1678 lines
49 KiB
C
1678 lines
49 KiB
C
/***************************************************************************/
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/* */
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/* ftgrays.c */
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/* */
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/* A new `perfect' anti-aliasing renderer (body). */
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/* */
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/* Copyright 2000-2003, 2005-2014 by */
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/* David Turner, Robert Wilhelm, and Werner Lemberg. */
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/* */
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/* This file is part of the FreeType project, and may only be used, */
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/* modified, and distributed under the terms of the FreeType project */
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/* license, LICENSE.TXT. By continuing to use, modify, or distribute */
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/* this file you indicate that you have read the license and */
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/* understand and accept it fully. */
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/* */
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/***************************************************************************/
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/*************************************************************************/
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/* */
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/* This is a new anti-aliasing scan-converter for FreeType 2. The */
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/* algorithm used here is _very_ different from the one in the standard */
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/* `ftraster' module. Actually, `ftgrays' computes the _exact_ */
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/* coverage of the outline on each pixel cell. */
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/* */
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/* It is based on ideas that I initially found in Raph Levien's */
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/* excellent LibArt graphics library (see http://www.levien.com/libart */
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/* for more information, though the web pages do not tell anything */
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/* about the renderer; you'll have to dive into the source code to */
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/* understand how it works). */
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/* */
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/* Note, however, that this is a _very_ different implementation */
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/* compared to Raph's. Coverage information is stored in a very */
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/* different way, and I don't use sorted vector paths. Also, it doesn't */
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/* use floating point values. */
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/* */
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/* This renderer has the following advantages: */
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/* */
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/* - It doesn't need an intermediate bitmap. Instead, one can supply a */
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/* callback function that will be called by the renderer to draw gray */
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/* spans on any target surface. You can thus do direct composition on */
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/* any kind of bitmap, provided that you give the renderer the right */
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/* callback. */
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/* */
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/* - A perfect anti-aliaser, i.e., it computes the _exact_ coverage on */
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/* each pixel cell. */
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/* */
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/* - It performs a single pass on the outline (the `standard' FT2 */
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/* renderer makes two passes). */
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/* */
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/* - It can easily be modified to render to _any_ number of gray levels */
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/* cheaply. */
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/* */
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/* - For small (< 20) pixel sizes, it is faster than the standard */
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/* renderer. */
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/* */
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/*************************************************************************/
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#include "sw_ft_raster.h"
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#include "sw_ft_math.h"
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/* Auxiliary macros for token concatenation. */
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#define SW_FT_ERR_XCAT( x, y ) x ## y
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#define SW_FT_ERR_CAT( x, y ) SW_FT_ERR_XCAT( x, y )
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#define SW_FT_BEGIN_STMNT do {
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#define SW_FT_END_STMNT } while ( 0 )
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#include <stddef.h>
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#include <string.h>
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#include <setjmp.h>
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#include <limits.h>
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#define SW_FT_UINT_MAX UINT_MAX
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#define SW_FT_INT_MAX INT_MAX
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#define SW_FT_ULONG_MAX ULONG_MAX
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#define SW_FT_CHAR_BIT CHAR_BIT
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#define ft_memset memset
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#define ft_setjmp setjmp
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#define ft_longjmp longjmp
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#define ft_jmp_buf jmp_buf
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typedef ptrdiff_t SW_FT_PtrDist;
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#define ErrRaster_Invalid_Mode -2
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#define ErrRaster_Invalid_Outline -1
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#define ErrRaster_Invalid_Argument -3
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#define ErrRaster_Memory_Overflow -4
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#define SW_FT_BEGIN_HEADER
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#define SW_FT_END_HEADER
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/* This macro is used to indicate that a function parameter is unused. */
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/* Its purpose is simply to reduce compiler warnings. Note also that */
