ref: c8b187f9db503465460d8bafa2d7a758bbcf59ca
dir: /libfreetype/ftraster.c/
/***************************************************************************/ /* */ /* ftraster.c */ /* */ /* The FreeType glyph rasterizer (body). */ /* */ /* Copyright 1996-2001, 2002 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 is a rewrite of the FreeType 1.x scan-line converter */ /* */ /*************************************************************************/ #include <ft2build.h> #include "ftraster.h" #include FT_INTERNAL_CALC_H /* for FT_MulDiv only */ /*************************************************************************/ /* */ /* A simple technical note on how the raster works */ /* ----------------------------------------------- */ /* */ /* Converting an outline into a bitmap is achieved in several steps: */ /* */ /* 1 - Decomposing the outline into successive `profiles'. Each */ /* profile is simply an array of scanline intersections on a given */ /* dimension. A profile's main attributes are */ /* */ /* o its scanline position boundaries, i.e. `Ymin' and `Ymax'. */ /* */ /* o an array of intersection coordinates for each scanline */ /* between `Ymin' and `Ymax'. */ /* */ /* o a direction, indicating whether it was built going `up' or */ /* `down', as this is very important for filling rules. */ /* */ /* 2 - Sweeping the target map's scanlines in order to compute segment */ /* `spans' which are then filled. Additionally, this pass */ /* performs drop-out control. */ /* */ /* The outline data is parsed during step 1 only. The profiles are */ /* built from the bottom of the render pool, used as a stack. The */ /* following graphics shows the profile list under construction: */ /* */ /* ____________________________________________________________ _ _ */ /* | | | | | */ /* | profile | coordinates for | profile | coordinates for |--> */ /* | 1 | profile 1 | 2 | profile 2 |--> */ /* |_________|___________________|_________|_________________|__ _ _ */ /* */ /* ^ ^ */ /* | | */ /* start of render pool top */ /* */ /* The top of the profile stack is kept in the `top' variable. */ /* */ /* As you can see, a profile record is pushed on top of the render */ /* pool, which is then followed by its coordinates/intersections. If */ /* a change of direction is detected in the outline, a new profile is */ /* generated until the end of the outline. */ /* */ /* Note that when all profiles have been generated, the function */ /* Finalize_Profile_Table() is used to record, for each profile, its */ /* bottom-most scanline as well as the scanline above its upmost */ /* boundary. These positions are called `y-turns' because they (sort */ /* of) correspond to local extrema. They are stored in a sorted list */ /* built from the top of the render pool as a downwards stack: */ /* */ /* _ _ _______________________________________ */ /* | | */ /* <--| sorted list of | */ /* <--| extrema scanlines | */ /* _ _ __________________|____________________| */ /* */ /* ^ ^ */ /* | | */ /* maxBuff sizeBuff = end of pool */ /* */ /* This list is later used during the sweep phase in order to */ /* optimize performance (see technical note on the sweep below). */ /* */ /* Of course, the raster detects whether the two stacks collide and */ /* handles the situation propertly. */ /* */ /*************************************************************************/ /*************************************************************************/ /*************************************************************************/ /** **/ /** CONFIGURATION MACROS **/ /** **/ /*************************************************************************/ /*************************************************************************/ /* define DEBUG_RASTER if you want to compile a debugging version */ #define xxxDEBUG_RASTER /* The default render pool size in bytes */ #define RASTER_RENDER_POOL 8192 /* undefine FT_RASTER_OPTION_ANTI_ALIASING if you do not want to support */ /* 5-levels anti-aliasing */ #ifdef FT_CONFIG_OPTION_5_GRAY_LEVELS #define FT_RASTER_OPTION_ANTI_ALIASING #endif /* The size of the two-lines intermediate bitmap used */ /* for anti-aliasing, in bytes. */ #define RASTER_GRAY_LINES 2048 /*************************************************************************/ /*************************************************************************/ /** **/ /** OTHER MACROS (do not change) **/ /** **/ /*************************************************************************/ /*************************************************************************/ /*************************************************************************/ /* */ /* 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_raster #ifdef _STANDALONE_ /* 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) /* 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 #define Raster_Err_None 0 #define Raster_Err_Not_Ini -1 #define Raster_Err_Overflow -2 #define Raster_Err_Neg_Height -3 #define Raster_Err_Invalid -4 #define Raster_Err_Unsupported -5 #else /* _STANDALONE_ */ #include FT_INTERNAL_OBJECTS_H #include FT_INTERNAL_DEBUG_H /* for FT_TRACE() and FT_ERROR() */ #include "rasterrs.h" #define Raster_Err_None Raster_Err_Ok #define Raster_Err_Not_Ini Raster_Err_Raster_Uninitialized #define Raster_Err_Overflow Raster_Err_Raster_Overflow #define Raster_Err_Neg_Height Raster_Err_Raster_Negative_Height #define Raster_Err_Invalid Raster_Err_Invalid_Outline #define Raster_Err_Unsupported Raster_Err_Cannot_Render_Glyph #endif /* _STANDALONE_ */ #ifndef FT_MEM_SET #define FT_MEM_SET( d, s, c ) ft_memset( d, s, c ) #endif /* FMulDiv means `Fast MulDiv'; it is used in case where `b' is */ /* typically a small value and the result of a*b is known to fit into */ /* 32 bits. */ #define FMulDiv( a, b, c ) ( (a) * (b) / (c) ) /* On the other hand, SMulDiv means `Slow MulDiv', and is used typically */ /* for clipping computations. It simply uses the FT_MulDiv() function */ /* defined in `ftcalc.h'. */ #define SMulDiv FT_MulDiv /* The rasterizer is a very general purpose component; please leave */ /* the following redefinitions there (you never know your target */ /* environment). */ #ifndef TRUE #define TRUE 1 #endif #ifndef FALSE #define FALSE 0 #endif #ifndef NULL #define NULL (void*)0 #endif #ifndef SUCCESS #define SUCCESS 0 #endif #ifndef FAILURE #define FAILURE 1 #endif #define MaxBezier 32 /* The maximum number of stacked Bezier curves. */ /* Setting this constant to more than 32 is a */ /* pure waste of space. */ #define Pixel_Bits 6 /* fractional bits of *input* coordinates */ /*************************************************************************/ /*************************************************************************/ /** **/ /** SIMPLE TYPE DECLARATIONS **/ /** **/ /*************************************************************************/ /*************************************************************************/ typedef int Int; typedef unsigned int UInt; typedef short Short; typedef unsigned short UShort, *PUShort; typedef long Long, *PLong; typedef unsigned long ULong; typedef unsigned char Byte, *PByte; typedef char Bool; typedef struct TPoint_ { Long x; Long y; } TPoint; typedef enum TFlow_ { Flow_None = 0, Flow_Up = 1, Flow_Down = -1 } TFlow; /* States of each line, arc, and profile */ typedef enum TStates_ { Unknown_State, Ascending_State, Descending_State, Flat_State } TStates; typedef struct TProfile_ TProfile; typedef TProfile* PProfile; struct TProfile_ { FT_F26Dot6 X; /* current coordinate during sweep */ PProfile link; /* link to next profile - various purpose */ PLong offset; /* start