/***************************************************************************/ | |
/* */ | |
/* 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/freetype/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_CHAR_BIT CHAR_BIT | |
#define FT_UINT_MAX UINT_MAX | |
#define FT_INT_MAX INT_MAX | |
#define FT_ULONG_MAX ULONG_MAX | |
#define ft_memset memset | |
#define ft_setjmp setjmp | |
#define ft_longjmp longjmp | |
#define ft_jmp_buf jmp_buf | |
typedef ptrdiff_t FT_PtrDist; | |
#define ErrRaster_Invalid_Mode -2 | |
#define ErrRaster_Invalid_Outline -1 | |
#define ErrRaster_Invalid_Argument -3 | |
#define ErrRaster_Memory_Overflow -4 | |
#define FT_BEGIN_HEADER | |
#define FT_END_HEADER | |
#include "ftimage.h" | |
#include "ftgrays.h" | |
/* This macro is used to indicate that a function parameter is unused. */ | |
/* Its purpose is simply to reduce compiler warnings. Note also that */ | |
/* simply defining it as `(void)x' doesn't avoid warnings with certain */ | |
/* ANSI compilers (e.g. LCC). */ | |
#define FT_UNUSED( x ) (x) = (x) | |
/* we only use level 5 & 7 tracing messages; cf. ftdebug.h */ | |
#ifdef FT_DEBUG_LEVEL_TRACE | |
void | |
FT_Message( const char* fmt, | |
... ) | |
{ | |
va_list ap; | |
va_start( ap, fmt ); | |
vfprintf( stderr, fmt, ap ); | |
va_end( ap ); | |
} | |
/* empty function useful for setting a breakpoint to catch errors */ | |
int | |
FT_Throw( int error, | |
int line, | |
const char* file ) | |
{ | |
FT_UNUSED( error ); | |
FT_UNUSED( line ); | |
FT_UNUSED( file ); | |
return 0; | |
} | |
/* we don't handle tracing levels in stand-alone mode; */ | |
#ifndef FT_TRACE5 | |
#define FT_TRACE5( varformat ) FT_Message varformat | |
#endif | |
#ifndef FT_TRACE7 | |
#define FT_TRACE7( varformat ) FT_Message varformat | |
#endif | |
#ifndef FT_ERROR | |
#define FT_ERROR( varformat ) FT_Message varformat | |
#endif | |
#define FT_THROW( e ) \ | |
( FT_Throw( FT_ERR_CAT( ErrRaster, e ), \ | |
__LINE__, \ | |
__FILE__ ) | \ | |
FT_ERR_CAT( ErrRaster, e ) ) | |
#else /* !FT_DEBUG_LEVEL_TRACE */ | |
#define FT_TRACE5( x ) do { } while ( 0 ) /* nothing */ | |
#define FT_TRACE7( x ) do { } while ( 0 ) /* nothing */ | |
#define FT_ERROR( x ) do { } while ( 0 ) /* nothing */ | |
#define FT_THROW( e ) FT_ERR_CAT( ErrRaster_, e ) | |
#endif /* !FT_DEBUG_LEVEL_TRACE */ | |
#define FT_DEFINE_OUTLINE_FUNCS( class_, \ | |
move_to_, line_to_, \ | |
conic_to_, cubic_to_, \ | |
shift_, delta_ ) \ | |
static const FT_Outline_Funcs class_ = \ | |
{ \ | |
move_to_, \ | |
line_to_, \ | |
conic_to_, \ | |
cubic_to_, \ | |
shift_, \ | |
delta_ \ | |
}; | |
#define FT_DEFINE_RASTER_FUNCS( class_, glyph_format_, \ | |
raster_new_, raster_reset_, \ | |
raster_set_mode_, raster_render_, \ | |
raster_done_ ) \ | |
const FT_Raster_Funcs class_ = \ | |
{ \ | |
glyph_format_, \ | |
raster_new_, \ | |
raster_reset_, \ | |
raster_set_mode_, \ | |
raster_render_, \ | |
raster_done_ \ | |
}; | |
#else /* !_STANDALONE_ */ | |