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/* simply defining it as `(void)x' doesn't avoid warnings with certain */
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/* ANSI compilers (e.g. LCC). */
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#define SW_FT_UNUSED( x ) (x) = (x)
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#define SW_FT_THROW( e ) SW_FT_ERR_CAT( ErrRaster_, e )
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/* The size in bytes of the render pool used by the scan-line converter */
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/* to do all of its work. */
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#define SW_FT_RENDER_POOL_SIZE 16384L
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typedef int
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(*SW_FT_Outline_MoveToFunc)( const SW_FT_Vector* to,
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void* user );
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#define SW_FT_Outline_MoveTo_Func SW_FT_Outline_MoveToFunc
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typedef int
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(*SW_FT_Outline_LineToFunc)( const SW_FT_Vector* to,
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void* user );
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#define SW_FT_Outline_LineTo_Func SW_FT_Outline_LineToFunc
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typedef int
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(*SW_FT_Outline_ConicToFunc)( const SW_FT_Vector* control,
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const SW_FT_Vector* to,
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void* user );
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#define SW_FT_Outline_ConicTo_Func SW_FT_Outline_ConicToFunc
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typedef int
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(*SW_FT_Outline_CubicToFunc)( const SW_FT_Vector* control1,
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const SW_FT_Vector* control2,
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const SW_FT_Vector* to,
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void* user );
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#define SW_FT_Outline_CubicTo_Func SW_FT_Outline_CubicToFunc
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typedef struct SW_FT_Outline_Funcs_
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{
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SW_FT_Outline_MoveToFunc move_to;
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SW_FT_Outline_LineToFunc line_to;
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SW_FT_Outline_ConicToFunc conic_to;
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SW_FT_Outline_CubicToFunc cubic_to;
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int shift;
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SW_FT_Pos delta;
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} SW_FT_Outline_Funcs;
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#define SW_FT_DEFINE_OUTLINE_FUNCS( class_, \
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move_to_, line_to_, \
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conic_to_, cubic_to_, \
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shift_, delta_ ) \
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static const SW_FT_Outline_Funcs class_ = \
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{ \
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move_to_, \
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line_to_, \
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conic_to_, \
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cubic_to_, \
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shift_, \
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delta_ \
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};
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#define SW_FT_DEFINE_RASTER_FUNCS( class_, \
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raster_new_, raster_reset_, \
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raster_render_, \
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raster_done_ ) \
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const SW_FT_Raster_Funcs class_ = \
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{ \
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raster_new_, \
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raster_reset_, \
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raster_render_, \
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raster_done_ \
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};
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#ifndef SW_FT_MEM_SET
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#define SW_FT_MEM_SET( d, s, c ) ft_memset( d, s, c )
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#endif
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#ifndef SW_FT_MEM_ZERO
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#define SW_FT_MEM_ZERO( dest, count ) SW_FT_MEM_SET( dest, 0, count )
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#endif
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/* as usual, for the speed hungry :-) */
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#undef RAS_ARG
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#undef RAS_ARG_
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#undef RAS_VAR
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#undef RAS_VAR_
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#ifndef SW_FT_STATIC_RASTER
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#define RAS_ARG gray_PWorker worker
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#define RAS_ARG_ gray_PWorker worker,
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#define RAS_VAR worker
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#define RAS_VAR_ worker,
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#else /* SW_FT_STATIC_RASTER */
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#define RAS_ARG /* empty */
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#define RAS_ARG_ /* empty */
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#define RAS_VAR /* empty */
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#define RAS_VAR_ /* empty */
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#endif /* SW_FT_STATIC_RASTER */
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/* must be at least 6 bits! */
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#define PIXEL_BITS 8
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#undef FLOOR
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#undef CEILING
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#undef TRUNC
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#undef SCALED
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#define ONE_PIXEL ( 1L << PIXEL_BITS )
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#define PIXEL_MASK ( -1L << PIXEL_BITS )
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#define TRUNC( x ) ( (TCoord)( (x) >> PIXEL_BITS ) )
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#define SUBPIXELS( x ) ( (TPos)(x) << PIXEL_BITS )
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#define FLOOR( x ) ( (x) & -ONE_PIXEL )
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#define CEILING( x ) ( ( (x) + ONE_PIXEL - 1 ) & -ONE_PIXEL )
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#define ROUND( x ) ( ( (x) + ONE_PIXEL / 2 ) & -ONE_PIXEL )
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#if PIXEL_BITS >= 6
