ref: ea44d5ec3d7460e56c4cc681e8a36637a39a71e3
dir: /src/base/ftraster.c/
/*******************************************************************
*
* ftraster.c 1.5
*
* The FreeType glyph rasterizer (body).
*
* Copyright 1996-2000 by
* David Turner, Robert Wilhelm, and Werner Lemberg.
*
* This file is part of the FreeType project, and may only be used
* modified and distributed under the terms of the FreeType project
* license, LICENSE.TXT. By continuing to use, modify, or distribute
* this file you indicate that you have read the license and
* understand and accept it fully.
*
*
* This is a rewrite of the FreeType 1.x scan-line converter
*
*
*
******************************************************************/
#include <freetype/ftraster.h>
#include <freetype/internal/ftcalc.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 */
/* which are: */
/* */
/* 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 wether is 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. Additionaly, 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) **/
/** **/
/****************************************************************/
/****************************************************************/
/* required by the tracing mode */
#undef FT_COMPONENT
#define FT_COMPONENT trace_raster
#include <freetype/internal/ftdebug.h>
#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_Gray_Unsupported -5
#define Raster_Err_Unsupported -6
/* 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 in 32 bits. */
#define FMulDiv( a, b, c ) ( (a) * (b) / (c) )
/* On the other hand, SMulDiv is for "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,
Ascending,
Descending,
Flat
} 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 */
UShort 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 */
#else
#define RAS_ARGS TRaster_Instance* raster,
#define RAS_ARG TRaster_Instance* raster
#define RAS_VARS raster,
#define RAS_VAR raster
#endif
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[2 * 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_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_TRACE7(( "Set_High_Precision(%s)\n", High ? "true" : "false" ));
ras.precision = 1L << 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 state/orientation of the new Profile */
/* */
/* Returns: 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:
ras.cProfile->flow = Flow_Up;
FT_TRACE7(( "New ascending profile = %lx\n", (long)ras.cProfile ));
break;
case Descending:
ras.cProfile->flow = Flow_Down;
FT_TRACE7(( "New descending profile = %lx\n", (long)ras.cProfile ));
break;
default:
FT_ERROR(( "Invalid profile direction in Raster:New_Profile !!\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. */
/* */
/* Input: None */
/* */
/* Returns: SUCCESS on success. */
/* FAILURE in case of overflow or incoherency. */
/* */
/****************************************************************************/
static Bool End_Profile( RAS_ARG )
{
Long h;
PProfile oldProfile;
h = ras.top - ras.cProfile->offset;
if ( h < 0 )
{
FT_ERROR(( "Negative height encountered in End_Profile!\n" ));
ras.error = Raster_Err_Neg_Height;
return FAILURE;
}
if ( h > 0 )
{
FT_TRACE1(( "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: Insert a salient into the sorted list placed on top */
/* of the render pool */
/* */
/* Input: New y scanline position */
/* */
/****************************************************************************/
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 = 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. */
/* */
/* Input: None */
/* */
/* Returns: None. */
/* */
/****************************************************************************/
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 = p->start - p->height+1;
top = p->start;
p->start = bottom;
p->offset += p->height-1;
break;
case Flow_Up:
default:
bottom = p->start;
top = 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). */
/* */
/* Returns: None. */
/* */
/* */
/* 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 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,y1,x2,y2 Segment start (x1,y1) and end (x2,y2) points */
/* */
/* Returns: 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 = TRUNC( y1 );
f1 = FRAC( y1 );
}
if ( y2 > maxy )
{
/* x2 += FMulDiv( Dx, maxy - y2, Dy ); UNNECESSARY */
e2 = TRUNC( maxy );
f2 = 0;
}
else
{
e2 = TRUNC( y2 );
f2 = 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 = ( 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;
}
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;
}
/****************************************************************************/
/* */
/* Function: Bezier_Up */
/* */
/* Description: Computes thes x-coordinates of an ascending bezier arc */
