| /***************************************************************************/ |
| /* */ |
| /* ftgrays.c */ |
| /* */ |
| /* A new `perfect' anti-aliasing renderer (body). */ |
| /* */ |
| /* Copyright 2000 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/base/ftgrays.c' to your current directory */ |
| /* */ |
| /* - copy `include/freetype/ftimage.h' and */ |
| /* `include/freetype/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_grays_raster.grays_raster_new'; an anti-aliased bitmap can be */ |
| /* generated with a call to `ft_grays_raster.grays_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 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. */ |
| /* */ |
| /*************************************************************************/ |
| |
| |
| #include <string.h> /* for memcpy() */ |
| |
| |
| /*************************************************************************/ |
| /* */ |
| /* 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_aaraster |
| |
| |
| #define ErrRaster_Invalid_Outline -1 |
| |
| |
| #ifdef _STANDALONE_ |
| |
| |
| #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 UNUSED( x ) (x) = (x) |
| |
| /* Disable the tracing mechanism for simplicity -- developers can */ |
| /* activate it easily by redefining these two macros. */ |
| #ifndef FT_ERROR |
| #define FT_ERROR( x ) do ; while ( 0 ) /* nothing */ |
| #endif |
| |
| #ifndef FT_TRACE |
| #define FT_TRACE( x ) do ; while ( 0 ) /* nothing */ |
| #endif |
| |
| |
| #else /* _STANDALONE_ */ |
| |
| |
| #include <freetype/ftgrays.h> |
| #include <freetype/internal/ftobjs.h> /* for UNUSED() */ |
| #include <freetype/internal/ftdebug.h> /* for FT_TRACE() and FT_ERROR() */ |
| #include <freetype/freetype.h> /* for FT_Outline_Decompose() */ |
| |
| |
| #endif /* _STANDALONE_ */ |
| |
| |
| /* define this to dump debugging information */ |
| #define xxxDEBUG_GRAYS |
| |
| /* as usual, for the speed hungry :-) */ |
| |
| #ifndef FT_STATIC_RASTER |
| |
| |
| #define RAS_ARG PRaster raster |
| #define RAS_ARG_ PRaster raster, |
| |
| #define RAS_VAR raster |
| #define RAS_VAR_ raster, |
| |
| #define ras (*raster) |
| |
| |
| #else /* FT_STATIC_RASTER */ |
| |
| |
| #define RAS_ARG /* empty */ |
| #define RAS_ARG_ /* empty */ |
| #define RAS_VAR /* empty */ |
| #define RAS_VAR_ /* empty */ |
| |
| static TRaster ras; |
| |
| |
| #endif /* FT_STATIC_RASTER */ |
| |
| |
| /* must be at least 6 bits! */ |
| #define PIXEL_BITS 8 |
| |
| #define ONE_PIXEL ( 1L << PIXEL_BITS ) |
| #define PIXEL_MASK ( -1L << PIXEL_BITS ) |
| #define TRUNC( x ) ( (x) >> PIXEL_BITS ) |
| #define SUBPIXELS( x ) ( (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 |
| |
| /* Define this if you want to use a more compact storage scheme. This */ |
| /* increases the number of cells available in the render pool but slows */ |
| /* down the rendering a bit. It is useful if you have a really tiny */ |
| /* render pool. */ |
| #define xxxGRAYS_COMPACT |
| |
| |
| /*************************************************************************/ |
| /* */ |
| /* TYPE DEFINITIONS */ |
| /* */ |
| typedef int TScan; /* integer scanline/pixel coordinate */ |
| typedef long TPos; /* sub-pixel coordinate */ |
| |
| /* maximal number of gray spans in a call to the span callback */ |
| #define FT_MAX_GRAY_SPANS 32 |
| |
| |
| #ifdef GRAYS_COMPACT |
| |
| typedef struct TCell_ |
| { |
| short x : 14; |
| short y : 14; |
| int cover : PIXEL_BITS + 2; |
| int area : PIXEL_BITS * 2 + 2; |
| |
| } TCell, *PCell; |
| |
| #else /* GRAYS_COMPACT */ |
| |
| typedef struct TCell_ |
| { |
| TScan x; |
| TScan y; |
| int cover; |
| int area; |
| |
| } TCell, *PCell; |
| |
| #endif /* GRAYS_COMPACT */ |
| |
| |
| typedef struct TRaster_ |
| { |
| PCell cells; |
| int max_cells; |
| int num_cells; |
| |
| TScan min_ex, max_ex; |
| TScan min_ey, max_ey; |
| |
| int area; |
| int cover; |
| int invalid; |
| |
| TScan ex, ey; |
| TScan cx, cy; |
| TPos x, y; |
| |
| TScan last_ey; |
| |
| FT_Vector bez_stack[32 * 3]; |
