { 0x0600, 0x0524, 0x0806, 0x0238, 0x0C13, 0x0F05,
434 0x0D17, 0xFFFF }, { 0x071A, 0x0B23, 0x0835, 0x0A27, 0xFFFF }, { 0x1309, 0x023B, 0x062F, 0xFFFF }, { 0x0612, 0x0434,
435 0x013A, 0x0C11, 0x0E19, 0xFFFF }, { 0x0526, 0x0C0C, 0x032E, 0x0B31, 0x0E03, 0x0D15, 0x1107, 0x092B, 0xFFFF }, { 0x0D01,
436 0x0A33, 0x0B25, 0x0737, 0x0F1B, 0x082D, 0x101D, 0xFFFF }, { 0x0610, 0x0A29, 0x190D, 0xFFFF }, { 0x0718, 0x042C, 0x0C21,
437 0x0539, 0x160B, 0x121F, 0xFFFF }, { 0x0532, 0x0702, 0x0D13, 0x0E17, 0xFFFF }, { 0x0528, 0x081C, 0x0935, 0x1005, 0x0B27,
438 0xFFFF }, { 0x0620, 0x0C23, 0x033B, 0x072F, 0xFFFF }, { 0x0D11, 0x0F19, 0x1409, 0xFFFF }, { 0x0716, 0x003C, 0x091E,
439 0x0F03, 0x0E15, 0x1207, 0x0A2B, 0x003D, 0xFFFF }, { 0x0622, 0x0804, 0x0B0A, 0x0C31, 0x0E01, 0x0B33, 0x092D, 0x111D,
440 0xFFFF }, { 0x0C25, 0x0837, 0x0B29, 0x101B, 0x1A0D, 0xFFFF }, { 0x052A, 0x0D21, 0x0639, 0x170B, 0x131F, 0xFFFF }, {
441 0x0630, 0x0714, 0x0436, 0x0A08, 0x0E13, 0x0F17, 0xFFFF }, { 0x0700, 0x0624, 0x0906, 0x0338, 0x0A35, 0x1105, 0xFFFF }, {
442 0x081A, 0x0D23, 0x0C27, 0xFFFF }, { 0x0E11, 0x1509, 0x043B, 0x082F, 0xFFFF }, { 0x0712, 0x0534, 0x023A, 0x0F15, 0x1307,
443 0x1019, 0x0B2B, 0x013D, 0xFFFF }, { 0x0626, 0x0D0C, 0x042E, 0x0D31, 0x0F01, 0x1003, 0x0A2D, 0x121D, 0xFFFF }, { 0x0C33,
444 0x0D25, 0x0937, 0x111B, 0x1B0D, 0xFFFF }, { 0x0710, 0x0E21, 0x0739, 0x0C29, 0xFFFF }, { 0x0818, 0x052C, 0x0F13, 0x180B,
445 0x141F, 0xFFFF }, { 0x0632, 0x0802, 0x0B35, 0x1205, 0x1017, 0xFFFF }, { 0x0628, 0x091C, 0x0E23, 0x0D27, 0xFFFF }, {
446 0x0720, 0x0F11, 0x1609, 0x053B, 0x092F, 0xFFFF }, { 0x1119, 0x023D, 0xFFFF }, { 0x0816, 0x013C, 0x0A1E, 0x0E31, 0x1103,
447 0x1015, 0x1407, 0x0C2B, 0x0B2D, 0x131D, 0xFFFF }, { 0x0722, 0x0904, 0x0C0A, 0x1001, 0x0D33, 0x0E25, 0x0A37, 0x121B,
448 0xFFFF }, { 0x0F21, 0x0D29, 0x1C0D, 0xFFFF }, { 0x062A, 0x0839, 0x190B, 0x151F, 0xFFFF }, { 0x0730, 0x0814, 0x0536,
449 0x0B08, 0x1013, 0x1305, 0x1117, 0xFFFF }, { 0x0800, 0x0724, 0x0A06, 0x0438, 0x0F23, 0x0C35, 0x0E27, 0xFFFF }, { 0x091A,
450 0x1709, 0x063B, 0x0A2F, 0xFFFF }, { 0x1011, 0x1219, 0x033D, 0xFFFF }, { 0x0812, 0x0634, 0x033A, 0x0F31, 0x1203, 0x1115,
451 0x1507, 0x0D2B, 0xFFFF }, { 0x0726, 0x0E0C, 0x052E, 0x1101, 0x0E33, 0x0F25, 0x0B37, 0x131B, 0x0C2D, 0x141D, 0xFFFF }, {
452 0x0E29, 0x1D0D, 0xFFFF }, { 0x0810, 0x1021, 0x0939, 0x1A0B, 0x161F, 0xFFFF }, { 0x0918, 0x062C, 0x1113, 0x1217, 0xFFFF
453 }, { 0x0732, 0x0902, 0x0D35, 0x1405, 0x0F27, 0xFFFF }, { 0x0728, 0x0A1C, 0x1023, 0x073B, 0x0B2F, 0xFFFF }, { 0x0820,
454 0x1111, 0x1319, 0x1809, 0xFFFF }, { 0x1303, 0x1215, 0x1607, 0x0E2B, 0x043D, 0xFFFF }, { 0x0916, 0x023C, 0x0B1E, 0x1031,
455 0x1201, 0x0F33, 0x0D2D, 0x151D, 0xFFFF }, { 0x0822, 0x0A04, 0x0D0A, 0x1025, 0x0C37, 0x0F29, 0x141B, 0x1E0D, 0xFFFF }, {
456 0x1121, 0x0A39, 0x1B0B, 0x171F, 0xFFFF }, { 0x072A, 0x1213, 0x1317, 0xFFFF }, { 0x0830, 0x0914, 0x0636, 0x0C08, 0x0E35,
457 0x1505, 0xFFFF }, { 0x0900, 0x0824, 0x0B06, 0x0538, 0x1123, 0x1027, 0xFFFF }, { 0x0A1A, 0x1211, 0x1909, 0x083B, 0x0C2F,
458 0xFFFF }, { 0x1315, 0x1707, 0x1419, 0x0F2B, 0x053D, 0xFFFF }, { 0x0912, 0x0734, 0x043A, 0x1131, 0x1301, 0x1403, 0x0E2D,
459 0x161D, 0xFFFF }, { 0x0826, 0x0F0C, 0x062E, 0x1033, 0x1125, 0x0D37, 0x151B, 0x1F0D, 0xFFFF }, { 0x1221, 0x0B39, 0x1029,
460 0xFFFF }, { 0x0910, 0x1313, 0x1C0B, 0x181F, 0xFFFF }, { 0x0A18, 0x072C, 0x0F35, 0x1605, 0x1417, 0xFFFF }, { 0x0832,
461 0x0A02, 0x1223, 0x1127, 0xFFFF }, { 0x0828, 0x0B1C, 0x1311, 0x1A09, 0x093B, 0x0D2F, 0xFFFF }, { 0x0920, 0x1519, 0x063D,
462 0xFFFF }, { 0x1231, 0x1503, 0x1415, 0x1807, 0x102B, 0x0F2D, 0x171D, 0xFFFF }, { 0x0A16, 0x033C, 0x0C1E, 0x1401, 0x1133,
463 0x1225, 0x0E37, 0x161B, 0xFFFF }, { 0x0922, 0x0B04, 0x0E0A, 0x1321, 0x1129, 0xFFFF }, { 0x0C39, 0x1D0B, 0x191F, 0xFFFF
464 }, { 0x082A, 0x1413, 0x1705, 0x1517, 0xFFFF }, { 0x0930, 0x0A14, 0x0736, 0x0D08, 0x1323, 0x1035, 0x1227, 0xFFFF }, {
465 0x0A00, 0x0924, 0x0C06, 0x0638, 0x1B09, 0x0A3B, 0x0E2F, 0xFFFF }, { 0x0B1A, 0x1411, 0x1619, 0x073D, 0xFFFF }, { 0x1331,
466 0x1603, 0x1515, 0x1907, 0x112B, 0xFFFF }, { 0x0A12, 0x0834, 0x053A, 0x1501, 0x1233, 0x1325, 0x0F37, 0x171B, 0x102D,
467 0x181D, 0xFFFF }, { 0x0926, 0x072E, 0x1229, 0xFFFF }, { 0x1421, 0x0D39, 0x1E0B, 0x1A1F, 0xFFFF }, { 0x0A10, 0x1513,
468 0x1617, 0xFFFF }, { 0x0B18, 0x082C, 0x1135, 0x1805, 0x1327, 0xFFFF }, { 0x0932, 0x0B02, 0x1423, 0x0B3B, 0x0F2F, 0xFFFF
469 }, { 0x0928, 0x0C1C, 0x1511, 0x1719, 0x1C09, 0xFFFF }, { 0x0A20, 0x1703, 0x1615, 0x1A07, 0x122B, 0x083D, 0xFFFF }, {
470 0x1431, 0x1601, 0x1333, 0x112D, 0x191D, 0xFFFF }, { 0x0B16, 0x043C, 0x0D1E, 0x1425, 0x1037, 0x1329, 0x181B, 0xFFFF }, {
471 0x0A22, 0x0C04, 0x0F0A, 0x1521, 0x0E39, 0x1F0B, 0x1B1F, 0xFFFF }, { 0x1613, 0x1717, 0xFFFF }, { 0x092A, 0x1235, 0x1905,
472 0xFFFF }, { 0x0A30, 0x0B14, 0x0836, 0x0E08, 0x1523, 0x1427, 0xFFFF }, { 0x0B00, 0x0A24, 0x0D06, 0x0738, 0x1611, 0x1D09,
473 0x0C3B, 0x102F, 0xFFFF }, { 0x0C1A, 0x1715, 0x1B07, 0x1819, 0x132B, 0x093D, 0xFFFF }, { 0x1531, 0x1701, 0x1803, 0x122D,
474 0x1A1D, 0xFFFF }, { 0x0B12, 0x0934, 0x063A, 0x1433, 0x1525, 0x1137, 0x191B, 0xFFFF }, { 0x0A26, 0x003E, 0x082E, 0x1621,
475 0x0F39, 0x1429, 0x003F, 0xFFFF }, { 0x1713, 0x1C1F, 0xFFFF }, { 0x0B10, 0x1335, 0x1A05, 0x1817, 0xFFFF }, { 0x0C18,
476 0x092C, 0x1623, 0x1527, 0xFFFF }, { 0x0A32, 0x0C02, 0x1711, 0x1E09, 0x0D3B, 0x112F, 0xFFFF }, { 0x0A28, 0x0D1C, 0x1919,
477 0x0A3D, 0xFFFF }, { 0x0B20, 0x1631, 0x1903, 0x1815, 0x1C07, 0x142B, 0x132D, 0x1B1D, 0xFFFF }, { 0x1801, 0x1533, 0x1625,
478 0x1237, 0x1A1B, 0xFFFF }, { 0x0C16, 0x053C, 0x0E1E, 0x1721, 0x1529, 0x013F, 0xFFFF }, { 0x0B22, 0x0D04, 0x1039, 0x1D1F,
479 0xFFFF }, { 0x1813, 0x1B05, 0x1917, 0xFFFF }, { 0x0A2A, 0x1723, 0x1435, 0x1627, 0xFFFF }, { 0x0B30, 0x0C14, 0x0936,
480 0x0F08, 0x1F09, 0x0E3B, 0x122F, 0xFFFF }, { 0x0C00, 0x0B24, 0x0E06, 0x0838, 0x1811, 0x1A19, 0x0B3D, 0xFFFF }, { 0x0D1A,
481 0x1731, 0x1A03, 0x1915, 0x1D07, 0x152B, 0xFFFF }, { 0x1901, 0x1633, 0x1725, 0x1337, 0x1B1B, 0x142D, 0x1C1D, 0xFFFF }, {
482 0x0C12, 0x0A34, 0x073A, 0x1629, 0x023F, 0xFFFF }, { 0x0B26, 0x013E, 0x092E, 0x1821, 0x1139, 0x1E1F, 0xFFFF }, { 0x1913,
483 0x1A17, 0xFFFF }, { 0x0C10, 0x1535, 0x1C05, 0x1727, 0xFFFF }, { 0x0D18, 0x0A2C, 0x1823, 0x0F3B, 0x132F, 0xFFFF }, {
484 0x0B32, 0x0D02, 0x1911, 0x1B19, 0xFFFF }, { 0x0B28, 0x0E1C, 0x1B03, 0x1A15, 0x1E07, 0x162B, 0x0C3D, 0xFFFF }, { 0x0C20,
485 0x1831, 0x1A01, 0x1733, 0x152D, 0x1D1D, 0xFFFF }, { 0x1825, 0x1437, 0x1729, 0x1C1B, 0x033F, 0xFFFF }, { 0x0D16, 0x063C,
486 0x0F1E, 0x1921, 0x1239, 0x1F1F, 0xFFFF }, { 0x0C22, 0x0E04, 0x1A13, 0x1B17, 0xFFFF }, { 0x1635, 0x1D05, 0xFFFF }, {
487 0x0B2A, 0x1923, 0x1827, 0xFFFF }, { 0x0C30, 0x0D14, 0x0A36, 0x1A11, 0x103B, 0x142F, 0xFFFF }, { 0x0D00, 0x0C24, 0x0F06,
488 0x0938, 0x1B15, 0x1F07, 0x1C19, 0x172B, 0x0D3D, 0xFFFF }, { 0x0E1A, 0x1931, 0x1B01, 0x1C03, 0x162D, 0x1E1D, 0xFFFF }, {
489 0x1833, 0x1925, 0x1537, 0x1D1B, 0xFFFF }, { 0x0D12, 0x0B34, 0x083A, 0x1A21, 0x1339, 0x1829, 0x043F, 0xFFFF }, { 0x0C26,
490 0x023E, 0x0A2E, 0x1B13, 0xFFFF }, { 0x1735, 0x1E05, 0x1C17, 0xFFFF }, { 0x0D10, 0x1A23, 0x1927, 0xFFFF }, { 0x0E18,
491 0x0B2C, 0x1B11, 0x113B, 0x152F, 0xFFFF }, { 0x0C32, 0x0E02, 0x1D19, 0x0E3D, 0xFFFF }, { 0x0C28, 0x0F1C, 0x1A31, 0x1D03,
492 0x1C15, 0x182B, 0x172D, 0x1F1D, 0xFFFF }, { 0x0D20, 0x1C01, 0x1933, 0x1A25, 0x1637, 0x1E1B, 0xFFFF }, { 0x1B21, 0x1929,
493 0x053F, 0xFFFF }, { 0x0E16, 0x073C, 0x1439, 0xFFFF }, { 0x0D22, 0x0F04, 0x1C13, 0x1F05, 0x1D17, 0xFFFF }, { 0x1B23,
494 0x1835, 0x1A27, 0xFFFF }, { 0x0C2A, 0x123B, 0x162F, 0xFFFF }, { 0x0D30, 0x0E14, 0x0B36, 0x1C11, 0x1E19, 0x0F3D, 0xFFFF
495 }, { 0x0E00, 0x0D24, 0x0A38, 0x1B31, 0x1E03, 0x1D15, 0x192B, 0xFFFF }, { 0x0F1A, 0x1D01, 0x1A33, 0x1B25, 0x1737, 0x1F1B,
496 0x182D, 0xFFFF }, { 0x1A29, 0x063F, 0xFFFF }, { 0x0E12, 0x0C34, 0x093A, 0x1C21, 0x1539, 0xFFFF }, { 0x0D26, 0x033E,
497 0x0B2E, 0x1D13, 0x1E17, 0xFFFF }, { 0x1935, 0x1B27, 0xFFFF }, { 0x0E10, 0x1C23, 0x133B, 0x172F, 0xFFFF }, { 0x0F18,
498 0x0C2C, 0x1D11, 0x1F19, 0xFFFF }, { 0x0D32, 0x0F02, 0x1F03, 0x1E15, 0x1A2B, 0x103D, 0xFFFF }, { 0x0D28, 0x1C31, 0x1E01,
499 0x1B33, 0x192D, 0xFFFF }, { 0x0E20, 0x1C25, 0x1837, 0x1B29, 0x073F, 0xFFFF }, { 0x1D21, 0x1639, 0xFFFF }, { 0x0F16,
500 0x083C, 0x1E13, 0x1F17, 0xFFFF }, { 0x0E22, 0x1A35, 0xFFFF }, { 0x1D23, 0x1C27, 0xFFFF }, { 0x0D2A, 0x1E11, 0x143B,