#include <ft2build.h> | |
#include "ftgrays.h" | |
#include FT_INTERNAL_OBJECTS_H | |
#include FT_INTERNAL_DEBUG_H | |
#include FT_OUTLINE_H | |
#include "ftsmerrs.h" | |
#include "ftspic.h" | |
#define Smooth_Err_Invalid_Mode Smooth_Err_Cannot_Render_Glyph | |
#define Smooth_Err_Memory_Overflow Smooth_Err_Out_Of_Memory | |
#define ErrRaster_Memory_Overflow Smooth_Err_Out_Of_Memory | |
#endif /* !_STANDALONE_ */ | |
#ifndef FT_MEM_SET | |
#define FT_MEM_SET( d, s, c ) ft_memset( d, s, c ) | |
#endif | |
#ifndef FT_MEM_ZERO | |
#define FT_MEM_ZERO( dest, count ) FT_MEM_SET( dest, 0, count ) | |
#endif | |
/* as usual, for the speed hungry :-) */ | |
#undef RAS_ARG | |
#undef RAS_ARG_ | |
#undef RAS_VAR | |
#undef RAS_VAR_ | |
#ifndef FT_STATIC_RASTER | |
#define RAS_ARG gray_PWorker worker | |
#define RAS_ARG_ gray_PWorker worker, | |
#define RAS_VAR worker | |
#define RAS_VAR_ worker, | |
#else /* FT_STATIC_RASTER */ | |
#define RAS_ARG /* empty */ | |
#define RAS_ARG_ /* empty */ | |
#define RAS_VAR /* empty */ | |
#define RAS_VAR_ /* empty */ | |
#endif /* FT_STATIC_RASTER */ | |
/* must be at least 6 bits! */ | |
#define PIXEL_BITS 8 | |
#undef FLOOR | |
#undef CEILING | |
#undef TRUNC | |
#undef SCALED | |
#define ONE_PIXEL ( 1L << PIXEL_BITS ) | |
#define TRUNC( x ) ( (TCoord)( (x) >> PIXEL_BITS ) ) | |
#define SUBPIXELS( x ) ( (TPos)(x) << 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__ */ | |
/* These macros speed up repetitive divisions by replacing them */ | |
/* with multiplications and right shifts. */ | |
#define FT_UDIVPREP( b ) \ | |
long b ## _r = (long)( FT_ULONG_MAX >> PIXEL_BITS ) / ( b ) | |
#define FT_UDIV( a, b ) \ | |
( ( (unsigned long)( a ) * (unsigned long)( b ## _r ) ) >> \ | |
( sizeof( long ) * FT_CHAR_BIT - PIXEL_BITS ) ) | |
/*************************************************************************/ | |
/* */ | |
/* TYPE DEFINITIONS */ | |
/* */ | |
/* don't change the following types to FT_Int or FT_Pos, since we might */ | |
/* need to define them to "float" or "double" when experimenting with */ | |
/* new algorithms */ | |
typedef long TCoord; /* integer scanline/pixel coordinate */ | |
typedef long TPos; /* sub-pixel coordinate */ | |
/* 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; | |
TPos x, y; | |
FT_Vector bez_stack[32 * 3 + 1]; | |
int lev_stack[32]; | |
FT_Outline outline; | |
FT_Bitmap target; | |
FT_BBox clip_box; | |
FT_Span gray_spans[FT_MAX_GRAY_SPANS]; | |
int num_gray_spans; | |
FT_Raster_Span_Func render_span; | |
void* render_span_data; | |
int span_y; | |
int band_size; | |
int band_shoot; | |
void* buffer; | |
long buffer_size; | |
PCell* ycells; | |
TPos ycount; | |
} gray_TWorker, *gray_PWorker; | |
#if defined( _MSC_VER ) | |
#pragma warning( pop ) | |
#endif | |
#ifndef FT_STATIC_RASTER | |
#define ras (*worker) | |
#else | |
static gray_TWorker ras; | |
#endif | |
typedef struct gray_TRaster_ | |
{ | |
void* memory; | |
} gray_TRaster, *gray_PRaster; | |