/* and stores them in the render pool. */
/* */
/* A function type describing the functions used to split bezier arcs */
typedef void (*TSplitter)( TPoint* base );
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 = 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 a descending bezier arc */
/* and stores them in the render pool. */
/* */
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, y : segment endpoint (start point in LastX,LastY) */
/* */
/* Returns: 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:
if ( y > ras.lastY )
{
if ( New_Profile( RAS_VARS Ascending ) ) return FAILURE;
}
else
{
if ( y < ras.lastY )
if ( New_Profile( RAS_VARS Descending ) ) return FAILURE;
}
break;
case Ascending:
if ( y < ras.lastY )
{
if ( End_Profile( RAS_VAR ) ||
New_Profile( RAS_VARS Descending ) ) return FAILURE;
}
break;
case Descending:
if ( y > ras.lastY )
{
if ( End_Profile( RAS_VAR ) ||
New_Profile( RAS_VARS Ascending ) ) return FAILURE;
}
break;
default:
;
}
/* Then compute the lines */
switch ( ras.state )
{
case Ascending:
if ( Line_Up ( RAS_VARS ras.lastX, ras.lastY,
x, y, ras.minY, ras.maxY ) )
return FAILURE;
break;
case Descending:
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. */
/* */
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 : Descending;
if ( ras.state != state_bez )
{
/* finalize current profile if any */
if ( ras.state != Unknown &&
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 )
{
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. */
/* */
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 : Descending;
/* detect a change of direction */
if ( ras.state != state_bez )
{
if ( ras.state != Unknown &&
End_Profile( RAS_VAR ) )
goto Fail;
if ( New_Profile( RAS_VARS state_bez ) )
goto Fail;
}
/* compute intersections */
if ( state_bez == Ascending )
{
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;
}
/****************************************************************************/
/* */
/* 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, last : indexes of first and last point in */
/* contour. */
/* */
/* Returns: SUCCESS on success. */
/* FAILURE on error. */
/* */
/****************************************************************************/
#undef SWAP_
#define SWAP_(x,y) { Long swap = x; x = y; y = swap; }
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;
char 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: _xCoord, _yCoord : coordinates tables. */
/* */
/* Uses the 'Flag' table too. */
/* */
/* Returns: SUCCESS on success. */
/* FAILURE if any error was encountered during rendering. */
/* */
/****************************************************************************/
static Bool Convert_Glyph( RAS_ARGS int flipped )
{
Short i;
UShort 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;
ras.gProfile = NULL;
if ( Decompose_Curve( RAS_VARS start, ras.outline.contours[i], flipped ) )
return FAILURE;
start = ras.outline.contours[i] + 1;
/* We must now see if 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 (ras.top < ras.maxBuff ? SUCCESS : FAILURE );
}
/****************************************************************/
/****************************************************************/
/** **/
/** SCAN-LINE SWEEPS AND DRAWING **/
/** **/
/****************************************************************/
/****************************************************************/
/************************************************/
/* */
/* Init_Linked */
/* */
/* Inits 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. */
}
/************************************************/
/* */
/* Update : */
/* */
/* Update all X offsets of a drawing list */
/* */
/************************************************/
static void Update( PProfile first )
{
PProfile current = first;
while ( current )
{
current->X = *current->offset;
current->offset += current->flow;
current->height--;
current = current->link;
}
}
/************************************************/
/* */
/* 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 */
Update( *list );
/* 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 three 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;
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;
Short c1, c2;
Byte f1, f2;
Byte* target;
UNUSED(y);
UNUSED(left);
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 = ((unsigned char)0xFF >> (e1 & 7));
f2 = ~((unsigned char)0x7F >> (e2 & 7));
if ( ras.gray_min_x > c1 ) ras.gray_min_x = c1;
if ( ras.gray_max_x < c2 ) ras.gray_max_x = 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 when: */
/* */
/* 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 ( x2-x1 < ras.precision_half ) */
{