501 0x182F, 0xFFFF }, { 0x0E30, 0x0F14, 0x0C36, 0x1F15, 0x1B2B, 0x113D, 0xFFFF }, { 0x0F00, 0x0E24, 0x0B38, 0x1D31, 0x1F01,
502 0x1A2D, 0xFFFF }, { 0x1C33, 0x1D25, 0x1937, 0xFFFF }, { 0x1E21, 0x1739, 0x1C29, 0x083F, 0xFFFF }, { 0x0F12, 0x0D34,
503 0x0A3A, 0x1F13, 0xFFFF }, { 0x0E26, 0x043E, 0x0C2E, 0x1B35, 0xFFFF }, { 0x1E23, 0x1D27, 0xFFFF }, { 0x0F10, 0x1F11,
504 0x153B, 0x192F, 0xFFFF }, { 0x0D2C, 0x123D, 0xFFFF },
505 };
506
507 struct etc1_block
508 {
509 // big endian uint64:
510 // bit ofs: 56 48 40 32 24 16 8 0
511 // byte ofs: b0, b1, b2, b3, b4, b5, b6, b7
512 union
513 {
514 uint64 m_uint64;
515 uint8 m_bytes[8];
516 };
517
518 uint8 m_low_color[2];
519 uint8 m_high_color[2];
520
521 enum { cNumSelectorBytes = 4 };
522 uint8 m_selectors[cNumSelectorBytes];
523
524 inline void clear()
525 {
526 zero_this(this);
527 }
528
529 inline uint get_byte_bits(uint ofs, uint num) const
530 {
531 RG_ETC1_ASSERT((ofs + num) <= 64U);
532 RG_ETC1_ASSERT(num && (num <= 8U));
533 RG_ETC1_ASSERT((ofs >> 3) == ((ofs + num - 1) >> 3));
534 const uint byte_ofs = 7 - (ofs >> 3);
535 const uint byte_bit_ofs = ofs & 7;
536 return (m_bytes[byte_ofs] >> byte_bit_ofs) & ((1 << num) - 1);
537 }
538
539 inline void set_byte_bits(uint ofs, uint num, uint bits)
540 {
541 RG_ETC1_ASSERT((ofs + num) <= 64U);
542 RG_ETC1_ASSERT(num && (num < 32U));
543 RG_ETC1_ASSERT((ofs >> 3) == ((ofs + num - 1) >> 3));
544 RG_ETC1_ASSERT(bits < (1U << num));
545 const uint byte_ofs = 7 - (ofs >> 3);
546 const uint byte_bit_ofs = ofs & 7;
547 const uint mask = (1 << num) - 1;
548 m_bytes[byte_ofs] &= ~(mask << byte_bit_ofs);
549 m_bytes[byte_ofs] |= (bits << byte_bit_ofs);
550 }
551
552 // false = left/right subblocks
553 // true = upper/lower subblocks
554 inline bool get_flip_bit() const
555 {
556 return (m_bytes[3] & 1) != 0;
557 }
558
559 inline void set_flip_bit(bool flip)
560 {
561 m_bytes[3] &= ~1;
562 m_bytes[3] |= static_cast<uint8>(flip);
563 }
564
565 inline bool get_diff_bit() const
566 {
567 return (m_bytes[3] & 2) != 0;
568 }
569
570 inline void set_diff_bit(bool diff)
571 {
572 m_bytes[3] &= ~2;
573 m_bytes[3] |= (static_cast<uint>(diff) << 1);
574 }
575
576 // Returns intensity modifier table (0-7) used by subblock subblock_id.
577 // subblock_id=0 left/top (CW 1), 1=right/bottom (CW 2)
578 inline uint get_inten_table(uint subblock_id) const
579 {
580 RG_ETC1_ASSERT(subblock_id < 2);
581 const uint ofs = subblock_id ? 2 : 5;
582 return (m_bytes[3] >> ofs) & 7;
583 }
584
585 // Sets intensity modifier table (0-7) used by subblock subblock_id (0 or 1)
586 inline void set_inten_table(uint subblock_id, uint t)
587 {
588 RG_ETC1_ASSERT(subblock_id < 2);
589 RG_ETC1_ASSERT(t < 8);
590 const uint ofs = subblock_id ? 2 : 5;
591 m_bytes[3] &= ~(7 << ofs);
592 m_bytes[3] |= (t << ofs);
593 }
594
595 // Returned selector value ranges from 0-3 and is a direct index into g_etc1_inten_tables.
596 inline uint get_selector(uint x, uint y) const
597 {
598 RG_ETC1_ASSERT((x | y) < 4);
599
600 const uint bit_index = x * 4 + y;
601 const uint byte_bit_ofs = bit_index & 7;
602 const uint8 *p = &m_bytes[7 - (bit_index >> 3)];
603 const uint lsb = (p[0] >> byte_bit_ofs) & 1;
604 const uint msb = (p[-2] >> byte_bit_ofs) & 1;
605 const uint val = lsb | (msb << 1);
606
607 return g_etc1_to_selector_index[val];
608 }
609
610 // Selector "val" ranges from 0-3 and is a direct index into g_etc1_inten_tables.
611 inline void set_selector(uint x, uint y, uint val)
612 {
613 RG_ETC1_ASSERT((x | y | val) < 4);
614 const uint bit_index = x * 4 + y;
615
616 uint8 *p = &m_bytes[7 - (bit_index >> 3)];
617
618 const uint byte_bit_ofs = bit_index & 7;
619 const uint mask = 1 << byte_bit_ofs;
620
621 const uint etc1_val = g_selector_index_to_etc1[val];
622
623 const uint lsb = etc1_val & 1;
624 const uint msb = etc1_val >> 1;
625
626 p[0] &= ~mask;
627 p[0] |= (lsb << byte_bit_ofs);
628
629 p[-2] &= ~mask;
630 p[-2] |= (msb << byte_bit_ofs);
631 }
632
633 inline void set_base4_color(uint idx, uint16 c)
634 {
635 if (idx)
636 {
637 set_byte_bits(cETC1AbsColor4R2BitOffset, 4, (c >> 8) & 15);
638 set_byte_bits(cETC1AbsColor4G2BitOffset, 4, (c >> 4) & 15);
639 set_byte_bits(cETC1AbsColor4B2BitOffset, 4, c & 15);
640 }
641 else
642 {
643 set_byte_bits(cETC1AbsColor4R1BitOffset, 4, (c >> 8) & 15);
644 set_byte_bits(cETC1AbsColor4G1BitOffset, 4, (c >> 4) & 15);
645 set_byte_bits(cETC1AbsColor4B1BitOffset, 4, c & 15);
646 }
647 }
648
649 inline uint16 get_base4_color(uint idx) const
650 {
651 uint r, g, b;
652 if (idx)
653 {
654 r = get_byte_bits(cETC1AbsColor4R2BitOffset, 4);
655 g = get_byte_bits(cETC1AbsColor4G2BitOffset, 4);
656 b = get_byte_bits(cETC1AbsColor4B2BitOffset, 4);
657 }
658 else
659 {
660 r = get_byte_bits(cETC1AbsColor4R1BitOffset, 4);
661 g = get_byte_bits(cETC1AbsColor4G1BitOffset, 4);
662 b = get_byte_bits(cETC1AbsColor4B1BitOffset, 4);
663 }
664 return static_cast<uint16>(b | (g << 4U) | (r << 8U));
665 }
666
667 inline void set_base5_color(uint16 c)
668 {
669 set_byte_bits(cETC1BaseColor5RBitOffset, 5, (c >> 10) & 31);
670 set_byte_bits(cETC1BaseColor5GBitOffset, 5, (c >> 5) & 31);
671 set_byte_bits(cETC1BaseColor5BBitOffset, 5, c & 31);
672 }
673
674 inline uint16 get_base5_color() const
675 {
676 const uint r = get_byte_bits(cETC1BaseColor5RBitOffset, 5);
677 const uint g = get_byte_bits(cETC1BaseColor5GBitOffset, 5);
678 const uint b = get_byte_bits(cETC1BaseColor5BBitOffset, 5);
679 return static_cast<uint16>(b | (g << 5U) | (r << 10U));
680 }
681
682 void set_delta3_color(uint16 c)
683 {
684 set_byte_bits(cETC1DeltaColor3RBitOffset, 3, (c >> 6) & 7);
685 set_byte_bits(cETC1DeltaColor3GBitOffset, 3, (c >> 3) & 7);
686 set_byte_bits(cETC1DeltaColor3BBitOffset, 3, c & 7);
687 }
688
689 inline uint16 get_delta3_color() const
690 {
691 const uint r = get_byte_bits(cETC1DeltaColor3RBitOffset, 3);
692 const uint g = get_byte_bits(cETC1DeltaColor3GBitOffset, 3);
693 const uint b = get_byte_bits(cETC1DeltaColor3BBitOffset, 3);
694 return static_cast<uint16>(b | (g << 3U) | (r << 6U));
695 }
696
697 // Base color 5
698 static uint16 pack_color5(const color_quad_u8& color, bool scaled, uint bias = 127U);
699 static uint16 pack_color5(uint r, uint g, uint b, bool scaled, uint bias = 127U);
700
701 static color_quad_u8 unpack_color5(uint16 packed_color5, bool scaled, uint alpha = 255U);
702 static void unpack_color5(uint& r, uint& g, uint& b, uint16 packed_color, bool scaled);
703
704 static bool unpack_color5(color_quad_u8& result, uint16 packed_color5, uint16 packed_delta3, bool scaled, uint alpha = 255U);
705 static bool unpack_color5(uint& r, uint& g, uint& b, uint16 packed_color5, uint16 packed_delta3, bool scaled, uint alpha = 255U);
706
707 // Delta color 3
708 // Inputs range from -4 to 3 (cETC1ColorDeltaMin to cETC1ColorDeltaMax)
709 static uint16 pack_delta3(int r, int g, int b);
710
711 // Results range from -4 to 3 (cETC1ColorDeltaMin to cETC1ColorDeltaMax)
712 static void unpack_delta3(int& r, int& g, int& b, uint16 packed_delta3);
713
714 // Abs color 4
715 static uint16 pack_color4(const color_quad_u8& color, bool scaled, uint bias = 127U);
716 static uint16 pack_color4(uint r, uint g, uint b, bool scaled, uint bias = 127U);
717
718 static color_quad_u8 unpack_color4(uint16 packed_color4, bool scaled, uint alpha = 255U);
719 static void unpack_color4(uint& r, uint& g, uint& b, uint16 packed_color4, bool scaled);
720
721 // subblock colors
722 static void get_diff_subblock_colors(color_quad_u8* pDst, uint16 packed_color5, uint table_idx);
723 static bool get_diff_subblock_colors(color_quad_u8* pDst, uint16 packed_color5, uint16 packed_delta3, uint table_idx);
724 static void get_abs_subblock_colors(color_quad_u8* pDst, uint16 packed_color4, uint table_idx);
725
726 static inline void unscaled_to_scaled_color(color_quad_u8& dst, const color_quad_u8& src, bool color4)
727 {
728 if (color4)
729 {
730 dst.r = src.r | (src.r << 4);
731 dst.g = src.g | (src.g << 4);
732 dst.b = src.b | (src.b << 4);
733 }
734 else
735 {
736 dst.r = (src.r >> 2) | (src.r << 3);
737 dst.g = (src.g >> 2) | (src.g << 3);
738 dst.b = (src.b >> 2) | (src.b << 3);
739 }
740 dst.a = src.a;
741 }
742 };
743
744 // Returns pointer to sorted array.