| int lev_stack[32]; |
| |
| FT_Outline outline; |
| FT_Bitmap target; |
| |
| 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; |
| int conic_level; |
| int cubic_level; |
| |
| void* memory; |
| |
| } TRaster, *PRaster; |
| |
| |
| /*************************************************************************/ |
| /* */ |
| /* Initialize the cells table. */ |
| /* */ |
| static |
| void init_cells( RAS_ARG_ void* buffer, |
| long byte_size ) |
| { |
| ras.cells = (PCell)buffer; |
| ras.max_cells = byte_size / sizeof ( TCell ); |
| ras.num_cells = 0; |
| ras.area = 0; |
| ras.cover = 0; |
| ras.invalid = 1; |
| } |
| |
| |
| /*************************************************************************/ |
| /* */ |
| /* Compute the outline bounding box. */ |
| /* */ |
| static |
| void compute_cbox( RAS_ARG_ FT_Outline* 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 |
| int record_cell( RAS_ARG ) |
| { |
| PCell cell; |
| |
| |
| if ( !ras.invalid && ( ras.area | ras.cover ) ) |
| { |
| if ( ras.num_cells >= ras.max_cells ) |
| return 1; |
| |
| cell = ras.cells + ras.num_cells++; |
| cell->x = ras.ex - ras.min_ex; |
| cell->y = ras.ey - ras.min_ey; |
| cell->area = ras.area; |
| cell->cover = ras.cover; |
| } |
| |
| return 0; |
| } |
| |
| |
| /*************************************************************************/ |
| /* */ |
| /* Set the current cell to a new position. */ |
| /* */ |
| static |
| int set_cell( RAS_ARG_ TScan ex, |
| TScan ey ) |
| { |
| int invalid, record, clean; |
| |
| |
| /* 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. */ |
| |
| record = 0; |
| clean = 1; |
| |
| invalid = ( ey < ras.min_ey || ey >= ras.max_ey || ex >= ras.max_ex ); |
| if ( !invalid ) |
| { |
| /* All cells that are on the left of the clipping region go to the */ |
| /* min_ex - 1 horizontal position. */ |
| if ( ex < ras.min_ex ) |
| ex = ras.min_ex - 1; |
| |
| /* if our position is new, then record the previous cell */ |
| if ( ex != ras.ex || ey != ras.ey ) |
| record = 1; |
| else |
| clean = ras.invalid; /* do not clean if we didn't move from */ |
| /* a valid cell */ |
| } |
| |
| /* record the previous cell if needed (i.e., if we changed the cell */ |
| /* position, of changed the `invalid' flag) */ |
| if ( ( ras.invalid != invalid || record ) && record_cell( RAS_VAR ) ) |
| return 1; |
| |
| if ( clean ) |
| { |
| ras.area = 0; |
| ras.cover = 0; |
| } |
| |
| ras.invalid = invalid; |
| ras.ex = ex; |
| ras.ey = ey; |
| return 0; |
| } |
| |
| |
| /*************************************************************************/ |
| /* */ |
| /* Start a new contour at a given cell. */ |
| /* */ |
| static |
| void start_cell( RAS_ARG_ TScan ex, |
| TScan ey ) |
| { |
| if ( ex < ras.min_ex ) |
| ex = ras.min_ex - 1; |
| |
| ras.area = 0; |
| ras.cover = 0; |
| ras.ex = ex; |
| ras.ey = ey; |
| ras.last_ey = SUBPIXELS( ey ); |
| ras.invalid = 0; |
| |
| (void)set_cell( RAS_VAR_ ex, ey ); |
| } |
| |
| |
| /*************************************************************************/ |
| /* */ |
| /* Render a scanline as one or more cells. */ |
| /* */ |
| static |
| int render_scanline( RAS_ARG_ TScan ey, |
| TPos x1, |
| TScan y1, |
| TPos x2, |
| TScan y2 ) |
| { |
| TScan ex1, ex2, fx1, fx2, delta; |
| long p, first, dx; |
| int incr, lift, mod, rem; |
| |
| |
| dx = x2 - x1; |
| |
| ex1 = TRUNC( x1 ); /* if (ex1 >= ras.max_ex) ex1 = ras.max_ex-1; */ |
| ex2 = TRUNC( x2 ); /* if (ex2 >= ras.max_ex) ex2 = ras.max_ex-1; */ |
| fx1 = x1 - SUBPIXELS( ex1 ); |
| fx2 = x2 - SUBPIXELS( ex2 ); |
| |
| /* trivial case. Happens often */ |
| if ( y1 == y2 ) |
| return set_cell( RAS_VAR_ ex2, ey ); |
| |
| /* everything is located in a single cell. That is easy! */ |
| /* */ |
| if ( ex1 == ex2 ) |
| { |
| delta = y2 - y1; |
| ras.area += ( fx1 + fx2 ) * delta; |
| ras.cover += delta; |
| return 0; |
| } |
| |
| /* 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; |
| } |
| |
| delta = p / dx; |
| mod = p % dx; |
