ref: 34207080c6e124356aee3db9aba2daeb00edf1b9
dir: /src/smooth/ftgrays.c/
/***************************************************************************/ /* */ /* ftgrays.c */ /* */ /* A new `perfect' anti-aliasing renderer (body). */ /* */ /* Copyright 2000-2016 by */ /* David Turner, Robert Wilhelm, and Werner Lemberg. */ /* */ /* This file is part of the FreeType project, and may only be used, */ /* modified, and distributed under the terms of the FreeType project */ /* license, LICENSE.TXT. By continuing to use, modify, or distribute */ /* this file you indicate that you have read the license and */ /* understand and accept it fully. */ /* */ /***************************************************************************/ /*************************************************************************/ /* */ /* This file can be compiled without the rest of the FreeType engine, by */ /* defining the STANDALONE_ macro when compiling it. You also need to */ /* put the files `ftgrays.h' and `ftimage.h' into the current */ /* compilation directory. Typically, you could do something like */ /* */ /* - copy `src/smooth/ftgrays.c' (this file) to your current directory */ /* */ /* - copy `include/freetype/ftimage.h' and `src/smooth/ftgrays.h' to the */ /* same directory */ /* */ /* - compile `ftgrays' with the STANDALONE_ macro defined, as in */ /* */ /* cc -c -DSTANDALONE_ ftgrays.c */ /* */ /* The renderer can be initialized with a call to */ /* `ft_gray_raster.raster_new'; an anti-aliased bitmap can be generated */ /* with a call to `ft_gray_raster.raster_render'. */ /* */ /* See the comments and documentation in the file `ftimage.h' for more */ /* details on how the raster works. */ /* */ /*************************************************************************/ /*************************************************************************/ /* */ /* This is a new anti-aliasing scan-converter for FreeType 2. The */ /* algorithm used here is _very_ different from the one in the standard */ /* `ftraster' module. Actually, `ftgrays' computes the _exact_ */ /* coverage of the outline on each pixel cell. */ /* */ /* It is based on ideas that I initially found in Raph Levien's */ /* excellent LibArt graphics library (see http://www.levien.com/libart */ /* for more information, though the web pages do not tell anything */ /* about the renderer; you'll have to dive into the source code to */ /* understand how it works). */ /* */ /* Note, however, that this is a _very_ different implementation */ /* compared to Raph's. Coverage information is stored in a very */ /* different way, and I don't use sorted vector paths. Also, it doesn't */ /* use floating point values. */ /* */ /* This renderer has the following advantages: */ /* */ /* - It doesn't need an intermediate bitmap. Instead, one can supply a */ /* callback function that will be called by the renderer to draw gray */ /* spans on any target surface. You can thus do direct composition on */ /* any kind of bitmap, provided that you give the renderer the right */ /* callback. */ /* */ /* - A perfect anti-aliaser, i.e., it computes the _exact_ coverage on */ /* each pixel cell. */ /* */ /* - It performs a single pass on the outline (the `standard' FT2 */ /* renderer makes two passes). */ /* */ /* - It can easily be modified to render to _any_ number of gray levels */ /* cheaply. */ /* */ /* - For small (< 20) pixel sizes, it is faster than the standard */ /* renderer. */ /* */ /*************************************************************************/ /*************************************************************************/ /* */ /* The macro FT_COMPONENT is used in trace mode. It is an implicit */ /* parameter of the FT_TRACE() and FT_ERROR() macros, used to print/log */ /* messages during execution. */ /* */ #undef FT_COMPONENT #define FT_COMPONENT trace_smooth #ifdef STANDALONE_ /* The size in bytes of the render pool used by the scan-line converter */ /* to do all of its work. */ #define FT_RENDER_POOL_SIZE 16384L /* Auxiliary macros for token concatenation. */ #define FT_ERR_XCAT( x, y ) x ## y #define FT_ERR_CAT( x, y ) FT_ERR_XCAT( x, y ) #define FT_BEGIN_STMNT do { #define FT_END_STMNT } while ( 0 ) #define FT_MAX( a, b ) ( (a) > (b) ? (a) : (b) ) #define FT_ABS( a ) ( (a) < 0 ? -(a) : (a) ) /* * Approximate sqrt(x*x+y*y) using the `alpha max plus beta min' * algorithm. We use alpha = 1, beta = 3/8, giving us results with a * largest error less than 7% compared to the exact value. */ #define FT_HYPOT( x, y ) \ ( x = FT_ABS( x ), \ y = FT_ABS( y ), \ x > y ? x + ( 3 * y >> 3 ) \ : y + ( 3 * x >> 3 ) ) /* define this to dump debugging information */ /* #define FT_DEBUG_LEVEL_TRACE */ #ifdef FT_DEBUG_LEVEL_TRACE #include <stdio.h> #include <stdarg.h> #endif #include <stddef.h> #include <string.h> #include <setjmp.h> #include <limits.h> #define FT_CHAR_BIT CHAR_BIT #define FT_UINT_MAX UINT_MAX #define FT_INT_MAX INT_MAX #define FT_ULONG_MAX ULONG_MAX #define ft_memset memset #define ft_setjmp setjmp #define ft_longjmp longjmp #define ft_jmp_buf jmp_buf typedef ptrdiff_t FT_PtrDist; #define ErrRaster_Invalid_Mode -2 #define ErrRaster_Invalid_Outline -1 #define ErrRaster_Invalid_Argument -3 #define ErrRaster_Memory_Overflow -4 #define FT_BEGIN_HEADER #define FT_END_HEADER #include "ftimage.h" #include "ftgrays.h" /* This macro is used to indicate that a function parameter is unused. */ /* Its purpose is simply to reduce compiler warnings. Note also that */ /* simply defining it as `(void)x' doesn't avoid warnings with certain */ /* ANSI compilers (e.g. LCC). */ #define FT_UNUSED( x ) (x) = (x) /* we only use level 5 & 7 tracing messages; cf. ftdebug.h */ #ifdef FT_DEBUG_LEVEL_TRACE void FT_Message( const char* fmt, ... ) { va_list ap; va_start( ap, fmt ); vfprintf( stderr, fmt, ap ); va_end( ap ); } /* empty function useful for setting a breakpoint to catch errors */ int FT_Throw( int error, int line, const char* file ) { FT_UNUSED( error ); FT_UNUSED( line ); FT_UNUSED( file ); return 0; } /* we don't handle tracing levels in stand-alone mode; */ #ifndef FT_TRACE5 #define FT_TRACE5( varformat ) FT_Message varformat #endif #ifndef FT_TRACE7 #define FT_TRACE7( varformat ) FT_Message varformat #endif #ifndef FT_ERROR #define FT_ERROR( varformat ) FT_Message varformat #endif #define FT_THROW( e ) \ ( FT_Throw( FT_ERR_CAT( ErrRaster, e ), \ __LINE__, \ __FILE__ ) | \ FT_ERR_CAT( ErrRaster, e ) ) #else /* !FT_DEBUG_LEVEL_TRACE */ #define FT_TRACE5( x ) do { } while ( 0 ) /* nothing */ #define FT_TRACE7( x ) do { } while ( 0 ) /* nothing */ #define FT_ERROR( x ) do { } while ( 0 ) /* nothing */ #define FT_THROW( e ) FT_ERR_CAT( ErrRaster_, e ) #endif /* !FT_DEBUG_LEVEL_TRACE */ #define FT_DEFINE_OUTLINE_FUNCS( class_, \ move_to_, line_to_, \ conic_to_, cubic_to_, \ shift_, delta_ ) \ static const FT_Outline_Funcs class_ = \ { \ move_to_, \ line_to_, \ conic_to_, \ cubic_to_, \ shift_, \ delta_ \ }; #define FT_DEFINE_RASTER_FUNCS( class_, glyph_format_, \ raster_new_, raster_reset_, \ raster_set_mode_, raster_render_, \ raster_done_ ) \ const FT_Raster_Funcs class_ = \ { \ glyph_format_, \ raster_new_, \ raster_reset_, \ raster_set_mode_, \ raster_render_, \ raster_done_ \ }; #else /* !STANDALONE_ */ #include <ft2build.h> #include "ftgrays.h" #include FT_INTERNAL_OBJECTS_H #include FT_INTERNAL_DEBUG_H #include FT_OUTLINE_H #include "ftsmerrs.h" #include "ftspic.h" #define Smooth_Err_Invalid_Mode Smooth_Err_Cannot_Render_Glyph #define Smooth_Err_Memory_Overflow Smooth_Err_Out_Of_Memory #define ErrRaster_Memory_Overflow Smooth_Err_Out_Of_Memory #endif /* !STANDALONE_ */ #ifndef FT_MEM_SET #define FT_MEM_SET( d, s, c ) ft_memset( d, s, c ) #endif #ifndef FT_MEM_ZERO #define FT_MEM_ZERO( dest, count ) FT_MEM_SET( dest, 0, count ) #endif /* as usual, for the speed hungry :-) */ #undef RAS_ARG #undef RAS_ARG_ #undef RAS_VAR #undef RAS_VAR_ #ifndef FT_STATIC_RASTER #define RAS_ARG gray_PWorker worker #define RAS_ARG_ gray_PWorker worker, #define RAS_VAR worker #define RAS_VAR_ worker, #else /* FT_STATIC_RASTER */ #define RAS_ARG /* empty */ #define RAS_ARG_ /* empty */ #define RAS_VAR /* empty */ #define RAS_VAR_ /* empty */ #endif /* FT_STATIC_RASTER */ /* must be at least 6 bits! */ #define PIXEL_BITS 8 #undef FLOOR #undef CEILING #undef TRUNC #undef SCALED #define ONE_PIXEL ( 1L << PIXEL_BITS ) #define TRUNC( x ) ( (TCoord)( (x) >> PIXEL_BITS ) ) #define SUBPIXELS( x ) ( (TPos)(x) * ONE_PIXEL ) #define FLOOR( x ) ( (x) & -ONE_PIXEL ) #define CEILING( x ) ( ( (x) + ONE_PIXEL - 1 ) & -ONE_PIXEL ) #define ROUND( x ) ( ( (x) + ONE_PIXEL / 2 ) & -ONE_PIXEL ) #if PIXEL_BITS >= 6 #define UPSCALE( x ) ( (x) * ( ONE_PIXEL >> 6 ) ) #define DOWNSCALE( x ) ( (x) >> ( PIXEL_BITS - 6 ) ) #else #define UPSCALE( x ) ( (x) >> ( 6 - PIXEL_BITS ) ) #define DOWNSCALE( x ) ( (x) * ( 64 >> PIXEL_BITS ) ) #endif /* Compute `dividend / divisor' and return both its quotient and */ /* remainder, cast to a specific type. This macro also ensures that */ /* the remainder is always positive. */ #define FT_DIV_MOD( type, dividend, divisor, quotient, remainder ) \ FT_BEGIN_STMNT \ (quotient) = (type)( (dividend) / (divisor) ); \ (remainder) = (type)( (dividend) % (divisor) ); \ if ( (remainder) < 0 ) \ { \ (quotient)--; \ (remainder) += (type)(divisor); \ } \ FT_END_STMNT #ifdef __arm__ /* Work around a bug specific to GCC which make the compiler fail to */ /* optimize a division and modulo operation on the same parameters */ /* into a single call to `__aeabi_idivmod'. See */ /* */ /* http://gcc.gnu.org/bugzilla/show_bug.cgi?id=43721 */ #undef FT_DIV_MOD #define FT_DIV_MOD( type, dividend, divisor, quotient, remainder ) \ FT_BEGIN_STMNT \ (quotient) = (type)( (dividend) / (divisor) ); \ (remainder) = (type)( (dividend) - (quotient) * (divisor) ); \ if ( (remainder) < 0 ) \ { \ (quotient)--; \ (remainder) += (type)(divisor); \ } \ FT_END_STMNT #endif /* __arm__ */ /* These macros speed up repetitive divisions by replacing them */ /* with multiplications and right shifts. */ #define FT_UDIVPREP( b ) \ long b ## _r = (long)( FT_ULONG_MAX >> PIXEL_BITS ) / ( b ) #define FT_UDIV( a, b ) \ ( ( (unsigned long)( a ) * (unsigned long)( b ## _r ) ) >> \ ( sizeof( long ) * FT_CHAR_BIT - PIXEL_BITS ) ) /*************************************************************************/ /* */ /* TYPE DEFINITIONS */ /* */ /* don't change the following types to FT_Int or FT_Pos, since we might */ /* need to define them to "float" or "double" when experimenting with */ /* new algorithms */ typedef long TCoord; /* integer scanline/pixel coordinate */ typedef long TPos; /* sub-pixel coordinate */ typedef long TArea; /* cell areas, coordinate products */ /* maximum number of gray spans in a call to the span callback */ #define FT_MAX_GRAY_SPANS 32 typedef struct TCell_* PCell; typedef struct TCell_ { TPos x; /* same with gray_TWorker.ex */ TCoord cover; /* same with gray_TWorker.cover */ TArea area; PCell next; } TCell; #if defined( _MSC_VER ) /* Visual C++ (and Intel C++) */ /* We disable the warning `structure was padded due to */ /* __declspec(align())' in order to compile cleanly with */ /* the maximum level of warnings. */ #pragma warning( push ) #pragma warning( disable : 4324 ) #endif /* _MSC_VER */ typedef struct gray_TWorker_ { ft_jmp_buf jump_buffer; TCoord ex, ey; TPos min_ex, max_ex; TPos min_ey, max_ey; TPos count_ex, count_ey; TArea area; TCoord cover; int invalid; PCell cells; FT_PtrDist max_cells; FT_PtrDist num_cells; TPos x, y; FT_Vector bez_stack[32 * 3 + 1]; int lev_stack[32]; FT_Outline outline; FT_Bitmap target; FT_BBox clip_box; FT_Span gray_spans[FT_MAX_GRAY_SPANS]; int num_gray_spans; FT_Raster_Span_Func render_span; void* render_span_data; int span_y; int band_size; int band_shoot; void* buffer; long buffer_size; PCell* ycells; TPos ycount; } gray_TWorker, *gray_PWorker; #if defined( _MSC_VER ) #pragma warning( pop ) #endif #ifndef FT_STATIC_RASTER #define ras (*worker) #else static gray_TWorker ras; #endif typedef struct gray_TRaster_ { void* memory; } gray_TRaster, *gray_PRaster; /*************************************************************************/ /* */ /* Initialize the cells table. */ /* */ static void gray_init_cells( RAS_ARG_ void* buffer, long byte_size ) { ras.buffer = buffer; ras.buffer_size = byte_size; ras.ycells = (PCell*) buffer; ras.cells = NULL; ras.max_cells = 0; ras.num_cells = 0; ras.area = 0; ras.cover = 0; ras.invalid = 1; } /*************************************************************************/ /* */ /* Compute the outline bounding box. */ /* */ static void gray_compute_cbox( RAS_ARG ) { FT_Outline* outline = &ras.outline; FT_Vector* vec = outline->points; FT_Vector* limit = vec + outline->n_points; if ( outline->n_points <= 0 ) { ras.min_ex = ras.max_ex = 0; ras.min_ey = ras.max_ey = 0; return; } ras.min_ex = ras.max_ex = vec->x; ras.min_ey = ras.max_ey = vec->y; vec++; for ( ; vec < limit; vec++ ) { TPos x = vec->x; TPos y = vec->y; if ( x < ras.min_ex ) ras.min_ex = x; if ( x > ras.max_ex ) ras.max_ex = x; if ( y < ras.min_ey ) ras.min_ey = y; if ( y > ras.max_ey ) ras.max_ey = y; } /* truncate the bounding box to integer pixels */ ras.min_ex = ras.min_ex >> 6; ras.min_ey = ras.min_ey >> 6; ras.max_ex = ( ras.max_ex + 63 ) >> 6; ras.max_ey = ( ras.max_ey + 63 ) >> 6; } /*************************************************************************/ /* */ /* Record the current cell in the table. */ /* */ static PCell gray_find_cell( RAS_ARG ) { PCell *pcell, cell; TPos x = ras.ex; if ( x > ras.count_ex ) x = ras.count_ex; pcell = &ras.ycells[ras.ey]; for (;;) { cell = *pcell; if ( cell == NULL || cell->x > x ) break; if ( cell->x == x ) goto Exit; pcell = &cell->next; } if ( ras.num_cells >= ras.max_cells ) ft_longjmp( ras.jump_buffer, 1 ); cell = ras.cells + ras.num_cells++; cell->x = x; cell->area = 0; cell->cover = 0; cell->next = *pcell; *pcell = cell; Exit: return cell; } static void gray_record_cell( RAS_ARG ) { if ( ras.area | ras.cover ) { PCell cell = gray_find_cell( RAS_VAR ); cell->area += ras.area; cell->cover += ras.cover; } } /*************************************************************************/ /* */ /* Set the current cell to a new position. */ /* */ static void gray_set_cell( RAS_ARG_ TCoord ex, TCoord ey ) { /* Move the cell pointer to a new position. We set the `invalid' */ /* flag to indicate that the cell isn't part of those we're interested */ /* in during the render phase. This means that: */ /* */ /* . the new vertical position must be within min_ey..max_ey-1. */ /* . the new horizontal position must be strictly less than max_ex */ /* */ /* Note that if a cell is to the left of the clipping region, it is */ /* actually set to the (min_ex-1) horizontal position. */ /* All cells that are on the left of the clipping region go to the */ /* min_ex - 1 horizontal position. */ ey -= ras.min_ey; if ( ex > ras.max_ex ) 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 int)ey >= (unsigned int)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 ); } #if 1 /*************************************************************************/ /* */ /* Render a scanline as one or more cells. */ /* */ static void gray_render_scanline( RAS_ARG_ TCoord ey, TPos x1, TCoord y1, TPos x2, TCoord y2 ) { TCoord ex1, ex2, fx1, fx2, delta, mod; long p, first, dx; int incr; ex1 = TRUNC( x1 ); ex2 = TRUNC( x2 ); /* trivial case. Happens often */ if ( y1 == y2 ) { gray_set_cell( RAS_VAR_ ex2, ey ); return; } fx1 = (TCoord)( x1 - SUBPIXELS( ex1 ) ); fx2 = (TCoord)( x2 - SUBPIXELS( ex2 ) ); /* everything is located in a single cell. That is easy! */ /* */ if ( ex1 == ex2 ) { delta = y2 - y1; ras.area += (TArea)(( fx1 + fx2 ) * delta); ras.cover += delta; return; } /* ok, we'll have to render a run of adjacent cells on the same */ /* scanline... */ /* */ p = ( ONE_PIXEL - fx1 ) * ( y2 - y1 ); first = ONE_PIXEL; incr = 1; dx = x2 - x1; if ( dx < 0 ) { p = fx1 * ( y2 - y1 ); first = 0; incr = -1; dx = -dx; } FT_DIV_MOD( TCoord, p, dx, delta, mod ); ras.area += (TArea)(( fx1 + first ) * delta); ras.cover += delta; ex1 += incr; gray_set_cell( RAS_VAR_ ex1, ey ); y1 += delta; if ( ex1 != ex2 ) { TCoord lift, rem; p = ONE_PIXEL * ( y2 - y1 + delta ); FT_DIV_MOD( TCoord, p, dx, lift, rem ); mod -= (int)dx; do { delta = lift; mod += rem; if ( mod >= 0 ) { mod -= (TCoord)dx; delta++; } ras.area += (TArea)(ONE_PIXEL * delta); ras.cover += delta; y1 += delta; ex1 += incr; gray_set_cell( RAS_VAR_ ex1, ey ); } while ( ex1 != ex2 ); } delta = y2 - y1; ras.area += (TArea)(( fx2 + ONE_PIXEL - first ) * delta); ras.cover += delta; } /*************************************************************************/ /* */ /* Render a given line as a series of scanlines. */ /* */ static void gray_render_line( RAS_ARG_ TPos to_x, TPos to_y ) { TCoord ey1, ey2, fy1, fy2, mod; TPos dx, dy, x, x2; long p, first; int delta, rem, lift, incr; ey1 = TRUNC( ras.y ); ey2 = TRUNC( to_y ); /* if (ey2 >= ras.max_ey) ey2 = ras.max_ey-1; */ /* perform vertical clipping */ if ( ( ey1 >= ras.max_ey && ey2 >= ras.max_ey ) || ( ey1 < ras.min_ey && ey2 < ras.min_ey ) ) goto End; fy1 = (TCoord)( ras.y - SUBPIXELS( ey1 ) ); fy2 = (TCoord)( to_y - SUBPIXELS( ey2 ) ); /* everything is on a single scanline */ if ( ey1 == ey2 ) { gray_render_scanline( RAS_VAR_ ey1, ras.x, fy1, to_x, fy2 ); goto End; } dx = to_x - ras.x; dy = to_y - ras.y; /* vertical line - avoid calling gray_render_scanline */ incr = 1; if ( dx == 0 ) { TCoord ex = TRUNC( ras.x ); TCoord two_fx = (TCoord)( ( ras.x - SUBPIXELS( ex ) ) << 1 ); TArea area; first = ONE_PIXEL; if ( dy < 0 ) { first = 0; incr = -1; } delta = (int)( first - fy1 ); ras.area += (TArea)two_fx * delta; ras.cover += delta; ey1 += incr; gray_set_cell( RAS_VAR_ ex, ey1 ); delta = (int)( first + first - ONE_PIXEL ); area = (TArea)two_fx * delta; while ( ey1 != ey2 ) { ras.area += area; ras.cover += delta; ey1 += incr; gray_set_cell( RAS_VAR_ ex, ey1 ); } delta = (int)( fy2 - ONE_PIXEL + first ); ras.area += (TArea)two_fx * delta; ras.cover += delta; goto End; } /* ok, we have to render several scanlines */ p = ( ONE_PIXEL - fy1 ) * dx; first = ONE_PIXEL; incr = 1; if ( dy < 0 ) { p = fy1 * dx; first = 0; incr = -1; dy = -dy; } FT_DIV_MOD( int, p, dy, delta, mod ); x = ras.x + delta; gray_render_scanline( RAS_VAR_ ey1, ras.x, fy1, x, (TCoord)first ); ey1 += incr; gray_set_cell( RAS_VAR_ TRUNC( x ), ey1 ); if ( ey1 != ey2 ) { p = ONE_PIXEL * dx; FT_DIV_MOD( int, p, dy, lift, rem ); mod -= (int)dy; do { delta = lift; mod += rem; if ( mod >= 0 ) { mod -= (int)dy; delta++; } x2 = x + delta; gray_render_scanline( RAS_VAR_ ey1, x, (TCoord)( ONE_PIXEL - first ), x2, (TCoord)first ); x = x2; ey1 += incr; gray_set_cell( RAS_VAR_ TRUNC( x ), ey1 ); } while ( ey1 != ey2 ); } gray_render_scanline( RAS_VAR_ ey1, x, (TCoord)( ONE_PIXEL - first ), to_x, fy2 ); End: ras.x = to_x; ras.y = to_y; } #else /*************************************************************************/ /* */ /* 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; 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; ex1 = TRUNC( ras.x ); ex2 = TRUNC( to_x ); fx1 = ras.x - SUBPIXELS( ex1 ); fy1 = ras.y - SUBPIXELS( ey1 ); dx = to_x - ras.x; dy = to_y - ras.y; 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; FT_UDIVPREP( dx ); 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)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)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)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)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; } #endif static void gray_split_conic( 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 ) { TPos dx, dy; int top, level; int* levels = ras.lev_stack; FT_Vector* arc = ras.bez_stack; top = 0; dx = FT_ABS( arc[2].x + arc[0].x - 2 * arc[1].x ); dy = FT_ABS( arc[2].y + arc[0].y - 2 * arc[1].y ); if ( dx < dy ) dx = dy; if ( dx < ONE_PIXEL / 4 ) goto Draw; /* we can calculate the number of necessary bisections because */ /* each bisection predictably reduces deviation at least 4-fold */ 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( 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 ) { FT_Vector* arc = ras.bez_stack; TPos dx, dy, dx_, dy_; TPos dx1, dy1, dx2, dy2; TPos L, s, s_limit; 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 */ /* 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 = 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 = 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 = 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; gray_render_line( RAS_VAR_ arc[0].x, arc[0].y ); if ( arc == ras.bez_stack ) return; arc -= 3; continue; Split: gray_split_cubic( arc ); arc += 3; } } static int gray_move_to( const 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 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 FT_Vector* control, const FT_Vector* to, gray_PWorker worker ) { FT_Vector* 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; /* short-cut the arc that crosses the current band */ if ( ( TRUNC( arc[0].y ) >= ras.max_ey && TRUNC( arc[1].y ) >= ras.max_ey && TRUNC( arc[2].y ) >= ras.max_ey ) || ( TRUNC( arc[0].y ) < ras.min_ey && TRUNC( arc[1].y ) < ras.min_ey && TRUNC( arc[2].y ) < ras.min_ey ) ) gray_render_line( RAS_VAR_ arc[0].x, arc[0].y ); else gray_render_conic( RAS_VAR ); return 0; } static int gray_cubic_to( const FT_Vector* control1, const FT_Vector* control2, const FT_Vector* to, gray_PWorker worker ) { FT_Vector* 