/*************************************************************************/ | |
/* */ | |
/* Initialize the cells table. */ | |
/* */ | |
static void | |
gray_init_cells( RAS_ARG_ void* buffer, | |
long byte_size ) | |
{ | |
ras.buffer = buffer; | |
ras.buffer_size = byte_size; | |
ras.ycells = (PCell*) buffer; | |
ras.cells = NULL; | |
ras.max_cells = 0; | |
ras.num_cells = 0; | |
ras.area = 0; | |
ras.cover = 0; | |
ras.invalid = 1; | |
} | |
/*************************************************************************/ | |
/* */ | |
/* Compute the outline bounding box. */ | |
/* */ | |
static void | |
gray_compute_cbox( RAS_ARG ) | |
{ | |
FT_Outline* outline = &ras.outline; | |
FT_Vector* vec = outline->points; | |
FT_Vector* limit = vec + outline->n_points; | |
if ( outline->n_points <= 0 ) | |
{ | |
ras.min_ex = ras.max_ex = 0; | |
ras.min_ey = ras.max_ey = 0; | |
return; | |
} | |
ras.min_ex = ras.max_ex = vec->x; | |
ras.min_ey = ras.max_ey = vec->y; | |
vec++; | |
for ( ; vec < limit; vec++ ) | |
{ | |
TPos x = vec->x; | |
TPos y = vec->y; | |
if ( x < ras.min_ex ) ras.min_ex = x; | |
if ( x > ras.max_ex ) ras.max_ex = x; | |
if ( y < ras.min_ey ) ras.min_ey = y; | |
if ( y > ras.max_ey ) ras.max_ey = y; | |
} | |
/* truncate the bounding box to integer pixels */ | |
ras.min_ex = ras.min_ex >> 6; | |
ras.min_ey = ras.min_ey >> 6; | |
ras.max_ex = ( ras.max_ex + 63 ) >> 6; | |
ras.max_ey = ( ras.max_ey + 63 ) >> 6; | |
} | |
/*************************************************************************/ | |
/* */ | |
/* Record the current cell in the table. */ | |
/* */ | |
static PCell | |
gray_find_cell( RAS_ARG ) | |
{ | |
PCell *pcell, cell; | |
TPos x = ras.ex; | |
if ( x > ras.count_ex ) | |
x = ras.count_ex; | |
pcell = &ras.ycells[ras.ey]; | |
for (;;) | |
{ | |
cell = *pcell; | |
if ( cell == NULL || cell->x > x ) | |
break; | |
if ( cell->x == x ) | |
goto Exit; | |
pcell = &cell->next; | |
} | |
if ( ras.num_cells >= ras.max_cells ) | |
ft_longjmp( ras.jump_buffer, 1 ); | |
cell = ras.cells + ras.num_cells++; | |
cell->x = x; | |
cell->area = 0; | |
cell->cover = 0; | |
cell->next = *pcell; | |
*pcell = cell; | |
Exit: | |
return cell; | |
} | |
static void | |
gray_record_cell( RAS_ARG ) | |
{ | |
if ( ras.area | ras.cover ) | |
{ | |
PCell cell = gray_find_cell( RAS_VAR ); | |
cell->area += ras.area; | |
cell->cover += ras.cover; | |
} | |
} | |
/*************************************************************************/ | |
/* */ | |
/* Set the current cell to a new position. */ | |
/* */ | |
static void | |
gray_set_cell( RAS_ARG_ TCoord ex, | |
TCoord ey ) | |
{ | |
/* Move the cell pointer to a new position. We set the `invalid' */ | |
/* flag to indicate that the cell isn't part of those we're interested */ | |
/* in during the render phase. This means that: */ | |
/* */ | |
/* . the new vertical position must be within min_ey..max_ey-1. */ | |
/* . the new horizontal position must be strictly less than max_ex */ | |
