| /***************************************************************************/ |
| /* */ |
| /* ftgrays.c */ |
| /* */ |
| /* A new `perfect' anti-aliasing renderer (body). */ |
| /* */ |
| /* Copyright 2000-2015 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/ftimage.h' and `src/smooth/ftgrays.h' to the same */ |
| /* directory */ |
| /* */ |
| /* - compile `ftgrays' with the _STANDALONE_ macro defined, as in */ |
| /* */ |
| /* cc -c -D_STANDALONE_ 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_UINT_MAX UINT_MAX |
| #define FT_INT_MAX INT_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 PIXEL_MASK ( -1L << PIXEL_BITS ) |
| #define TRUNC( x ) ( (TCoord)( (x) >> PIXEL_BITS ) ) |
| #define SUBPIXELS( x ) ( (TPos)(x) << PIXEL_BITS ) |
| #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) << ( PIXEL_BITS - 6 ) ) |
| #define DOWNSCALE( x ) ( (x) >> ( PIXEL_BITS - 6 ) ) |
| #else |
| #define UPSCALE( x ) ( (x) >> ( 6 - PIXEL_BITS ) ) |
| #define DOWNSCALE( x ) ( (x) << ( 6 - 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__ */ |
| |
| |
| /*************************************************************************/ |
| /* */ |
| /* 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 */ |
| |
| /* determine the type used to store cell areas. This normally takes at */ |
| /* least PIXEL_BITS*2 + 1 bits. On 16-bit systems, we need to use */ |
| /* `long' instead of `int', otherwise bad things happen */ |
| |
| #if PIXEL_BITS <= 7 |
| |
| typedef int TArea; |
| |
| #else /* PIXEL_BITS >= 8 */ |
| |
| /* approximately determine the size of integers using an ANSI-C header */ |
| #if FT_UINT_MAX == 0xFFFFU |
| typedef long TArea; |
| #else |
| typedef int TArea; |
| #endif |
| |
| #endif /* PIXEL_BITS >= 8 */ |
| |
| |
| /* 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; |
| |
| TCoord cx, cy; |
| TPos x, y; |
| |
| TPos last_ey; |
| |
| 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.last_ey = SUBPIXELS( ey ); |
| ras.invalid = 0; |
| |
| gray_set_cell( RAS_VAR_ ex, ey ); |
| } |
| |
| |
| /*************************************************************************/ |
| /* */ |
| /* 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; |
| |
| |
| dx = x2 - x1; |
| |
| ex1 = TRUNC( x1 ); |
| ex2 = TRUNC( x2 ); |
| fx1 = (TCoord)( x1 - SUBPIXELS( ex1 ) ); |
| fx2 = (TCoord)( x2 - SUBPIXELS( ex2 ) ); |
| |
| /* trivial case. Happens often */ |
| if ( y1 == y2 ) |
| { |
| gray_set_cell( RAS_VAR_ ex2, ey ); |
| return; |
| } |
| |
| /* 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; |
| |
| 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; |
| |
| while ( ex1 != ex2 ) |
| { |
| 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 ); |
| } |
| } |
| |
| 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.last_ey ); |
| ey2 = TRUNC( to_y ); /* if (ey2 >= ras.max_ey) ey2 = ras.max_ey-1; */ |
| fy1 = (TCoord)( ras.y - ras.last_ey ); |
| fy2 = (TCoord)( to_y - SUBPIXELS( ey2 ) ); |
| |
| dx = to_x - ras.x; |
| dy = to_y - ras.y; |
| |
| /* perform vertical clipping */ |
| { |
| TCoord min, max; |
| |
| |
| min = ey1; |
| max = ey2; |
| if ( ey1 > ey2 ) |
| { |
| min = ey2; |
| max = ey1; |
| } |
| if ( min >= ras.max_ey || max < ras.min_ey ) |
| goto End; |
| } |
| |
| /* everything is on a single scanline */ |
| if ( ey1 == ey2 ) |
| { |
| gray_render_scanline( RAS_VAR_ ey1, ras.x, fy1, to_x, fy2 ); |
| goto End; |
| } |
| |
| /* 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; |
| |
| while ( ey1 != ey2 ) |
| { |
| 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 ); |
| } |
| } |
| |
| gray_render_scanline( RAS_VAR_ ey1, x, |
| (TCoord)( ONE_PIXEL - first ), to_x, |
| fy2 ); |
| |
| End: |
| ras.x = to_x; |
| ras.y = to_y; |
| ras.last_ey = SUBPIXELS( ey2 ); |
| } |
| |
| |
| 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_ const FT_Vector* control, |
| const FT_Vector* to ) |
| { |
| TPos dx, dy; |
| TPos min, max, y; |
| int top, level; |
| int* levels; |
| 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 = 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; |
| |
| /* 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( 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 FT_Vector* control1, |
| const FT_Vector* control2, |
| const FT_Vector* to ) |
| { |
| 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 = 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; |
| |
| /* 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 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 ) |
| { |
| gray_render_conic( RAS_VAR_ control, to ); |
| return 0; |
| } |
| |
| |
| static int |
| gray_cubic_to( const FT_Vector* control1, |
| const FT_Vector* control2, |
| const FT_Vector* to, |
| gray_PWorker worker ) |
| { |
| gray_render_cubic( RAS_VAR_ control1, control2, to ); |
| 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:%6d)", 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; |
| |
| 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 = (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++; |
| } |
| } |
| |
| 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 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 ); |
| |
| /* 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, |
| char* pool_base, |
| 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: */ |