745 template<typename T, typename Q>
746 T* indirect_radix_sort(uint num_indices, T* pIndices0, T* pIndices1, const Q* pKeys, uint key_ofs, uint key_size, bool init_indices)
747 {
748 RG_ETC1_ASSERT((key_ofs >= 0) && (key_ofs < sizeof(T)));
749 RG_ETC1_ASSERT((key_size >= 1) && (key_size <= 4));
750
751 if (init_indices)
752 {
753 T* p = pIndices0;
754 T* q = pIndices0 + (num_indices >> 1) * 2;
755 uint i;
756 for (i = 0; p != q; p += 2, i += 2)
757 {
758 p[0] = static_cast<T>(i);
759 p[1] = static_cast<T>(i + 1);
760 }
761
762 if (num_indices & 1)
763 *p = static_cast<T>(i);
764 }
765
766 uint hist[256 * 4];
767
768 memset(hist, 0, sizeof(hist[0]) * 256 * key_size);
769
770#define RG_ETC1_GET_KEY(p) (*(const uint*)((const uint8*)(pKeys + *(p)) + key_ofs))
771#define RG_ETC1_GET_KEY_FROM_INDEX(i) (*(const uint*)((const uint8*)(pKeys + (i)) + key_ofs))
772
773 if (key_size == 4)
774 {
775 T* p = pIndices0;
776 T* q = pIndices0 + num_indices;
777 for ( ; p != q; p++)
778 {
779 const uint key = RG_ETC1_GET_KEY(p);
780
781 hist[ key & 0xFF]++;
782 hist[256 + ((key >> 8) & 0xFF)]++;
783 hist[512 + ((key >> 16) & 0xFF)]++;
784 hist[768 + ((key >> 24) & 0xFF)]++;
785 }
786 }
787 else if (key_size == 3)
788 {
789 T* p = pIndices0;
790 T* q = pIndices0 + num_indices;
791 for ( ; p != q; p++)
792 {
793 const uint key = RG_ETC1_GET_KEY(p);
794
795 hist[ key & 0xFF]++;
796 hist[256 + ((key >> 8) & 0xFF)]++;
797 hist[512 + ((key >> 16) & 0xFF)]++;
798 }
799 }
800 else if (key_size == 2)
801 {
802 T* p = pIndices0;
803 T* q = pIndices0 + (num_indices >> 1) * 2;
804
805 for ( ; p != q; p += 2)
806 {
807 const uint key0 = RG_ETC1_GET_KEY(p);
808 const uint key1 = RG_ETC1_GET_KEY(p+1);
809
810 hist[ key0 & 0xFF]++;
811 hist[256 + ((key0 >> 8) & 0xFF)]++;
812
813 hist[ key1 & 0xFF]++;
814 hist[256 + ((key1 >> 8) & 0xFF)]++;
815 }
816
817 if (num_indices & 1)
818 {
819 const uint key = RG_ETC1_GET_KEY(p);
820
821 hist[ key & 0xFF]++;
822 hist[256 + ((key >> 8) & 0xFF)]++;
823 }
824 }
825 else
826 {
827 RG_ETC1_ASSERT(key_size == 1);
828 if (key_size != 1)
829 return NULL;
830
831 T* p = pIndices0;
832 T* q = pIndices0 + (num_indices >> 1) * 2;
833
834 for ( ; p != q; p += 2)
835 {
836 const uint key0 = RG_ETC1_GET_KEY(p);
837 const uint key1 = RG_ETC1_GET_KEY(p+1);
838
839 hist[key0 & 0xFF]++;
840 hist[key1 & 0xFF]++;
841 }
842
843 if (num_indices & 1)
844 {
845 const uint key = RG_ETC1_GET_KEY(p);
846
847 hist[key & 0xFF]++;
848 }
849 }
850
851 T* pCur = pIndices0;
852 T* pNew = pIndices1;
853
854 for (uint pass = 0; pass < key_size; pass++)
855 {
856 const uint* pHist = &hist[pass << 8];
857
858 uint offsets[256];
859
860 uint cur_ofs = 0;
861 for (uint i = 0; i < 256; i += 2)
862 {
863 offsets[i] = cur_ofs;
864 cur_ofs += pHist[i];
865
866 offsets[i+1] = cur_ofs;
867 cur_ofs += pHist[i+1];
868 }
869
870 const uint pass_shift = pass << 3;
871
872 T* p = pCur;
873 T* q = pCur + (num_indices >> 1) * 2;
874
875 for ( ; p != q; p += 2)
876 {
877 uint index0 = p[0];
878 uint index1 = p[1];
879
880 uint c0 = (RG_ETC1_GET_KEY_FROM_INDEX(index0) >> pass_shift) & 0xFF;
881 uint c1 = (RG_ETC1_GET_KEY_FROM_INDEX(index1) >> pass_shift) & 0xFF;
882
883 if (c0 == c1)
884 {
885 uint dst_offset0 = offsets[c0];
886
887 offsets[c0] = dst_offset0 + 2;
888
889 pNew[dst_offset0] = static_cast<T>(index0);
890 pNew[dst_offset0 + 1] = static_cast<T>(index1);
891 }
892 else
893 {
894 uint dst_offset0 = offsets[c0]++;
895 uint dst_offset1 = offsets[c1]++;
896
897 pNew[dst_offset0] = static_cast<T>(index0);
898 pNew[dst_offset1] = static_cast<T>(index1);
899 }
900 }
901
902 if (num_indices & 1)
903 {
904 uint index = *p;
905 uint c = (RG_ETC1_GET_KEY_FROM_INDEX(index) >> pass_shift) & 0xFF;
906
907 uint dst_offset = offsets[c];
908 offsets[c] = dst_offset + 1;
909
910 pNew[dst_offset] = static_cast<T>(index);
911 }
912
913 T* t = pCur;
914 pCur = pNew;
915 pNew = t;
916 }
917
918 return pCur;
919 }
920
921#undef RG_ETC1_GET_KEY
922#undef RG_ETC1_GET_KEY_FROM_INDEX
923
924 uint16 etc1_block::pack_color5(const color_quad_u8& color, bool scaled, uint bias)
925 {
926 return pack_color5(color.r, color.g, color.b, scaled, bias);
927 }
928
929 uint16 etc1_block::pack_color5(uint r, uint g, uint b, bool scaled, uint bias)
930 {
931 if (scaled)
932 {
933 r = (r * 31U + bias) / 255U;
934 g = (g * 31U + bias) / 255U;
935 b = (b * 31U + bias) / 255U;
936 }
937
938 r = rg_etc1::minimum(r, 31U);
939 g = rg_etc1::minimum(g, 31U);
940 b = rg_etc1::minimum(b, 31U);
941
942 return static_cast<uint16>(b | (g << 5U) | (r << 10U));
943 }
944
945 color_quad_u8 etc1_block::unpack_color5(uint16 packed_color5, bool scaled, uint alpha)
946 {
947 uint b = packed_color5 & 31U;
948 uint g = (packed_color5 >> 5U) & 31U;
949 uint r = (packed_color5 >> 10U) & 31U;
950
951 if (scaled)
952 {
953 b = (b << 3U) | (b >> 2U);
954 g = (g << 3U) | (g >> 2U);
955 r = (r << 3U) | (r >> 2U);
956 }
957
958 return color_quad_u8(cNoClamp, r, g, b, rg_etc1::minimum(alpha, 255U));
959 }
960
961 void etc1_block::unpack_color5(uint& r, uint& g, uint& b, uint16 packed_color5, bool scaled)
962 {
963 color_quad_u8 c(unpack_color5(packed_color5, scaled, 0));
964 r = c.r;
965 g = c.g;
966 b = c.b;
967 }
968
969 bool etc1_block::unpack_color5(color_quad_u8& result, uint16 packed_color5, uint16 packed_delta3, bool scaled, uint alpha)
970 {
971 int dc_r, dc_g, dc_b;
972 unpack_delta3(dc_r, dc_g, dc_b, packed_delta3);
973
974 int b = (packed_color5 & 31U) + dc_b;
975 int g = ((packed_color5 >> 5U) & 31U) + dc_g;
976 int r = ((packed_color5 >> 10U) & 31U) + dc_r;
977
978 bool success = true;
979 if (static_cast<uint>(r | g | b) > 31U)
980 {
981 success = false;
982 r = rg_etc1::clamp<int>(r, 0, 31);
983 g = rg_etc1::clamp<int>(g, 0, 31);
984 b = rg_etc1::clamp<int>(b, 0, 31);
985 }
986
987 if (scaled)
988 {
989 b = (b << 3U) | (b >> 2U);
990 g = (g << 3U) | (g >> 2U);
991 r = (r << 3U) | (r >> 2U);
992 }
993
994 result.set_noclamp_rgba(r, g, b, rg_etc1::minimum(alpha, 255U));
995 return success;
996 }
997
998 bool etc1_block::unpack_color5(uint& r, uint& g, uint& b, uint16 packed_color5, uint16 packed_delta3, bool scaled, uint alpha)
999 {
1000 color_quad_u8 result;
1001 const bool success = unpack_color5(result, packed_color5, packed_delta3, scaled, alpha);
1002 r = result.r;
1003 g = result.g;
1004 b = result.b;
1005 return success;
1006 }
1007
1008 uint16 etc1_block::pack_delta3(int r, int g, int b)
1009 {
1010 RG_ETC1_ASSERT((r >= cETC1ColorDeltaMin) && (r <= cETC1ColorDeltaMax));
1011 RG_ETC1_ASSERT((g >= cETC1ColorDeltaMin) && (g <= cETC1ColorDeltaMax));
1012 RG_ETC1_ASSERT((b >= cETC1ColorDeltaMin) && (b <= cETC1ColorDeltaMax));
1013 if (r < 0) r += 8;
1014 if (g < 0) g += 8;
1015 if (b < 0) b += 8;
1016 return static_cast<uint16>(b | (g << 3) | (r << 6));
1017 }
1018
1019 void etc1_block::unpack_delta3(int& r, int& g, int& b, uint16 packed_delta3)
1020 {
1021 r = (packed_delta3 >> 6) & 7;
1022 g = (packed_delta3 >> 3) & 7;
1023 b = packed_delta3 & 7;
1024 if (r >= 4) r -= 8;
1025 if (g >= 4) g -= 8;
1026 if (b >= 4) b -= 8;
1027 }
1028
1029 uint16 etc1_block::pack_color4(const color_quad_u8& color, bool scaled, uint bias)
1030 {
1031 return pack_color4(color.r, color.g, color.b, scaled, bias);
1032 }
1033
1034 uint16 etc1_block::pack_color4(uint r, uint g, uint b, bool scaled, uint bias)
1035 {
1036 if (scaled)
1037 {
1038 r = (r * 15U + bias) / 255U;
1039 g = (g * 15U + bias) / 255U;
1040 b = (b * 15U + bias) / 255U;
1041 }
1042
1043 r = rg_etc1::minimum(r, 15U);
1044 g = rg_etc1::minimum(g, 15U);
1045 b = rg_etc1::minimum(b, 15U);
1046
1047 return static_cast<uint16>(b | (g << 4U) | (r << 8U));
1048 }
1049
1050 color_quad_u8 etc1_block::unpack_color4(uint16 packed_color4, bool scaled, uint alpha)
1051 {
1052 uint b = packed_color4 & 15U;
1053 uint g = (packed_color4 >> 4U) & 15U;
1054 uint r = (packed_color4 >> 8U) & 15U;
1055
1056 if (scaled)
1057 {
1058 b = (b << 4U) | b;
1059 g = (g << 4U) | g;
1060 r = (r << 4U) | r;
1061 }
1062
1063 return color_quad_u8(cNoClamp, r, g, b, rg_etc1::minimum(alpha, 255U));
1064 }
1065
1066 void etc1_block::unpack_color4(uint& r, uint& g, uint& b, uint16 packed_color4, bool scaled)
1067 {
1068 color_quad_u8 c(unpack_color4(packed_color4, scaled, 0));
1069 r = c.r;
1070 g = c.g;
1071 b = c.b;
1072 }
1073
1074 void etc1_block::get_diff_subblock_colors(color_quad_u8* pDst, uint16 packed_color5, uint table_idx)
1075 {
1076 RG_ETC1_ASSERT(table_idx < cETC1IntenModifierValues);
1077 const int *pInten_modifer_table = &g_etc1_inten_tables[table_idx][0];
1078
1079 uint r, g, b;
1080 unpack_color5(r, g, b, packed_color5, true);
1081
1082 const int ir = static_cast<int>(r), ig = static_cast<int>(g), ib = static_cast<int>(b);
1083
1084 const int y0 = pInten_modifer_table[0];
1085 pDst[0].set(ir + y0, ig + y0, ib + y0);
1086
1087 const int y1 = pInten_modifer_table[1];
1088 pDst[1].set(ir + y1, ig + y1, ib + y1);
1089
1090 const int y2 = pInten_modifer_table[2];
1091 pDst[2].set(ir + y2, ig + y2, ib + y2);
1092
1093 const int y3 = pInten_modifer_table[3];
1094 pDst[3].set(ir + y3, ig + y3, ib + y3);
1095 }
1096
1097 bool etc1_block::get_diff_subblock_colors(color_quad_u8* pDst, uint16 packed_color5, uint16 packed_delta3, uint table_idx)
1098 {
1099 RG_ETC1_ASSERT(table_idx < cETC1IntenModifierValues);
1100 const int *pInten_modifer_table = &g_etc1_inten_tables[table_idx][0];
1101
1102 uint r, g, b;
1103 bool success = unpack_color5(r, g, b, packed_color5, packed_delta3, true);
1104
1105 const int ir = static_cast<int>(r), ig = static_cast<int>(g), ib = static_cast<int>(b);
1106
1107 const int y0 = pInten_modifer_table[0];
1108 pDst[0].set(ir + y0, ig + y0, ib + y0);
1109
1110 const int y1 = pInten_modifer_table[1];
1111 pDst[1].set(ir + y1, ig + y1, ib + y1);
1112
1113 const int y2 = pInten_modifer_table[2];
1114 pDst[2].set(ir + y2, ig + y2, ib + y2);
1115
1116 const int y3 = pInten_modifer_table[3];
1117 pDst[3].set(ir + y3, ig + y3, ib + y3);
1118
1119 return success;
1120 }
1121
1122 void etc1_block::get_abs_subblock_colors(color_quad_u8* pDst, uint16 packed_color4, uint table_idx)
1123 {
1124 RG_ETC1_ASSERT(table_idx < cETC1IntenModifierValues);