| if ( mod < 0 ) |
| { |
| delta--; |
| mod += dx; |
| } |
| |
| ras.area += ( fx1 + first ) * delta; |
| ras.cover += delta; |
| |
| ex1 += incr; |
| if ( set_cell( RAS_VAR_ ex1, ey ) ) |
| goto Error; |
| y1 += delta; |
| |
| if ( ex1 != ex2 ) |
| { |
| p = ONE_PIXEL * ( y2 - y1 ); |
| lift = p / dx; |
| rem = p % dx; |
| if ( rem < 0 ) |
| { |
| lift--; |
| rem += dx; |
| } |
| |
| mod -= dx; |
| |
| while ( ex1 != ex2 ) |
| { |
| delta = lift; |
| mod += rem; |
| if ( mod >= 0 ) |
| { |
| mod -= dx; |
| delta++; |
| } |
| |
| ras.area += ONE_PIXEL * delta; |
| ras.cover += delta; |
| y1 += delta; |
| ex1 += incr; |
| if ( set_cell( RAS_VAR_ ex1, ey ) ) |
| goto Error; |
| } |
| } |
| |
| delta = y2 - y1; |
| ras.area += ( fx2 + ONE_PIXEL - first ) * delta; |
| ras.cover += delta; |
| |
| return 0; |
| |
| Error: |
| return 1; |
| } |
| |
| |
| /*************************************************************************/ |
| /* */ |
| /* Render a given line as a series of scanlines. */ |
| /* */ |
| static |
| int render_line( RAS_ARG_ TPos to_x, |
| TPos to_y ) |
| { |
| TScan ey1, ey2, fy1, fy2; |
| TPos dx, dy, x, x2; |
| int p, rem, mod, lift, delta, first, incr; |
| |
| |
| ey1 = TRUNC( ras.last_ey ); |
| ey2 = TRUNC( to_y ); /* if (ey2 >= ras.max_ey) ey2 = ras.max_ey-1; */ |
| fy1 = ras.y - ras.last_ey; |
| fy2 = to_y - SUBPIXELS( ey2 ); |
| |
| dx = to_x - ras.x; |
| dy = to_y - ras.y; |
| |
| /* we should do something about the trivial case where dx == 0, */ |
| /* as it happens very often! XXXXX */ |
| |
| /* perform vertical clipping */ |
| { |
| TScan 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 ) |
| { |
| if ( render_scanline( RAS_VAR_ ey1, ras.x, fy1, to_x, fy2 ) ) |
| goto Error; |
| goto End; |
| } |
| |
| /* ok, we'll 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; |
| } |
| |
| delta = p / dy; |
| mod = p % dy; |
| if ( mod < 0 ) |
| { |
| delta--; |
| mod += dy; |
| } |
| |
| x = ras.x + delta; |
| if ( render_scanline( RAS_VAR_ ey1, ras.x, fy1, x, first ) ) |
| goto Error; |
| |
| ey1 += incr; |
| if ( set_cell( RAS_VAR_ TRUNC( x ), ey1 ) ) |
| goto Error; |
| |
| if ( ey1 != ey2 ) |
| { |
| p = ONE_PIXEL * dx; |
| lift = p / dy; |
| rem = p % dy; |
| if ( rem < 0 ) |
| { |
| lift--; |
| rem += dy; |
| } |
| mod -= dy; |
| |
| while ( ey1 != ey2 ) |
| { |
| delta = lift; |
| mod += rem; |
| if ( mod >= 0 ) |
| { |
| mod -= dy; |
| delta++; |
| } |
| |
| x2 = x + delta; |
| if ( render_scanline( RAS_VAR_ ey1, |
| x, ONE_PIXEL - first, x2, first ) ) |
| goto Error; |
| x = x2; |
| ey1 += incr; |
| if ( set_cell( RAS_VAR_ TRUNC( x ), ey1 ) ) |
| goto Error; |
| } |
| } |
| |
| if ( render_scanline( RAS_VAR_ ey1, |
| x, ONE_PIXEL - first, to_x, fy2 ) ) |
| goto Error; |
| |
| End: |
| ras.x = to_x; |
| ras.y = to_y; |
| ras.last_ey = SUBPIXELS( ey2 ); |
| |
| return 0; |
| |
| Error: |
| return 1; |
| } |
| |
| |
| static |
| void 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 |
| int render_conic( RAS_ARG_ FT_Vector* control, |
| FT_Vector* to ) |
| { |
| TPos dx, dy; |
| int top, level; |
| int* levels; |
| FT_Vector* arc; |
| |
| |
| dx = DOWNSCALE( ras.x ) + to->x - ( control->x << 1 ); |
| if ( dx < 0 ) |
| dx = -dx; |
| dy = DOWNSCALE( ras.y ) + to->y - ( control->y << 1 ); |
| if ( dy < 0 ) |
| dy = -dy; |
| if ( dx < dy ) |
| dx = dy; |
| |
| level = 1; |
| dx = dx / ras.conic_level; |
| while ( dx > 0 ) |
| { |
| dx >>= 1; |
| level++; |
| } |
| |
| /* a shortcut to speed things up */ |
| if ( level <= 1 ) |
| { |
| /* we compute the mid-point directly in order to avoid */ |
| /* calling split_conic() */ |
| TPos to_x, to_y, mid_x, mid_y; |
| |
| |
| to_x = UPSCALE( to->x ); |
| to_y = UPSCALE( to->y ); |
| mid_x = ( ras.x + to_x + 2 * UPSCALE( control->x ) ) / 4; |
| mid_y = ( ras.y + to_y + 2 * UPSCALE( control->y ) ) / 4; |
| |
| return render_line( RAS_VAR_ mid_x, mid_y ) || |
| render_line( RAS_VAR_ to_x, to_y ); |
| } |
| |
| arc = ras.bez_stack; |
| levels = ras.lev_stack; |