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#define UPSCALE( x ) ( (x) << ( PIXEL_BITS - 6 ) )
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#define DOWNSCALE( x ) ( (x) >> ( PIXEL_BITS - 6 ) )
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#else
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#define UPSCALE( x ) ( (x) >> ( 6 - PIXEL_BITS ) )
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#define DOWNSCALE( x ) ( (x) << ( 6 - PIXEL_BITS ) )
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#endif
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/* Compute `dividend / divisor' and return both its quotient and */
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/* remainder, cast to a specific type. This macro also ensures that */
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/* the remainder is always positive. */
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#define SW_FT_DIV_MOD( type, dividend, divisor, quotient, remainder ) \
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SW_FT_BEGIN_STMNT \
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(quotient) = (type)( (dividend) / (divisor) ); \
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(remainder) = (type)( (dividend) % (divisor) ); \
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if ( (remainder) < 0 ) \
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{ \
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(quotient)--; \
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(remainder) += (type)(divisor); \
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} \
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SW_FT_END_STMNT
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#ifdef __arm__
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/* Work around a bug specific to GCC which make the compiler fail to */
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/* optimize a division and modulo operation on the same parameters */
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/* into a single call to `__aeabi_idivmod'. See */
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/* */
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/* http://gcc.gnu.org/bugzilla/show_bug.cgi?id=43721 */
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#undef SW_FT_DIV_MOD
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#define SW_FT_DIV_MOD( type, dividend, divisor, quotient, remainder ) \
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SW_FT_BEGIN_STMNT \
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(quotient) = (type)( (dividend) / (divisor) ); \
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(remainder) = (type)( (dividend) - (quotient) * (divisor) ); \
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if ( (remainder) < 0 ) \
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{ \
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(quotient)--; \
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(remainder) += (type)(divisor); \
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} \
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SW_FT_END_STMNT
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#endif /* __arm__ */
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/* These macros speed up repetitive divisions by replacing them */
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/* with multiplications and right shifts. */
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#define SW_FT_UDIVPREP( b ) \
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long b ## _r = (long)( SW_FT_ULONG_MAX >> PIXEL_BITS ) / ( b )
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#define SW_FT_UDIV( a, b ) \
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( ( (unsigned long)( a ) * (unsigned long)( b ## _r ) ) >> \
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( sizeof( long ) * SW_FT_CHAR_BIT - PIXEL_BITS ) )
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/*************************************************************************/
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/* */
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/* TYPE DEFINITIONS */
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/* */
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/* don't change the following types to SW_FT_Int or SW_FT_Pos, since we might */
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/* need to define them to "float" or "double" when experimenting with */
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/* new algorithms */
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typedef long TCoord; /* integer scanline/pixel coordinate */
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typedef long TPos; /* sub-pixel coordinate */
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/* determine the type used to store cell areas. This normally takes at */
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/* least PIXEL_BITS*2 + 1 bits. On 16-bit systems, we need to use */
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/* `long' instead of `int', otherwise bad things happen */
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#if PIXEL_BITS <= 7
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typedef int TArea;
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#else /* PIXEL_BITS >= 8 */
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/* approximately determine the size of integers using an ANSI-C header */
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#if SW_FT_UINT_MAX == 0xFFFFU
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typedef long TArea;
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#else
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typedef int TArea;
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#endif
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#endif /* PIXEL_BITS >= 8 */
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/* maximum number of gray spans in a call to the span callback */
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#define SW_FT_MAX_GRAY_SPANS 256
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typedef struct TCell_* PCell;
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typedef struct TCell_
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{
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TPos x; /* same with gray_TWorker.ex */
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TCoord cover; /* same with gray_TWorker.cover */
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TArea area;
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PCell next;
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} TCell;
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#if defined( _MSC_VER ) /* Visual C++ (and Intel C++) */
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/* We disable the warning `structure was padded due to */
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/* __declspec(align())' in order to compile cleanly with */
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/* the maximum level of warnings. */
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#pragma warning( push )
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#pragma warning( disable : 4324 )
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#endif /* _MSC_VER */
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typedef struct gray_TWorker_
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{
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TCoord ex, ey;
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TPos min_ex, max_ex;
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TPos min_ey, max_ey;