/* */ | |
/* Note that if a cell is to the left of the clipping region, it is */ | |
/* actually set to the (min_ex-1) horizontal position. */ | |
/* All cells that are on the left of the clipping region go to the */ | |
/* min_ex - 1 horizontal position. */ | |
ey -= ras.min_ey; | |
if ( ex > ras.max_ex ) | |
ex = ras.max_ex; | |
ex -= ras.min_ex; | |
if ( ex < 0 ) | |
ex = -1; | |
/* are we moving to a different cell ? */ | |
if ( ex != ras.ex || ey != ras.ey ) | |
{ | |
/* record the current one if it is valid */ | |
if ( !ras.invalid ) | |
gray_record_cell( RAS_VAR ); | |
ras.area = 0; | |
ras.cover = 0; | |
ras.ex = ex; | |
ras.ey = ey; | |
} | |
ras.invalid = ( (unsigned int)ey >= (unsigned int)ras.count_ey || | |
ex >= ras.count_ex ); | |
} | |
/*************************************************************************/ | |
/* */ | |
/* Start a new contour at a given cell. */ | |
/* */ | |
static void | |
gray_start_cell( RAS_ARG_ TCoord ex, | |
TCoord ey ) | |
{ | |
if ( ex > ras.max_ex ) | |
ex = (TCoord)( ras.max_ex ); | |
if ( ex < ras.min_ex ) | |
ex = (TCoord)( ras.min_ex - 1 ); | |
ras.area = 0; | |
ras.cover = 0; | |
ras.ex = ex - ras.min_ex; | |
ras.ey = ey - ras.min_ey; | |
ras.invalid = 0; | |
gray_set_cell( RAS_VAR_ ex, ey ); | |
} | |
#if 0 | |
/*************************************************************************/ | |
/* */ | |
/* 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; | |
do | |
{ | |
delta = lift; | |
mod += rem; | |
if ( mod >= 0 ) | |
{ | |
mod -= (TCoord)dx; | |
delta++; | |
} | |
ras.area += (TArea)(ONE_PIXEL * delta); | |
ras.cover += delta; | |
y1 += delta; | |
ex1 += incr; | |
gray_set_cell( RAS_VAR_ ex1, ey ); | |
} while ( ex1 != ex2 ); | |
} | |
delta = y2 - y1; | |
ras.area += (TArea)(( fx2 + ONE_PIXEL - first ) * delta); | |
ras.cover += delta; | |
} | |
/*************************************************************************/ | |
/* */ | |
/* Render a given line as a series of scanlines. */ | |
/* */ | |
static void | |
gray_render_line( RAS_ARG_ TPos to_x, | |
TPos to_y ) | |
{ | |
TCoord ey1, ey2, fy1, fy2, mod; | |
TPos dx, dy, x, x2; | |
long p, first; | |
int delta, rem, lift, incr; | |
ey1 = TRUNC( ras.y ); | |
ey2 = TRUNC( to_y ); /* if (ey2 >= ras.max_ey) ey2 = ras.max_ey-1; */ | |
fy1 = (TCoord)( ras.y - SUBPIXELS( ey1 ) ); | |
fy2 = (TCoord)( to_y - SUBPIXELS( ey2 ) ); | |
dx = to_x - ras.x; | |
dy = to_y - ras.y; | |
/* perform vertical clipping */ | |
if ( ( ey1 >= ras.max_ey && ey2 >= ras.max_ey ) || | |
( ey1 < ras.min_ey && ey2 < 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; | |
do | |
{ | |
delta = lift; | |
mod += rem; | |
if ( mod >= 0 ) | |
{ | |
mod -= (int)dy; | |
delta++; | |
} | |
x2 = x + delta; | |
gray_render_scanline( RAS_VAR_ ey1, x, | |
(TCoord)( ONE_PIXEL - first ), x2, | |
(TCoord)first ); | |
x = x2; | |
ey1 += incr; | |
gray_set_cell( RAS_VAR_ TRUNC( x ), ey1 ); | |
} while ( ey1 != ey2 ); | |
} | |