| top = 0; |
| levels[0] = level; |
| |
| 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; |
| |
| while ( top >= 0 ) |
| { |
| level = levels[top]; |
| if ( level > 1 ) |
| { |
| /* check that the arc crosses the current band */ |
| TPos min, max, y; |
| |
| |
| 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 ) < 0 ) |
| goto Draw; |
| |
| split_conic( arc ); |
| arc += 2; |
| top++; |
| levels[top] = levels[top - 1] = level - 1; |
| continue; |
| } |
| |
| Draw: |
| { |
| TPos to_x, to_y, mid_x, mid_y; |
| |
| |
| to_x = arc[0].x; |
| to_y = arc[0].y; |
| mid_x = ( ras.x + to_x + 2 * arc[1].x ) / 4; |
| mid_y = ( ras.y + to_y + 2 * arc[1].y ) / 4; |
| |
| if ( render_line( RAS_VAR_ mid_x, mid_y ) || |
| render_line( RAS_VAR_ to_x, to_y ) ) |
| return 1; |
| |
| top--; |
| arc -= 2; |
| } |
| } |
| return 0; |
| } |
| |
| |
| static |
| void 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 |
| int render_cubic( RAS_ARG_ FT_Vector* control1, |
| FT_Vector* control2, |
| FT_Vector* to ) |
| { |
| TPos dx, dy, da, db; |
| int top, level; |
| int* levels; |
| FT_Vector* arc; |
| |
| |
| dx = DOWNSCALE( ras.x ) + to->x - ( control1->x << 1 ); |
| if ( dx < 0 ) |
| dx = -dx; |
| dy = DOWNSCALE( ras.y ) + to->y - ( control1->y << 1 ); |
| if ( dy < 0 ) |
| dy = -dy; |
| if ( dx < dy ) |
| dx = dy; |
| da = dx; |
| |
| dx = DOWNSCALE( ras.x ) + to->x - 3 * ( control1->x + control2->x ); |
| if ( dx < 0 ) |
| dx = -dx; |
| dy = DOWNSCALE( ras.y ) + to->y - 3 * ( control1->x + control2->y ); |
| if ( dy < 0 ) |
| dy = -dy; |
| if ( dx < dy ) |
| dx = dy; |
| db = dx; |
| |
| level = 1; |
| da = da / ras.cubic_level; |
| db = db / ras.conic_level; |
| while ( da > 0 || db > 0 ) |
| { |
| da >>= 1; |
| db >>= 2; |
| level++; |
| } |
| |
| if ( level <= 1 ) |
| { |
| TPos to_x, to_y, mid_x, mid_y; |
| |
| |
| to_x = UPSCALE( to->x ); |
| to_y = UPSCALE( to->y ); |
| mid_x = ( ras.x + to_x + |
| 3 * UPSCALE( control1->x + control2->x ) ) / 8; |
| mid_y = ( ras.y + to_y + |
| 3 * UPSCALE( control1->y + control2->y ) ) / 8; |
| |
| return render_line( RAS_VAR_ mid_x, mid_y ) || |
| render_line( RAS_VAR_ to_x, to_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; |
| |
| levels = ras.lev_stack; |
| top = 0; |
| levels[0] = level; |
| |
| while ( top >= 0 ) |
| { |
| level = levels[top]; |
| if ( level > 1 ) |
| { |
| /* check that the arc crosses the current band */ |
| TPos min, max, y; |
| |
| |
| 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 ) < 0 ) |
| goto Draw; |
| split_cubic( arc ); |
| arc += 3; |
| top ++; |
| levels[top] = levels[top - 1] = level - 1; |
| continue; |
| } |
| |
| Draw: |
| { |
| TPos to_x, to_y, mid_x, mid_y; |
| |
| |
| to_x = arc[0].x; |
| to_y = arc[0].y; |
| mid_x = ( ras.x + to_x + 3 * ( arc[1].x + arc[2].x ) ) / 8; |
| mid_y = ( ras.y + to_y + 3 * ( arc[1].y + arc[2].y ) ) / 8; |
| |
| if ( render_line( RAS_VAR_ mid_x, mid_y ) || |
| render_line( RAS_VAR_ to_x, to_y ) ) |
| return 1; |
| top --; |
| arc -= 3; |
| } |
| } |
| return 0; |
| } |
| |
| |
| /* a macro comparing two cell pointers. Returns true if a <= b. */ |
| #if 1 |
| #define PACK( a ) ( ( (long)(a)->y << 16 ) | (a)->x ) |
| #define LESS_THAN( a, b ) ( PACK(a) < PACK(b) ) |
| #else /* 1 */ |
| #define LESS_THAN( a, b ) ( (a)->y < (b)->y || \ |
| ( (a)->y == (b)->y && (a)->x < (b)->x ) ) |
| #endif /* 1 */ |
| |
| #define SWAP_CELLS( a, b, temp ) do \ |
| { \ |
| temp = *(a); \ |
| *(a) = *(b); \ |
| *(b) = temp; \ |
| } while ( 0 ) |
| #define DEBUG_SORT |
| #define QUICK_SORT |
| |
| #ifdef SHELL_SORT |
| |
| /* A simple shell sort algorithm that works directly on our */ |
| /* cells table.. */ |
| static |
| void shell_sort ( PCell cells, |
| int count ) |
| { |
| PCell i, j, limit = cells + count; |
| TCell temp; |
| int gap; |
| |
| |
| /* compute initial gap */ |
| for ( gap = 0; ++gap < count; gap *= 3 ) |
| ; |
| |
| while ( gap /= 3 ) |
| { |
| for ( i = cells + gap; i < limit; i++ ) |
| { |
| for ( j = i - gap; ; j -= gap ) |