of profile's data in render pool */ int flow; /* Profile orientation: Asc/Descending */ long height; /* profile's height in scanlines */ long start; /* profile's starting scanline */ unsigned countL; /* number of lines to step before this */ /* profile becomes drawable */ PProfile next; /* next profile in same contour, used */ /* during drop-out control */ }; typedef PProfile TProfileList; typedef PProfile* PProfileList; /* Simple record used to implement a stack of bands, required */ /* by the sub-banding mechanism */ typedef struct TBand_ { Short y_min; /* band's minimum */ Short y_max; /* band's maximum */ } TBand; #define AlignProfileSize \ ( ( sizeof ( TProfile ) + sizeof ( long ) - 1 ) / sizeof ( long ) ) #ifdef TT_STATIC_RASTER #define RAS_ARGS /* void */ #define RAS_ARG /* void */ #define RAS_VARS /* void */ #define RAS_VAR /* void */ #define FT_UNUSED_RASTER do ; while ( 0 ) #else /* TT_STATIC_RASTER */ #define RAS_ARGS TRaster_Instance* raster, #define RAS_ARG TRaster_Instance* raster #define RAS_VARS raster, #define RAS_VAR raster #define FT_UNUSED_RASTER FT_UNUSED( raster ) #endif /* TT_STATIC_RASTER */ typedef struct TRaster_Instance_ TRaster_Instance; /* prototypes used for sweep function dispatch */ typedef void Function_Sweep_Init( RAS_ARGS Short* min, Short* max ); typedef void Function_Sweep_Span( RAS_ARGS Short y, FT_F26Dot6 x1, FT_F26Dot6 x2, PProfile left, PProfile right ); typedef void Function_Sweep_Step( RAS_ARG ); /* NOTE: These operations are only valid on 2's complement processors */ #define FLOOR( x ) ( (x) & -ras.precision ) #define CEILING( x ) ( ( (x) + ras.precision - 1 ) & -ras.precision ) #define TRUNC( x ) ( (signed long)(x) >> ras.precision_bits ) #define FRAC( x ) ( (x) & ( ras.precision - 1 ) ) #define SCALED( x ) ( ( (x) << ras.scale_shift ) - ras.precision_half ) /* Note that I have moved the location of some fields in the */ /* structure to ensure that the most used variables are used */ /* at the top. Thus, their offset can be coded with less */ /* opcodes, and it results in a smaller executable. */ struct TRaster_Instance_ { Int precision_bits; /* precision related variables */ Int precision; Int precision_half; Long precision_mask; Int precision_shift; Int precision_step; Int precision_jitter; Int scale_shift; /* == precision_shift for bitmaps */ /* == precision_shift+1 for pixmaps */ PLong buff; /* The profiles buffer */ PLong sizeBuff; /* Render pool size */ PLong maxBuff; /* Profiles buffer size */ PLong top; /* Current cursor in buffer */ FT_Error error; Int numTurns; /* number of Y-turns in outline */ TPoint* arc; /* current Bezier arc pointer */ UShort bWidth; /* target bitmap width */ PByte bTarget; /* target bitmap buffer */ PByte gTarget; /* target pixmap buffer */ Long lastX, lastY, minY, maxY; UShort num_Profs; /* current number of profiles */ Bool fresh; /* signals a fresh new profile which */ /* 'start' field must be completed */ Bool joint; /* signals that the last arc ended */ /* exactly on a scanline. Allows */ /* removal of doublets */ PProfile cProfile; /* current profile */ PProfile fProfile; /* head of linked list of profiles */ PProfile gProfile; /* contour's first profile in case */ /* of impact */ TStates state; /* rendering state */ FT_Bitmap target; /* description of target bit/pixmap */ FT_Outline outline; Long traceOfs; /* current offset in target bitmap */ Long traceG; /* current offset in target pixmap */ Short traceIncr; /* sweep's increment in target bitmap */ Short gray_min_x; /* current min x during gray rendering */ Short gray_max_x; /* current max x during gray rendering */ /* dispatch variables */ Function_Sweep_Init* Proc_Sweep_Init; Function_Sweep_Span* Proc_Sweep_Span; Function_Sweep_Span* Proc_Sweep_Drop; Function_Sweep_Step* Proc_Sweep_Step; Byte dropOutControl; /* current drop_out control method */ Bool second_pass; /* indicates wether a horizontal pass */ /* should be performed to control */ /* drop-out accurately when calling */ /* Render_Glyph. Note that there is */ /* no horizontal pass during gray */ /* rendering. */ TPoint arcs[3 * MaxBezier + 1]; /* The Bezier stack */ TBand band_stack[16]; /* band stack used for sub-banding */ Int band_top; /* band stack top */ Int count_table[256]; /* Look-up table used to quickly count */ /* set bits in a gray 2x2 cell */ void* memory; #ifdef FT_RASTER_OPTION_ANTI_ALIASING Byte grays[5]; /* Palette of gray levels used for */ /* render. */ Byte gray_lines[RASTER_GRAY_LINES]; /* Intermediate table used to render the */ /* graylevels pixmaps. */ /* gray_lines is a buffer holding two */ /* monochrome scanlines */ Short gray_width; /* width in bytes of one monochrome */ /* intermediate scanline of gray_lines. */ /* Each gray pixel takes 2 bits long there */ /* The gray_lines must hold 2 lines, thus with size */ /* in bytes of at least `gray_width*2'. */ #endif /* FT_RASTER_ANTI_ALIASING */ #if 0 PByte flags; /* current flags table */ PUShort outs; /* current outlines table */ FT_Vector* coords; UShort nPoints; /* number of points in current glyph */ Short nContours; /* number of contours in current glyph */ #endif }; #ifdef FT_CONFIG_OPTION_STATIC_RASTER static TRaster_Instance cur_ras; #define ras cur_ras #else #define ras (*raster) #endif /* FT_CONFIG_OPTION_STATIC_RASTER */ /*************************************************************************/ /*************************************************************************/ /** **/ /** PROFILES COMPUTATION **/ /** **/ /*************************************************************************/ /*************************************************************************/ /*************************************************************************/ /* */ /* <Function> */ /* Set_High_Precision */ /* */ /* <Description> */ /* Sets precision variables according to param flag. */ /* */ /* <Input> */ /* High :: Set to True for high precision (typically for ppem < 18), */ /* false otherwise. */ /* */ static void Set_High_Precision( RAS_ARGS Int High ) { if ( High ) { ras.precision_bits = 10; ras.precision_step = 128; ras.precision_jitter = 24; } else { ras.precision_bits = 6; ras.precision_step = 32; ras.precision_jitter = 2; } FT_TRACE6(( "Set_High_Precision(%s)\n", High ? "true" : "false" )); ras.precision = 1 << ras.precision_bits; ras.precision_half = ras.precision / 2; ras.precision_shift = ras.precision_bits - Pixel_Bits; ras.precision_mask = -ras.precision; } /*************************************************************************/ /* */ /* <Function> */ /* New_Profile */ /* */ /* <Description> */ /* Creates a new profile in the render pool. */ /* */ /* <Input> */ /* aState :: The state/orientation of the new profile. */ /* */ /* <Return> */ /* SUCCESS on success. FAILURE in case of overflow or of incoherent */ /* profile. */ /* */ static Bool New_Profile( RAS_ARGS TStates aState ) { if ( !ras.fProfile ) { ras.cProfile = (PProfile)ras.top; ras.fProfile = ras.cProfile; ras.top += AlignProfileSize; } if ( ras.top >= ras.maxBuff ) { ras.error = Raster_Err_Overflow; return FAILURE; } switch ( aState ) { case Ascending_State: ras.cProfile->flow = Flow_Up; FT_TRACE6(( "New ascending profile = %lx\n", (long)ras.cProfile )); break; case Descending_State: ras.cProfile->flow = Flow_Down; FT_TRACE6(( "New descending profile = %lx\n", (long)ras.cProfile )); break; default: FT_ERROR(( "New_Profile: invalid profile direction!