1125 const int *pInten_modifer_table = &g_etc1_inten_tables[table_idx][0];
1126
1127 uint r, g, b;
1128 unpack_color4(r, g, b, packed_color4, true);
1129
1130 const int ir = static_cast<int>(r), ig = static_cast<int>(g), ib = static_cast<int>(b);
1131
1132 const int y0 = pInten_modifer_table[0];
1133 pDst[0].set(ir + y0, ig + y0, ib + y0);
1134
1135 const int y1 = pInten_modifer_table[1];
1136 pDst[1].set(ir + y1, ig + y1, ib + y1);
1137
1138 const int y2 = pInten_modifer_table[2];
1139 pDst[2].set(ir + y2, ig + y2, ib + y2);
1140
1141 const int y3 = pInten_modifer_table[3];
1142 pDst[3].set(ir + y3, ig + y3, ib + y3);
1143 }
1144
1145 bool unpack_etc1_block(const void* pETC1_block, unsigned int* pDst_pixels_rgba, bool preserve_alpha)
1146 {
1147 color_quad_u8* pDst = reinterpret_cast<color_quad_u8*>(pDst_pixels_rgba);
1148 const etc1_block& block = *static_cast<const etc1_block*>(pETC1_block);
1149
1150 const bool diff_flag = block.get_diff_bit();
1151 const bool flip_flag = block.get_flip_bit();
1152 const uint table_index0 = block.get_inten_table(0);
1153 const uint table_index1 = block.get_inten_table(1);
1154
1155 color_quad_u8 subblock_colors0[4];
1156 color_quad_u8 subblock_colors1[4];
1157 bool success = true;
1158
1159 if (diff_flag)
1160 {
1161 const uint16 base_color5 = block.get_base5_color();
1162 const uint16 delta_color3 = block.get_delta3_color();
1163 etc1_block::get_diff_subblock_colors(subblock_colors0, base_color5, table_index0);
1164
1165 if (!etc1_block::get_diff_subblock_colors(subblock_colors1, base_color5, delta_color3, table_index1))
1166 success = false;
1167 }
1168 else
1169 {
1170 const uint16 base_color4_0 = block.get_base4_color(0);
1171 etc1_block::get_abs_subblock_colors(subblock_colors0, base_color4_0, table_index0);
1172
1173 const uint16 base_color4_1 = block.get_base4_color(1);
1174 etc1_block::get_abs_subblock_colors(subblock_colors1, base_color4_1, table_index1);
1175 }
1176
1177 if (preserve_alpha)
1178 {
1179 if (flip_flag)
1180 {
1181 for (uint y = 0; y < 2; y++)
1182 {
1183 pDst[0].set_rgb(subblock_colors0[block.get_selector(0, y)]);
1184 pDst[1].set_rgb(subblock_colors0[block.get_selector(1, y)]);
1185 pDst[2].set_rgb(subblock_colors0[block.get_selector(2, y)]);
1186 pDst[3].set_rgb(subblock_colors0[block.get_selector(3, y)]);
1187 pDst += 4;
1188 }
1189
1190 for (uint y = 2; y < 4; y++)
1191 {
1192 pDst[0].set_rgb(subblock_colors1[block.get_selector(0, y)]);
1193 pDst[1].set_rgb(subblock_colors1[block.get_selector(1, y)]);
1194 pDst[2].set_rgb(subblock_colors1[block.get_selector(2, y)]);
1195 pDst[3].set_rgb(subblock_colors1[block.get_selector(3, y)]);
1196 pDst += 4;
1197 }
1198 }
1199 else
1200 {
1201 for (uint y = 0; y < 4; y++)
1202 {
1203 pDst[0].set_rgb(subblock_colors0[block.get_selector(0, y)]);
1204 pDst[1].set_rgb(subblock_colors0[block.get_selector(1, y)]);
1205 pDst[2].set_rgb(subblock_colors1[block.get_selector(2, y)]);
1206 pDst[3].set_rgb(subblock_colors1[block.get_selector(3, y)]);
1207 pDst += 4;
1208 }
1209 }
1210 }
1211 else
1212 {
1213 if (flip_flag)
1214 {
1215 // 0000
1216 // 0000
1217 // 1111
1218 // 1111
1219 for (uint y = 0; y < 2; y++)
1220 {
1221 pDst[0] = subblock_colors0[block.get_selector(0, y)];
1222 pDst[1] = subblock_colors0[block.get_selector(1, y)];
1223 pDst[2] = subblock_colors0[block.get_selector(2, y)];
1224 pDst[3] = subblock_colors0[block.get_selector(3, y)];
1225 pDst += 4;
1226 }
1227
1228 for (uint y = 2; y < 4; y++)
1229 {
1230 pDst[0] = subblock_colors1[block.get_selector(0, y)];
1231 pDst[1] = subblock_colors1[block.get_selector(1, y)];
1232 pDst[2] = subblock_colors1[block.get_selector(2, y)];
1233 pDst[3] = subblock_colors1[block.get_selector(3, y)];
1234 pDst += 4;
1235 }
1236 }
1237 else
1238 {
1239 // 0011
1240 // 0011
1241 // 0011
1242 // 0011
1243 for (uint y = 0; y < 4; y++)
1244 {
1245 pDst[0] = subblock_colors0[block.get_selector(0, y)];
1246 pDst[1] = subblock_colors0[block.get_selector(1, y)];
1247 pDst[2] = subblock_colors1[block.get_selector(2, y)];
1248 pDst[3] = subblock_colors1[block.get_selector(3, y)];
1249 pDst += 4;
1250 }
1251 }
1252 }
1253
1254 return success;
1255 }
1256
1257 struct etc1_solution_coordinates
1258 {
1259 inline etc1_solution_coordinates() :
1260 m_unscaled_color(0, 0, 0, 0),
1261 m_inten_table(0),
1262 m_color4(false)
1263 {
1264 }
1265
1266 inline etc1_solution_coordinates(uint r, uint g, uint b, uint inten_table, bool color4) :
1267 m_unscaled_color(r, g, b, 255),
1268 m_inten_table(inten_table),
1269 m_color4(color4)
1270 {
1271 }
1272
1273 inline etc1_solution_coordinates(const color_quad_u8& c, uint inten_table, bool color4) :
1274 m_unscaled_color(c),
1275 m_inten_table(inten_table),
1276 m_color4(color4)
1277 {
1278 }
1279
1280 inline etc1_solution_coordinates(const etc1_solution_coordinates& other)
1281 {
1282 *this = other;
1283 }
1284
1285 inline etc1_solution_coordinates& operator= (const etc1_solution_coordinates& rhs)
1286 {
1287 m_unscaled_color = rhs.m_unscaled_color;
1288 m_inten_table = rhs.m_inten_table;
1289 m_color4 = rhs.m_color4;
1290 return *this;
1291 }
1292
1293 inline void clear()
1294 {
1295 m_unscaled_color.clear();
1296 m_inten_table = 0;
1297 m_color4 = false;
1298 }
1299
1300 inline color_quad_u8 get_scaled_color() const
1301 {
1302 int br, bg, bb;
1303 if (m_color4)
1304 {
1305 br = m_unscaled_color.r | (m_unscaled_color.r << 4);
1306 bg = m_unscaled_color.g | (m_unscaled_color.g << 4);
1307 bb = m_unscaled_color.b | (m_unscaled_color.b << 4);
1308 }
1309 else
1310 {
1311 br = (m_unscaled_color.r >> 2) | (m_unscaled_color.r << 3);
1312 bg = (m_unscaled_color.g >> 2) | (m_unscaled_color.g << 3);
1313 bb = (m_unscaled_color.b >> 2) | (m_unscaled_color.b << 3);
1314 }
1315 return color_quad_u8(br, bg, bb);
1316 }
1317
1318 inline void get_block_colors(color_quad_u8* pBlock_colors)
1319 {
1320 int br, bg, bb;
1321 if (m_color4)
1322 {
1323 br = m_unscaled_color.r | (m_unscaled_color.r << 4);
1324 bg = m_unscaled_color.g | (m_unscaled_color.g << 4);
1325 bb = m_unscaled_color.b | (m_unscaled_color.b << 4);
1326 }
1327 else
1328 {
1329 br = (m_unscaled_color.r >> 2) | (m_unscaled_color.r << 3);
1330 bg = (m_unscaled_color.g >> 2) | (m_unscaled_color.g << 3);
1331 bb = (m_unscaled_color.b >> 2) | (m_unscaled_color.b << 3);
1332 }
1333 const int* pInten_table = g_etc1_inten_tables[m_inten_table];
1334 pBlock_colors[0].set(br + pInten_table[0], bg + pInten_table[0], bb + pInten_table[0]);
1335 pBlock_colors[1].set(br + pInten_table[1], bg + pInten_table[1], bb + pInten_table[1]);
1336 pBlock_colors[2].set(br + pInten_table[2], bg + pInten_table[2], bb + pInten_table[2]);
1337 pBlock_colors[3].set(br + pInten_table[3], bg + pInten_table[3], bb + pInten_table[3]);
1338 }
1339
1340 color_quad_u8 m_unscaled_color;
1341 uint m_inten_table;
1342 bool m_color4;
1343 };
1344
1345 class etc1_optimizer
1346 {
1347 etc1_optimizer(const etc1_optimizer&);
1348 etc1_optimizer& operator= (const etc1_optimizer&);
1349
1350 public:
1351 etc1_optimizer()
1352 {
1353 clear();
1354 }
1355
1356 void clear()
1357 {
1358 m_pParams = NULL;
1359 m_pResult = NULL;
1360 m_pSorted_luma = NULL;
1361 m_pSorted_luma_indices = NULL;
1362 }
1363
1364 struct params : etc1_pack_params
1365 {
1366 params()
1367 {
1368 clear();
1369 }
1370
1371 params(const etc1_pack_params& base_params) :
1372 etc1_pack_params(base_params)
1373 {
1374 clear_optimizer_params();
1375 }
1376
1377 void clear()
1378 {
1379 etc1_pack_params::clear();
1380 clear_optimizer_params();
1381 }
1382
1383 void clear_optimizer_params()
1384 {
1385 m_num_src_pixels = 0;
1386 m_pSrc_pixels = 0;
1387
1388 m_use_color4 = false;
1389 static const int s_default_scan_delta[] = { 0 };
1390 m_pScan_deltas = s_default_scan_delta;
1391 m_scan_delta_size = 1;
1392
1393 m_base_color5.clear();
1394 m_constrain_against_base_color5 = false;
1395 }
1396
1397 uint m_num_src_pixels;
1398 const color_quad_u8* m_pSrc_pixels;
1399
1400 bool m_use_color4;
1401 const int* m_pScan_deltas;
1402 uint m_scan_delta_size;
1403
1404 color_quad_u8 m_base_color5;
1405 bool m_constrain_against_base_color5;
1406 };
1407
1408 struct results
1409 {
1410 uint64 m_error;
1411 color_quad_u8 m_block_color_unscaled;
1412 uint m_block_inten_table;
1413 uint m_n;
1414 uint8* m_pSelectors;
1415 bool m_block_color4;
1416
1417 inline results& operator= (const results& rhs)
1418 {
1419 m_block_color_unscaled = rhs.m_block_color_unscaled;
1420 m_block_color4 = rhs.m_block_color4;
1421 m_block_inten_table = rhs.m_block_inten_table;
1422 m_error = rhs.m_error;
1423 RG_ETC1_ASSERT(m_n == rhs.m_n);
1424 memcpy(m_pSelectors, rhs.m_pSelectors, rhs.m_n);
1425 return *this;
1426 }
1427 };
1428
1429 void init(const params& params, results& result);
1430 bool compute();
1431
1432 private:
1433 struct potential_solution
1434 {
1435 potential_solution() : m_coords(), m_error(cUINT64_MAX), m_valid(false)
1436 {
1437 }
1438
1439 etc1_solution_coordinates m_coords;
1440 uint8 m_selectors[8];
1441 uint64 m_error;
1442 bool m_valid;
1443
1444 void clear()
1445 {
1446 m_coords.clear();
1447 m_error = cUINT64_MAX;
1448 m_valid = false;
1449 }
1450 };
1451
1452 const params* m_pParams;
1453 results* m_pResult;
1454
1455 int m_limit;
1456
1457 vec3F m_avg_color;
1458 int m_br, m_bg, m_bb;
1459 uint16 m_luma[8];
1460 uint32 m_sorted_luma[2][8];
1461 const uint32* m_pSorted_luma_indices;
1462 uint32* m_pSorted_luma;
1463
1464 uint8 m_selectors[8];
1465 uint8 m_best_selectors[8];
1466
1467 potential_solution m_best_solution;
1468 potential_solution m_trial_solution;
1469 uint8 m_temp_selectors[8];
1470
1471 bool evaluate_solution(const etc1_solution_coordinates& coords, potential_solution& trial_solution, potential_solution* pBest_solution);
1472 bool evaluate_solution_fast(const etc1_solution_coordinates& coords, potential_solution& trial_solution, potential_solution* pBest_solution);
1473 };
1474
1475 bool etc1_optimizer::compute()
1476 {
1477 const uint n = m_pParams->m_num_src_pixels;
1478 const int scan_delta_size = m_pParams->m_scan_delta_size;
1479
1480 // Scan through a subset of the 3D lattice centered around the avg block color trying each 3D (555 or 444) lattice point as a potential block color.