| { |
| PCell k = j + gap; |
| |
| |
| if ( LESS_THAN( j, k ) ) |
| break; |
| |
| SWAP_CELLS( j, k, temp ); |
| |
| if ( j < cells + gap ) |
| break; |
| } |
| } |
| } |
| } |
| |
| #endif /* SHELL_SORT */ |
| |
| |
| #ifdef QUICK_SORT |
| |
| /* This is a non-recursive quicksort that directly process our cells */ |
| /* array. It should be faster than calling the stdlib qsort(), and we */ |
| /* can even tailor our insertion threshold... */ |
| |
| #define QSORT_THRESHOLD 9 /* below this size, a sub-array will be sorted */ |
| /* through a normal insertion sort.. */ |
| |
| static |
| void quick_sort( PCell cells, |
| int count ) |
| { |
| PCell stack[40]; /* should be enough ;-) */ |
| PCell* top; /* top of stack */ |
| PCell base, limit; |
| TCell temp; |
| |
| |
| limit = cells + count; |
| base = cells; |
| top = stack; |
| |
| for (;;) |
| { |
| int len = limit - base; |
| PCell i, j, pivot; |
| |
| |
| if ( len > QSORT_THRESHOLD ) |
| { |
| /* we use base + len/2 as the pivot */ |
| pivot = base + len / 2; |
| SWAP_CELLS( base, pivot, temp ); |
| |
| i = base + 1; |
| j = limit - 1; |
| |
| /* now ensure that *i <= *base <= *j */ |
| if ( LESS_THAN( j, i ) ) |
| SWAP_CELLS( i, j, temp ); |
| |
| if ( LESS_THAN( base, i ) ) |
| SWAP_CELLS( base, i, temp ); |
| |
| if ( LESS_THAN( j, base ) ) |
| SWAP_CELLS( base, j, temp ); |
| |
| for (;;) |
| { |
| do i++; while ( LESS_THAN( i, base ) ); |
| do j--; while ( LESS_THAN( base, j ) ); |
| |
| if ( i > j ) |
| break; |
| |
| SWAP_CELLS( i, j, temp ); |
| } |
| |
| SWAP_CELLS( base, j, temp ); |
| |
| /* now, push the largest sub-array */ |
| if ( j - base > limit - i ) |
| { |
| top[0] = base; |
| top[1] = j; |
| base = i; |
| } |
| else |
| { |
| top[0] = i; |
| top[1] = limit; |
| limit = j; |
| } |
| top += 2; |
| } |
| else |
| { |
| /* the sub-array is small, perform insertion sort */ |
| j = base; |
| i = j + 1; |
| |
| for ( ; i < limit; j = i, i++ ) |
| { |
| for ( ; LESS_THAN( j + 1, j ); j-- ) |
| { |
| SWAP_CELLS( j + 1, j, temp ); |
| if ( j == base ) |
| break; |
| } |
| } |
| if ( top > stack ) |
| { |
| top -= 2; |
| base = top[0]; |
| limit = top[1]; |
| } |
| else |
| break; |
| } |
| } |
| } |
| |
| #endif /* QUICK_SORT */ |
| |
| |
| #ifdef DEBUG_GRAYS |
| #ifdef DEBUG_SORT |
| |
| static |
| int check_sort( PCell cells, |
| int count ) |
| { |
| PCell p, q; |
| |
| |
| for ( p = cells + count - 2; p >= cells; p-- ) |
| { |
| q = p + 1; |
| if ( !LESS_THAN( p, q ) ) |
| return 0; |
| } |
| return 1; |
| } |
| |
| #endif /* DEBUG_SORT */ |
| #endif /* DEBUG_GRAYS */ |
| |
| |
| static |
| int Move_To( FT_Vector* to, |
| FT_Raster raster ) |
| { |
| TPos x, y; |
| |
| |
| /* record current cell, if any */ |
| record_cell( (PRaster)raster ); |
| |
| /* start to a new position */ |
| x = UPSCALE( to->x ); |
| y = UPSCALE( to->y ); |
| start_cell( (PRaster)raster, TRUNC( x ), TRUNC( y ) ); |
| ((PRaster)raster)->x = x; |
| ((PRaster)raster)->y = y; |
| return 0; |
| } |
| |
| |
| static |
| int Line_To( FT_Vector* to, |
| FT_Raster raster ) |
| { |
| return render_line( (PRaster)raster, |
| UPSCALE( to->x ), UPSCALE( to->y ) ); |
| } |
| |
| |
| static |
| int Conic_To( FT_Vector* control, |
| FT_Vector* to, |
| FT_Raster raster ) |
| { |
| return render_conic( (PRaster)raster, control, to ); |
| } |
| |
| |
| static |
| int Cubic_To( FT_Vector* control1, |
| FT_Vector* control2, |
| FT_Vector* to, |
| FT_Raster raster ) |
| { |
| return render_cubic( (PRaster)raster, control1, control2, to ); |
| } |
| |
| |
| static |
| void grays_render_span( int y, |
| int count, |
| FT_Span* spans, |
| PRaster raster ) |
| { |
| unsigned char* p; |
| FT_Bitmap* map = &raster->target; |
| |
| |
| /* first of all, compute the scanline offset */ |
| p = (unsigned char*)map->buffer - y * map->pitch; |
| if ( map->pitch >= 0 ) |
| p += ( map->rows - 1 ) * map->pitch; |
| |
| for ( ; count > 0; count--, spans++ ) |
| { |
| if ( spans->coverage ) |
| #if 1 |