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 */ if ( ( TRUNC( arc[0].y ) >= ras.max_ey && TRUNC( arc[1].y ) >= ras.max_ey && TRUNC( arc[2].y ) >= ras.max_ey && TRUNC( arc[3].y ) >= ras.max_ey ) || ( TRUNC( arc[0].y ) < ras.min_ey && TRUNC( arc[1].y ) < ras.min_ey && TRUNC( arc[2].y ) < ras.min_ey && TRUNC( arc[3].y ) < ras.min_ey ) ) gray_render_line( RAS_VAR_ arc[0].x, arc[0].y ); else gray_render_cubic( RAS_VAR ); return 0; } static void gray_render_span( int y, int count, const FT_Span* spans, gray_PWorker worker ) { unsigned char* p; FT_Bitmap* map = &worker->target; /* first of all, compute the scanline offset */ p = (unsigned char*)map->buffer - y * map->pitch; if ( map->pitch >= 0 ) p += ( map->rows - 1 ) * (unsigned int)map->pitch; for ( ; count > 0; count--, spans++ ) { unsigned char coverage = spans->coverage; if ( coverage ) { /* For small-spans it is faster to do it by ourselves than * calling `memset'. This is mainly due to the cost of the * function call. */ if ( spans->len >= 8 ) FT_MEM_SET( p + spans->x, (unsigned char)coverage, spans->len ); else { unsigned char* q = p + spans->x; switch ( spans->len ) { case 7: *q++ = (unsigned char)coverage; case 6: *q++ = (unsigned char)coverage; case 5: *q++ = (unsigned char)coverage; case 4: *q++ = (unsigned char)coverage; case 3: *q++ = (unsigned char)coverage; case 2: *q++ = (unsigned char)coverage; case 1: *q = (unsigned char)coverage; default: ; } } } } } 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 & 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; /* FT_Span.x is a 16-bit short, so limit our coordinates appropriately */ if ( x >= 32767 ) x = 32767; /* FT_Span.y is an integer, so limit our coordinates appropriately */ if ( y >= FT_INT_MAX ) y = FT_INT_MAX; if ( coverage ) { 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 ( ras.span_y != y || count >= FT_MAX_GRAY_SPANS ) { if ( ras.render_span && count > 0 ) ras.render_span( ras.span_y, count, ras.gray_spans, ras.render_span_data ); #ifdef FT_DEBUG_LEVEL_TRACE if ( count > 0 ) { int n; FT_TRACE7(( "y = %3d ", ras.span_y )); span = ras.gray_spans; for ( n = 0; n < count; n++, span++ ) FT_TRACE7(( "[%d..%d]:%02x ", span->x, span->x + span->len - 1, span->coverage )); FT_TRACE7(( "\n" )); } #endif /* FT_DEBUG_LEVEL_TRACE */ 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->len = (unsigned short)acount; span->coverage = (unsigned char)coverage; ras.num_gray_spans++; } } #ifdef FT_DEBUG_LEVEL_TRACE /* to be called while in the debugger -- */ /* this function causes a compiler warning since it is unused otherwise */ static void gray_dump_cells( RAS_ARG ) { int yindex; for ( yindex = 0; yindex < ras.ycount; yindex++ ) { PCell cell; printf( "%3d:", yindex ); for ( cell = ras.ycells[yindex]; cell != NULL; cell = cell->next ) printf( " (%3ld, c:%4ld, a:%6ld)", cell->x, cell->cover, cell->area ); printf( "\n" ); } } #endif /* FT_DEBUG_LEVEL_TRACE */ static void gray_sweep( RAS_ARG_ const FT_Bitmap* target ) { int yindex; FT_UNUSED( target ); if ( ras.num_cells == 0 ) return; ras.num_gray_spans = 0; FT_TRACE7(( "gray_sweep: start\n" )); 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.span_y, ras.num_gray_spans, ras.gray_spans, ras.render_span_data ); #ifdef FT_DEBUG_LEVEL_TRACE if ( ras.num_gray_spans > 0 ) { FT_Span* span; int n; FT_TRACE7(( "y = %3d ", ras.span_y )); span = ras.gray_spans; for ( n = 0; n < ras.num_gray_spans; n++, span++ ) FT_TRACE7(( "[%d..%d]:%02x ", span->x, span->x + span->len - 1, span->coverage )); FT_TRACE7(( "\n" )); } FT_TRACE7(( "gray_sweep: end\n" )); #endif /* FT_DEBUG_LEVEL_TRACE */ } #ifdef STANDALONE_ /*************************************************************************/ /* */ /* The following function should only compile in stand-alone mode, */ /* i.e., when building this component without the rest of FreeType. */ /* */ /*************************************************************************/ /*************************************************************************/ /* */ /* <Function> */ /* 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 FT_Outline_Decompose( const FT_Outline* outline, const FT_Outline_Funcs* func_interface, void* user ) { #undef SCALED #define SCALED( x ) ( ( (x) << shift ) - delta ) FT_Vector v_last; FT_Vector v_control; FT_Vector