\n" )); ras.error = Raster_Err_Invalid; return FAILURE; } ras.cProfile->start = 0; ras.cProfile->height = 0; ras.cProfile->offset = ras.top; ras.cProfile->link = (PProfile)0; ras.cProfile->next = (PProfile)0; if ( !ras.gProfile ) ras.gProfile = ras.cProfile; ras.state = aState; ras.fresh = TRUE; ras.joint = FALSE; return SUCCESS; } /*************************************************************************/ /* */ /* <Function> */ /* End_Profile */ /* */ /* <Description> */ /* Finalizes the current profile. */ /* */ /* <Return> */ /* SUCCESS on success. FAILURE in case of overflow or incoherency. */ /* */ static Bool End_Profile( RAS_ARG ) { Long h; PProfile oldProfile; h = (Long)( ras.top - ras.cProfile->offset ); if ( h < 0 ) { FT_ERROR(( "End_Profile: negative height encountered!\n" )); ras.error = Raster_Err_Neg_Height; return FAILURE; } if ( h > 0 ) { FT_TRACE6(( "Ending profile %lx, start = %ld, height = %ld\n", (long)ras.cProfile, ras.cProfile->start, h )); oldProfile = ras.cProfile; ras.cProfile->height = h; ras.cProfile = (PProfile)ras.top; ras.top += AlignProfileSize; ras.cProfile->height = 0; ras.cProfile->offset = ras.top; oldProfile->next = ras.cProfile; ras.num_Profs++; } if ( ras.top >= ras.maxBuff ) { FT_TRACE1(( "overflow in End_Profile\n" )); ras.error = Raster_Err_Overflow; return FAILURE; } ras.joint = FALSE; return SUCCESS; } /*************************************************************************/ /* */ /* <Function> */ /* Insert_Y_Turn */ /* */ /* <Description> */ /* Inserts a salient into the sorted list placed on top of the render */ /* pool. */ /* */ /* <Input> */ /* New y scanline position. */ /* */ /* <Return> */ /* SUCCESS on success. FAILURE in case of overflow. */ /* */ static Bool Insert_Y_Turn( RAS_ARGS Int y ) { PLong y_turns; Int y2, n; n = ras.numTurns - 1; y_turns = ras.sizeBuff - ras.numTurns; /* look for first y value that is <= */ while ( n >= 0 && y < y_turns[n] ) n--; /* if it is <, simply insert it, ignore if == */ if ( n >= 0 && y > y_turns[n] ) while ( n >= 0 ) { y2 = (Int)y_turns[n]; y_turns[n] = y; y = y2; n--; } if ( n < 0 ) { if ( ras.maxBuff <= ras.top ) { ras.error = Raster_Err_Overflow; return FAILURE; } ras.maxBuff--; ras.numTurns++; ras.sizeBuff[-ras.numTurns] = y; } return SUCCESS; } /*************************************************************************/ /* */ /* <Function> */ /* Finalize_Profile_Table */ /* */ /* <Description> */ /* Adjusts all links in the profiles list. */ /* */ /* <Return> */ /* SUCCESS on success. FAILURE in case of overflow. */ /* */ static Bool Finalize_Profile_Table( RAS_ARG ) { Int bottom, top; UShort n; PProfile p; n = ras.num_Profs; if ( n > 1 ) { p = ras.fProfile; while ( n > 0 ) { if ( n > 1 ) p->link = (PProfile)( p->offset + p->height ); else p->link = NULL; switch ( p->flow ) { case Flow_Down: bottom = (Int)( p->start - p->height + 1 ); top = (Int)p->start; p->start = bottom; p->offset += p->height - 1; break; case Flow_Up: default: bottom = (Int)p->start; top = (Int)( p->start + p->height - 1 ); } if ( Insert_Y_Turn( RAS_VARS bottom ) || Insert_Y_Turn( RAS_VARS top + 1 ) ) return FAILURE; p = p->link; n--; } } else ras.fProfile = NULL; return SUCCESS; } /*************************************************************************/ /* */ /* <Function> */ /* Split_Conic */ /* */ /* <Description> */ /* Subdivides one conic Bezier into two joint sub-arcs in the Bezier */ /* stack. */ /* */ /* <Input> */ /* None (subdivided Bezier is taken from the top of the stack). */ /* */ /* <Note> */ /* This routine is the `beef' of this component. It is _the_ inner */ /* loop that should be optimized to hell to get the best performance. */ /* */ static void Split_Conic( TPoint* base ) { Long 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; /* hand optimized. gcc doesn't seem to be too good at common */ /* expression substitution and instruction scheduling ;-) */ } /*************************************************************************/ /* */ /* <Function> */ /* Split_Cubic */ /* */ /* <Description> */ /* Subdivides a third-order Bezier arc into two joint sub-arcs in the */ /* Bezier stack. */ /* */ /* <Note> */ /* This routine is the `beef' of the component. It is one of _the_ */ /* inner loops that should be optimized like hell to get the best */ /* performance. */ /* */ static void Split_Cubic( TPoint* base ) { Long 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 + 1 ) >> 1; base[5].x = b = ( base[3].x + d + 1 ) >> 1; c = ( c + d + 1 ) >> 1; base[2].x = a = ( a + c + 1 ) >> 1; base[4].x = b = ( b + c + 1 ) >> 1; base[3].x = ( a + b + 1 ) >> 1; base[6].y = base[3].y; c = base[1].y; d = base[2].y; base[1].y = a = ( base[0].y + c + 1 ) >> 1; base[5].y = b = ( base[3].y + d + 1 ) >> 1; c = ( c + d + 1 ) >> 1; base[2].y = a = ( a + c + 1 ) >> 1; base[4].y = b = ( b + c + 1 ) >> 1; base[3].y = ( a + b + 1 ) >> 1; } /*************************************************************************/ /* */ /* <Function> */ /* Line_Up */ /* */ /* <Description> */ /* Computes the x-coordinates of an ascending line segment and stores */ /* them in the render pool. */ /* */ /* <Input> */ /* x1 :: The x-coordinate of the segment's start point. */ /* */ /* y1 :: The y-coordinate of the segment's start point. */ /* */ /* x2 :: The x-coordinate of the segment's end point. */ /* */ /* y2 :: The y-coordinate of the segment's end point. */ /* */ /* miny :: A lower vertical clipping bound value. */ /* */ /* maxy :: An upper vertical clipping bound value. */ /* */ /* <Return> */ /* SUCCESS on success, FAILURE on render pool overflow. */ /* */ static Bool Line_Up( RAS_ARGS Long x1, Long y1, Long x2, Long y2, Long miny, Long maxy ) { Long Dx, Dy; Int e1, e2, f1, f2, size; /* XXX: is `Short' sufficient? */ Long Ix, Rx, Ax; PLong top; Dx = x2 - x1; Dy = y2 - y1; if ( Dy <= 0 || y2 < miny || y1 > maxy ) return SUCCESS; if ( y1 < miny ) { /* Take care: miny-y1 can be a very large value; we use */ /* a slow MulDiv function to avoid clipping bugs */ x1 += SMulDiv( Dx, miny - y1, Dy ); e1 = TRUNC( miny ); f1 = 0; } else { e1 = (Int)TRUNC( y1 ); f1 = (Int)FRAC( y1 ); } if ( y2 > maxy ) { /* x2 += FMulDiv( Dx, maxy - y2, Dy ); UNNECESSARY */ e2 = (Int)TRUNC( maxy ); f2 = 0; } else { e2 = (Int)TRUNC( y2 ); f2 = (Int)FRAC( y2 ); } if ( f1 > 0 ) { if ( e1 == e2 ) return SUCCESS; else { x1 += FMulDiv( Dx, ras.precision - f1, Dy ); e1 += 1; } } else if ( ras.joint ) { ras.top--; ras.joint = FALSE; } ras.joint = (char)( f2 == 0 ); if ( ras.fresh ) { ras.cProfile->start = e1; ras.fresh = FALSE; } size = e2 - e1 + 1; if ( ras.top + size >= ras.maxBuff ) { ras.error = Raster_Err_Overflow; return FAILURE; } if ( Dx > 0 ) { Ix = ( ras.precision * Dx ) / Dy; Rx = ( ras.precision * Dx ) % Dy; Dx = 1; } else { Ix = -( ( ras.precision * -Dx ) / Dy ); Rx = ( ras.precision * -Dx ) % Dy; Dx = -1; } Ax = -Dy; top = ras.top; while ( size > 0 ) { *top++ = x1; x1 += Ix; Ax += Rx; if ( Ax >= 0 ) { Ax -= Dy; x1 += Dx; } size--; } ras.top = top; return SUCCESS; } /*************************************************************************/ /* */ /* <Function> */ /* Line_Down */ /* */ /* <Description> */ /* Computes the x-coordinates of an descending line segment and */ /* stores them in the render pool. */ /* */ /* <Input> */ /* x1 :: The x-coordinate of the segment's start point. */ /* */ /* y1 :: The y-coordinate of the segment's start point. */ /* */ /* x2 :: The x-coordinate of the segment's end point. */ /* */ /* y2 :: The y-coordinate of the segment's end point. */ /* */ /* miny :: A lower vertical clipping bound value. */ /* */ /* maxy :: An upper vertical clipping bound value. */ /* */ /* <Return> */ /* SUCCESS on success, FAILURE on render pool overflow. */ /* */ static Bool Line_Down( RAS_ARGS Long x1, Long y1, Long x2, Long y2, Long