gray_render_scanline( RAS_VAR_ ey1, x, | |
(TCoord)( ONE_PIXEL - first ), to_x, | |
fy2 ); | |
End: | |
ras.x = to_x; | |
ras.y = to_y; | |
} | |
#else | |
/*************************************************************************/ | |
/* */ | |
/* Render a straight line across multiple cells in any direction. */ | |
/* */ | |
static void | |
gray_render_line( RAS_ARG_ TPos to_x, | |
TPos to_y ) | |
{ | |
TPos dx, dy, fx1, fy1, fx2, fy2; | |
TCoord ex1, ex2, ey1, ey2; | |
ex1 = TRUNC( ras.x ); | |
ex2 = TRUNC( to_x ); | |
ey1 = TRUNC( ras.y ); | |
ey2 = TRUNC( to_y ); | |
/* perform vertical clipping */ | |
if ( ( ey1 >= ras.max_ey && ey2 >= ras.max_ey ) || | |
( ey1 < ras.min_ey && ey2 < ras.min_ey ) ) | |
goto End; | |
dx = to_x - ras.x; | |
dy = to_y - ras.y; | |
fx1 = ras.x - SUBPIXELS( ex1 ); | |
fy1 = ras.y - SUBPIXELS( ey1 ); | |
if ( ex1 == ex2 && ey1 == ey2 ) /* inside one cell */ | |
; | |
else if ( dy == 0 ) /* ex1 != ex2 */ /* any horizontal line */ | |
{ | |
ex1 = ex2; | |
gray_set_cell( RAS_VAR_ ex1, ey1 ); | |
} | |
else if ( dx == 0 ) | |
{ | |
if ( dy > 0 ) /* vertical line up */ | |
do | |
{ | |
fy2 = ONE_PIXEL; | |
ras.cover += ( fy2 - fy1 ); | |
ras.area += ( fy2 - fy1 ) * fx1 * 2; | |
fy1 = 0; | |
ey1++; | |
gray_set_cell( RAS_VAR_ ex1, ey1 ); | |
} while ( ey1 != ey2 ); | |
else /* vertical line down */ | |
do | |
{ | |
fy2 = 0; | |
ras.cover += ( fy2 - fy1 ); | |
ras.area += ( fy2 - fy1 ) * fx1 * 2; | |
fy1 = ONE_PIXEL; | |
ey1--; | |
gray_set_cell( RAS_VAR_ ex1, ey1 ); | |
} while ( ey1 != ey2 ); | |
} | |
else /* any other line */ | |
{ | |
TArea prod = dx * fy1 - dy * fx1; | |
FT_UDIVPREP( dx ); | |
FT_UDIVPREP( dy ); | |
/* The fundamental value `prod' determines which side and the */ | |
/* exact coordinate where the line exits current cell. It is */ | |
/* also easily updated when moving from one cell to the next. */ | |
do | |
{ | |
if ( prod <= 0 && | |
prod - dx * ONE_PIXEL > 0 ) /* left */ | |
{ | |
fx2 = 0; | |
fy2 = (TPos)FT_UDIV( -prod, -dx ); | |
prod -= dy * ONE_PIXEL; | |
ras.cover += ( fy2 - fy1 ); | |
ras.area += ( fy2 - fy1 ) * ( fx1 + fx2 ); | |
fx1 = ONE_PIXEL; | |
fy1 = fy2; | |
ex1--; | |
} | |
else if ( prod - dx * ONE_PIXEL <= 0 && | |
prod - dx * ONE_PIXEL + dy * ONE_PIXEL > 0 ) /* up */ | |
{ | |
prod -= dx * ONE_PIXEL; | |
fx2 = (TPos)FT_UDIV( -prod, dy ); | |
fy2 = ONE_PIXEL; | |
ras.cover += ( fy2 - fy1 ); | |
ras.area += ( fy2 - fy1 ) * ( fx1 + fx2 ); | |
fx1 = fx2; | |
fy1 = 0; | |
ey1++; | |
} | |
else if ( prod - dx * ONE_PIXEL + dy * ONE_PIXEL <= 0 && | |
prod + dy * ONE_PIXEL >= 0 ) /* right */ | |
{ | |
prod += dy * ONE_PIXEL; | |
fx2 = ONE_PIXEL; | |
fy2 = (TPos)FT_UDIV( prod, dx ); | |
ras.cover += ( fy2 - fy1 ); | |
ras.area += ( fy2 - fy1 ) * ( fx1 + fx2 ); | |
fx1 = 0; | |
fy1 = fy2; | |
ex1++; | |
} | |
else /* ( prod + dy * ONE_PIXEL < 0 && | |
prod > 0 ) down */ | |
{ | |
fx2 = (TPos)FT_UDIV( prod, -dy ); | |
fy2 = 0; | |
prod += dx * ONE_PIXEL; | |