| memset( p + spans->x, (unsigned char)spans->coverage, spans->len ); |
| #else /* 1 */ |
| { |
| q = p + spans->x; |
| limit = q + spans->len; |
| for ( ; q < limit; q++ ) |
| q[0] = (unsigned char)spans->coverage; |
| } |
| #endif /* 1 */ |
| } |
| } |
| |
| |
| #ifdef DEBUG_GRAYS |
| |
| #include <stdio.h> |
| |
| static |
| void dump_cells( RAS_ARG ) |
| { |
| PCell cell, limit; |
| int y = -1; |
| |
| |
| cell = ras.cells; |
| limit = cell + ras.num_cells; |
| |
| for ( ; cell < limit; cell++ ) |
| { |
| if ( cell->y != y ) |
| { |
| fprintf( stderr, "\n%2d: ", cell->y ); |
| y = cell->y; |
| } |
| fprintf( stderr, "[%d %d %d]", |
| cell->x, cell->area, cell->cover ); |
| } |
| fprintf(stderr, "\n" ); |
| } |
| |
| #endif /* DEBUG_GRAYS */ |
| |
| |
| static |
| void grays_hline( RAS_ARG_ TScan x, |
| TScan y, |
| TPos area, |
| int acount ) |
| { |
| FT_Span* span; |
| int count; |
| 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 = area >> ( PIXEL_BITS * 2 + 1 - 8); /* use range 0..256 */ |
| |
| if ( ras.outline.flags & ft_outline_even_odd_fill ) |
| { |
| if ( coverage < 0 ) |
| coverage = -coverage; |
| |
| while ( coverage >= 512 ) |
| coverage -= 512; |
| |
| if ( coverage > 256 ) |
| coverage = 512 - coverage; |
| else if ( coverage == 256 ) |
| coverage = 255; |
| } |
| else |
| { |
| /* normal non-zero winding rule */ |
| if ( coverage < 0 ) |
| coverage = -coverage; |
| |
| if ( coverage >= 256 ) |
| coverage = 255; |
| } |
| |
| y += ras.min_ey; |
| x += ras.min_ex; |
| |
| if ( coverage ) |
| { |
| /* see if 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 += acount; |
| return; |
| } |
| |
| if ( ras.span_y != y || count >= FT_MAX_GRAY_SPANS ) |
| { |
| if ( ras.render_span ) |
| ras.render_span( ras.span_y, count, ras.gray_spans, |
| ras.render_span_data ); |
| /* ras.render_span( span->y, ras.gray_spans, count ); */ |
| |
| #ifdef DEBUG_GRAYS |
| |
| if ( ras.span_y >= 0 ) |
| { |
| int n; |
| |
| |
| fprintf( stderr, "y=%3d ", ras.span_y ); |
| span = ras.gray_spans; |
| for ( n = 0; n < count; n++, span++ ) |
| fprintf( stderr, "[%d..%d]:%02x ", |
| span->x, span->x + span->len - 1, span->coverage ); |
| fprintf( stderr, "\n" ); |
| } |
| |
| #endif /* DEBUG_GRAYS */ |
| |
| ras.num_gray_spans = 0; |
| ras.span_y = y; |
| |
| count = 0; |
| 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++; |
| } |
| } |
| |
| |
| static |
| void grays_sweep( RAS_ARG_ FT_Bitmap* target ) |
| { |
| TScan x, y, cover, area; |
| PCell start, cur, limit; |
| |
| UNUSED( target ); |
| |
| |
| cur = ras.cells; |
| limit = cur + ras.num_cells; |
| |
| cover = 0; |
| ras.span_y = -1; |
| ras.num_gray_spans = 0; |
| |
| for (;;) |
| { |
| start = cur; |
| y = start->y; |
| x = start->x; |
| |
| area = start->area; |
| cover += start->cover; |
| |
| /* accumulate all start cells */ |
| for (;;) |
| { |
| ++cur; |
| if ( cur >= limit || cur->y != start->y || cur->x != start->x ) |
| break; |
| |
| area += cur->area; |
| cover += cur->cover; |
| } |
| |
| /* if the start cell has a non-null area, we must draw an */ |
| /* individual gray pixel there */ |
| if ( area && x >= 0 ) |
| { |
| grays_hline( RAS_VAR_ x, y, cover * ( ONE_PIXEL * 2 ) - area, 1 ); |
| x++; |
| } |
| |
| if ( x < 0 ) |
| x = 0; |
| |
| if ( cur < limit && start->y == cur->y ) |
| { |
| /* draw a gray span between the start cell and the current one */ |
| if ( cur->x > x ) |
| grays_hline( RAS_VAR_ x, y, |
| cover * ( ONE_PIXEL * 2 ), cur->x - x ); |
| } |
| else |
| { |
| /* draw a gray span until the end of the clipping region */ |
| if ( cover && x < ras.max_ex - ras.min_ex ) |
| grays_hline( RAS_VAR_ x, y, |
| cover * ( ONE_PIXEL * 2 ), |
| ras.max_ex - x - ras.min_ex ); |
| cover = 0; |
| } |
| |
| if ( cur >= limit ) |
| break; |
| } |
| |
| 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 DEBUG_GRAYS |
| |
| { |
| int n; |
| FT_Span* span; |
| |
| |
| fprintf( stderr, "y=%3d ", ras.span_y ); |
| span = ras.gray_spans; |
| for ( n = 0; n < ras.num_gray_spans; n++, span++ ) |