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TPos count_ex, count_ey;
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TArea area;
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TCoord cover;
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int invalid;
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PCell cells;
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SW_FT_PtrDist max_cells;
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SW_FT_PtrDist num_cells;
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TPos x, y;
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SW_FT_Vector bez_stack[32 * 3 + 1];
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int lev_stack[32];
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SW_FT_Outline outline;
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SW_FT_BBox clip_box;
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SW_FT_Span gray_spans[SW_FT_MAX_GRAY_SPANS];
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int num_gray_spans;
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SW_FT_Raster_Span_Func render_span;
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void* render_span_data;
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int span_y;
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int band_size;
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int band_shoot;
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ft_jmp_buf jump_buffer;
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void* buffer;
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long buffer_size;
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PCell* ycells;
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TPos ycount;
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} gray_TWorker, *gray_PWorker;
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#if defined( _MSC_VER )
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#pragma warning( pop )
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#endif
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#ifndef SW_FT_STATIC_RASTER
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#define ras (*worker)
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#else
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static gray_TWorker ras;
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#endif
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typedef struct gray_TRaster_
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{
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void* memory;
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} gray_TRaster, *gray_PRaster;
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/*************************************************************************/
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/* */
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/* Initialize the cells table. */
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/* */
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static void
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gray_init_cells( RAS_ARG_ void* buffer,
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long byte_size )
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{
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ras.buffer = buffer;
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ras.buffer_size = byte_size;
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ras.ycells = (PCell*) buffer;
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ras.cells = NULL;
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ras.max_cells = 0;
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ras.num_cells = 0;
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ras.area = 0;
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ras.cover = 0;
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ras.invalid = 1;
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}
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/*************************************************************************/
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/* */
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/* Compute the outline bounding box. */
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/* */
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static void
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gray_compute_cbox( RAS_ARG )
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{
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SW_FT_Outline* outline = &ras.outline;
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SW_FT_Vector* vec = outline->points;
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SW_FT_Vector* limit = vec + outline->n_points;
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if ( outline->n_points <= 0 )
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{
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ras.min_ex = ras.max_ex = 0;
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ras.min_ey = ras.max_ey = 0;
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return;
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}
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ras.min_ex = ras.max_ex = vec->x;
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ras.min_ey = ras.max_ey = vec->y;
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vec++;
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for ( ; vec < limit; vec++ )
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{
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TPos x = vec->x;
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TPos y = vec->y;
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if ( x < ras.min_ex ) ras.min_ex = x;
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if ( x > ras.max_ex ) ras.max_ex = x;
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if ( y < ras.min_ey ) ras.min_ey = y;
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if ( y > ras.max_ey ) ras.max_ey = y;
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}
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/* truncate the bounding box to integer pixels */
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ras.min_ex = ras.min_ex >> 6;
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ras.min_ey = ras.min_ey >> 6;
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ras.max_ex = ( ras.max_ex + 63 ) >> 6;
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ras.max_ey = ( ras.max_ey + 63 ) >> 6;
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}
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/*************************************************************************/
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/* */
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/* Record the current cell in the table. */
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/* */
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static PCell
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gray_find_cell( RAS_ARG )
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{
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PCell *pcell, cell;
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TPos x = ras.ex;
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if ( x > ras.count_ex )
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x = ras.count_ex;
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pcell = &ras.ycells[ras.ey];
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for (;;)
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{