1481 // Each time a better solution is found try to refine the current solution's block color based of the current selectors and intensity table index.
1482 for (int zdi = 0; zdi < scan_delta_size; zdi++)
1483 {
1484 const int zd = m_pParams->m_pScan_deltas[zdi];
1485 const int mbb = m_bb + zd;
1486 if (mbb < 0) continue; else if (mbb > m_limit) break;
1487
1488 for (int ydi = 0; ydi < scan_delta_size; ydi++)
1489 {
1490 const int yd = m_pParams->m_pScan_deltas[ydi];
1491 const int mbg = m_bg + yd;
1492 if (mbg < 0) continue; else if (mbg > m_limit) break;
1493
1494 for (int xdi = 0; xdi < scan_delta_size; xdi++)
1495 {
1496 const int xd = m_pParams->m_pScan_deltas[xdi];
1497 const int mbr = m_br + xd;
1498 if (mbr < 0) continue; else if (mbr > m_limit) break;
1499
1500 etc1_solution_coordinates coords(mbr, mbg, mbb, 0, m_pParams->m_use_color4);
1501 if (m_pParams->m_quality == cHighQuality)
1502 {
1503 if (!evaluate_solution(coords, m_trial_solution, &m_best_solution))
1504 continue;
1505 }
1506 else
1507 {
1508 if (!evaluate_solution_fast(coords, m_trial_solution, &m_best_solution))
1509 continue;
1510 }
1511
1512 // Now we have the input block, the avg. color of the input pixels, a set of trial selector indices, and the block color+intensity index.
1513 // Now, for each component, attempt to refine the current solution by solving a simple linear equation. For example, for 4 colors:
1514 // The goal is:
1515 // pixel0 - (block_color+inten_table[selector0]) + pixel1 - (block_color+inten_table[selector1]) + pixel2 - (block_color+inten_table[selector2]) + pixel3 - (block_color+inten_table[selector3]) = 0
1516 // Rearranging this:
1517 // (pixel0 + pixel1 + pixel2 + pixel3) - (block_color+inten_table[selector0]) - (block_color+inten_table[selector1]) - (block_color+inten_table[selector2]) - (block_color+inten_table[selector3]) = 0
1518 // (pixel0 + pixel1 + pixel2 + pixel3) - block_color - inten_table[selector0] - block_color-inten_table[selector1] - block_color-inten_table[selector2] - block_color-inten_table[selector3] = 0
1519 // (pixel0 + pixel1 + pixel2 + pixel3) - 4*block_color - inten_table[selector0] - inten_table[selector1] - inten_table[selector2] - inten_table[selector3] = 0
1520 // (pixel0 + pixel1 + pixel2 + pixel3) - 4*block_color - (inten_table[selector0] + inten_table[selector1] + inten_table[selector2] + inten_table[selector3]) = 0
1521 // (pixel0 + pixel1 + pixel2 + pixel3)/4 - block_color - (inten_table[selector0] + inten_table[selector1] + inten_table[selector2] + inten_table[selector3])/4 = 0
1522 // block_color = (pixel0 + pixel1 + pixel2 + pixel3)/4 - (inten_table[selector0] + inten_table[selector1] + inten_table[selector2] + inten_table[selector3])/4
1523 // So what this means:
1524 // optimal_block_color = avg_input - avg_inten_delta
1525 // So the optimal block color can be computed by taking the average block color and subtracting the current average of the intensity delta.
1526 // Unfortunately, optimal_block_color must then be quantized to 555 or 444 so it's not always possible to improve matters using this formula.
1527 // Also, the above formula is for unclamped intensity deltas. The actual implementation takes into account clamping.
1528
1529 const uint max_refinement_trials = (m_pParams->m_quality == cLowQuality) ? 2 : (((xd | yd | zd) == 0) ? 4 : 2);
1530 for (uint refinement_trial = 0; refinement_trial < max_refinement_trials; refinement_trial++)
1531 {
1532 const uint8* pSelectors = m_best_solution.m_selectors;
1533 const int* pInten_table = g_etc1_inten_tables[m_best_solution.m_coords.m_inten_table];
1534
1535 int delta_sum_r = 0, delta_sum_g = 0, delta_sum_b = 0;
1536 const color_quad_u8 base_color(m_best_solution.m_coords.get_scaled_color());
1537 for (uint r = 0; r < n; r++)
1538 {
1539 const uint s = *pSelectors++;
1540 const int yd = pInten_table[s];
1541 // Compute actual delta being applied to each pixel, taking into account clamping.
1542 delta_sum_r += rg_etc1::clamp<int>(base_color.r + yd, 0, 255) - base_color.r;
1543 delta_sum_g += rg_etc1::clamp<int>(base_color.g + yd, 0, 255) - base_color.g;
1544 delta_sum_b += rg_etc1::clamp<int>(base_color.b + yd, 0, 255) - base_color.b;
1545 }
1546 if ((!delta_sum_r) && (!delta_sum_g) && (!delta_sum_b))
1547 break;
1548 const float avg_delta_r_f = static_cast<float>(delta_sum_r) / n;
1549 const float avg_delta_g_f = static_cast<float>(delta_sum_g) / n;
1550 const float avg_delta_b_f = static_cast<float>(delta_sum_b) / n;
1551 const int br1 = rg_etc1::clamp<int>(static_cast<uint>((m_avg_color[0] - avg_delta_r_f) * m_limit / 255.0f + .5f), 0, m_limit);
1552 const int bg1 = rg_etc1::clamp<int>(static_cast<uint>((m_avg_color[1] - avg_delta_g_f) * m_limit / 255.0f + .5f), 0, m_limit);
1553 const int bb1 = rg_etc1::clamp<int>(static_cast<uint>((m_avg_color[2] - avg_delta_b_f) * m_limit / 255.0f + .5f), 0, m_limit);
1554
1555 bool skip = false;
1556
1557 if ((mbr == br1) && (mbg == bg1) && (mbb == bb1))
1558 skip = true;
1559 else if ((br1 == m_best_solution.m_coords.m_unscaled_color.r) && (bg1 == m_best_solution.m_coords.m_unscaled_color.g) && (bb1 == m_best_solution.m_coords.m_unscaled_color.b))
1560 skip = true;
1561 else if ((m_br == br1) && (m_bg == bg1) && (m_bb == bb1))
1562 skip = true;
1563
1564 if (skip)
1565 break;
1566
1567 etc1_solution_coordinates coords1(br1, bg1, bb1, 0, m_pParams->m_use_color4);
1568 if (m_pParams->m_quality == cHighQuality)
1569 {
1570 if (!evaluate_solution(coords1, m_trial_solution, &m_best_solution))
1571 break;
1572 }
1573 else
1574 {
1575 if (!evaluate_solution_fast(coords1, m_trial_solution, &m_best_solution))
1576 break;
1577 }
1578
1579 } // refinement_trial
1580
1581 } // xdi
1582 } // ydi
1583 } // zdi
1584
1585 if (!m_best_solution.m_valid)
1586 {
1587 m_pResult->m_error = cUINT32_MAX;
1588 return false;
1589 }
1590
1591 const uint8* pSelectors = m_best_solution.m_selectors;
1592
1593#ifdef RG_ETC1_BUILD_DEBUG
1594 {
1595 color_quad_u8 block_colors[4];
1596 m_best_solution.m_coords.get_block_colors(block_colors);
1597
1598 const color_quad_u8* pSrc_pixels = m_pParams->m_pSrc_pixels;
1599 uint64 actual_error = 0;
1600 for (uint i = 0; i < n; i++)
1601 actual_error += pSrc_pixels[i].squared_distance_rgb(block_colors[pSelectors[i]]);
1602
1603 RG_ETC1_ASSERT(actual_error == m_best_solution.m_error);
1604 }
1605#endif
1606
1607 m_pResult->m_error = m_best_solution.m_error;
1608
1609 m_pResult->m_block_color_unscaled = m_best_solution.m_coords.m_unscaled_color;
1610 m_pResult->m_block_color4 = m_best_solution.m_coords.m_color4;
1611
1612 m_pResult->m_block_inten_table = m_best_solution.m_coords.m_inten_table;
1613 memcpy(m_pResult->m_pSelectors, pSelectors, n);
1614 m_pResult->m_n = n;
1615
1616 return true;
1617 }
1618
1619 void etc1_optimizer::init(const params& p, results& r)
1620 {
1621 // This version is hardcoded for 8 pixel subblocks.