v_start; FT_Vector* point; 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 ) return FT_THROW( Invalid_Outline ); if ( !func_interface ) return 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 */ FT_TRACE5(( "FT_Outline_Decompose: Outline %d\n", n )); 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 = FT_CURVE_TAG( tags[0] ); /* A contour cannot start with a cubic control point! */ if ( tag == FT_CURVE_TAG_CUBIC ) goto Invalid_Outline; /* check first point to determine origin */ if ( tag == FT_CURVE_TAG_CONIC ) { /* first point is conic control. Yes, this happens. */ if ( FT_CURVE_TAG( outline->tags[last] ) == 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; v_last = v_start; } point--; tags--; } FT_TRACE5(( " move to (%.2f, %.2f)\n", v_start.x / 64.0, v_start.y / 64.0 )); error = func_interface->move_to( &v_start, user ); if ( error ) goto Exit; while ( point < limit ) { point++; tags++; tag = FT_CURVE_TAG( tags[0] ); switch ( tag ) { case FT_CURVE_TAG_ON: /* emit a single line_to */ { FT_Vector vec; vec.x = SCALED( point->x ); vec.y = SCALED( point->y ); FT_TRACE5(( " line to (%.2f, %.2f)\n", vec.x / 64.0, vec.y / 64.0 )); error = func_interface->line_to( &vec, user ); if ( error ) goto Exit; continue; } case FT_CURVE_TAG_CONIC: /* consume conic arcs */ v_control.x = SCALED( point->x ); v_control.y = SCALED( point->y ); Do_Conic: if ( point < limit ) { FT_Vector vec; FT_Vector v_middle; point++; tags++; tag = FT_CURVE_TAG( tags[0] ); vec.x = SCALED( point->x ); vec.y = SCALED( point->y ); if ( tag == FT_CURVE_TAG_ON ) { FT_TRACE5(( " conic to (%.2f, %.2f)" " with control (%.2f, %.2f)\n", vec.x / 64.0, vec.y / 64.0, v_control.x / 64.0, v_control.y / 64.0 )); error = func_interface->conic_to( &v_control, &vec, user ); if ( error ) goto Exit; continue; } if ( tag != 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; FT_TRACE5(( " conic to (%.2f, %.2f)" " with control (%.2f, %.2f)\n", v_middle.x / 64.0, v_middle.y / 64.0, v_control.x / 64.0, v_control.y / 64.0 )); error = func_interface->conic_to( &v_control, &v_middle, user ); if ( error ) goto Exit; v_control = vec; goto Do_Conic; } FT_TRACE5(( " conic to (%.2f, %.2f)" " with control (%.2f, %.2f)\n", v_start.x / 64.0, v_start.y / 64.0, v_control.x / 64.0, v_control.y / 64.0 )); error = func_interface->conic_to( &v_control, &v_start, user ); goto Close; default: /* FT_CURVE_TAG_CUBIC */ { FT_Vector vec1, vec2; if ( point + 1 > limit || FT_CURVE_TAG( tags[1] ) != 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 ) { FT_Vector vec; vec.x = SCALED( point->x ); vec.y = SCALED( point->y ); FT_TRACE5(( " cubic to (%.2f, %.2f)" " with controls (%.2f, %.2f) and (%.2f, %.2f)\n", vec.x / 64.0, vec.y / 64.0, vec1.x / 64.0, vec1.y / 64.0, vec2.x / 64.0, vec2.y / 64.0 )); error = func_interface->cubic_to( &vec1, &vec2, &vec, user ); if ( error ) goto Exit; continue; } FT_TRACE5(( " cubic to (%.2f, %.2f)" " with controls (%.2f, %.2f) and (%.2f, %.2f)\n", v_start.x / 64.0, v_start.y / 64.0, vec1.x / 64.0, vec1.y / 64.0, vec2.x / 64.0, vec2.y / 64.0 )); error = func_interface->cubic_to( &vec1, &vec2, &v_start, user ); goto Close; } } } /* close the contour with a line segment */ FT_TRACE5(( " line to (%.2f, %.2f)\n", v_start.x / 64.0, v_start.y / 64.0 )); error = func_interface->line_to( &v_start, user ); Close: if ( error ) goto Exit; first = last + 1; } FT_TRACE5(( "FT_Outline_Decompose: Done\n", n )); return 0; Exit: FT_TRACE5(( "FT_Outline_Decompose: Error %d\n", error )); return error; Invalid_Outline: return FT_THROW( Invalid_Outline ); } #endif /* STANDALONE_ */ typedef struct gray_TBand_ { TPos min, max; } gray_TBand; FT_DEFINE_OUTLINE_FUNCS( func_interface, (FT_Outline_MoveTo_Func) gray_move_to, (FT_Outline_LineTo_Func) gray_line_to, (FT_Outline_ConicTo_Func)gray_conic_to, (FT_Outline_CubicTo_Func)gray_cubic_to, 0, 0 ) static int gray_convert_glyph_inner( RAS_ARG ) { volatile int error = 0; #ifdef FT_CONFIG_OPTION_PIC FT_Outline_Funcs func_interface; Init_Class_func_interface(&func_interface); #endif if ( ft_setjmp( ras.jump_buffer ) == 0 ) { error = FT_Outline_Decompose( &ras.outline, &func_interface, &ras ); if ( !ras.invalid ) gray_record_cell( RAS_VAR ); } else error = 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; 