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cell = *pcell;
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if ( cell == NULL || cell->x > x )
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break;
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if ( cell->x == x )
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goto Exit;
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pcell = &cell->next;
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}
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if ( ras.num_cells >= ras.max_cells )
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ft_longjmp( ras.jump_buffer, 1 );
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cell = ras.cells + ras.num_cells++;
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cell->x = x;
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cell->area = 0;
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cell->cover = 0;
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cell->next = *pcell;
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*pcell = cell;
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Exit:
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return cell;
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}
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static void
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gray_record_cell( RAS_ARG )
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{
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if ( ras.area | ras.cover )
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{
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PCell cell = gray_find_cell( RAS_VAR );
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cell->area += ras.area;
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cell->cover += ras.cover;
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}
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}
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/*************************************************************************/
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/* */
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/* Set the current cell to a new position. */
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/* */
|
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static void
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gray_set_cell( RAS_ARG_ TCoord ex,
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TCoord ey )
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{
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/* Move the cell pointer to a new position. We set the `invalid' */
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|
/* flag to indicate that the cell isn't part of those we're interested */
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|
/* in during the render phase. This means that: */
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/* */
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/* . the new vertical position must be within min_ey..max_ey-1. */
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/* . the new horizontal position must be strictly less than max_ex */
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/* */
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/* Note that if a cell is to the left of the clipping region, it is */
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|
/* actually set to the (min_ex-1) horizontal position. */
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/* All cells that are on the left of the clipping region go to the */
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/* min_ex - 1 horizontal position. */
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ey -= ras.min_ey;
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if ( ex > ras.max_ex )
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ex = ras.max_ex;
|
|
|
|
ex -= ras.min_ex;
|
|
if ( ex < 0 )
|
|
ex = -1;
|
|
|
|
/* are we moving to a different cell ? */
|
|
if ( ex != ras.ex || ey != ras.ey )
|
|
{
|
|
/* record the current one if it is valid */
|
|
if ( !ras.invalid )
|
|
gray_record_cell( RAS_VAR );
|
|
|
|
ras.area = 0;
|
|
ras.cover = 0;
|
|
ras.ex = ex;
|
|
ras.ey = ey;
|
|
}
|
|
|
|
ras.invalid = ( (unsigned)ey >= (unsigned)ras.count_ey ||
|
|
ex >= ras.count_ex );
|
|
}
|
|
|
|
|
|
/*************************************************************************/
|
|
/* */
|
|
/* Start a new contour at a given cell. */
|
|
/* */
|
|
static void
|
|
gray_start_cell( RAS_ARG_ TCoord ex,
|
|
TCoord ey )
|
|
{
|
|
if ( ex > ras.max_ex )
|
|
ex = (TCoord)( ras.max_ex );
|
|
|
|
if ( ex < ras.min_ex )
|
|
ex = (TCoord)( ras.min_ex - 1 );
|
|
|
|
ras.area = 0;
|
|
ras.cover = 0;
|
|
ras.ex = ex - ras.min_ex;
|
|
ras.ey = ey - ras.min_ey;
|
|
ras.invalid = 0;
|
|
|
|
gray_set_cell( RAS_VAR_ ex, ey );
|
|
}
|
|
|
|
/*************************************************************************/
|
|
/* */
|
|
/* Render a straight line across multiple cells in any direction. */
|
|
/* */
|
|
static void
|
|
gray_render_line( RAS_ARG_ TPos to_x,
|
|
TPos to_y )
|
|
{
|
|
TPos dx, dy, fx1, fy1, fx2, fy2;
|
|
TCoord ex1, ex2, ey1, ey2;
|
|
|
|
|
|
ex1 = TRUNC( ras.x );
|
|
ex2 = TRUNC( to_x );
|
|
ey1 = TRUNC( ras.y );
|
|
ey2 = TRUNC( to_y );
|
|
|
|
/* perform vertical clipping */
|
|
if ( ( ey1 >= ras.max_ey && ey2 >= ras.max_ey ) ||
|
|
( ey1 < ras.min_ey && ey2 < ras.min_ey ) )
|
|
goto End;
|
|
|
|
dx = to_x - ras.x;
|
|
dy = to_y - ras.y;
|
|
|
|
fx1 = ras.x - SUBPIXELS( ex1 );
|
|
fy1 = ras.y - SUBPIXELS( ey1 );
|
|
|
|
if ( ex1 == ex2 && ey1 == ey2 ) /* inside one cell */
|
|
;
|
|
else if ( dy == 0 ) /* ex1 != ex2 */ /* any horizontal line */
|
|
{
|
|
ex1 = ex2;
|
|
gray_set_cell( RAS_VAR_ ex1, ey1 );
|
|
}
|
|
else if ( dx == 0 )
|
|
{
|
|
if ( dy > 0 ) /* vertical line up */
|
|
do
|
|
{
|
|
fy2 = ONE_PIXEL;
|
|
ras.cover += ( fy2 - fy1 );
|
|
ras.area += ( fy2 - fy1 ) * fx1 * 2;
|
|
fy1 = 0;
|
|
ey1++;
|
|
gray_set_cell( RAS_VAR_ ex1, ey1 );
|
|
} while ( ey1 != ey2 );
|
|
else /* vertical line down */
|
|
do
|
|
{
|
|
fy2 = 0;
|
|
ras.cover += ( fy2 - fy1 );
|
|
ras.area += ( fy2 - fy1 ) * fx1 * 2;
|
|
fy1 = ONE_PIXEL;
|
|
ey1--;
|
|
gray_set_cell( RAS_VAR_ ex1, ey1 );
|
|
} while ( ey1 != ey2 );
|
|
}
|
|
else /* any other line */
|
|
{
|
|
TArea prod = dx * fy1 - dy * fx1;
|
|
SW_FT_UDIVPREP( dx );
|
|
SW_FT_UDIVPREP( dy );
|
|
|
|
|
|
/* The fundamental value `prod' determines which side and the */
|
|
/* exact coordinate where the line exits current cell. It is */
|
|
/* also easily updated when moving from one cell to the next. */
|
|
do
|
|
{
|
|
if ( prod <= 0 &&
|
|
prod - dx * ONE_PIXEL > 0 ) /* left */
|
|
{
|
|
fx2 = 0;
|
|
fy2 = (TPos)SW_FT_UDIV( -prod, -dx );
|
|
prod -= dy * ONE_PIXEL;
|
|
ras.cover += ( fy2 - fy1 );
|
|
ras.area += ( fy2 - fy1 ) * ( fx1 + fx2 );
|
|
fx1 = ONE_PIXEL;
|
|
fy1 = fy2;
|
|
ex1--;
|
|
}
|
|
else if ( prod - dx * ONE_PIXEL <= 0 &&
|
|
prod - dx * ONE_PIXEL + dy * ONE_PIXEL > 0 ) /* up */
|
|
{
|
|
prod -= dx * ONE_PIXEL;
|
|
fx2 = (TPos)SW_FT_UDIV( -prod, dy );
|
|
fy2 = ONE_PIXEL;
|
|
ras.cover += ( fy2 - fy1 );
|
|
ras.area += ( fy2 - fy1 ) * ( fx1 + fx2 );
|
|
fx1 = fx2;
|
|
fy1 = 0;
|
|
ey1++;
|
|
}
|
|
else if ( prod - dx * ONE_PIXEL + dy * ONE_PIXEL <= 0 &&
|
|
prod + dy * ONE_PIXEL >= 0 ) /* right */
|
|
{
|
|
prod += dy * ONE_PIXEL;
|
|
fx2 = ONE_PIXEL;
|
|
fy2 = (TPos)SW_FT_UDIV( prod, dx );
|
|
ras.cover += ( fy2 - fy1 );
|
|
ras.area += ( fy2 - fy1 ) * ( fx1 + fx2 );
|
|
fx1 = 0;
|
|
fy1 = fy2;
|
|
ex1++;
|
|
}
|
|
else /* ( prod + dy * ONE_PIXEL < 0 &&
|
|
prod > 0 ) down */
|
|
{
|
|
fx2 = (TPos)SW_FT_UDIV( prod, -dy );
|
|
fy2 = 0;
|
|