| fprintf( stderr, "[%d..%d]:%02x ", |
| span->x, span->x + span->len - 1, span->coverage ); |
| fprintf( stderr, "\n" ); |
| } |
| |
| #endif /* DEBUG_GRAYS */ |
| |
| } |
| |
| |
| #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> */ |
| /* Walks over an outline's structure to decompose it into individual */ |
| /* segments and Bezier 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. */ |
| /* */ |
| /* interface :: A table of `emitters', i.e,. function pointers called */ |
| /* during decomposition to indicate path operations. */ |
| /* */ |
| /* 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 sucess. */ |
| /* */ |
| static |
| int FT_Outline_Decompose( FT_Outline* outline, |
| FT_Outline_Funcs* 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 n; /* index of contour in outline */ |
| int first; /* index of first point in contour */ |
| int error; |
| char tag; /* current point's state */ |
| |
| int shift = interface->shift; |
| FT_Pos delta = interface->delta; |
| |
| |
| first = 0; |
| |
| for ( n = 0; n < outline->n_contours; n++ ) |
| { |
| int last; /* index of last point in contour */ |
| |
| |
| last = outline->contours[n]; |
| limit = outline->points + last; |
| |
| v_start = outline->points[first]; |
| v_last = outline->points[last]; |
| |
| v_start.x = SCALED( v_start.x ); v_start.y = SCALED( v_start.y ); |
| 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--; |
| } |
| |
| error = 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 ); |
| |
| error = 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 ) |
| { |
| error = 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; |
| |
| error = interface->conic_to( &v_control, &v_middle, user ); |
| if ( error ) |
| goto Exit; |
| |
| v_control = vec; |
| goto Do_Conic; |
| } |
| |
| error = 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 ); |
| |
| error = interface->cubic_to( &vec1, &vec2, &vec, user ); |
| if ( error ) |
| goto Exit; |
| continue; |
| } |
| |
| error = interface->cubic_to( &vec1, &vec2, &v_start, user ); |
| goto Close; |
| } |
| } |
| } |
| |
| /* close the contour with a line segment */ |
| error = interface->line_to( &v_start, user ); |
| |
| Close: |
| if ( error ) |
| goto Exit; |
| |
| first = last + 1; |
| } |
| |
| return 0; |
| |
| Exit: |
| return error; |
| |
| Invalid_Outline: |
| return ErrRaster_Invalid_Outline; |
| } |
| |
| #endif /* _STANDALONE_ */ |
| |
| |
| typedef struct TBand_ |
| { |
| FT_Pos min, max; |
| |
| } TBand; |
| |
| |
| static |
| int grays_convert_glyph( RAS_ARG_ FT_Outline* outline ) |
| { |
| static |
| FT_Outline_Funcs interface = |
| { |
| (FT_Outline_MoveTo_Func)Move_To, |
| (FT_Outline_LineTo_Func)Line_To, |
| (FT_Outline_ConicTo_Func)Conic_To, |
| (FT_Outline_CubicTo_Func)Cubic_To, |
| 0, |
| 0 |
| }; |
| |
| TBand bands[40], *band; |
| int n, num_bands; |
| TPos min, max, max_y; |
| |
| |
| /* Set up state in the raster object */ |
| compute_cbox( RAS_VAR_ outline ); |
| |
| /* clip to target bitmap, exit if nothing to do */ |
| if ( ras.max_ex <= 0 || ras.min_ex >= ras.target.width || |
| ras.max_ey <= 0 || ras.min_ey >= ras.target.rows ) |
| return 0; |
| |
| if ( ras.min_ex < 0 ) ras.min_ex = 0; |
| if ( ras.min_ey < 0 ) ras.min_ey = 0; |
| |
| if ( ras.max_ex > ras.target.width ) ras.max_ex = ras.target.width; |
| if ( ras.max_ey > ras.target.rows ) ras.max_ey = ras.target.rows; |
| |
| /* simple heuristic used to speed-up the bezier decomposition */ |
| /* see the code in render_conic and render_cubic for more details */ |
| ras.conic_level = 32; |
| ras.cubic_level = 16; |
| |
| { |
| int level = 0; |
| |
| |
| if ( ras.max_ex > 24 || ras.max_ey > 24 ) |
| level++; |
| if ( ras.max_ex > 120 || ras.max_ey > 120 ) |
| level += 2; |
| |
| ras.conic_level <<= level; |
| ras.cubic_level <<= level; |
| } |
| |
| /* setup vertical bands */ |
| num_bands = ( 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 ) |
| { |
| FT_Pos bottom, top, middle; |
| int error; |