1622 RG_ETC1_ASSERT(p.m_num_src_pixels == 8);
1623
1624 m_pParams = &p;
1625 m_pResult = &r;
1626
1627 const uint n = 8;
1628
1629 m_limit = m_pParams->m_use_color4 ? 15 : 31;
1630
1631 vec3F avg_color(0.0f);
1632
1633 for (uint i = 0; i < n; i++)
1634 {
1635 const color_quad_u8& c = m_pParams->m_pSrc_pixels[i];
1636 const vec3F fc(c.r, c.g, c.b);
1637
1638 avg_color += fc;
1639
1640 m_luma[i] = static_cast<uint16>(c.r + c.g + c.b);
1641 m_sorted_luma[0][i] = i;
1642 }
1643 avg_color *= (1.0f / static_cast<float>(n));
1644 m_avg_color = avg_color;
1645
1646 m_br = rg_etc1::clamp<int>(static_cast<uint>(m_avg_color[0] * m_limit / 255.0f + .5f), 0, m_limit);
1647 m_bg = rg_etc1::clamp<int>(static_cast<uint>(m_avg_color[1] * m_limit / 255.0f + .5f), 0, m_limit);
1648 m_bb = rg_etc1::clamp<int>(static_cast<uint>(m_avg_color[2] * m_limit / 255.0f + .5f), 0, m_limit);
1649
1650 if (m_pParams->m_quality <= cMediumQuality)
1651 {
1652 m_pSorted_luma_indices = indirect_radix_sort(n, m_sorted_luma[0], m_sorted_luma[1], m_luma, 0, sizeof(m_luma[0]), false);
1653 m_pSorted_luma = m_sorted_luma[0];
1654 if (m_pSorted_luma_indices == m_sorted_luma[0])
1655 m_pSorted_luma = m_sorted_luma[1];
1656
1657 for (uint i = 0; i < n; i++)
1658 m_pSorted_luma[i] = m_luma[m_pSorted_luma_indices[i]];
1659 }
1660
1661 m_best_solution.m_coords.clear();
1662 m_best_solution.m_valid = false;
1663 m_best_solution.m_error = cUINT64_MAX;
1664 }
1665
1666 bool etc1_optimizer::evaluate_solution(const etc1_solution_coordinates& coords, potential_solution& trial_solution, potential_solution* pBest_solution)
1667 {
1668 trial_solution.m_valid = false;
1669
1670 if (m_pParams->m_constrain_against_base_color5)
1671 {
1672 const int dr = coords.m_unscaled_color.r - m_pParams->m_base_color5.r;
1673 const int dg = coords.m_unscaled_color.g - m_pParams->m_base_color5.g;
1674 const int db = coords.m_unscaled_color.b - m_pParams->m_base_color5.b;
1675
1676 if ((rg_etc1::minimum(dr, dg, db) < cETC1ColorDeltaMin) || (rg_etc1::maximum(dr, dg, db) > cETC1ColorDeltaMax))
1677 return false;
1678 }
1679
1680 const color_quad_u8 base_color(coords.get_scaled_color());
1681
1682 const uint n = 8;
1683
1684 trial_solution.m_error = cUINT64_MAX;
1685
1686 for (uint inten_table = 0; inten_table < cETC1IntenModifierValues; inten_table++)
1687 {
1688 const int* pInten_table = g_etc1_inten_tables[inten_table];
1689
1690 color_quad_u8 block_colors[4];
1691 for (uint s = 0; s < 4; s++)
1692 {
1693 const int yd = pInten_table[s];
1694 block_colors[s].set(base_color.r + yd, base_color.g + yd, base_color.b + yd, 0);
1695 }
1696
1697 uint64 total_error = 0;
1698
1699 const color_quad_u8* pSrc_pixels = m_pParams->m_pSrc_pixels;
1700 for (uint c = 0; c < n; c++)
1701 {
1702 const color_quad_u8& src_pixel = *pSrc_pixels++;
1703
1704 uint best_selector_index = 0;
1705 uint best_error = rg_etc1::square(src_pixel.r - block_colors[0].r) + rg_etc1::square(src_pixel.g - block_colors[0].g) + rg_etc1::square(src_pixel.b - block_colors[0].b);
1706
1707 uint trial_error = rg_etc1::square(src_pixel.r - block_colors[1].r) + rg_etc1::square(src_pixel.g - block_colors[1].g) + rg_etc1::square(src_pixel.b - block_colors[1].b);
1708 if (trial_error < best_error)
1709 {
1710 best_error = trial_error;
1711 best_selector_index = 1;
1712 }
1713
1714 trial_error = rg_etc1::square(src_pixel.r - block_colors[2].r) + rg_etc1::square(src_pixel.g - block_colors[2].g) + rg_etc1::square(src_pixel.b - block_colors[2].b);
1715 if (trial_error < best_error)
1716 {
1717 best_error = trial_error;
1718 best_selector_index = 2;
1719 }
1720
1721 trial_error = rg_etc1::square(src_pixel.r - block_colors[3].r) + rg_etc1::square(src_pixel.g - block_colors[3].g) + rg_etc1::square(src_pixel.b - block_colors[3].b);
1722 if (trial_error < best_error)
1723 {
1724 best_error = trial_error;
1725 best_selector_index = 3;
1726 }
1727
1728 m_temp_selectors[c] = static_cast<uint8>(best_selector_index);
1729
1730 total_error += best_error;
1731 if (total_error >= trial_solution.m_error)
1732 break;
1733 }
1734
1735 if (total_error < trial_solution.m_error)
1736 {
1737 trial_solution.m_error = total_error;
1738 trial_solution.m_coords.m_inten_table = inten_table;
1739 memcpy(trial_solution.m_selectors, m_temp_selectors, 8);
1740 trial_solution.m_valid = true;
1741 }
1742 }
1743 trial_solution.m_coords.m_unscaled_color = coords.m_unscaled_color;
1744 trial_solution.m_coords.m_color4 = m_pParams->m_use_color4;
1745
1746 bool success = false;
1747 if (pBest_solution)
1748 {
1749 if (trial_solution.m_error < pBest_solution->m_error)
1750 {
1751 *pBest_solution = trial_solution;
1752 success = true;
1753 }
1754 }
1755
1756 return success;
1757 }
1758
1759 bool etc1_optimizer::evaluate_solution_fast(const etc1_solution_coordinates& coords, potential_solution& trial_solution, potential_solution* pBest_solution)
1760 {
1761 if (m_pParams->m_constrain_against_base_color5)
1762 {
1763 const int dr = coords.m_unscaled_color.r - m_pParams->m_base_color5.r;
1764 const int dg = coords.m_unscaled_color.g - m_pParams->m_base_color5.g;
1765 const int db = coords.m_unscaled_color.b - m_pParams->m_base_color5.b;
1766
1767 if ((rg_etc1::minimum(dr, dg, db) < cETC1ColorDeltaMin) || (rg_etc1::maximum(dr, dg, db) > cETC1ColorDeltaMax))
1768 {
1769 trial_solution.m_valid = false;
1770 return false;
1771 }
1772 }
1773
1774 const color_quad_u8 base_color(coords.get_scaled_color());
1775
1776 const uint n = 8;
1777
1778 trial_solution.m_error = cUINT64_MAX;
1779
1780 for (int inten_table = cETC1IntenModifierValues - 1; inten_table >= 0; --inten_table)
1781 {
1782 const int* pInten_table = g_etc1_inten_tables[inten_table];
1783
1784 uint block_inten[4];
1785 color_quad_u8 block_colors[4];
1786 for (uint s = 0; s < 4; s++)
1787 {
1788 const int yd = pInten_table[s];
1789 color_quad_u8 block_color(base_color.r + yd, base_color.g + yd, base_color.b + yd, 0);
1790 block_colors[s] = block_color;
1791 block_inten[s] = block_color.r + block_color.g + block_color.b;
1792 }
1793
1794 // evaluate_solution_fast() enforces/assumesd a total ordering of the input colors along the intensity (1,1,1) axis to more quickly classify the inputs to selectors.
1795 // The inputs colors have been presorted along the projection onto this axis, and ETC1 block colors are always ordered along the intensity axis, so this classification is fast.
1796 // 0 1 2 3
1797 // 01 12 23
1798 const uint block_inten_midpoints[3] = { block_inten[0] + block_inten[1], block_inten[1] + block_inten[2], block_inten[2] + block_inten[3] };
1799
1800 uint64 total_error = 0;
1801 const color_quad_u8* pSrc_pixels = m_pParams->m_pSrc_pixels;
1802 if ((m_pSorted_luma[n - 1] * 2) < block_inten_midpoints[0])
1803 {
1804 if (block_inten[0] > m_pSorted_luma[n - 1])
1805 {
1806 const uint min_error = labs(block_inten[0] - m_pSorted_luma[n - 1]);
1807 if (min_error >= trial_solution.m_error)
1808 continue;
1809 }
1810
1811 memset(&m_temp_selectors[0], 0, n);
1812
1813 for (uint c = 0; c < n; c++)
1814 total_error += block_colors[0].squared_distance_rgb(pSrc_pixels[c]);
1815 }
1816 else if ((m_pSorted_luma[0] * 2) >= block_inten_midpoints[2])
1817 {
1818 if (m_pSorted_luma[0] > block_inten[3])
1819 {
1820 const uint min_error = labs(m_pSorted_luma[0] - block_inten[3]);
1821 if (min_error >= trial_solution.m_error)
1822 continue;
1823 }
1824
1825 memset(&m_temp_selectors[0], 3, n);
1826
1827 for (uint c = 0; c < n; c++)
1828 total_error += block_colors[3].squared_distance_rgb(pSrc_pixels[c]);
1829 }
1830 else
1831 {
1832 uint cur_selector = 0, c;
1833 for (c = 0; c < n; c++)
1834 {
1835 const uint y = m_pSorted_luma[c];
1836 while ((y * 2) >= block_inten_midpoints[cur_selector])
1837 if (++cur_selector > 2)
1838 goto done;
1839 const uint sorted_pixel_index = m_pSorted_luma_indices[c];
1840 m_temp_selectors[sorted_pixel_index] = static_cast<uint8>(cur_selector);
1841 total_error += block_colors[cur_selector].squared_distance_rgb(pSrc_pixels[sorted_pixel_index]);
1842 }
1843done:
1844 while (c < n)
1845 {
1846 const uint sorted_pixel_index = m_pSorted_luma_indices[c];
1847 m_temp_selectors[sorted_pixel_index] = 3;
1848 total_error += block_colors[3].squared_distance_rgb(pSrc_pixels[sorted_pixel_index]);
1849 ++c;
1850 }
1851 }
1852
1853 if (total_error < trial_solution.m_error)
1854 {
1855 trial_solution.m_error = total_error;
1856 trial_solution.m_coords.m_inten_table = inten_table;
1857 memcpy(trial_solution.m_selectors, m_temp_selectors, n);
1858 trial_solution.m_valid = true;
1859 if (!total_error)
1860 break;
1861 }
1862 }
1863 trial_solution.m_coords.m_unscaled_color = coords.m_unscaled_color;
1864 trial_solution.m_coords.m_color4 = m_pParams->m_use_color4;
1865
1866 bool success = false;
1867 if (pBest_solution)
1868 {
1869 if (trial_solution.m_error < pBest_solution->m_error)
1870 {
1871 *pBest_solution = trial_solution;
1872 success = true;
1873 }
1874 }
1875
1876 return success;
1877 }
1878
1879 static uint etc1_decode_value(uint diff, uint inten, uint selector, uint packed_c)
1880 {
1881 const uint limit = diff ? 32 : 16; limit;
1882 RG_ETC1_ASSERT((diff < 2) && (inten < 8) && (selector < 4) && (packed_c < limit));
1883 int c;
1884 if (diff)
1885 c = (packed_c >> 2) | (packed_c << 3);
1886 else
1887 c = packed_c | (packed_c << 4);
1888 c += g_etc1_inten_tables[inten][selector];
1889 c = rg_etc1::clamp<int>(c, 0, 255);
1890 return c;
1891 }
1892
1893 static inline int mul_8bit(int a, int b) { int t = a*b + 128; return (t + (t >> 8)) >> 8; }
1894
1895 void pack_etc1_block_init()
1896 {
1897 for (uint diff = 0; diff < 2; diff++)
1898 {
1899 const uint limit = diff ? 32 : 16;
1900
1901 for (uint inten = 0; inten < 8; inten++)
1902 {
1903 for (uint selector = 0; selector < 4; selector++)
1904 {
1905 const uint inverse_table_index = diff + (inten << 1) + (selector << 4);
1906 for (uint color = 0; color < 256; color++)
1907 {
1908 uint best_error = cUINT32_MAX, best_packed_c = 0;
1909 for (uint packed_c = 0; packed_c < limit; packed_c++)
1910 {
1911 int v = etc1_decode_value(diff, inten, selector, packed_c);
1912 uint err = labs(v - static_cast<int>(color));
1913 if (err < best_error)
1914 {
1915 best_error = err;
1916 best_packed_c = packed_c;
1917 if (!best_error)
1918 break;
1919 }
1920 }
1921 RG_ETC1_ASSERT(best_error <= 255);
1922 g_etc1_inverse_lookup[inverse_table_index][color] = static_cast<uint16>(best_packed_c | (best_error << 8));
1923 }
1924 }
1925 }
1926 }
1927
1928 uint expand5[32];
1929 for(int i = 0; i < 32; i++)
1930 expand5[i] = (i << 3) | (i >> 2);
1931
1932 for(int i = 0; i < 256 + 16; i++)
1933 {
1934 int v = clamp<int>(i - 8, 0, 255);
1935 g_quant5_tab[i] = static_cast<uint8>(expand5[mul_8bit(v,31)]);
1936 }
1937 }
1938
1939 // Packs solid color blocks efficiently using a set of small precomputed tables.
1940 // For random 888 inputs, MSE results are better than Erricson's ETC1 packer in "slow" mode ~9.5% of the time, is slightly worse only ~.01% of the time, and is equal the rest of the time.
1941 static uint64 pack_etc1_block_solid_color(etc1_block& block, const uint8* pColor, etc1_pack_params& pack_params)
1942 {
1943 pack_params;
1944 RG_ETC1_ASSERT(g_etc1_inverse_lookup[0][255]);
1945
1946 static uint s_next_comp[4] = { 1, 2, 0, 1 };
1947
1948 uint best_error = cUINT32_MAX, best_i = 0;
1949 int best_x = 0, best_packed_c1 = 0, best_packed_c2 = 0;
1950
1951 // For each possible 8-bit value, there is a precomputed list of diff/inten/selector configurations that allow that 8-bit value to be encoded with no error.