prod += dx * ONE_PIXEL;
|
|
ras.cover += ( fy2 - fy1 );
|
|
ras.area += ( fy2 - fy1 ) * ( fx1 + fx2 );
|
|
fx1 = fx2;
|
|
fy1 = ONE_PIXEL;
|
|
ey1--;
|
|
}
|
|
|
|
gray_set_cell( RAS_VAR_ ex1, ey1 );
|
|
} while ( ex1 != ex2 || ey1 != ey2 );
|
|
}
|
|
|
|
fx2 = to_x - SUBPIXELS( ex2 );
|
|
fy2 = to_y - SUBPIXELS( ey2 );
|
|
|
|
ras.cover += ( fy2 - fy1 );
|
|
ras.area += ( fy2 - fy1 ) * ( fx1 + fx2 );
|
|
|
|
End:
|
|
ras.x = to_x;
|
|
ras.y = to_y;
|
|
}
|
|
|
|
static void
|
|
gray_split_conic( SW_FT_Vector* base )
|
|
{
|
|
TPos a, b;
|
|
|
|
|
|
base[4].x = base[2].x;
|
|
b = base[1].x;
|
|
a = base[3].x = ( base[2].x + b ) / 2;
|
|
b = base[1].x = ( base[0].x + b ) / 2;
|
|
base[2].x = ( a + b ) / 2;
|
|
|
|
base[4].y = base[2].y;
|
|
b = base[1].y;
|
|
a = base[3].y = ( base[2].y + b ) / 2;
|
|
b = base[1].y = ( base[0].y + b ) / 2;
|
|
base[2].y = ( a + b ) / 2;
|
|
}
|
|
|
|
|
|
static void
|
|
gray_render_conic( RAS_ARG_ const SW_FT_Vector* control,
|
|
const SW_FT_Vector* to )
|
|
{
|
|
TPos dx, dy;
|
|
TPos min, max, y;
|
|
int top, level;
|
|
int* levels;
|
|
SW_FT_Vector* arc;
|
|
|
|
|
|
levels = ras.lev_stack;
|
|
|
|
arc = ras.bez_stack;
|
|
arc[0].x = UPSCALE( to->x );
|
|
arc[0].y = UPSCALE( to->y );
|
|
arc[1].x = UPSCALE( control->x );
|
|
arc[1].y = UPSCALE( control->y );
|
|
arc[2].x = ras.x;
|
|
arc[2].y = ras.y;
|
|
top = 0;
|
|
|
|
dx = SW_FT_ABS( arc[2].x + arc[0].x - 2 * arc[1].x );
|
|
dy = SW_FT_ABS( arc[2].y + arc[0].y - 2 * arc[1].y );
|
|
if ( dx < dy )
|
|
dx = dy;
|
|
|
|
if ( dx < ONE_PIXEL / 4 )
|
|
goto Draw;
|
|
|
|
/* short-cut the arc that crosses the current band */
|
|
min = max = arc[0].y;
|
|
|
|
y = arc[1].y;
|
|
if ( y < min ) min = y;
|
|
if ( y > max ) max = y;
|
|
|
|
y = arc[2].y;
|
|
if ( y < min ) min = y;
|
|
if ( y > max ) max = y;
|
|
|
|
if ( TRUNC( min ) >= ras.max_ey || TRUNC( max ) < ras.min_ey )
|
|
goto Draw;
|
|
|
|
level = 0;
|
|
do
|
|
{
|
|
dx >>= 2;
|
|
level++;
|
|
} while ( dx > ONE_PIXEL / 4 );
|
|
|
|
levels[0] = level;
|
|
|
|
do
|
|
{
|
|
level = levels[top];
|
|
if ( level > 0 )
|
|
{
|
|
gray_split_conic( arc );
|
|
arc += 2;
|
|
top++;
|
|
levels[top] = levels[top - 1] = level - 1;
|
|
continue;
|
|
}
|
|
|
|
Draw:
|
|
gray_render_line( RAS_VAR_ arc[0].x, arc[0].y );
|
|
top--;
|
|
arc -= 2;
|
|
|
|
} while ( top >= 0 );
|
|
}
|
|
|
|
|
|
static void
|
|
gray_split_cubic( SW_FT_Vector* base )
|
|
{
|
|
TPos a, b, c, d;
|
|
|
|
|
|
base[6].x = base[3].x;
|
|
c = base[1].x;
|
|
d = base[2].x;
|
|
base[1].x = a = ( base[0].x + c ) / 2;
|
|
base[5].x = b = ( base[3].x + d ) / 2;
|
|
c = ( c + d ) / 2;
|
|
base[2].x = a = ( a + c ) / 2;
|
|
base[4].x = b = ( b + c ) / 2;
|
|
base[3].x = ( a + b ) / 2;
|
|
|
|
base[6].y = base[3].y;
|
|
c = base[1].y;
|
|
d = base[2].y;
|
|
base[1].y = a = ( base[0].y + c ) / 2;
|
|
base[5].y = b = ( base[3].y + d ) / 2;
|
|
c = ( c + d ) / 2;
|
|
base[2].y = a = ( a + c ) / 2;
|
|
base[4].y = b = ( b + c ) / 2;
|
|
base[3].y = ( a + b ) / 2;
|
|
}
|
|
|
|
|
|
static void
|
|
gray_render_cubic( RAS_ARG_ const SW_FT_Vector* control1,
|
|
const SW_FT_Vector* control2,
|
|
const SW_FT_Vector* to )
|
|
{
|
|
SW_FT_Vector* arc;
|
|
TPos min, max, y;
|
|
|
|
|
|
arc = ras.bez_stack;
|
|
arc[0].x = UPSCALE( to->x );
|
|
arc[0].y = UPSCALE( to->y );
|
|
arc[1].x = UPSCALE( control2->x );
|
|
arc[1].y = UPSCALE( control2->y );
|
|
arc[2].x = UPSCALE( control1->x );
|
|
arc[2].y = UPSCALE( control1->y );
|
|
arc[3].x = ras.x;
|
|
arc[3].y = ras.y;
|
|
|
|
/* Short-cut the arc that crosses the current band. */
|
|
min = max = arc[0].y;
|
|
|
|
y = arc[1].y;
|
|
if ( y < min )
|
|
min = y;
|
|
if ( y > max )
|
|
max = y;
|
|
|
|
y = arc[2].y;
|
|
if ( y < min )
|
|
min = y;
|
|
if ( y > max )
|
|
max = y;
|
|
|
|
y = arc[3].y;
|
|
if ( y < min )
|
|
min = y;
|
|
if ( y > max )
|
|
max = y;
|
|
|
|
if ( TRUNC( min ) >= ras.max_ey || TRUNC( max ) < ras.min_ey )
|
|
goto Draw;
|
|
|
|
for (;;)
|
|
{
|
|
/* Decide whether to split or draw. See `Rapid Termination */
|
|
/* Evaluation for Recursive Subdivision of Bezier Curves' by Thomas */
|
|
/* F. Hain, at */
|
|
/* http://www.cis.southalabama.edu/~hain/general/Publications/Bezier/Camera-ready%20CISST02%202.pdf */
|
|
|
|
{
|
|
TPos dx, dy, dx_, dy_;
|
|
TPos dx1, dy1, dx2, dy2;
|
|
TPos L, s, s_limit;
|
|
|
|
|
|
/* dx and dy are x and y components of the P0-P3 chord vector. */
|
|
dx = dx_ = arc[3].x - arc[0].x;
|
|
dy = dy_ = arc[3].y - arc[0].y;
|
|
|
|
L = SW_FT_HYPOT( dx_, dy_ );
|
|
|
|
/* Avoid possible arithmetic overflow below by splitting. */
|
|
if ( L > 32767 )
|
|
goto Split;
|
|
|
|
/* Max deviation may be as much as (s/L) * 3/4 (if Hain's v = 1). */
|
|
s_limit = L * (TPos)( ONE_PIXEL / 6 );
|
|
|
|
/* s is L * the perpendicular distance from P1 to the line P0-P3. */
|
|
dx1 = arc[1].x - arc[0].x;
|
|
dy1 = arc[1].y - arc[0].y;
|
|
s = SW_FT_ABS( dy * dx1 - dx * dy1 );
|
|
|
|
if ( s > s_limit )
|
|
goto Split;
|
|
|
|
/* s is L * the perpendicular distance from P2 to the line P0-P3. */
|
|
dx2 = arc[2].x - arc[0].x;
|
|
dy2 = arc[2].y - arc[0].y;
|
|
s = SW_FT_ABS( dy * dx2 - dx * dy2 );
|
|
|
|
if ( s > s_limit )
|
|
goto Split;
|
|
|
|
/* Split super curvy segments where the off points are so far
|
|
from the chord that the angles P0-P1-P3 or P0-P2-P3 become
|
|
acute as detected by appropriate dot products. */
|
|
if ( dx1 * ( dx1 - dx ) + dy1 * ( dy1 - dy ) > 0 ||
|
|
dx2 * ( dx2 - dx ) + dy2 * ( dy2 - dy ) > 0 )
|
|
goto Split;
|
|
|
|
/* No reason to split. */
|
|
goto Draw;
|
|
}
|
|
|
|
Split:
|
|
gray_split_cubic( arc );
|
|
arc += 3;
|
|
continue;
|
|
|
|
Draw:
|
|
gray_render_line( RAS_VAR_ arc[0].x, arc[0].y );
|
|
|
|
if ( arc == ras.bez_stack )
|
|
return;
|
|
|
|
arc -= 3;
|
|
}
|
|
}
|
|
|
|
|
|
static int
|
|
gray_move_to( const SW_FT_Vector* to,
|
|
gray_PWorker worker )
|
|
{
|
|
TPos x, y;
|
|
|
|
|
|
/* record current cell, if any */
|
|
if ( !ras.invalid )
|
|
gray_record_cell( RAS_VAR );
|
|
|
|
/* start to a new position */
|
|
x = UPSCALE( to->x );
|
|
y = UPSCALE( to->y );
|
|
|
|
gray_start_cell( RAS_VAR_ TRUNC( x ), TRUNC( y ) );
|
|
|
|
worker->x = x;
|
|
worker->y = y;
|
|
return 0;
|
|
}
|
|
|
|
|
|
static int
|
|
gray_line_to( const SW_FT_Vector* to,
|
|
gray_PWorker worker )
|
|
{
|
|
gray_render_line( RAS_VAR_ UPSCALE( to->x ), UPSCALE( to->y ) );
|
|
return 0;
|
|
}
|
|
|
|
|
|
static int
|
|
gray_conic_to( const SW_FT_Vector* control,
|
|
const SW_FT_Vector* to,
|
|
gray_PWorker worker )
|
|
{
|
|
gray_render_conic( RAS_VAR_ control, to );
|
|
return 0;
|
|
}
|
|
|
|
|
|
static int
|
|
gray_cubic_to( const SW_FT_Vector* control1,
|
|
const SW_FT_Vector* control2,
|
|
const SW_FT_Vector* to,
|
|
gray_PWorker worker )
|
|
{
|
|
gray_render_cubic( RAS_VAR_ control1, control2, to );
|
|
return 0;
|
|
}
|
|
|
|
|
|
static void
|
|
gray_hline( RAS_ARG_ TCoord x,
|
|
TCoord y,
|
|
TPos area,
|
|
TCoord acount )
|
|
{
|
|
int coverage;
|
|
|
|
|
|
/* compute the coverage line's coverage, depending on the */
|
|
/* outline fill rule */
|
|
/* */
|
|
/* the coverage percentage is area/(PIXEL_BITS*PIXEL_BITS*2) */
|
|
/* */
|
|
coverage = (int)( area >> ( PIXEL_BITS * 2 + 1 - 8 ) );
|
|
/* use range 0..256 */
|
|
if ( coverage < 0 )
|
|
coverage = -coverage;
|
|
|
|
if ( ras.outline.flags & SW_FT_OUTLINE_EVEN_ODD_FILL )
|
|
{
|
|
coverage &= 511;
|
|
|
|
if ( coverage > 256 )
|
|
coverage = 512 - coverage;
|
|
else if ( coverage == 256 )
|
|
coverage = 255;
|
|
}
|
|
else
|
|
{
|
|
/* normal non-zero winding rule */
|
|
if ( coverage >= 256 )
|
|
coverage = 255;
|
|
}
|
|
|
|
y += (TCoord)ras.min_ey;
|
|
x += (TCoord)ras.min_ex;
|
|
|
|
/* SW_FT_Span.x is a 16-bit short, so limit our coordinates appropriately */
|
|
if ( x >= 32767 )
|
|
x = 32767;
|
|
|
|