miny, Long maxy ) { Bool result, fresh; fresh = ras.fresh; result = Line_Up( RAS_VARS x1, -y1, x2, -y2, -maxy, -miny ); if ( fresh && !ras.fresh ) ras.cProfile->start = -ras.cProfile->start; return result; } /* A function type describing the functions used to split Bezier arcs */ typedef void (*TSplitter)( TPoint* base ); /*************************************************************************/ /* */ /* <Function> */ /* Bezier_Up */ /* */ /* <Description> */ /* Computes the x-coordinates of an ascending Bezier arc and stores */ /* them in the render pool. */ /* */ /* <Input> */ /* degree :: The degree of the Bezier arc (either 2 or 3). */ /* */ /* splitter :: The function to split Bezier arcs. */ /* */ /* miny :: A lower vertical clipping bound value. */ /* */ /* maxy :: An upper vertical clipping bound value. */ /* */ /* <Return> */ /* SUCCESS on success, FAILURE on render pool overflow. */ /* */ static Bool Bezier_Up( RAS_ARGS Int degree, TSplitter splitter, Long miny, Long maxy ) { Long y1, y2, e, e2, e0; Short f1; TPoint* arc; TPoint* start_arc; PLong top; arc = ras.arc; y1 = arc[degree].y; y2 = arc[0].y; top = ras.top; if ( y2 < miny || y1 > maxy ) goto Fin; e2 = FLOOR( y2 ); if ( e2 > maxy ) e2 = maxy; e0 = miny; if ( y1 < miny ) e = miny; else { e = CEILING( y1 ); f1 = (Short)( FRAC( y1 ) ); e0 = e; if ( f1 == 0 ) { if ( ras.joint ) { top--; ras.joint = FALSE; } *top++ = arc[degree].x; e += ras.precision; } } if ( ras.fresh ) { ras.cProfile->start = TRUNC( e0 ); ras.fresh = FALSE; } if ( e2 < e ) goto Fin; if ( ( top + TRUNC( e2 - e ) + 1 ) >= ras.maxBuff ) { ras.top = top; ras.error = Raster_Err_Overflow; return FAILURE; } start_arc = arc; while ( arc >= start_arc && e <= e2 ) { ras.joint = FALSE; y2 = arc[0].y; if ( y2 > e ) { y1 = arc[degree].y; if ( y2 - y1 >= ras.precision_step ) { splitter( arc ); arc += degree; } else { *top++ = arc[degree].x + FMulDiv( arc[0].x-arc[degree].x, e - y1, y2 - y1 ); arc -= degree; e += ras.precision; } } else { if ( y2 == e ) { ras.joint = TRUE; *top++ = arc[0].x; e += ras.precision; } arc -= degree; } } Fin: ras.top = top; ras.arc -= degree; return SUCCESS; } /*************************************************************************/ /* */ /* <Function> */ /* Bezier_Down */ /* */ /* <Description> */ /* Computes the x-coordinates of an descending Bezier arc and stores */ /* them in the render pool. */ /* */ /* <Input> */ /* degree :: The degree of the Bezier arc (either 2 or 3). */ /* */ /* splitter :: The function to split Bezier arcs. */ /* */ /* miny :: A lower vertical clipping bound value. */ /* */ /* maxy :: An upper vertical clipping bound value. */ /* */ /* <Return> */ /* SUCCESS on success, FAILURE on render pool overflow. */ /* */ static Bool Bezier_Down( RAS_ARGS Int degree, TSplitter splitter, Long miny, Long maxy ) { TPoint* arc = ras.arc; Bool result, fresh; arc[0].y = -arc[0].y; arc[1].y = -arc[1].y; arc[2].y = -arc[2].y; if ( degree > 2 ) arc[3].y = -arc[3].y; fresh = ras.fresh; result = Bezier_Up( RAS_VARS degree, splitter, -maxy, -miny ); if ( fresh && !ras.fresh ) ras.cProfile->start = -ras.cProfile->start; arc[0].y = -arc[0].y; return result; } /*************************************************************************/ /* */ /* <Function> */ /* Line_To */ /* */ /* <Description> */ /* Injects a new line segment and adjusts Profiles list. */ /* */ /* <Input> */ /* x :: The x-coordinate of the segment's end point (its start point */ /* is stored in `LastX'). */ /* */ /* y :: The y-coordinate of the segment's end point (its start point */ /* is stored in `LastY'). */ /* */ /* <Return> */ /* SUCCESS on success, FAILURE on render pool overflow or incorrect */ /* profile. */ /* */ static Bool Line_To( RAS_ARGS Long x, Long y ) { /* First, detect a change of direction */ switch ( ras.state ) { case Unknown_State: if ( y > ras.lastY ) { if ( New_Profile( RAS_VARS Ascending_State ) ) return FAILURE; } else { if ( y < ras.lastY ) if ( New_Profile( RAS_VARS Descending_State ) ) return FAILURE; } break; case Ascending_State: if ( y < ras.lastY ) { if ( End_Profile( RAS_VAR ) || New_Profile( RAS_VARS Descending_State ) ) return FAILURE; } break; case Descending_State: if ( y > ras.lastY ) { if ( End_Profile( RAS_VAR ) || New_Profile( RAS_VARS Ascending_State ) ) return FAILURE; } break; default: ; } /* Then compute the lines */ switch ( ras.state ) { case Ascending_State: if ( Line_Up( RAS_VARS ras.lastX, ras.lastY, x, y, ras.minY, ras.maxY ) ) return FAILURE; break; case Descending_State: if ( Line_Down( RAS_VARS ras.lastX, ras.lastY, x, y, ras.minY, ras.maxY ) ) return FAILURE; break; default: ; } ras.lastX = x; ras.lastY = y; return SUCCESS; } /*************************************************************************/ /* */ /* <Function> */ /* Conic_To */ /* */ /* <Description> */ /* Injects a new conic arc and adjusts the profile list. */ /* */ /* <Input> */ /* cx :: The x-coordinate of the arc's new control point. */ /* */ /* cy :: The y-coordinate of the arc's new control point. */ /* */ /* x :: The x-coordinate of the arc's end point (its start point is */ /* stored in `LastX'). */ /* */ /* y :: The y-coordinate of the arc's end point (its start point is */ /* stored in `LastY'). */ /* */ /* <Return> */ /* SUCCESS on success, FAILURE on render pool overflow or incorrect */ /* profile. */ /* */ static Bool Conic_To( RAS_ARGS Long cx, Long cy, Long x, Long y ) { Long y1, y2, y3, x3, ymin, ymax; TStates state_bez; ras.arc = ras.arcs; ras.arc[2].x = ras.lastX; ras.arc[2].y = ras.lastY; ras.arc[1].x = cx; ras.arc[1].y = cy; ras.arc[0].x = x; ras.arc[0].y = y; do { y1 = ras.arc[2].y; y2 = ras.arc[1].y; y3 = ras.arc[0].y; x3 = ras.arc[0].x; /* first, categorize the Bezier arc */ if ( y1 <= y3 ) { ymin = y1; ymax = y3; } else { ymin = y3; ymax = y1; } if ( y2 < ymin || y2 > ymax ) { /* this arc has no given direction, split it! */ Split_Conic( ras.arc ); ras.arc += 2; } else if ( y1 == y3 ) { /* this arc is flat, ignore it and pop it from the Bezier stack */ ras.arc -= 2; } else { /* the arc is y-monotonous, either ascending or descending */ /* detect a change of direction */ state_bez = y1 < y3 ? Ascending_State : Descending_State; if ( ras.state != state_bez ) { /* finalize current profile if any */ if ( ras.state != Unknown_State && End_Profile( RAS_VAR ) ) goto Fail; /* create a new profile */ if ( New_Profile( RAS_VARS state_bez ) ) goto Fail; } /* now call the appropriate routine */ if ( state_bez == Ascending_State ) { if ( Bezier_Up( RAS_VARS 2, Split_Conic, ras.minY, ras.maxY ) ) goto Fail; } else if ( Bezier_Down( RAS_VARS 2, Split_Conic, ras.minY, ras.maxY ) ) goto Fail; } } while ( ras.arc >= ras.arcs ); ras.lastX = x3; ras.lastY = y3; return SUCCESS; Fail: return FAILURE; } /*************************************************************************/ /* */ /* <Function> */ /* Cubic_To */ /* */ /* <Description> */ /* Injects a new cubic arc and adjusts the profile list. */ /* */ /* <Input> */ /* cx1 :: The x-coordinate of the arc's first new control point. */ /* */ /* cy1 :: The y-coordinate of the arc's first new control point. */ /* */ /* cx2 :: The x-coordinate of the arc's second new control point. */ /* */ /* cy2 :: The y-coordinate of the arc's second new control point. */ /* */ /* x :: The x-coordinate of the arc's end point (its start point is */ /* stored in `LastX'). */ /* */ /* y :: The y-coordinate of the arc's end point (its start point is */ /* stored in `LastY'). */ /* */ /* <Return> */ /* SUCCESS on success, FAILURE on render pool overflow or incorrect */ /* profile. */ /* */ static Bool Cubic_To( RAS_ARGS Long