ras.cover += ( fy2 - fy1 ); | |
ras.area += ( fy2 - fy1 ) * ( fx1 + fx2 ); | |
fx1 = fx2; | |
fy1 = ONE_PIXEL; | |
ey1--; | |
} | |
gray_set_cell( RAS_VAR_ ex1, ey1 ); | |
} while ( ex1 != ex2 || ey1 != ey2 ); | |
} | |
fx2 = to_x - SUBPIXELS( ex2 ); | |
fy2 = to_y - SUBPIXELS( ey2 ); | |
ras.cover += ( fy2 - fy1 ); | |
ras.area += ( fy2 - fy1 ) * ( fx1 + fx2 ); | |
End: | |
ras.x = to_x; | |
ras.y = to_y; | |
} | |
#endif | |
static void | |
gray_split_conic( FT_Vector* base ) | |
{ | |
TPos a, b; | |
base[4].x = base[2].x; | |
b = base[1].x; | |
a = base[3].x = ( base[2].x + b ) / 2; | |
b = base[1].x = ( base[0].x + b ) / 2; | |
base[2].x = ( a + b ) / 2; | |
base[4].y = base[2].y; | |
b = base[1].y; | |
a = base[3].y = ( base[2].y + b ) / 2; | |
b = base[1].y = ( base[0].y + b ) / 2; | |
base[2].y = ( a + b ) / 2; | |
} | |
static void | |
gray_render_conic( RAS_ARG_ 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; | |
do | |
{ | |
TPos bottom, top, middle; | |
int error; | |
{ | |
PCell cells_max; | |
int yindex; | |
long cell_start, cell_end, cell_mod; | |
ras.ycells = (PCell*)ras.buffer; | |
ras.ycount = band->max - band->min; | |
cell_start = (long)sizeof ( PCell ) * ras.ycount; | |
cell_mod = cell_start % (long)sizeof ( TCell ); | |
if ( cell_mod > 0 ) | |
cell_start += (long)sizeof ( TCell ) - cell_mod; | |
cell_end = ras.buffer_size; | |
cell_end -= cell_end % (long)sizeof ( TCell ); | |
cells_max = (PCell)( (char*)ras.buffer + cell_end ); | |
ras.cells = (PCell)( (char*)ras.buffer + cell_start ); | |
if ( ras.cells >= cells_max ) | |
goto ReduceBands; | |
ras.max_cells = cells_max - ras.cells; | |
if ( ras.max_cells < 2 ) | |
goto ReduceBands; | |
for ( yindex = 0; yindex < ras.ycount; yindex++ ) | |
ras.ycells[yindex] = NULL; | |
} | |
ras.num_cells = 0; | |
ras.invalid = 1; | |
ras.min_ey = band->min; | |
ras.max_ey = band->max; | |
ras.count_ey = band->max - band->min; | |
error = gray_convert_glyph_inner( RAS_VAR ); | |
if ( !error ) | |
{ | |
gray_sweep( RAS_VAR_ &ras.target ); | |
band--; | |
continue; | |
} | |
else if ( error != ErrRaster_Memory_Overflow ) | |
return 1; | |
ReduceBands: | |
/* render pool overflow; we will reduce the render band by half */ | |
bottom = band->min; | |
top = band->max; | |
middle = bottom + ( ( top - bottom ) >> 1 ); | |
/* This is too complex for a single scanline; there must */ | |
/* be some problems. */ | |
if ( middle == bottom ) | |
{ | |
#ifdef FT_DEBUG_LEVEL_TRACE | |
FT_TRACE7(( "gray_convert_glyph: rotten glyph\n" )); | |
#endif | |
return 1; | |
} | |
if ( bottom-top >= ras.band_size ) | |
ras.band_shoot++; | |
band[1].min = bottom; | |
band[1].max = middle; | |
band[0].min = middle; | |
band[0].max = top; | |
band++; | |
} while ( band >= bands ); | |
} | |
if ( ras.band_shoot > 8 && ras.band_size > 16 ) | |
ras.band_size = ras.band_size / 2; | |
return 0; | |
} | |
static int | |
gray_raster_render( 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: */ |