/* SW_FT_Span.y is an integer, so limit our coordinates appropriately */
|
|
if ( y >= SW_FT_INT_MAX )
|
|
y = SW_FT_INT_MAX;
|
|
|
|
if ( coverage )
|
|
{
|
|
SW_FT_Span* span;
|
|
int count;
|
|
|
|
|
|
/* see whether we can add this span to the current list */
|
|
count = ras.num_gray_spans;
|
|
span = ras.gray_spans + count - 1;
|
|
if ( count > 0 &&
|
|
ras.span_y == y &&
|
|
(int)span->x + span->len == (int)x &&
|
|
span->coverage == coverage )
|
|
{
|
|
span->len = (unsigned short)( span->len + acount );
|
|
return;
|
|
}
|
|
|
|
if ( count >= SW_FT_MAX_GRAY_SPANS )
|
|
{
|
|
if ( ras.render_span && count > 0 )
|
|
ras.render_span(count, ras.gray_spans,
|
|
ras.render_span_data );
|
|
|
|
#ifdef DEBUG_GRAYS
|
|
|
|
if ( 1 )
|
|
{
|
|
int n;
|
|
|
|
|
|
fprintf( stderr, "count = %3d ", count );
|
|
span = ras.gray_spans;
|
|
for ( n = 0; n < count; n++, span++ )
|
|
fprintf( stderr, "[%d , %d..%d] : %d ",
|
|
span->y, span->x, span->x + span->len - 1, span->coverage );
|
|
fprintf( stderr, "\n" );
|
|
}
|
|
|
|
#endif /* DEBUG_GRAYS */
|
|
|
|
ras.num_gray_spans = 0;
|
|
//ras.span_y = (int)y;
|
|
|
|
span = ras.gray_spans;
|
|
}
|
|
else
|
|
span++;
|
|
|
|
/* add a gray span to the current list */
|
|
span->x = (short)x;
|
|
span->y = (short)y;
|
|
span->len = (unsigned short)acount;
|
|
span->coverage = (unsigned char)coverage;
|
|
|
|
ras.num_gray_spans++;
|
|
}
|
|
}
|
|
|
|
static void
|
|
gray_sweep( RAS_ARG)
|
|
{
|
|
int yindex;
|
|
|
|
if ( ras.num_cells == 0 )
|
|
return;
|
|
|
|
ras.num_gray_spans = 0;
|
|
|
|
for ( yindex = 0; yindex < ras.ycount; yindex++ )
|
|
{
|
|
PCell cell = ras.ycells[yindex];
|
|
TCoord cover = 0;
|
|
TCoord x = 0;
|
|
|
|
|
|
for ( ; cell != NULL; cell = cell->next )
|
|
{
|
|
TPos area;
|
|
|
|
|
|
if ( cell->x > x && cover != 0 )
|
|
gray_hline( RAS_VAR_ x, yindex, cover * ( ONE_PIXEL * 2 ),
|
|
cell->x - x );
|
|
|
|
cover += cell->cover;
|
|
area = cover * ( ONE_PIXEL * 2 ) - cell->area;
|
|
|
|
if ( area != 0 && cell->x >= 0 )
|
|
gray_hline( RAS_VAR_ cell->x, yindex, area, 1 );
|
|
|
|
x = cell->x + 1;
|
|
}
|
|
|
|
if ( cover != 0 )
|
|
gray_hline( RAS_VAR_ x, yindex, cover * ( ONE_PIXEL * 2 ),
|
|
ras.count_ex - x );
|
|
}
|
|
|
|
if ( ras.render_span && ras.num_gray_spans > 0 )
|
|
ras.render_span(ras.num_gray_spans,
|
|
ras.gray_spans, ras.render_span_data );
|
|
}
|
|
|
|
|
|
/*************************************************************************/
|
|
/* */
|
|
/* The following function should only compile in stand-alone mode, */
|
|
/* i.e., when building this component without the rest of FreeType. */
|
|
/* */
|
|
/*************************************************************************/
|
|
|
|
/*************************************************************************/
|
|
/* */
|
|
/* <Function> */
|
|
/* SW_FT_Outline_Decompose */
|
|
/* */
|
|
/* <Description> */
|
|
/* Walk over an outline's structure to decompose it into individual */
|
|
/* segments and Bézier arcs. This function is also able to emit */
|
|
/* `move to' and `close to' operations to indicate the start and end */
|
|
/* of new contours in the outline. */
|
|
/* */
|
|
/* <Input> */
|
|
/* outline :: A pointer to the source target. */
|
|
/* */
|
|
/* func_interface :: A table of `emitters', i.e., function pointers */
|
|
/* called during decomposition to indicate path */
|
|
/* operations. */
|
|
/* */
|
|
/* <InOut> */
|
|
/* user :: A typeless pointer which is passed to each */
|
|
/* emitter during the decomposition. It can be */
|
|
/* used to store the state during the */
|
|
/* decomposition. */
|
|
/* */
|
|
/* <Return> */
|
|
/* Error code. 0 means success. */
|
|
/* */
|
|
static int
|
|
SW_FT_Outline_Decompose( const SW_FT_Outline* outline,
|
|
const SW_FT_Outline_Funcs* func_interface,
|
|
void* user )
|
|
{
|
|
#undef SCALED
|
|
#define SCALED( x ) ( ( (x) << shift ) - delta )
|
|
|
|
SW_FT_Vector v_last;
|
|
SW_FT_Vector v_control;
|
|
SW_FT_Vector v_start;
|
|
|
|
SW_FT_Vector* point;
|
|
SW_FT_Vector* limit;
|
|
char* tags;
|
|
|
|
int error;
|
|
|
|
int n; /* index of contour in outline */
|
|
int first; /* index of first point in contour */
|
|
char tag; /* current point's state */
|
|
|
|
int shift;
|
|
TPos delta;
|
|
|
|
|
|
if ( !outline || !func_interface )
|
|
return SW_FT_THROW( Invalid_Argument );
|
|
|
|
shift = func_interface->shift;
|
|
delta = func_interface->delta;
|
|
first = 0;
|
|
|
|
for ( n = 0; n < outline->n_contours; n++ )
|
|
{
|
|
int last; /* index of last point in contour */
|
|
|
|
|
|
last = outline->contours[n];
|
|
if ( last < 0 )
|
|
goto Invalid_Outline;
|
|
limit = outline->points + last;
|
|
|
|
v_start = outline->points[first];
|
|
v_start.x = SCALED( v_start.x );
|
|
v_start.y = SCALED( v_start.y );
|
|
|
|
v_last = outline->points[last];
|
|
v_last.x = SCALED( v_last.x );
|
|
v_last.y = SCALED( v_last.y );
|
|
|
|
v_control = v_start;
|
|
|
|
point = outline->points + first;
|
|
tags = outline->tags + first;
|
|
tag = SW_FT_CURVE_TAG( tags[0] );
|
|
|
|
/* A contour cannot start with a cubic control point! */
|
|
if ( tag == SW_FT_CURVE_TAG_CUBIC )
|
|
goto Invalid_Outline;
|
|
|
|
/* check first point to determine origin */
|
|
if ( tag == SW_FT_CURVE_TAG_CONIC )
|
|
{
|
|
/* first point is conic control. Yes, this happens. */
|
|
if ( SW_FT_CURVE_TAG( outline->tags[last] ) == SW_FT_CURVE_TAG_ON )
|
|
{
|
|
/* start at last point if it is on the curve */
|
|
v_start = v_last;
|
|
limit--;
|
|
}
|
|
else
|
|
{
|
|
/* if both first and last points are conic, */
|
|
/* start at their middle and record its position */
|
|
/* for closure */
|
|
v_start.x = ( v_start.x + v_last.x ) / 2;
|
|
v_start.y = ( v_start.y + v_last.y ) / 2;
|
|
}
|
|
point--;
|
|
tags--;
|
|
}
|
|
|
|
error = func_interface->move_to( &v_start, user );
|
|
if ( error )
|
|
goto Exit;
|
|
|
|
while ( point < limit )
|
|
{
|
|
point++;
|
|
tags++;
|
|
|
|
tag = SW_FT_CURVE_TAG( tags[0] );
|
|
switch ( tag )
|
|
{
|
|
case SW_FT_CURVE_TAG_ON: /* emit a single line_to */
|
|
{
|
|
SW_FT_Vector vec;
|
|
|
|
|
|
vec.x = SCALED( point->x );
|
|
vec.y = SCALED( point->y );
|
|
|
|
error = func_interface->line_to( &vec, user );
|
|
if ( error )
|
|
goto Exit;
|
|
continue;
|
|
}
|
|
|
|
case SW_FT_CURVE_TAG_CONIC: /* consume conic arcs */
|
|
v_control.x = SCALED( point->x );
|
|
v_control.y = SCALED( point->y );
|
|
|
|
Do_Conic:
|
|
if ( point < limit )
|
|
{
|
|
SW_FT_Vector vec;
|
|
SW_FT_Vector v_middle;
|
|
|
|
|
|
point++;
|
|
tags++;
|
|
tag = SW_FT_CURVE_TAG( tags[0] );
|
|
|
|
vec.x = SCALED( point->x );
|
|
vec.y = SCALED( point->y );
|
|
|
|
if ( tag == SW_FT_CURVE_TAG_ON )
|
|
{
|
|
error = func_interface->conic_to( &v_control, &vec, user );
|
|
if ( error )
|
|
goto Exit;
|
|
continue;
|
|
}
|
|
|
|
if ( tag != SW_FT_CURVE_TAG_CONIC )
|
|
goto Invalid_Outline;
|
|
|
|
v_middle.x = ( v_control.x + vec.x ) / 2;
|
|
v_middle.y = ( v_control.y + vec.y ) / 2;
|
|
|
|
error = func_interface->conic_to( &v_control, &v_middle, user );
|
|
if ( error )
|
|
goto Exit;
|
|
|
|
v_control = vec;
|
|
goto Do_Conic;
|
|
}
|
|
|
|
error = func_interface->conic_to( &v_control, &v_start, user );
|
|
goto Close;
|
|
|
|
default: /* SW_FT_CURVE_TAG_CUBIC */
|
|
{
|
|
SW_FT_Vector vec1, vec2;
|
|
|
|
|
|
if ( point + 1 > limit ||
|
|
SW_FT_CURVE_TAG( tags[1] ) != SW_FT_CURVE_TAG_CUBIC )
|
|
goto Invalid_Outline;
|
|
|
|
point += 2;
|
|
tags += 2;
|
|
|
|
vec1.x = SCALED( point[-2].x );
|
|
vec1.y = SCALED( point[-2].y );
|
|
|
|
vec2.x = SCALED( point[-1].x );
|
|
vec2.y = SCALED( point[-1].y );
|
|
|
|
if ( point <= limit )
|
|
{
|
|
SW_FT_Vector vec;
|
|
|
|
|
|
vec.x = SCALED( point->x );
|
|
vec.y = SCALED( point->y );
|
|
|
|
error = func_interface->cubic_to( &vec1, &vec2, &vec, user );
|
|
