and now i added "line dither". what is this. it's only for non-rotated 16bpp

565. what it does is it's a half-way house between no dither and "small
dither mask". what is does is change the "rounding" between odd and even
lines. the resolt is not as nice as small (or large) dither mask - but its
almost "good". it gives a horizontal-blinds like look to dithering. it's
almost as fast as no-dither in my tests on a core2 (of course making lots of
use of branch prediction or conditional instructins - whihc arm nd x86 have).



SVN revision: 36373

legacy/evas/configure.ac

@@ -1555,6 +1555,29 @@ AC_ARG_ENABLE(small-dither-mask,
   ]
 )
 
+#######################################
+## Alternate Line dither mask instead of big one (lower quality - but fastest)
+conv_line_dither="no"
+AC_MSG_CHECKING(whether to build line dither mask code)
+AC_ARG_ENABLE(line-dither-mask,
+  AC_HELP_STRING([--enable-line-dither-mask], [enable line dither mask code]),
+  [
+      if test "x$enableval" = "xyes" ; then
+        AC_MSG_RESULT(yes)
+        AC_DEFINE(BUILD_LINE_DITHER_MASK, 1, [Line Dither Mask Support])
+        conv_line_dither="yes"
+      else
+        AC_MSG_RESULT(no)
+        conv_line_dither="no"
+      fi
+  ], [
+      AC_MSG_RESULT($conv_line_dither)
+      if test "x$conv_line_dither" = "xyes" ; then
+        AC_DEFINE(BUILD_LINE_DITHER_MASK, 1, [Line Dither Mask Support])
+      fi
+  ]
+)
+
 #######################################
 ## No dither mask at all for 16bpp
 conv_no_dither="no"
@@ -1904,6 +1927,7 @@ echo "  YUV Converter...........: $conv_yuv"
 echo
 echo "ARGB Conversion Options:"
 echo "  Smaller Dither Mask.....: $conv_small_dither"
+echo "  Line Dither Mask........: $conv_line_dither"
 echo "  No Dither Mask for 16bpp: $conv_no_dither"
 echo "  8bpp RGB 332............: $conv_8_rgb_332"
 echo "  8bpp RGB 666............: $conv_8_rgb_666"

legacy/evas/src/lib/engines/common/evas_convert_rgb_16.c

@@ -26,6 +26,60 @@ evas_common_convert_rgba2_to_16bpp_rgb_565_dith (DATA32 *src, DATA8 *dst, int sr
    int dith, dith2;
    int x, y;
 