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; do { 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 = (long)sizeof ( PCell ) * ras.ycount; cell_mod = cell_start % (long)sizeof ( TCell ); if ( cell_mod > 0 ) cell_start += (long)sizeof ( TCell ) - cell_mod; cell_end = ras.buffer_size; cell_end -= cell_end % (long)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_ &ras.target ); 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 ) { #ifdef FT_DEBUG_LEVEL_TRACE FT_TRACE7(( "gray_convert_glyph: rotten glyph\n" )); #endif 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++; } while ( band >= bands ); } if ( ras.band_shoot > 8 && ras.band_size > 16 ) ras.band_size = ras.band_size / 2; return 0; } static int gray_raster_render( FT_Raster raster, const FT_Raster_Params* params ) { const FT_Outline* outline = (const FT_Outline*)params->source; const FT_Bitmap* target_map = params->target; gray_TWorker worker[1]; TCell buffer[FT_MAX( FT_RENDER_POOL_SIZE, 2048 ) / sizeof ( TCell )]; long buffer_size = sizeof ( buffer ); int band_size = (int)( buffer_size / (long)( sizeof ( TCell ) * 8 ) ); if ( !raster ) return FT_THROW( Invalid_Argument ); if ( !outline ) return 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 FT_THROW( Invalid_Outline ); if ( outline->n_points != outline->contours[outline->n_contours - 1] + 1 ) return FT_THROW( Invalid_Outline ); /* if direct mode is not set, we must have a target bitmap */ if ( !( params->flags & FT_RASTER_FLAG_DIRECT ) ) { if ( !target_map ) return FT_THROW( Invalid_Argument ); /* nothing to do */ if ( !target_map->width || !target_map->rows ) return 0; if ( !target_map->buffer ) return FT_THROW( Invalid_Argument ); } /* this version does not support monochrome rendering */ if ( !( params->flags & FT_RASTER_FLAG_AA ) ) return FT_THROW( Invalid_Mode ); /* reject too large outline coordinates */ { FT_Vector* vec = outline->points; FT_Vector* limit = vec + outline->n_points; for ( ; vec < limit; vec++ ) { if ( vec->x < -0x1000000L || vec->x > 0x1000000L || vec->y < -0x1000000L || vec->y > 0x1000000L ) return FT_THROW( Invalid_Outline ); } } /* compute clipping box */ if ( !( params->flags & FT_RASTER_FLAG_DIRECT ) ) { /* compute clip box from target pixmap */ ras.clip_box.xMin = 0; ras.clip_box.yMin = 0; ras.clip_box.xMax = (FT_Pos)target_map->width; ras.clip_box.yMax = (FT_Pos)target_map->rows; } else if ( params->flags & 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; if ( params->flags & FT_RASTER_FLAG_DIRECT ) { ras.render_span = (FT_Raster_Span_Func)params->gray_spans; ras.render_span_data = params->user; } else { ras.target = *target_map; ras.render_span = (FT_Raster_Span_Func)gray_render_span; ras.render_span_data = &ras; } return gray_convert_glyph( RAS_VAR ); } /**** RASTER OBJECT CREATION: In stand-alone mode, we simply use *****/ /**** a static object. *****/ #ifdef STANDALONE_ static int gray_raster_new( void* memory, FT_Raster* araster ) { static gray_TRaster the_raster; FT_UNUSED( memory ); *araster = (FT_Raster)&the_raster; FT_MEM_ZERO( &the_raster, sizeof ( the_raster ) ); return 0; } static void gray_raster_done( FT_Raster raster ) { /* nothing */ FT_UNUSED( raster ); } #else /* !STANDALONE_ */ static int gray_raster_new( FT_Memory memory, FT_Raster* araster ) { FT_Error error; gray_PRaster raster = NULL; *araster = 0; if ( !FT_ALLOC( raster, sizeof ( gray_TRaster ) ) ) { raster->memory = memory; *araster = (FT_Raster)raster; } return error; } static void gray_raster_done( FT_Raster raster ) { FT_Memory memory = (FT_Memory)((gray_PRaster)raster)->memory; FT_FREE( raster ); } #endif /* !STANDALONE_ */ static void gray_raster_reset( FT_Raster raster, unsigned char* pool_base, unsigned long pool_size ) { FT_UNUSED( raster ); FT_UNUSED( pool_base ); FT_UNUSED( pool_size ); } static int gray_raster_set_mode( FT_Raster raster, unsigned long mode, void* args ) { FT_UNUSED( raster ); FT_UNUSED( mode ); FT_UNUSED( args ); return 0; /* nothing to do */ } FT_DEFINE_RASTER_FUNCS( ft_grays_raster, FT_GLYPH_FORMAT_OUTLINE, (FT_Raster_New_Func) gray_raster_new, (FT_Raster_Reset_Func) gray_raster_reset, (FT_Raster_Set_Mode_Func)gray_raster_set_mode, (FT_Raster_Render_Func) gray_raster_render, (FT_Raster_Done_Func) gray_raster_done ) /* END */ /* Local Variables: */ /* coding: utf-8 */ /* End: */