/* 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 = 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 = 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 three 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 */
UNUSED(raster);
UNUSED(min);
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;
UNUSED(left);
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 */
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 */
UNUSED(raster);
UNUSED(y);
UNUSED(x1);
UNUSED(x2);
UNUSED(left);
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 wait;
TProfileList draw_left, draw_right;
/* Init empty linked lists */
Init_Linked( &wait );
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( &wait, 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 = wait;
while ( P )
{
P->countL = 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 wait list for new activations */
P = wait;
while ( P )
{
Q = P->link;
P->countL -= y_height;
if ( P->countL == 0 )
{
DelOld( &wait, 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 = 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 */
{
PProfile Q, P;
P = draw_left;
while ( P )
{
Q = P->link;
if ( P->height == 0 )
DelOld( &draw_left, P );
P = Q;
}
}
{
PProfile 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;
/* dropouts--; -- this is useful when debugging only */
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: _XCoord, _YCoord : x and y coordinates arrays */
/* */
/* Returns: SUCCESS on success */
/* FAILURE if any error was encountered during render. */
/* */
/****************************************************************************/
static FT_Error 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 = ( 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 = k - 1;
ras.band_top++;
}
else
{
if ( ras.fProfile )
if ( Draw_Sweep( RAS_VAR ) ) return ras.error;
ras.band_top--;
}
}
return FT_Err_Ok;
}
/****************************************************************************/
/* */
/* Function: Render_Glyph */
/* */
/* Description: Renders a glyph in a bitmap. Sub-banding if needed. */
/* */
/* Input: AGlyph Glyph record */
/* */
/* Returns: SUCCESS on success. */
/* FAILURE if any error was encountered during rendering. */
/* */
/****************************************************************************/
LOCAL_FUNC
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 = !(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 = ras.target.rows - 1;
ras.bWidth = 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 = ras.target.width - 1;
if ( (error = Render_Single_Pass( RAS_VARS 1 )) != 0 )
return error;
}
return FT_Err_Ok;
}
/****************************************************************************/
/* */
/* Function: Render_Gray_Glyph */
/* */
/* Description: Renders a glyph with grayscaling. Sub-banding if needed. */
/* */
/* Input: AGlyph Glyph record */
/* */
/* Returns: SUCCESS on success */
/* FAILURE if any error was encountered during rendering. */
/* */
/****************************************************************************/
#ifdef FT_RASTER_OPTION_ANTI_ALIASING
LOCAL_FUNC
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 FT_Err_Ok;
}
#else
LOCAL_FUNC
FT_Error Render_Gray_Glyph( RAS_ARG )
{
UNUSED_RASTER
return Raster_Err_Unsupported;
}
#endif
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] = c;
}
/* set default 5-levels gray palette */
for ( n = 0; n < 5; n++ )
raster->grays[n] = (n*127/4);
raster->gray_width = RASTER_GRAY_LINES/2;
}
/**** 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;
memset( &the_raster, sizeof(the_raster), 0 );
ft_black_init( &the_raster );
return 0;
}
static
void ft_black_done( FT_Raster raster )
{
/* nothing */
raster->init = 0;
}
#else
#include <freetype/internal/ftobjs.h>
static
int ft_black_new( FT_Memory memory, TRaster_Instance* *araster )
{
FT_Error error;
TRaster_Instance* raster;
*araster = 0;
if ( !ALLOC( raster, sizeof(*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;
FREE( raster );
}
#endif
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 )
{
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];
}
}
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;
if ( !outline || !outline->contours || !outline->points )
return Raster_Err_Invalid;
/* return immediately if the outline is empty */
if ( outline->n_points == 0 || outline->n_contours <= 0 )
return Raster_Err_None;
if ( outline->n_points != outline->contours[outline->n_contours - 1] + 1 )
return Raster_Err_Invalid;
if ( !target_map || !target_map->buffer )
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;
ras.outline = *outline;
ras.target = *target_map;
return ( params->flags & ft_raster_flag_aa
? Render_Gray_Glyph( raster )
: Render_Glyph( raster ) );
}
FT_Raster_Funcs ft_default_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 */