cx1, Long cy1, Long cx2, Long cy2, Long x, Long y ) { Long y1, y2, y3, y4, x4, ymin1, ymax1, ymin2, ymax2; TStates state_bez; ras.arc = ras.arcs; ras.arc[3].x = ras.lastX; ras.arc[3].y = ras.lastY; ras.arc[2].x = cx1; ras.arc[2].y = cy1; ras.arc[1].x = cx2; ras.arc[1].y = cy2; ras.arc[0].x = x; ras.arc[0].y = y; do { y1 = ras.arc[3].y; y2 = ras.arc[2].y; y3 = ras.arc[1].y; y4 = ras.arc[0].y; x4 = ras.arc[0].x; /* first, categorize the Bezier arc */ if ( y1 <= y4 ) { ymin1 = y1; ymax1 = y4; } else { ymin1 = y4; ymax1 = y1; } if ( y2 <= y3 ) { ymin2 = y2; ymax2 = y3; } else { ymin2 = y3; ymax2 = y2; } if ( ymin2 < ymin1 || ymax2 > ymax1 ) { /* this arc has no given direction, split it! */ Split_Cubic( ras.arc ); ras.arc += 3; } else if ( y1 == y4 ) { /* this arc is flat, ignore it and pop it from the Bezier stack */ ras.arc -= 3; } else { state_bez = ( y1 <= y4 ) ? Ascending_State : Descending_State; /* detect a change of direction */ if ( ras.state != state_bez ) { if ( ras.state != Unknown_State && End_Profile( RAS_VAR ) ) goto Fail; if ( New_Profile( RAS_VARS state_bez ) ) goto Fail; } /* compute intersections */ if ( state_bez == Ascending_State ) { if ( Bezier_Up( RAS_VARS 3, Split_Cubic, ras.minY, ras.maxY ) ) goto Fail; } else if ( Bezier_Down( RAS_VARS 3, Split_Cubic, ras.minY, ras.maxY ) ) goto Fail; } } while ( ras.arc >= ras.arcs ); ras.lastX = x4; ras.lastY = y4; return SUCCESS; Fail: return FAILURE; } #undef SWAP_ #define SWAP_( x, y ) do \ { \ Long swap = x; \ \ \ x = y; \ y = swap; \ } while ( 0 ) /*************************************************************************/ /* */ /* <Function> */ /* Decompose_Curve */ /* */ /* <Description> */ /* Scans the outline arays in order to emit individual segments and */ /* Beziers by calling Line_To() and Bezier_To(). It handles all */ /* weird cases, like when the first point is off the curve, or when */ /* there are simply no `on' points in the contour! */ /* */ /* <Input> */ /* first :: The index of the first point in the contour. */ /* */ /* last :: The index of the last point in the contour. */ /* */ /* flipped :: If set, flip the direction of the curve. */ /* */ /* <Return> */ /* SUCCESS on success, FAILURE on error. */ /* */ static Bool Decompose_Curve( RAS_ARGS UShort first, UShort last, int flipped ) { FT_Vector v_last; FT_Vector v_control; FT_Vector v_start; FT_Vector* points; FT_Vector* point; FT_Vector* limit; char* tags; unsigned tag; /* current point's state */ points = ras.outline.points; limit = points + last; v_start.x = SCALED( points[first].x ); v_start.y = SCALED( points[first].y ); v_last.x = SCALED( points[last].x ); v_last.y = SCALED( points[last].y ); if ( flipped ) { SWAP_( v_start.x, v_start.y ); SWAP_( v_last.x, v_last.y ); } v_control = v_start; point = points + first; tags = ras.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( ras.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--; } ras.lastX = v_start.x; ras.lastY = v_start.y; while ( point < limit ) { point++; tags++; tag = FT_CURVE_TAG( tags[0] ); switch ( tag ) { case FT_CURVE_TAG_ON: /* emit a single line_to */ { Long x, y; x = SCALED( point->x ); y = SCALED( point->y ); if ( flipped ) SWAP_( x, y ); if ( Line_To( RAS_VARS x, y ) ) goto Fail; continue; } case FT_CURVE_TAG_CONIC: /* consume conic arcs */ v_control.x = SCALED( point[0].x ); v_control.y = SCALED( point[0].y ); if ( flipped ) SWAP_( v_control.x, v_control.y ); Do_Conic: if ( point < limit ) { FT_Vector v_middle; Long x, y; point++; tags++; tag = FT_CURVE_TAG( tags[0] ); x = SCALED( point[0].x ); y = SCALED( point[0].y ); if ( flipped ) SWAP_( x, y ); if ( tag == FT_CURVE_TAG_ON ) { if ( Conic_To( RAS_VARS v_control.x, v_control.y, x, y ) ) goto Fail; continue; } if ( tag != FT_CURVE_TAG_CONIC ) goto Invalid_Outline; v_middle.x = ( v_control.x + x ) / 2; v_middle.y = ( v_control.y + y ) / 2; if ( Conic_To( RAS_VARS v_control.x, v_control.y, v_middle.x, v_middle.y ) ) goto Fail; v_control.x = x; v_control.y = y; goto Do_Conic; } if ( Conic_To( RAS_VARS v_control.x, v_control.y, v_start.x, v_start.y ) ) goto Fail; goto Close; default: /* FT_CURVE_TAG_CUBIC */ { Long x1, y1, x2, y2, x3, y3; if ( point + 1 > limit || FT_CURVE_TAG( tags[1] ) != FT_CURVE_TAG_CUBIC ) goto Invalid_Outline; point += 2; tags += 2; x1 = SCALED( point[-2].x ); y1 = SCALED( point[-2].y ); x2 = SCALED( point[-1].x ); y2 = SCALED( point[-1].y ); x3 = SCALED( point[ 0].x ); y3 = SCALED( point[ 0].y ); if ( flipped ) { SWAP_( x1, y1 ); SWAP_( x2, y2 ); SWAP_( x3, y3 ); } if ( point <= limit ) { if ( Cubic_To( RAS_VARS x1, y1, x2, y2, x3, y3 ) ) goto Fail; continue; } if ( Cubic_To( RAS_VARS x1, y1, x2, y2, v_start.x, v_start.y ) ) goto Fail; goto Close; } } } /* close the contour with a line segment */ if ( Line_To( RAS_VARS v_start.x, v_start.y ) ) goto Fail; Close: return SUCCESS; Invalid_Outline: ras.error = Raster_Err_Invalid; Fail: return FAILURE; } /*************************************************************************/ /* */ /* <Function> */ /* Convert_Glyph */ /* */ /* <Description> */ /* Converts a glyph into a series of segments and arcs and makes a */ /* profiles list with them. */ /* */ /* <Input> */ /* flipped :: If set, flip the direction of curve. */ /* */ /* <Return> */ /* SUCCESS on success, FAILURE if any error was encountered during */ /* rendering. */ /* */ static Bool Convert_Glyph( RAS_ARGS int flipped ) { int i; unsigned start; PProfile lastProfile; ras.fProfile = NULL; ras.joint = FALSE; ras.fresh = FALSE; ras.maxBuff = ras.sizeBuff - AlignProfileSize; ras.numTurns = 0; ras.cProfile = (PProfile)ras.top; ras.cProfile->offset = ras.top; ras.num_Profs = 0; start = 0; for ( i = 0; i < ras.outline.n_contours; i++ ) { ras.state = Unknown_State; ras.gProfile = NULL; if ( Decompose_Curve( RAS_VARS (unsigned short)start, ras.outline.contours[i], flipped ) ) return FAILURE; start = ras.outline.contours[i] + 1; /* We must now see whether the extreme arcs join or not */ if ( FRAC( ras.lastY ) == 0 && ras.lastY >= ras.minY && ras.lastY <= ras.maxY ) if ( ras.gProfile && ras.gProfile->flow == ras.cProfile->flow ) ras.top--; /* Note that ras.gProfile can be nil if the contour was too small */ /* to be drawn. */ lastProfile = ras.cProfile; if ( End_Profile( RAS_VAR ) ) return FAILURE; /* close the `next profile in contour' linked list */ if ( ras.gProfile ) lastProfile->next = ras.gProfile; } if ( Finalize_Profile_Table( RAS_VAR ) ) return FAILURE; return (Bool)( ras.top < ras.maxBuff ? SUCCESS : FAILURE ); } /*************************************************************************/ /*************************************************************************/ /** **/ /** SCAN-LINE SWEEPS AND DRAWING **/ /** **/ /*************************************************************************/ /*************************************************************************/ /*************************************************************************/ /* */ /* Init_Linked */ /* */ /* Initializes an empty linked list. */ /* */ static void Init_Linked( TProfileList* l ) { *l = NULL; } /*************************************************************************/ /* */ /* InsNew */ /* */ /* Inserts a new profile in a linked list. */ /* */ static void InsNew( PProfileList list, PProfile profile ) { PProfile *old, current; Long x; old = list; current = *old; x = profile->X; while ( current ) { if ( x < current->X ) break; old = ¤t->link; current = *old; } profile->link = current; *old = profile; } /*************************************************************************/ /* */ /* DelOld */ /* */ /* Removes an old