+#ifdef BUILD_LINE_DITHER_MASK
+   for (y = 0; y < h; y++)
+     {
+	if ((y + dith_y) & 0x1)
+	  {
+	     for (x = 0; x < w; x+=2)
+	       {
+		  DATA32  p = *src++,  q = *src++;
+		  r1 = ((p & 0xff0000) + 0x030000) >> 19;
+		  if (r1 > 0x1f) r1 = 0x1f;
+		  g1 = ((p & 0xff00) + 0x000100) >> 10;
+		  if (g1 > 0x3f) g1 = 0x3f;
+		  b1 = ((p & 0xff) + 0x000003) >> 3;
+		  if (b1 > 0x1f) b1 = 0x1f;
+		  r2 = ((q & 0xff0000) + 0x030000) >> 19;
+		  if (r2 > 0x1f) r2 = 0x1f;
+		  g2 = ((q & 0xff00) + 0x000100) >> 10;
+		  if (g2 > 0x3f) g2 = 0x3f;
+		  b2 = ((q & 0xff) + 0x000003) >> 3;
+		  if (b2 > 0x1f) b2 = 0x1f;
+#ifndef WORDS_BIGENDIAN
+		  *((DATA32 *)d) = (r2 << 27) | (g2 << 21) | (b2 << 16) |
+		    (r1 << 11) | (g1 << 5) | (b1);
+#else
+		  *((DATA32 *)d) = (r1 << 27) | (g1 << 21) | (b1 << 16) |
+		    (r2 << 11) | (g2 << 5) | (b2);
+#endif
+		  d += 2;
+	       }
+	  }
+	else
+	  {
+	     x = w;
+	     while (w > 0)
+	       {
+		  DATA32  p = *src++, q = *src++;
+
+#ifndef WORDS_BIGENDIAN
+		  *((DATA32 *)d) =
+		    (((q & 0xff0000) >> 19) << 27) | (((q & 0xff00) >> 10) << 21) | (((q & 0xff) >> 3) << 16) |
+		    (((p & 0xff0000) >> 19) << 11) | (((p & 0xff00) >> 10) << 5) | ((p & 0xff) >> 3);
+#else
+		  *((DATA32 *)d) =
+		    (((p & 0xff0000) >> 19) << 27) | (((p & 0xff00) >> 10) << 21) | (((p & 0xff) >> 3) << 16) |
+		    (((q & 0xff0000) >> 19) << 11) | (((q & 0xff00) >> 10) << 5) | ((q & 0xff) >> 3);
+#endif
+		  d += 2;  w -= 2;
+	       }
+	     w = x;
+	  }
+	src += src_jump;
+	d += dst_jump;
+     }
+#else
    for (y = 0; y < h; y++)
      {
 	for (x = 0; x < w; x++)
@@ -52,7 +106,7 @@ evas_common_convert_rgba2_to_16bpp_rgb_565_dith (DATA32 *src, DATA8 *dst, int sr
 	    if ((r2 < 0x1f) && ((((q & 0xff0000) >> 16) - (r2 << 3)) >= dith )) r2++;
 	    if ((g2 < 0x3f) && ((((q & 0xff00) >> 8) - (g2 << 2)) >= dith2)) g2++;
 	    if ((b2 < 0x1f) && (((q & 0xff) - (b2 << 3)) >= dith )) b2++;
-
+	     
 #ifndef WORDS_BIGENDIAN
 	    *((DATA32 *)d) = (r2 << 27) | (g2 << 21) | (b2 << 16) |
 	                     (r1 << 11) | (g1 << 5) | (b1);
@@ -65,6 +119,7 @@ evas_common_convert_rgba2_to_16bpp_rgb_565_dith (DATA32 *src, DATA8 *dst, int sr
 	src += src_jump;
 	d += dst_jump;
      }
+#endif   
    return;
    pal = 0;
 #else
@@ -110,6 +165,38 @@ evas_common_convert_rgba_to_16bpp_rgb_565_dith (DATA32 *src, DATA8 *dst, int src
    int dith, dith2;
    int x, y;
 
+#ifdef BUILD_LINE_DITHER_MASK
+   for (y = 0; y < h; y++)
+     {
+	if ((y + dith_y) & 0x1)
+	  {
+	     for (x = 0; x < w; x++)
+	       {
+		  DATA32  p = *src++;
+		  
+		  r = (p & 0xff0000) >> 19;
+		  if (r > 0x1f) r = 0x1f;
+		  g = (p & 0xff00) >> 10;
+		  if (g > 0x3f) g = 0x3f;
+		  b = (p & 0xff) >> 3;
+		  if (b > 0x1f) b = 0x1f;
+		  *d++ = (r << 11) | (g << 5) | b;
+	       }
+	  }
+	else
+	  {
+	     x = w;
+	     while (w--)
+	       {
+		  *d++ = (((*src & 0xff0000) >> 19) << 11) | (((*src & 0xff00) >> 10) << 5) | ((*src & 0xff) >> 3);
+		  src++;
+	       }
+	     w = x;
+	  }
+	src += src_jump;
+	d += dst_jump;
+     }
+#else   
    for (y = 0; y < h; y++)
      {
 	for (x = 0; x < w; x++)
@@ -131,6 +218,7 @@ evas_common_convert_rgba_to_16bpp_rgb_565_dith (DATA32 *src, DATA8 *dst, int src
 	src += src_jump;
 	d += dst_jump;
      }
+#endif   
    return;
    pal = 0;
 #else