1952 for (uint i = 0; i < 3; i++)
1953 {
1954 const uint c1 = pColor[s_next_comp[i]], c2 = pColor[s_next_comp[i + 1]];
1955
1956 const int delta_range = 1;
1957 for (int delta = -delta_range; delta <= delta_range; delta++)
1958 {
1959 const int c_plus_delta = rg_etc1::clamp<int>(pColor[i] + delta, 0, 255);
1960
1961 const uint16* pTable;
1962 if (!c_plus_delta)
1963 pTable = g_color8_to_etc_block_config_0_255[0];
1964 else if (c_plus_delta == 255)
1965 pTable = g_color8_to_etc_block_config_0_255[1];
1966 else
1967 pTable = g_color8_to_etc_block_config_1_to_254[c_plus_delta - 1];
1968
1969 do
1970 {
1971 const uint x = *pTable++;
1972
1973#ifdef RG_ETC1_BUILD_DEBUG
1974 const uint diff = x & 1;
1975 const uint inten = (x >> 1) & 7;
1976 const uint selector = (x >> 4) & 3;
1977 const uint p0 = (x >> 8) & 255;
1978 RG_ETC1_ASSERT(etc1_decode_value(diff, inten, selector, p0) == (uint)c_plus_delta);
1979#endif
1980
1981 const uint16* pInverse_table = g_etc1_inverse_lookup[x & 0xFF];
1982 uint16 p1 = pInverse_table[c1];
1983 uint16 p2 = pInverse_table[c2];
1984 const uint trial_error = rg_etc1::square(c_plus_delta - pColor[i]) + rg_etc1::square(p1 >> 8) + rg_etc1::square(p2 >> 8);
1985 if (trial_error < best_error)
1986 {
1987 best_error = trial_error;
1988 best_x = x;
1989 best_packed_c1 = p1 & 0xFF;
1990 best_packed_c2 = p2 & 0xFF;
1991 best_i = i;
1992 if (!best_error)
1993 goto found_perfect_match;
1994 }
1995 } while (*pTable != 0xFFFF);
1996 }
1997 }
1998found_perfect_match:
1999
2000 const uint diff = best_x & 1;
2001 const uint inten = (best_x >> 1) & 7;
2002
2003 block.m_bytes[3] = static_cast<uint8>(((inten | (inten << 3)) << 2) | (diff << 1));
2004
2005 const uint etc1_selector = g_selector_index_to_etc1[(best_x >> 4) & 3];
2006 *reinterpret_cast<uint16*>(&block.m_bytes[4]) = (etc1_selector & 2) ? 0xFFFF : 0;
2007 *reinterpret_cast<uint16*>(&block.m_bytes[6]) = (etc1_selector & 1) ? 0xFFFF : 0;
2008
2009 const uint best_packed_c0 = (best_x >> 8) & 255;
2010 if (diff)
2011 {
2012 block.m_bytes[best_i] = static_cast<uint8>(best_packed_c0 << 3);
2013 block.m_bytes[s_next_comp[best_i]] = static_cast<uint8>(best_packed_c1 << 3);
2014 block.m_bytes[s_next_comp[best_i+1]] = static_cast<uint8>(best_packed_c2 << 3);
2015 }
2016 else
2017 {
2018 block.m_bytes[best_i] = static_cast<uint8>(best_packed_c0 | (best_packed_c0 << 4));
2019 block.m_bytes[s_next_comp[best_i]] = static_cast<uint8>(best_packed_c1 | (best_packed_c1 << 4));
2020 block.m_bytes[s_next_comp[best_i+1]] = static_cast<uint8>(best_packed_c2 | (best_packed_c2 << 4));
2021 }
2022
2023 return best_error;
2024 }
2025
2026 static uint pack_etc1_block_solid_color_constrained(
2027 etc1_optimizer::results& results,
2028 uint num_colors, const uint8* pColor,
2029 etc1_pack_params& pack_params,
2030 bool use_diff,
2031 const color_quad_u8* pBase_color5_unscaled)
2032 {
2033 RG_ETC1_ASSERT(g_etc1_inverse_lookup[0][255]);
2034
2035 pack_params;
2036 static uint s_next_comp[4] = { 1, 2, 0, 1 };
2037
2038 uint best_error = cUINT32_MAX, best_i = 0;
2039 int best_x = 0, best_packed_c1 = 0, best_packed_c2 = 0;
2040
2041 // For each possible 8-bit value, there is a precomputed list of diff/inten/selector configurations that allow that 8-bit value to be encoded with no error.
2042 for (uint i = 0; i < 3; i++)
2043 {
2044 const uint c1 = pColor[s_next_comp[i]], c2 = pColor[s_next_comp[i + 1]];
2045
2046 const int delta_range = 1;
2047 for (int delta = -delta_range; delta <= delta_range; delta++)
2048 {
2049 const int c_plus_delta = rg_etc1::clamp<int>(pColor[i] + delta, 0, 255);
2050
2051 const uint16* pTable;
2052 if (!c_plus_delta)
2053 pTable = g_color8_to_etc_block_config_0_255[0];
2054 else if (c_plus_delta == 255)
2055 pTable = g_color8_to_etc_block_config_0_255[1];
2056 else
2057 pTable = g_color8_to_etc_block_config_1_to_254[c_plus_delta - 1];
2058
2059 do
2060 {
2061 const uint x = *pTable++;
2062 const uint diff = x & 1;
2063 if (static_cast<uint>(use_diff) != diff)
2064 {
2065 if (*pTable == 0xFFFF)
2066 break;
2067 continue;
2068 }
2069
2070 if ((diff) && (pBase_color5_unscaled))
2071 {
2072 const int p0 = (x >> 8) & 255;
2073 int delta = p0 - static_cast<int>(pBase_color5_unscaled->c[i]);
2074 if ((delta < cETC1ColorDeltaMin) || (delta > cETC1ColorDeltaMax))
2075 {
2076 if (*pTable == 0xFFFF)
2077 break;
2078 continue;
2079 }
2080 }
2081
2082#ifdef RG_ETC1_BUILD_DEBUG
2083 {
2084 const uint inten = (x >> 1) & 7;
2085 const uint selector = (x >> 4) & 3;
2086 const uint p0 = (x >> 8) & 255;
2087 RG_ETC1_ASSERT(etc1_decode_value(diff, inten, selector, p0) == (uint)c_plus_delta);
2088 }
2089#endif
2090
2091 const uint16* pInverse_table = g_etc1_inverse_lookup[x & 0xFF];
2092 uint16 p1 = pInverse_table[c1];
2093 uint16 p2 = pInverse_table[c2];
2094
2095 if ((diff) && (pBase_color5_unscaled))
2096 {
2097 int delta1 = (p1 & 0xFF) - static_cast<int>(pBase_color5_unscaled->c[s_next_comp[i]]);
2098 int delta2 = (p2 & 0xFF) - static_cast<int>(pBase_color5_unscaled->c[s_next_comp[i + 1]]);
2099 if ((delta1 < cETC1ColorDeltaMin) || (delta1 > cETC1ColorDeltaMax) || (delta2 < cETC1ColorDeltaMin) || (delta2 > cETC1ColorDeltaMax))
2100 {
2101 if (*pTable == 0xFFFF)
2102 break;
2103 continue;
2104 }
2105 }
2106
2107 const uint trial_error = rg_etc1::square(c_plus_delta - pColor[i]) + rg_etc1::square(p1 >> 8) + rg_etc1::square(p2 >> 8);
2108 if (trial_error < best_error)
2109 {
2110 best_error = trial_error;
2111 best_x = x;
2112 best_packed_c1 = p1 & 0xFF;
2113 best_packed_c2 = p2 & 0xFF;
2114 best_i = i;
2115 if (!best_error)
2116 goto found_perfect_match;
2117 }
2118 } while (*pTable != 0xFFFF);
2119 }
2120 }
2121found_perfect_match:
2122
2123 if (best_error == cUINT32_MAX)
2124 return best_error;
2125
2126 best_error *= num_colors;
2127
2128 results.m_n = num_colors;
2129 results.m_block_color4 = !(best_x & 1);
2130 results.m_block_inten_table = (best_x >> 1) & 7;
2131 memset(results.m_pSelectors, (best_x >> 4) & 3, num_colors);
2132
2133 const uint best_packed_c0 = (best_x >> 8) & 255;
2134 results.m_block_color_unscaled[best_i] = static_cast<uint8>(best_packed_c0);
2135 results.m_block_color_unscaled[s_next_comp[best_i]] = static_cast<uint8>(best_packed_c1);
2136 results.m_block_color_unscaled[s_next_comp[best_i + 1]] = static_cast<uint8>(best_packed_c2);
2137 results.m_error = best_error;
2138
2139 return best_error;
2140 }
2141
2142 // Function originally from RYG's public domain real-time DXT1 compressor, modified for 555.
2143 static void dither_block_555(color_quad_u8* dest, const color_quad_u8* block)
2144 {
2145 int err[8],*ep1 = err,*ep2 = err+4;
2146 uint8 *quant = g_quant5_tab+8;
2147
2148 memset(dest, 0xFF, sizeof(color_quad_u8)*16);
2149
2150 // process channels seperately
2151 for(int ch=0;ch<3;ch++)
2152 {
2153 uint8* bp = (uint8*)block;
2154 uint8* dp = (uint8*)dest;
2155
2156 bp += ch; dp += ch;
2157
2158 memset(err,0, sizeof(err));
2159 for(int y = 0; y < 4; y++)
2160 {
2161 // pixel 0
2162 dp[ 0] = quant[bp[ 0] + ((3*ep2[1] + 5*ep2[0]) >> 4)];
2163 ep1[0] = bp[ 0] - dp[ 0];
2164
2165 // pixel 1
2166 dp[ 4] = quant[bp[ 4] + ((7*ep1[0] + 3*ep2[2] + 5*ep2[1] + ep2[0]) >> 4)];
2167 ep1[1] = bp[ 4] - dp[ 4];
2168
2169 // pixel 2
2170 dp[ 8] = quant[bp[ 8] + ((7*ep1[1] + 3*ep2[3] + 5*ep2[2] + ep2[1]) >> 4)];
2171 ep1[2] = bp[ 8] - dp[ 8];
2172
2173 // pixel 3
2174 dp[12] = quant[bp[12] + ((7*ep1[2] + 5*ep2[3] + ep2[2]) >> 4)];
2175 ep1[3] = bp[12] - dp[12];
2176
2177 // advance to next line
2178 int* tmp = ep1; ep1 = ep2; ep2 = tmp;
2179 bp += 16;
2180 dp += 16;
2181 }
2182 }
2183 }
2184
2185 unsigned int pack_etc1_block(void* pETC1_block, const unsigned int* pSrc_pixels_rgba, etc1_pack_params& pack_params)
2186 {
2187 const color_quad_u8* pSrc_pixels = reinterpret_cast<const color_quad_u8*>(pSrc_pixels_rgba);
2188 etc1_block& dst_block = *static_cast<etc1_block*>(pETC1_block);
2189
2190#ifdef RG_ETC1_BUILD_DEBUG
2191 // Ensure all alpha values are 0xFF.
2192 for (uint i = 0; i < 16; i++)
2193 {
2194 RG_ETC1_ASSERT(pSrc_pixels[i].a == 255);
2195 }
2196#endif
2197
2198 color_quad_u8 src_pixel0(pSrc_pixels[0]);
2199
2200 // Check for solid block.
2201 const uint32 first_pixel_u32 = pSrc_pixels->m_u32;
2202 int r;
2203 for (r = 15; r >= 1; --r)
2204 if (pSrc_pixels[r].m_u32 != first_pixel_u32)
2205 break;
2206 if (!r)
2207 return static_cast<unsigned int>(16 * pack_etc1_block_solid_color(dst_block, &pSrc_pixels[0].r, pack_params));
2208
2209 color_quad_u8 dithered_pixels[16];
2210 if (pack_params.m_dithering)
2211 {
2212 dither_block_555(dithered_pixels, pSrc_pixels);
2213 pSrc_pixels = dithered_pixels;
2214 }
2215
2216 etc1_optimizer optimizer;
2217
2218 uint64 best_error = cUINT64_MAX;
2219 uint best_flip = false, best_use_color4 = false;
2220
2221 uint8 best_selectors[2][8];
2222 etc1_optimizer::results best_results[2];
2223 for (uint i = 0; i < 2; i++)
2224 {
2225 best_results[i].m_n = 8;
2226 best_results[i].m_pSelectors = best_selectors[i];
2227 }
2228
2229 uint8 selectors[3][8];
2230 etc1_optimizer::results results[3];
2231
2232 for (uint i = 0; i < 3; i++)
2233 {
2234 results[i].m_n = 8;
2235 results[i].m_pSelectors = selectors[i];
2236 }
2237
2238 color_quad_u8 subblock_pixels[8];
2239
2240 etc1_optimizer::params params(pack_params);
2241 params.m_num_src_pixels = 8;
2242 params.m_pSrc_pixels = subblock_pixels;
2243
2244 for (uint flip = 0; flip < 2; flip++)
2245 {
2246 for (uint use_color4 = 0; use_color4 < 2; use_color4++)
2247 {
2248 uint64 trial_error = 0;
2249
2250 uint subblock;
2251 for (subblock = 0; subblock < 2; subblock++)
2252 {
2253 if (flip)
2254 memcpy(subblock_pixels, pSrc_pixels + subblock * 8, sizeof(color_quad_u8) * 8);
2255 else
2256 {
2257 const color_quad_u8* pSrc_col = pSrc_pixels + subblock * 2;
2258 subblock_pixels[0] = pSrc_col[0]; subblock_pixels[1] = pSrc_col[4]; subblock_pixels[2] = pSrc_col[8]; subblock_pixels[3] = pSrc_col[12];
2259 subblock_pixels[4] = pSrc_col[1]; subblock_pixels[5] = pSrc_col[5]; subblock_pixels[6] = pSrc_col[9]; subblock_pixels[7] = pSrc_col[13];
2260 }
2261
2262 results[2].m_error = cUINT64_MAX;
2263 if ((params.m_quality >= cMediumQuality) && ((subblock) || (use_color4)))
2264 {
2265 const uint32 subblock_pixel0_u32 = subblock_pixels[0].m_u32;
2266 for (r = 7; r >= 1; --r)
2267 if (subblock_pixels[r].m_u32 != subblock_pixel0_u32)
2268 break;
2269 if (!r)
2270 {
2271 pack_etc1_block_solid_color_constrained(results[2], 8, &subblock_pixels[0].r, pack_params, !use_color4, (subblock && !use_color4) ? &results[0].m_block_color_unscaled : NULL);
2272 }
2273 }
2274
2275 params.m_use_color4 = (use_color4 != 0);
2276 params.m_constrain_against_base_color5 = false;
2277
2278 if ((!use_color4) && (subblock))
2279 {
2280 params.m_constrain_against_base_color5 = true;
2281 params.m_base_color5 = results[0].m_block_color_unscaled;
2282 }
2283
2284 if (params.m_quality == cHighQuality)
2285 {
2286 static const int s_scan_delta_0_to_4[] = { -4, -3, -2, -1, 0, 1, 2, 3, 4 };
2287 params.m_scan_delta_size = RG_ETC1_ARRAY_SIZE(s_scan_delta_0_to_4);
2288 params.m_pScan_deltas = s_scan_delta_0_to_4;
2289 }
2290 else if (params.m_quality == cMediumQuality)
2291 {
2292 static const int s_scan_delta_0_to_1[] = { -1, 0, 1 };
2293 params.m_scan_delta_size = RG_ETC1_ARRAY_SIZE(s_scan_delta_0_to_1);
2294 params.m_pScan_deltas = s_scan_delta_0_to_1;
2295 }
2296 else
2297 {
2298 static const int s_scan_delta_0[] = { 0 };
2299 params.m_scan_delta_size = RG_ETC1_ARRAY_SIZE(s_scan_delta_0);
2300 params.m_pScan_deltas = s_scan_delta_0;
2301 }
2302
2303 optimizer.init(params, results[subblock]);
2304 if (!optimizer.compute())
2305 break;
2306
2307 if (params.m_quality >= cMediumQuality)
2308 {
2309 // TODO: Fix fairly arbitrary/unrefined thresholds that control how far away to scan for potentially better solutions.