profile from a linked list. */ /* */ static void DelOld( PProfileList list, PProfile profile ) { PProfile *old, current; old = list; current = *old; while ( current ) { if ( current == profile ) { *old = current->link; return; } old = ¤t->link; current = *old; } /* we should never get there, unless the profile was not part of */ /* the list. */ } /*************************************************************************/ /* */ /* Sort */ /* */ /* Sorts a trace list. In 95%, the list is already sorted. We need */ /* an algorithm which is fast in this case. Bubble sort is enough */ /* and simple. */ /* */ static void Sort( PProfileList list ) { PProfile *old, current, next; /* First, set the new X coordinate of each profile */ current = *list; while ( current ) { current->X = *current->offset; current->offset += current->flow; current->height--; current = current->link; } /* Then sort them */ old = list; current = *old; if ( !current ) return; next = current->link; while ( next ) { if ( current->X <= next->X ) { old = ¤t->link; current = *old; if ( !current ) return; } else { *old = next; current->link = next->link; next->link = current; old = list; current = *old; } next = current->link; } } /*************************************************************************/ /* */ /* Vertical Sweep Procedure Set */ /* */ /* These four routines are used during the vertical black/white sweep */ /* phase by the generic Draw_Sweep() function. */ /* */ /*************************************************************************/ static void Vertical_Sweep_Init( RAS_ARGS Short* min, Short* max ) { Long pitch = ras.target.pitch; FT_UNUSED( max ); ras.traceIncr = (Short)-pitch; ras.traceOfs = -*min * pitch; if ( pitch > 0 ) ras.traceOfs += ( ras.target.rows - 1 ) * pitch; ras.gray_min_x = 0; ras.gray_max_x = 0; } static void Vertical_Sweep_Span( RAS_ARGS Short y, FT_F26Dot6 x1, FT_F26Dot6 x2, PProfile left, PProfile right ) { Long e1, e2; int c1, c2; Byte f1, f2; Byte* target; FT_UNUSED( y ); FT_UNUSED( left ); FT_UNUSED( right ); /* Drop-out control */ e1 = TRUNC( CEILING( x1 ) ); if ( x2 - x1 - ras.precision <= ras.precision_jitter ) e2 = e1; else e2 = TRUNC( FLOOR( x2 ) ); if ( e2 >= 0 && e1 < ras.bWidth ) { if ( e1 < 0 ) e1 = 0; if ( e2 >= ras.bWidth ) e2 = ras.bWidth - 1; c1 = (Short)( e1 >> 3 ); c2 = (Short)( e2 >> 3 ); f1 = (Byte) ( 0xFF >> ( e1 & 7 ) ); f2 = (Byte) ~( 0x7F >> ( e2 & 7 ) ); if ( ras.gray_min_x > c1 ) ras.gray_min_x = (short)c1; if ( ras.gray_max_x < c2 ) ras.gray_max_x = (short)c2; target = ras.bTarget + ras.traceOfs + c1; c2 -= c1; if ( c2 > 0 ) { target[0] |= f1; /* memset() is slower than the following code on many platforms. */ /* This is due to the fact that, in the vast majority of cases, */ /* the span length in bytes is relatively small. */ c2--; while ( c2 > 0 ) { *(++target) = 0xFF; c2--; } target[1] |= f2; } else *target |= ( f1 & f2 ); } } static void Vertical_Sweep_Drop( RAS_ARGS Short y, FT_F26Dot6 x1, FT_F26Dot6 x2, PProfile left, PProfile right ) { Long e1, e2; Short c1, f1; /* Drop-out control */ e1 = CEILING( x1 ); e2 = FLOOR ( x2 ); if ( e1 > e2 ) { if ( e1 == e2 + ras.precision ) { switch ( ras.dropOutControl ) { case 1: e1 = e2; break; case 4: e1 = CEILING( (x1 + x2 + 1) / 2 ); break; case 2: case 5: /* Drop-out Control Rule #4 */ /* The spec is not very clear regarding rule #4. It */ /* presents a method that is way too costly to implement */ /* while the general idea seems to get rid of `stubs'. */ /* */ /* Here, we only get rid of stubs recognized if: */ /* */ /* upper stub: */ /* */ /* - P_Left and P_Right are in the same contour */ /* - P_Right is the successor of P_Left in that contour */ /* - y is the top of P_Left and P_Right */ /* */ /* lower stub: */ /* */ /* - P_Left and P_Right are in the same contour */ /* - P_Left is the successor of P_Right in that contour */ /* - y is the bottom of P_Left */ /* */ /* FIXXXME: uncommenting this line solves the disappearing */ /* bit problem in the `7' of verdana 10pts, but */ /* makes a new one in the `C' of arial 14pts */ #if 0 if ( x2 - x1 < ras.precision_half ) #endif { /* upper stub test */ if ( left->next == right && left->height <= 0 ) return; /* lower stub test */ if ( right->next == left && left->start == y ) return; } /* check that the rightmost pixel isn't set */ e1 = TRUNC( e1 ); c1 = (Short)( e1 >> 3 ); f1 = (Short)( e1 & 7 ); if ( e1 >= 0 && e1 < ras.bWidth && ras.bTarget[ras.traceOfs + c1] & ( 0x80 >> f1 ) ) return; if ( ras.dropOutControl == 2 ) e1 = e2; else e1 = CEILING( ( x1 + x2 + 1 ) / 2 ); break; default: return; /* unsupported mode */ } } else return; } e1 = TRUNC( e1 ); if ( e1 >= 0 && e1 < ras.bWidth ) { c1 = (Short)( e1 >> 3 ); f1 = (Short)( e1 & 7 ); if ( ras.gray_min_x > c1 ) ras.gray_min_x = c1; if ( ras.gray_max_x < c1 ) ras.gray_max_x = c1; ras.bTarget[ras.traceOfs + c1] |= (char)( 0x80 >> f1 ); } } static void Vertical_Sweep_Step( RAS_ARG ) { ras.traceOfs += ras.traceIncr; } /***********************************************************************/ /* */ /* Horizontal Sweep Procedure Set */ /* */ /* These four routines are used during the horizontal black/white */ /* sweep phase by the generic Draw_Sweep() function. */ /* */ /***********************************************************************/ static void Horizontal_Sweep_Init( RAS_ARGS Short* min, Short* max ) { /* nothing, really */ FT_UNUSED( raster ); FT_UNUSED( min ); FT_UNUSED( max ); } static void Horizontal_Sweep_Span( RAS_ARGS Short y, FT_F26Dot6 x1, FT_F26Dot6 x2, PProfile left, PProfile right ) { Long e1, e2; PByte bits; Byte f1; FT_UNUSED( left ); FT_UNUSED( right ); if ( x2 - x1 < ras.precision ) { e1 = CEILING( x1 ); e2 = FLOOR ( x2 ); if ( e1 == e2 ) { bits = ras.bTarget + ( y >> 3 ); f1 = (Byte)( 0x80 >> ( y & 7 ) ); e1 = TRUNC( e1 ); if ( e1 >= 0 && e1 < ras.target.rows ) { PByte p; p = bits - e1*ras.target.pitch; if ( ras.target.pitch > 0 ) p += ( ras.target.rows - 1 ) * ras.target.pitch; p[0] |= f1; } } } } static void Horizontal_Sweep_Drop( RAS_ARGS Short y, FT_F26Dot6 x1, FT_F26Dot6 x2, PProfile left, PProfile right ) { Long e1, e2; PByte bits; Byte f1; /* During the horizontal sweep, we only take care of drop-outs */ e1 = CEILING( x1 ); e2 = FLOOR ( x2 ); if ( e1 > e2 ) { if ( e1 == e2 + ras.precision ) { switch ( ras.dropOutControl ) { case 1: e1 = e2; break; case 4: e1 = CEILING( ( x1 + x2 + 1 ) / 2 ); break; case 2: case 5: /* Drop-out Control Rule #4 */ /* The spec is not very clear regarding rule #4. It */ /* presents a method that is way too costly to implement */ /* while the general idea seems to get rid of `stubs'. */ /* */ /* rightmost stub test */ if ( left->next == right && left->height <= 0 ) return; /* leftmost stub test */ if ( right->next == left && left->start == y ) return; /* check that the rightmost pixel isn't set */ e1 = TRUNC( e1 ); bits = ras.bTarget + ( y >> 3 ); f1 = (Byte)( 0x80 >> ( y & 7 ) ); bits -= e1 * ras.target.pitch; if ( ras.target.pitch > 0 ) bits += ( ras.target.rows - 1 ) * ras.target.pitch; if ( e1 >= 0 && e1 < ras.target.rows && *bits & f1 ) return; if ( ras.dropOutControl == 2 ) e1 = e2; else e1 = CEILING( ( x1 + x2 + 1 ) / 2 ); break; default: return; /* unsupported mode */ } } else return; } bits = ras.bTarget + ( y >> 3 ); f1 = (Byte)( 0x80 >> ( y & 7 ) ); e1 = TRUNC( e1 ); if ( e1 >= 0 && e1 < ras.target.rows ) { bits -= e1 * ras.target.pitch; if ( ras.target.pitch > 0 ) bits += ( ras.target.rows - 1 ) * ras.target.pitch; bits[0] |= f1; } } static void Horizontal_Sweep_Step( RAS_ARG ) { /* Nothing, really */ FT_UNUSED( raster ); } #ifdef FT_RASTER_OPTION_ANTI_ALIASING /*************************************************************************/ /* */ /* Vertical Gray Sweep Procedure Set */ /* */ /* These two routines are used during the vertical gray-levels sweep */ /* phase by the generic Draw_Sweep() function. */ /* */ /* NOTES */ /* */ /* - The target pixmap's width *must* be a multiple of 4. */ /* */ /* - You have to use the function Vertical_Sweep_Span() for the gray */ /* span call. */ /* */ /*************************************************************************/ static void Vertical_Gray_Sweep_Init( RAS_ARGS Short* min, Short* max ) { Long pitch, byte_len; *min = *min & -2; *max = ( *max + 3 ) & -2; ras.traceOfs = 0; pitch = ras.target.pitch; byte_len = -pitch; ras.traceIncr = (Short)byte_len; ras.traceG = ( *min / 2 ) * byte_len; if ( pitch > 0 ) { ras.traceG += ( ras.target.rows - 1 ) * pitch; byte_len = -byte_len; } ras.gray_min_x = (Short)byte_len; ras.gray_max_x = -(Short)byte_len; } static void Vertical_Gray_Sweep_Step( RAS_ARG ) { Int c1, c2; PByte pix, bit, bit2; Int* count = ras.count_table; Byte* grays; ras.traceOfs += ras.gray_width; if ( ras.traceOfs > ras.gray_width ) { pix = ras.gTarget + ras.traceG + ras.gray_min_x * 4; grays = ras.grays; if ( ras.gray_max_x >= 0 ) { Long last_pixel = ras.target.width - 1; Int last_cell = last_pixel >> 2; Int last_bit = last_pixel & 3; Bool over = 0; if ( ras.gray_max_x >= last_cell && last_bit != 3 ) { ras.gray_max_x = last_cell - 1; over = 1; } if ( ras.gray_min_x < 0 ) ras.gray_min_x = 0; bit = ras.bTarget + ras.gray_min_x; bit2 = bit + ras.gray_width; c1 = ras.gray_max_x - ras.gray_min_x; while ( c1 >= 0 ) { c2 = count[*bit] + count[*bit2]; if ( c2 ) { pix[0] = grays[(c2 >> 12) & 0x000F]; pix[1] = grays[(c2 >> 8 ) & 0x000F]; pix[2] = grays[(c2 >> 4 ) & 0x000F]; pix[3] = grays[ c2 & 0x000F]; *bit = 0; *bit2 = 0; } bit++; bit2++; pix += 4; c1--; } if ( over ) { c2 = count[*bit] + count[*bit2]; if ( c2 ) { switch ( last_bit ) { case 2: pix[2] = grays[(c2 >> 4 ) & 0x000F]; case 1: pix[1] = grays[(c2 >> 8 ) & 0x000F]; default: pix[0] = grays[(c2 >> 12) & 0x000F]; } *bit = 0; *bit2 = 0; } } } ras.traceOfs = 0; ras.traceG += ras.traceIncr; ras.gray_min_x = 32000; ras.gray_max_x = -32000; } } static void Horizontal_Gray_Sweep_Span( RAS_ARGS Short y, FT_F26Dot6 x1, FT_F26Dot6 x2, PProfile left, PProfile right ) { /* nothing, really */ FT_UNUSED( raster ); FT_UNUSED( y ); FT_UNUSED( x1 ); FT_UNUSED( x2 ); FT_UNUSED( left ); FT_UNUSED( right ); } static void Horizontal_Gray_Sweep_Drop( RAS_ARGS Short y, FT_F26Dot6 x1, FT_F26Dot6 x2, PProfile left, PProfile right ) { Long e1, e2; PByte pixel; Byte color; /* During the horizontal sweep, we only take care of drop-outs */ e1 = CEILING( x1 ); e2 = FLOOR ( x2 ); if ( e1 > e2 ) { if ( e1 == e2 + ras.precision ) { switch ( ras.dropOutControl ) { case 1: e1 = e2; break; case 4: e1 = CEILING( ( x1 + x2 + 1 ) / 2 ); break; case 2: case 5: /* Drop-out Control Rule #4 */ /* The spec is not very clear regarding rule #4. It */ /* presents a method that is way too costly to implement */ /* while the general idea seems to get rid of `stubs'. */ /* */ /* rightmost stub test */ if ( left->next == right && left->height <= 0 ) return; /* leftmost stub test */ if ( right->next == left && left->start == y ) return; if ( ras.dropOutControl == 2 ) e1 = e2; else e1 = CEILING( ( x1 + x2 + 1 ) / 2 ); break; default: return; /* unsupported mode */ } } else return; } if ( e1 >= 0 ) { if ( x2 - x1 >= ras.precision_half ) color = ras.grays[2]; else color = ras.grays[1]; e1 = TRUNC( e1 ) / 2; if ( e1 < ras.target.rows ) { pixel = ras.gTarget - e1 * ras.target.pitch + y / 2; if ( ras.target.pitch > 0 ) pixel += ( ras.target.rows - 1 ) * ras.target.pitch; if ( pixel[0] == ras.grays[0] ) pixel[0] = color; } } } #endif /* FT_RASTER_OPTION_ANTI_ALIASING */ /*************************************************************************/ /* */ /* Generic Sweep Drawing routine */ /* */ /*************************************************************************/ static Bool Draw_Sweep( RAS_ARG ) { Short y, y_change, y_height; PProfile P, Q, P_Left, P_Right; Short min_Y, max_Y, top, bottom, dropouts; Long x1, x2, xs, e1, e2; TProfileList waiting; TProfileList draw_left, draw_right; /* Init empty linked lists */ Init_Linked( &waiting ); Init_Linked( &draw_left ); Init_Linked( &draw_right ); /* first, compute min and max Y */ P = ras.fProfile; max_Y = (Short)TRUNC( ras.minY ); min_Y = (Short)TRUNC( ras.maxY ); while ( P ) { Q = P->link; bottom = (Short)P->start; top = (Short)( P->start + P->height - 1 ); if ( min_Y > bottom ) min_Y = bottom; if ( max_Y < top ) max_Y = top; P->X = 0; InsNew( &waiting, P ); P = Q; } /* Check the Y-turns */ if ( ras.numTurns == 0 ) { ras.error = Raster_Err_Invalid; return FAILURE; } /* Now inits the sweep */ ras.Proc_Sweep_Init( RAS_VARS &min_Y, &max_Y ); /* Then compute the distance of each profile from min_Y */ P = waiting; while ( P ) { P->countL = (UShort)( P->start - min_Y ); P = P->link; } /* Let's go */ y = min_Y; y_height = 0; if ( ras.numTurns > 0 && ras.sizeBuff[-ras.numTurns] == min_Y ) ras.numTurns--; while ( ras.numTurns > 0 ) { /* look in the waiting list for new activations */ P = waiting; while ( P ) { Q = P->link; P->countL -= y_height; if ( P->countL == 0 ) { DelOld( &waiting, P ); switch ( P->flow ) { case Flow_Up: InsNew( &draw_left, P ); break; case Flow_Down: InsNew( &draw_right, P ); break; } } P = Q; } /* Sort the drawing lists */ Sort( &draw_left ); Sort( &draw_right ); y_change = (Short)ras.sizeBuff[-ras.numTurns--]; y_height = (Short)( y_change - y ); while ( y < y_change ) { /* Let's trace */ dropouts = 0; P_Left = draw_left; P_Right = draw_right; while ( P_Left ) { x1 = P_Left ->X; x2 = P_Right->X; if ( x1 > x2 ) { xs = x1; x1 = x2; x2 = xs; } if ( x2 - x1 <= ras.precision ) { e1 = FLOOR( x1 ); e2 = CEILING( x2 ); if ( ras.dropOutControl != 0 && ( e1 > e2 || e2 == e1 + ras.precision ) ) { /* a drop out was detected */ P_Left ->X = x1; P_Right->X = x2; /* mark profile for drop-out processing */ P_Left->countL = 1; dropouts++; goto Skip_To_Next; } } ras.Proc_Sweep_Span( RAS_VARS y, x1, x2, P_Left, P_Right ); Skip_To_Next: P_Left = P_Left->link; P_Right = P_Right->link; } /* now perform the dropouts _after_ the span drawing -- */ /* drop-outs processing has been moved out of the loop */ /* for performance tuning */ if ( dropouts > 0 ) goto Scan_DropOuts; Next_Line: ras.Proc_Sweep_Step( RAS_VAR ); y++; if ( y < y_change ) { Sort( &draw_left ); Sort( &draw_right ); } } /* Now finalize the profiles that needs it */ P = draw_left; while ( P ) { Q = P->link; if ( P->height == 0 ) DelOld( &draw_left, P ); P = Q; } P = draw_right; while ( P ) { Q = P->link; if ( P->height == 0 ) DelOld( &draw_right, P ); P = Q; } } /* for gray-scaling, flushes the bitmap scanline cache */ while ( y <= max_Y ) { ras.Proc_Sweep_Step( RAS_VAR ); y++; } return SUCCESS; Scan_DropOuts: P_Left = draw_left; P_Right = draw_right; while ( P_Left ) { if ( P_Left->countL ) { P_Left->countL = 0; #if 0 dropouts--; /* -- this is useful when debugging only */ #endif ras.Proc_Sweep_Drop( RAS_VARS y, P_Left->X, P_Right->X, P_Left, P_Right ); } P_Left = P_Left->link; P_Right = P_Right->link; } goto Next_Line; } /*************************************************************************/ /* */ /* <Function> */ /* Render_Single_Pass */ /* */ /* <Description> */ /* Performs one sweep with sub-banding. */ /* */ /* <Input> */ /* flipped :: If set, flip the direction of the outline. */ /* */ /* <Return> */ /* Renderer error code. */ /* */ static int Render_Single_Pass( RAS_ARGS