if ( error )
|
|
goto Exit;
|
|
continue;
|
|
}
|
|
|
|
error = func_interface->cubic_to( &vec1, &vec2, &v_start, user );
|
|
goto Close;
|
|
}
|
|
}
|
|
}
|
|
|
|
/* close the contour with a line segment */
|
|
error = func_interface->line_to( &v_start, user );
|
|
|
|
Close:
|
|
if ( error )
|
|
goto Exit;
|
|
|
|
first = last + 1;
|
|
}
|
|
|
|
return 0;
|
|
|
|
Exit:
|
|
return error;
|
|
|
|
Invalid_Outline:
|
|
return SW_FT_THROW( Invalid_Outline );
|
|
}
|
|
|
|
|
|
typedef struct gray_TBand_
|
|
{
|
|
TPos min, max;
|
|
|
|
} gray_TBand;
|
|
|
|
|
|
|
|
SW_FT_DEFINE_OUTLINE_FUNCS(func_interface,
|
|
(SW_FT_Outline_MoveTo_Func) gray_move_to,
|
|
(SW_FT_Outline_LineTo_Func) gray_line_to,
|
|
(SW_FT_Outline_ConicTo_Func)gray_conic_to,
|
|
(SW_FT_Outline_CubicTo_Func)gray_cubic_to,
|
|
0,
|
|
0
|
|
)
|
|
|
|
static int
|
|
gray_convert_glyph_inner( RAS_ARG )
|
|
{
|
|
|
|
volatile int error = 0;
|
|
|
|
if ( ft_setjmp( ras.jump_buffer ) == 0 )
|
|
{
|
|
error = SW_FT_Outline_Decompose( &ras.outline, &func_interface, &ras );
|
|
if ( !ras.invalid )
|
|
gray_record_cell( RAS_VAR );
|
|
}
|
|
else
|
|
error = SW_FT_THROW( Memory_Overflow );
|
|
|
|
return error;
|
|
}
|
|
|
|
|
|
static int
|
|
gray_convert_glyph( RAS_ARG )
|
|
{
|
|
gray_TBand bands[40];
|
|
gray_TBand* volatile band;
|
|
int volatile n, num_bands;
|
|
TPos volatile min, max, max_y;
|
|
SW_FT_BBox* clip;
|
|
|
|
|
|
/* Set up state in the raster object */
|
|
gray_compute_cbox( RAS_VAR );
|
|
|
|
/* clip to target bitmap, exit if nothing to do */
|
|
clip = &ras.clip_box;
|
|
|
|
if ( ras.max_ex <= clip->xMin || ras.min_ex >= clip->xMax ||
|
|
ras.max_ey <= clip->yMin || ras.min_ey >= clip->yMax )
|
|
return 0;
|
|
|
|
if ( ras.min_ex < clip->xMin ) ras.min_ex = clip->xMin;
|
|
if ( ras.min_ey < clip->yMin ) ras.min_ey = clip->yMin;
|
|
|
|
if ( ras.max_ex > clip->xMax ) ras.max_ex = clip->xMax;
|
|
if ( ras.max_ey > clip->yMax ) ras.max_ey = clip->yMax;
|
|
|
|
ras.count_ex = ras.max_ex - ras.min_ex;
|
|
ras.count_ey = ras.max_ey - ras.min_ey;
|
|
|
|
/* set up vertical bands */
|
|
num_bands = (int)( ( ras.max_ey - ras.min_ey ) / ras.band_size );
|
|
if ( num_bands == 0 )
|
|
num_bands = 1;
|
|
if ( num_bands >= 39 )
|
|
num_bands = 39;
|
|
|
|
ras.band_shoot = 0;
|
|
|
|
min = ras.min_ey;
|
|
max_y = ras.max_ey;
|
|
|
|
for ( n = 0; n < num_bands; n++, min = max )
|
|
{
|
|
max = min + ras.band_size;
|
|
if ( n == num_bands - 1 || max > max_y )
|
|
max = max_y;
|
|
|
|
bands[0].min = min;
|
|
bands[0].max = max;
|
|
band = bands;
|
|
|
|
while ( band >= bands )
|
|
{
|
|
TPos bottom, top, middle;
|
|
int error;
|
|
|
|
{
|
|
PCell cells_max;
|
|
int yindex;
|
|
long cell_start, cell_end, cell_mod;
|
|
|
|
|
|
ras.ycells = (PCell*)ras.buffer;
|
|
ras.ycount = band->max - band->min;
|
|
|
|
cell_start = sizeof ( PCell ) * ras.ycount;
|
|
cell_mod = cell_start % sizeof ( TCell );
|
|
if ( cell_mod > 0 )
|
|
cell_start += sizeof ( TCell ) - cell_mod;
|
|
|
|
cell_end = ras.buffer_size;
|
|
cell_end -= cell_end % sizeof ( TCell );
|
|
|
|
cells_max = (PCell)( (char*)ras.buffer + cell_end );
|
|
ras.cells = (PCell)( (char*)ras.buffer + cell_start );
|
|
if ( ras.cells >= cells_max )
|
|
goto ReduceBands;
|
|
|
|
ras.max_cells = cells_max - ras.cells;
|
|
if ( ras.max_cells < 2 )
|
|
goto ReduceBands;
|
|
|
|
for ( yindex = 0; yindex < ras.ycount; yindex++ )
|
|
ras.ycells[yindex] = NULL;
|
|
}
|
|
|
|
ras.num_cells = 0;
|
|
ras.invalid = 1;
|
|
ras.min_ey = band->min;
|
|
ras.max_ey = band->max;
|
|
ras.count_ey = band->max - band->min;
|
|
|
|
error = gray_convert_glyph_inner( RAS_VAR );
|
|
|
|
if ( !error )
|
|
{
|
|
gray_sweep( RAS_VAR);
|
|
band--;
|
|
continue;
|
|
}
|
|
else if ( error != ErrRaster_Memory_Overflow )
|
|
return 1;
|
|
|
|
ReduceBands:
|
|
/* render pool overflow; we will reduce the render band by half */
|
|
bottom = band->min;
|
|
top = band->max;
|
|
middle = bottom + ( ( top - bottom ) >> 1 );
|
|
|
|
/* This is too complex for a single scanline; there must */
|
|
/* be some problems. */
|
|
if ( middle == bottom )
|
|
{
|
|
return 1;
|
|
}
|
|
|
|
if ( bottom-top >= ras.band_size )
|
|
ras.band_shoot++;
|
|
|
|
band[1].min = bottom;
|
|
band[1].max = middle;
|
|
band[0].min = middle;
|
|
band[0].max = top;
|
|
band++;
|
|
}
|
|
}
|
|
|
|
if ( ras.band_shoot > 8 && ras.band_size > 16 )
|
|
ras.band_size = ras.band_size / 2;
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int
|
|
gray_raster_render( gray_PRaster raster,
|
|
const SW_FT_Raster_Params* params )
|
|
{
|
|
const SW_FT_Outline* outline = (const SW_FT_Outline*)params->source;
|
|
|
|
gray_TWorker worker[1];
|
|
|
|
TCell buffer[SW_FT_RENDER_POOL_SIZE / sizeof ( TCell )];
|
|
long buffer_size = sizeof ( buffer );
|
|
int band_size = (int)( buffer_size /
|
|
(long)( sizeof ( TCell ) * 8 ) );
|
|
|
|
if ( !raster)
|
|
return SW_FT_THROW( Invalid_Argument );
|
|
|
|
if ( !outline )
|
|
return SW_FT_THROW( Invalid_Outline );
|
|
|
|
/* return immediately if the outline is empty */
|
|
if ( outline->n_points == 0 || outline->n_contours <= 0 )
|
|
return 0;
|
|
|
|
if ( !outline->contours || !outline->points )
|
|
return SW_FT_THROW( Invalid_Outline );
|
|
|
|
if ( outline->n_points !=
|
|
outline->contours[outline->n_contours - 1] + 1 )
|
|
return SW_FT_THROW( Invalid_Outline );
|
|
|
|
/* this version does not support monochrome rendering */
|
|
if ( !( params->flags & SW_FT_RASTER_FLAG_AA ) )
|
|
return SW_FT_THROW( Invalid_Mode );
|
|
|
|
if ( params->flags & SW_FT_RASTER_FLAG_CLIP )
|
|
ras.clip_box = params->clip_box;
|
|
else
|
|
{
|
|
ras.clip_box.xMin = -32768L;
|
|
ras.clip_box.yMin = -32768L;
|
|
ras.clip_box.xMax = 32767L;
|
|
ras.clip_box.yMax = 32767L;
|
|
}
|
|
|
|
gray_init_cells( RAS_VAR_ buffer, buffer_size );
|
|
|
|
ras.outline = *outline;
|
|
ras.num_cells = 0;
|
|
ras.invalid = 1;
|
|
ras.band_size = band_size;
|
|
ras.num_gray_spans = 0;
|
|
ras.span_y = 0;
|
|
|
|
ras.render_span = (SW_FT_Raster_Span_Func)params->gray_spans;
|
|
ras.render_span_data = params->user;
|
|
|
|
return gray_convert_glyph( RAS_VAR );
|
|
}
|
|
|
|
/**** RASTER OBJECT CREATION: In stand-alone mode, we simply use *****/
|
|
/**** a static object. *****/
|
|
|
|
static int
|
|
gray_raster_new(SW_FT_Raster* araster )
|
|
{
|
|
static gray_TRaster the_raster;
|
|
|
|
*araster = (SW_FT_Raster)&the_raster;
|
|
SW_FT_MEM_ZERO( &the_raster, sizeof ( the_raster ) );
|
|
|
|
return 0;
|
|
}
|
|
|
|
|
|
static void
|
|
gray_raster_done( SW_FT_Raster raster )
|
|
{
|
|
/* nothing */
|
|
SW_FT_UNUSED( raster );
|
|
}
|
|
|
|
static void
|
|
gray_raster_reset( SW_FT_Raster raster,
|
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char* pool_base,
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long pool_size )
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{
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SW_FT_UNUSED( raster );
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SW_FT_UNUSED( pool_base );
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SW_FT_UNUSED( pool_size );
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}
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SW_FT_DEFINE_RASTER_FUNCS(sw_ft_grays_raster,
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(SW_FT_Raster_New_Func) gray_raster_new,
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(SW_FT_Raster_Reset_Func) gray_raster_reset,
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(SW_FT_Raster_Render_Func) gray_raster_render,
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(SW_FT_Raster_Done_Func) gray_raster_done
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)
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/* END */
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