| |
| |
| ras.num_cells = 0; |
| ras.invalid = 1; |
| ras.min_ey = band->min; |
| ras.max_ey = band->max; |
| |
| error = FT_Outline_Decompose( outline, &interface, &ras ) || |
| record_cell( RAS_VAR ); |
| |
| if ( !error ) |
| { |
| #ifdef SHELL_SORT |
| shell_sort( ras.cells, ras.num_cells ); |
| #else |
| quick_sort( ras.cells, ras.num_cells ); |
| #endif |
| |
| #ifdef DEBUG_GRAYS |
| check_sort( ras.cells, ras.num_cells ); |
| dump_cells( RAS_VAR ); |
| #endif |
| |
| grays_sweep( RAS_VAR_ &ras.target ); |
| band--; |
| continue; |
| } |
| |
| /* render pool overflow, we will reduce the render band by half */ |
| bottom = band->min; |
| top = band->max; |
| middle = bottom + ( ( top - bottom ) >> 1 ); |
| |
| /* waoow! This is too complex for a single scanline, something */ |
| /* must be really rotten here! */ |
| if ( middle == bottom ) |
| { |
| #ifdef DEBUG_GRAYS |
| fprintf( stderr, "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; |
| } |
| |
| |
| extern |
| int grays_raster_render( PRaster raster, |
| FT_Raster_Params* params ) |
| { |
| FT_Outline* outline = (FT_Outline*)params->source; |
| FT_Bitmap* target_map = params->target; |
| |
| |
| if ( !raster || !raster->cells || !raster->max_cells ) |
| return -1; |
| |
| /* return immediately if the outline is empty */ |
| if ( outline->n_points == 0 || outline->n_contours <= 0 ) |
| return 0; |
| |
| if ( !outline || !outline->contours || !outline->points ) |
| return ErrRaster_Invalid_Outline; |
| |
| if ( outline->n_points != |
| outline->contours[outline->n_contours - 1] + 1 ) |
| return ErrRaster_Invalid_Outline; |
| |
| if ( !target_map || !target_map->buffer ) |
| return -1; |
| |
| /* XXXX: this version does not support monochrome rendering yet! */ |
| if ( !(params->flags & ft_raster_flag_aa) ) |
| return -1; |
| |
| ras.outline = *outline; |
| ras.target = *target_map; |
| ras.num_cells = 0; |
| ras.invalid = 1; |
| |
| ras.render_span = (FT_Raster_Span_Func)grays_render_span; |
| ras.render_span_data = &ras; |
| |
| if ( params->flags & ft_raster_flag_direct ) |
| { |
| ras.render_span = (FT_Raster_Span_Func)params->gray_spans; |
| ras.render_span_data = params->user; |
| } |
| |
| return grays_convert_glyph( (PRaster)raster, outline ); |
| } |
| |
| |
| /**** RASTER OBJECT CREATION: In standalone mode, we simply use *****/ |
| /**** a static object. *****/ |
| |
| #ifdef _STANDALONE_ |
| |
| static |
| int grays_raster_new( void* memory, |
| FT_Raster* araster ) |
| { |
| static TRaster the_raster; |
| |
| UNUSED( memory ); |
| |
| |
| *araster = (FT_Raster)&the_raster; |
| memset( &the_raster, 0, sizeof ( the_raster ) ); |
| |
| return 0; |
| } |
| |
| |
| static |
| void grays_raster_done( FT_Raster raster ) |
| { |
| /* nothing */ |
| UNUSED( raster ); |
| } |
| |
| #else /* _STANDALONE_ */ |
| |
| static |
| int grays_raster_new( FT_Memory memory, |
| FT_Raster* araster ) |
| { |
| FT_Error error; |
| PRaster raster; |
| |
| |
| *araster = 0; |
| if ( !ALLOC( raster, sizeof ( TRaster ) ) ) |
| { |
| raster->memory = memory; |
| *araster = (FT_Raster)raster; |
| } |
| |
| return error; |
| } |
| |
| |
| static |
| void grays_raster_done( FT_Raster raster ) |
| { |
| FT_Memory memory = (FT_Memory)((PRaster)raster)->memory; |
| |
| |
| FREE( raster ); |
| } |
| |
| #endif /* _STANDALONE_ */ |
| |
| |
| static |
| void grays_raster_reset( FT_Raster raster, |
| const char* pool_base, |
| long pool_size ) |
| { |
| PRaster rast = (PRaster)raster; |
| |
| |
| if ( raster && pool_base && pool_size >= 4096 ) |
| init_cells( rast, (char*)pool_base, pool_size ); |
| |
| rast->band_size = ( pool_size / sizeof ( TCell ) ) / 8; |
| } |
| |
| |
| FT_Raster_Funcs ft_grays_raster = |
| { |
| ft_glyph_format_outline, |
| |
| (FT_Raster_New_Func) grays_raster_new, |
| (FT_Raster_Reset_Func) grays_raster_reset, |
| (FT_Raster_Set_Mode_Func)0, |
| (FT_Raster_Render_Func) grays_raster_render, |
| (FT_Raster_Done_Func) grays_raster_done |
| }; |
| |
| |
| /* END */ |