Bool flipped ) { Short i, j, k; while ( ras.band_top >= 0 ) { ras.maxY = (Long)ras.band_stack[ras.band_top].y_max * ras.precision; ras.minY = (Long)ras.band_stack[ras.band_top].y_min * ras.precision; ras.top = ras.buff; ras.error = Raster_Err_None; if ( Convert_Glyph( RAS_VARS flipped ) ) { if ( ras.error != Raster_Err_Overflow ) return FAILURE; ras.error = Raster_Err_None; /* sub-banding */ #ifdef DEBUG_RASTER ClearBand( RAS_VARS TRUNC( ras.minY ), TRUNC( ras.maxY ) ); #endif i = ras.band_stack[ras.band_top].y_min; j = ras.band_stack[ras.band_top].y_max; k = (Short)( ( i + j ) / 2 ); if ( ras.band_top >= 7 || k < i ) { ras.band_top = 0; ras.error = Raster_Err_Invalid; return ras.error; } ras.band_stack[ras.band_top + 1].y_min = k; ras.band_stack[ras.band_top + 1].y_max = j; ras.band_stack[ras.band_top].y_max = (Short)( k - 1 ); ras.band_top++; } else { if ( ras.fProfile ) if ( Draw_Sweep( RAS_VAR ) ) return ras.error; ras.band_top--; } } return SUCCESS; } /*************************************************************************/ /* */ /* <Function> */ /* Render_Glyph */ /* */ /* <Description> */ /* Renders a glyph in a bitmap. Sub-banding if needed. */ /* */ /* <Return> */ /* FreeType error code. 0 means success. */ /* */ FT_LOCAL_DEF( FT_Error ) Render_Glyph( RAS_ARG ) { FT_Error error; Set_High_Precision( RAS_VARS ras.outline.flags & FT_OUTLINE_HIGH_PRECISION ); ras.scale_shift = ras.precision_shift; ras.dropOutControl = 2; ras.second_pass = (FT_Byte)( !( ras.outline.flags & FT_OUTLINE_SINGLE_PASS ) ); /* Vertical Sweep */ ras.Proc_Sweep_Init = Vertical_Sweep_Init; ras.Proc_Sweep_Span = Vertical_Sweep_Span; ras.Proc_Sweep_Drop = Vertical_Sweep_Drop; ras.Proc_Sweep_Step = Vertical_Sweep_Step; ras.band_top = 0; ras.band_stack[0].y_min = 0; ras.band_stack[0].y_max = (short)( ras.target.rows - 1 ); ras.bWidth = (unsigned short)ras.target.width; ras.bTarget = (Byte*)ras.target.buffer; if ( ( error = Render_Single_Pass( RAS_VARS 0 ) ) != 0 ) return error; /* Horizontal Sweep */ if ( ras.second_pass && ras.dropOutControl != 0 ) { ras.Proc_Sweep_Init = Horizontal_Sweep_Init; ras.Proc_Sweep_Span = Horizontal_Sweep_Span; ras.Proc_Sweep_Drop = Horizontal_Sweep_Drop; ras.Proc_Sweep_Step = Horizontal_Sweep_Step; ras.band_top = 0; ras.band_stack[0].y_min = 0; ras.band_stack[0].y_max = (short)( ras.target.width - 1 ); if ( ( error = Render_Single_Pass( RAS_VARS 1 ) ) != 0 ) return error; } return Raster_Err_Ok; } #ifdef FT_RASTER_OPTION_ANTI_ALIASING /*************************************************************************/ /* */ /* <Function> */ /* Render_Gray_Glyph */ /* */ /* <Description> */ /* Renders a glyph with grayscaling. Sub-banding if needed. */ /* */ /* <Return> */ /* FreeType error code. 0 means success. */ /* */ FT_LOCAL_DEF( FT_Error ) Render_Gray_Glyph( RAS_ARG ) { Long pixel_width; FT_Error error; Set_High_Precision( RAS_VARS ras.outline.flags & FT_OUTLINE_HIGH_PRECISION ); ras.scale_shift = ras.precision_shift + 1; ras.dropOutControl = 2; ras.second_pass = !( ras.outline.flags & FT_OUTLINE_SINGLE_PASS ); /* Vertical Sweep */ ras.band_top = 0; ras.band_stack[0].y_min = 0; ras.band_stack[0].y_max = 2 * ras.target.rows - 1; ras.bWidth = ras.gray_width; pixel_width = 2 * ( ( ras.target.width + 3 ) >> 2 ); if ( ras.bWidth > pixel_width ) ras.bWidth = pixel_width; ras.bWidth = ras.bWidth * 8; ras.bTarget = (Byte*)ras.gray_lines; ras.gTarget = (Byte*)ras.target.buffer; ras.Proc_Sweep_Init = Vertical_Gray_Sweep_Init; ras.Proc_Sweep_Span = Vertical_Sweep_Span; ras.Proc_Sweep_Drop = Vertical_Sweep_Drop; ras.Proc_Sweep_Step = Vertical_Gray_Sweep_Step; error = Render_Single_Pass( RAS_VARS 0 ); if ( error ) return error; /* Horizontal Sweep */ if ( ras.second_pass && ras.dropOutControl != 0 ) { ras.Proc_Sweep_Init = Horizontal_Sweep_Init; ras.Proc_Sweep_Span = Horizontal_Gray_Sweep_Span; ras.Proc_Sweep_Drop = Horizontal_Gray_Sweep_Drop; ras.Proc_Sweep_Step = Horizontal_Sweep_Step; ras.band_top = 0; ras.band_stack[0].y_min = 0; ras.band_stack[0].y_max = ras.target.width * 2 - 1; error = Render_Single_Pass( RAS_VARS 1 ); if ( error ) return error; } return Raster_Err_Ok; } #else /* !FT_RASTER_OPTION_ANTI_ALIASING */ FT_LOCAL_DEF( FT_Error ) Render_Gray_Glyph( RAS_ARG ) { FT_UNUSED_RASTER; return Raster_Err_Cannot_Render_Glyph; } #endif /* !FT_RASTER_OPTION_ANTI_ALIASING */ static void ft_black_init( TRaster_Instance* raster ) { FT_UInt n; FT_ULong c; /* setup count table */ for ( n = 0; n < 256; n++ ) { c = ( n & 0x55 ) + ( ( n & 0xAA ) >> 1 ); c = ( ( c << 6 ) & 0x3000 ) | ( ( c << 4 ) & 0x0300 ) | ( ( c << 2 ) & 0x0030 ) | (c & 0x0003 ); raster->count_table[n] = (UInt)c; } #ifdef FT_RASTER_OPTION_ANTI_ALIASING /* set default 5-levels gray palette */ for ( n = 0; n < 5; n++ ) raster->grays[n] = n * 255 / 4; raster->gray_width = RASTER_GRAY_LINES / 2; #endif } /**** RASTER OBJECT CREATION: In standalone mode, we simply use *****/ /**** a static object. *****/ #ifdef _STANDALONE_ static int ft_black_new( void* memory, FT_Raster *araster ) { static FT_RasterRec_ the_raster; *araster = &the_raster; FT_MEM_ZERO( &the_raster, sizeof ( the_raster ) ); ft_black_init( &the_raster ); return 0; } static void ft_black_done( FT_Raster raster ) { /* nothing */ raster->init = 0; } #else /* _STANDALONE_ */ static int ft_black_new( FT_Memory memory, TRaster_Instance** araster ) { FT_Error error; TRaster_Instance* raster; *araster = 0; if ( !FT_NEW( raster ) ) { raster->memory = memory; ft_black_init( raster ); *araster = raster; } return error; } static void ft_black_done( TRaster_Instance* raster ) { FT_Memory memory = (FT_Memory)raster->memory; FT_FREE( raster ); } #endif /* _STANDALONE_ */ static void ft_black_reset( TRaster_Instance* raster, const char* pool_base, long pool_size ) { if ( raster && pool_base && pool_size >= 4096 ) { /* save the pool */ raster->buff = (PLong)pool_base; raster->sizeBuff = raster->buff + pool_size / sizeof ( Long ); } } static void ft_black_set_mode( TRaster_Instance* raster, unsigned long mode, const char* palette ) { #ifdef FT_RASTER_OPTION_ANTI_ALIASING if ( mode == FT_MAKE_TAG( 'p', 'a', 'l', '5' ) ) { /* set 5-levels gray palette */ raster->grays[0] = palette[0]; raster->grays[1] = palette[1]; raster->grays[2] = palette[2]; raster->grays[3] = palette[3]; raster->grays[4] = palette[4]; } #else FT_UNUSED( raster ); FT_UNUSED( mode ); FT_UNUSED( palette ); #endif } static int ft_black_render( TRaster_Instance* raster, FT_Raster_Params* params ) { FT_Outline* outline = (FT_Outline*)params->source; FT_Bitmap* target_map = params->target; if ( !raster || !raster->buff || !raster->sizeBuff ) return Raster_Err_Not_Ini; /* return immediately if the outline is empty */ if ( outline->n_points == 0 || outline->n_contours <= 0 ) return Raster_Err_None; if ( !outline || !outline->contours || !outline->points ) return Raster_Err_Invalid; if ( outline->n_points != outline->contours[outline->n_contours - 1] + 1 ) return Raster_Err_Invalid; /* this version of the raster does not support direct rendering, sorry */ if ( params->flags & FT_RASTER_FLAG_DIRECT ) return Raster_Err_Unsupported; if ( !target_map || !target_map->buffer ) return Raster_Err_Invalid; ras.outline = *outline; ras.target = *target_map; return ( ( params->flags & FT_RASTER_FLAG_AA ) ? Render_Gray_Glyph( raster ) : Render_Glyph( raster ) ); } const FT_Raster_Funcs ft_standard_raster = { FT_GLYPH_FORMAT_OUTLINE, (FT_Raster_New_Func) ft_black_new, (FT_Raster_Reset_Func) ft_black_reset, (FT_Raster_Set_Mode_Func)ft_black_set_mode, (FT_Raster_Render_Func) ft_black_render, (FT_Raster_Done_Func) ft_black_done }; /* END */