2310 const uint refinement_error_thresh0 = 3000;
2311 const uint refinement_error_thresh1 = 6000;
2312 if (results[subblock].m_error > refinement_error_thresh0)
2313 {
2314 if (params.m_quality == cMediumQuality)
2315 {
2316 static const int s_scan_delta_2_to_3[] = { -3, -2, 2, 3 };
2317 params.m_scan_delta_size = RG_ETC1_ARRAY_SIZE(s_scan_delta_2_to_3);
2318 params.m_pScan_deltas = s_scan_delta_2_to_3;
2319 }
2320 else
2321 {
2322 static const int s_scan_delta_5_to_5[] = { -5, 5 };
2323 static const int s_scan_delta_5_to_8[] = { -8, -7, -6, -5, 5, 6, 7, 8 };
2324 if (results[subblock].m_error > refinement_error_thresh1)
2325 {
2326 params.m_scan_delta_size = RG_ETC1_ARRAY_SIZE(s_scan_delta_5_to_8);
2327 params.m_pScan_deltas = s_scan_delta_5_to_8;
2328 }
2329 else
2330 {
2331 params.m_scan_delta_size = RG_ETC1_ARRAY_SIZE(s_scan_delta_5_to_5);
2332 params.m_pScan_deltas = s_scan_delta_5_to_5;
2333 }
2334 }
2335
2336 if (!optimizer.compute())
2337 break;
2338 }
2339
2340 if (results[2].m_error < results[subblock].m_error)
2341 results[subblock] = results[2];
2342 }
2343
2344 trial_error += results[subblock].m_error;
2345 if (trial_error >= best_error)
2346 break;
2347 }
2348
2349 if (subblock < 2)
2350 continue;
2351
2352 best_error = trial_error;
2353 best_results[0] = results[0];
2354 best_results[1] = results[1];
2355 best_flip = flip;
2356 best_use_color4 = use_color4;
2357
2358 } // use_color4
2359
2360 } // flip
2361
2362 int dr = best_results[1].m_block_color_unscaled.r - best_results[0].m_block_color_unscaled.r;
2363 int dg = best_results[1].m_block_color_unscaled.g - best_results[0].m_block_color_unscaled.g;
2364 int db = best_results[1].m_block_color_unscaled.b - best_results[0].m_block_color_unscaled.b;
2365 RG_ETC1_ASSERT(best_use_color4 || (rg_etc1::minimum(dr, dg, db) >= cETC1ColorDeltaMin) && (rg_etc1::maximum(dr, dg, db) <= cETC1ColorDeltaMax));
2366
2367 if (best_use_color4)
2368 {
2369 dst_block.m_bytes[0] = static_cast<uint8>(best_results[1].m_block_color_unscaled.r | (best_results[0].m_block_color_unscaled.r << 4));
2370 dst_block.m_bytes[1] = static_cast<uint8>(best_results[1].m_block_color_unscaled.g | (best_results[0].m_block_color_unscaled.g << 4));
2371 dst_block.m_bytes[2] = static_cast<uint8>(best_results[1].m_block_color_unscaled.b | (best_results[0].m_block_color_unscaled.b << 4));
2372 }
2373 else
2374 {
2375 if (dr < 0) dr += 8; dst_block.m_bytes[0] = static_cast<uint8>((best_results[0].m_block_color_unscaled.r << 3) | dr);
2376 if (dg < 0) dg += 8; dst_block.m_bytes[1] = static_cast<uint8>((best_results[0].m_block_color_unscaled.g << 3) | dg);
2377 if (db < 0) db += 8; dst_block.m_bytes[2] = static_cast<uint8>((best_results[0].m_block_color_unscaled.b << 3) | db);
2378 }
2379
2380 dst_block.m_bytes[3] = static_cast<uint8>( (best_results[1].m_block_inten_table << 2) | (best_results[0].m_block_inten_table << 5) | ((~best_use_color4 & 1) << 1) | best_flip );
2381
2382 uint selector0 = 0, selector1 = 0;
2383 if (best_flip)
2384 {
2385 // flipped:
2386 // { 0, 0 }, { 1, 0 }, { 2, 0 }, { 3, 0 },
2387 // { 0, 1 }, { 1, 1 }, { 2, 1 }, { 3, 1 }
2388 //
2389 // { 0, 2 }, { 1, 2 }, { 2, 2 }, { 3, 2 },
2390 // { 0, 3 }, { 1, 3 }, { 2, 3 }, { 3, 3 }
2391 const uint8* pSelectors0 = best_results[0].m_pSelectors;
2392 const uint8* pSelectors1 = best_results[1].m_pSelectors;
2393 for (int x = 3; x >= 0; --x)
2394 {
2395 uint b;
2396 b = g_selector_index_to_etc1[pSelectors1[4 + x]];
2397 selector0 = (selector0 << 1) | (b & 1); selector1 = (selector1 << 1) | (b >> 1);
2398
2399 b = g_selector_index_to_etc1[pSelectors1[x]];
2400 selector0 = (selector0 << 1) | (b & 1); selector1 = (selector1 << 1) | (b >> 1);
2401
2402 b = g_selector_index_to_etc1[pSelectors0[4 + x]];
2403 selector0 = (selector0 << 1) | (b & 1); selector1 = (selector1 << 1) | (b >> 1);
2404
2405 b = g_selector_index_to_etc1[pSelectors0[x]];
2406 selector0 = (selector0 << 1) | (b & 1); selector1 = (selector1 << 1) | (b >> 1);
2407 }
2408 }
2409 else
2410 {
2411 // non-flipped:
2412 // { 0, 0 }, { 0, 1 }, { 0, 2 }, { 0, 3 },
2413 // { 1, 0 }, { 1, 1 }, { 1, 2 }, { 1, 3 }
2414 //
2415 // { 2, 0 }, { 2, 1 }, { 2, 2 }, { 2, 3 },
2416 // { 3, 0 }, { 3, 1 }, { 3, 2 }, { 3, 3 }
2417 for (int subblock = 1; subblock >= 0; --subblock)
2418 {
2419 const uint8* pSelectors = best_results[subblock].m_pSelectors + 4;
2420 for (uint i = 0; i < 2; i++)
2421 {
2422 uint b;
2423 b = g_selector_index_to_etc1[pSelectors[3]];
2424 selector0 = (selector0 << 1) | (b & 1); selector1 = (selector1 << 1) | (b >> 1);
2425
2426 b = g_selector_index_to_etc1[pSelectors[2]];
2427 selector0 = (selector0 << 1) | (b & 1); selector1 = (selector1 << 1) | (b >> 1);
2428
2429 b = g_selector_index_to_etc1[pSelectors[1]];
2430 selector0 = (selector0 << 1) | (b & 1); selector1 = (selector1 << 1) | (b >> 1);
2431
2432 b = g_selector_index_to_etc1[pSelectors[0]];
2433 selector0 = (selector0 << 1) | (b & 1);selector1 = (selector1 << 1) | (b >> 1);
2434
2435 pSelectors -= 4;
2436 }
2437 }
2438 }
2439
2440 dst_block.m_bytes[4] = static_cast<uint8>(selector1 >> 8); dst_block.m_bytes[5] = static_cast<uint8>(selector1 & 0xFF);
2441 dst_block.m_bytes[6] = static_cast<uint8>(selector0 >> 8); dst_block.m_bytes[7] = static_cast<uint8>(selector0 & 0xFF);
2442
2443 return static_cast<unsigned int>(best_error);
2444 }
2445
2446} // namespace rg_etc1
diff --git a/src/static_libs/rg_etc/rg_etc1.h b/src/static_libs/rg_etc/rg_etc1.h
new file mode 100644
index 0000000..9a70150
--- /dev/null
+++ b/src/static_libs/rg_etc/rg_etc1.h
@@ -0,0 +1,76 @@
1// File: rg_etc1.h - Fast, high quality ETC1 block packer/unpacker - Rich Geldreich <richgel99@gmail.com>
2// Please see ZLIB license at the end of this file.
3#pragma once
4
5namespace rg_etc1
6{
7 // Unpacks an 8-byte ETC1 compressed block to a block of 4x4 32bpp RGBA pixels.
8 // Returns false if the block is invalid. Invalid blocks will still be unpacked with clamping.
9 // This function is thread safe, and does not dynamically allocate any memory.
10 // If preserve_alpha is true, the alpha channel of the destination pixels will not be overwritten. Otherwise, alpha will be set to 255.
11 bool unpack_etc1_block(const void *pETC1_block, unsigned int* pDst_pixels_rgba, bool preserve_alpha = false);
12
13 // Quality setting = the higher the quality, the slower.
14 // To pack large textures, it is highly recommended to call pack_etc1_block() in parallel, on different blocks, from multiple threads (particularly when using cHighQuality).
15 enum etc1_quality
16 {
17 cLowQuality,
18 cMediumQuality,
19 cHighQuality,
20 };
21
22 struct etc1_pack_params
23 {
24 etc1_quality m_quality;
25 bool m_dithering;
26
27 inline etc1_pack_params()
28 {
29 clear();
30 }
31
32 void clear()
33 {
34 m_quality = cHighQuality;
35 m_dithering = false;
36 }
37 };
38
39 // Important: pack_etc1_block_init() must be called before calling pack_etc1_block().
40 void pack_etc1_block_init();
41
42 // Packs a 4x4 block of 32bpp RGBA pixels to an 8-byte ETC1 block.
43 // 32-bit RGBA pixels must always be arranged as (R,G,B,A) (R first, A last) in memory, independent of platform endianness. A should always be 255.
44 // Returns squared error of result.
45 // This function is thread safe, and does not dynamically allocate any memory.
46 // pack_etc1_block() does not currently support "perceptual" colorspace metrics - it primarily optimizes for RGB RMSE.
47 unsigned int pack_etc1_block(void* pETC1_block, const unsigned int* pSrc_pixels_rgba, etc1_pack_params& pack_params);
48
49} // namespace rg_etc1
50
51//------------------------------------------------------------------------------
52//
53// rg_etc1 uses the ZLIB license:
54// http://opensource.org/licenses/Zlib
55//
56// Copyright (c) 2012 Rich Geldreich
57//
58// This software is provided 'as-is', without any express or implied
59// warranty. In no event will the authors be held liable for any damages
60// arising from the use of this software.
61//
62// Permission is granted to anyone to use this software for any purpose,
63// including commercial applications, and to alter it and redistribute it
64// freely, subject to the following restrictions:
65//
66// 1. The origin of this software must not be misrepresented; you must not
67// claim that you wrote the original software. If you use this software
68// in a product, an acknowledgment in the product documentation would be
69// appreciated but is not required.
70//
71// 2. Altered source versions must be plainly marked as such, and must not be
72// misrepresented as being the original software.
73//
74// 3. This notice may not be removed or altered from any source distribution.
75//
76//------------------------------------------------------------------------------