ref: 3562d014e6579746f1876a6952c6567f9294c5a4
dir: /src/base/ftoutln.c/
/***************************************************************************/
/* */
/* ftoutln.c */
/* */
/* FreeType outline management (body). */
/* */
/* Copyright 1996-1999 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. */
/* */
/***************************************************************************/
/*************************************************************************/
/* */
/* All functions are declared in freetype.h. */
/* */
/*************************************************************************/
#include <freetype.h>
#include <ftconfig.h>
#include <ftobjs.h>
#include <ftimage.h>
#include <ftoutln.h>
static
const FT_Outline null_outline = { 0, 0, 0, 0, 0, 0 };
/*************************************************************************/
/* */
/* <Function> */
/* FT_Outline_Decompose */
/* */
/* <Description> */
/* Walks over an outline's structure to decompose it into individual */
/* segments and Bezier arcs. This function is also able to emit */
/* `move to' and `close to' operations to indicate the start and end */
/* of new contours in the outline. */
/* */
/* <Input> */
/* outline :: A pointer to the source target. */
/* */
/* interface :: A table of `emitters', i.e,. function pointers called */
/* during decomposition to indicate path operations. */
/* */
/* user :: A typeless pointer which is passed to each emitter */
/* during the decomposition. It can be used to store */
/* the state during the decomposition. */
/* */
/* <Return> */
/* Error code. 0 means sucess. */
/* */
EXPORT_FUNC
int FT_Outline_Decompose( FT_Outline* outline,
FT_Outline_Funcs* interface,
void* user )
{
typedef enum _phases
{
phase_point,
phase_conic,
phase_cubic,
phase_cubic2
} TPhase;
FT_Vector v_first;
FT_Vector v_last;
FT_Vector v_control;
FT_Vector v_start;
FT_Vector* point;
FT_Vector* limit;
char* tags;
int n; /* index of contour in outline */
int first; /* index of first point in contour */
int error;
char tag; /* current point's state */
first = 0;
for ( n = 0; n < outline->n_contours; n++ )
{
int last; /* index of last point in contour */
last = outline->contours[n];
limit = outline->points + last;
v_first = outline->points[first];
v_last = outline->points[last];
v_start = v_control = v_first;
point = outline->points + first;
tags = outline->tags + first;
tag = FT_CURVE_TAG( tags[0] );
/* A contour cannot start with a cubic control point! */
if ( tag == FT_Curve_Tag_Cubic )
goto Invalid_Outline;
/* check first point to determine origin */
if ( tag == FT_Curve_Tag_Conic )
{
/* first point is conic control. Yes, this happens. */
if ( FT_CURVE_TAG( outline->tags[last] ) == FT_Curve_Tag_On )
{
/* start at last point if it is on the curve */
v_start = v_last;
limit--;
}
else
{
/* if both first and last points are conic, */
/* start at their middle and record its position */
/* for closure */
v_start.x = ( v_start.x + v_last.x ) / 2;
v_start.y = ( v_start.y + v_last.y ) / 2;
v_last = v_start;
}
point--;
tags--;
}
error = interface->move_to( &v_start, user );
if (error) goto Exit;
while (point < limit)
{
point++;
tags++;
tag = FT_CURVE_TAG( tags[0] );
switch (tag)
{
case FT_Curve_Tag_On: /* emit a single line_to */
{
error = interface->line_to( point, user );
if (error) goto Exit;
continue;
}
case FT_Curve_Tag_Conic: /* consume conic arcs */
{
v_control = point[0];
Do_Conic:
if (point < limit)
{
FT_Vector v_middle;
point++;
tags++;
tag = FT_CURVE_TAG( tags[0] );
if (tag == FT_Curve_Tag_On)
{
error = interface->conic_to( &v_control, point, user );
if (error) goto Exit;
continue;
}
if (tag != FT_Curve_Tag_Conic)
goto Invalid_Outline;
v_middle.x = (v_control.x + point->x)/2;
v_middle.y = (v_control.y + point->y)/2;
error = interface->conic_to( &v_control, &v_middle, user );
if (error) goto Exit;
v_control = point[0];
goto Do_Conic;
}
error = interface->conic_to( &v_control, &v_start, user );
goto Close;
}
default: /* FT_Curve_Tag_Cubic */
{
if ( point+1 > limit ||
FT_CURVE_TAG( tags[1] ) != FT_Curve_Tag_Cubic )
goto Invalid_Outline;
point += 2;
tags += 2;
if (point <= limit)
{
error = interface->cubic_to( point-2, point-1, point, user );
if (error) goto Exit;
continue;
}
error = interface->cubic_to( point-2, point-1, &v_start, user );
goto Close;
}
}
}
/* close the contour with a line segment */
error = interface->line_to( &v_start, user );
Close:
if (error) goto Exit;
first = last+1;
}
return 0;
Exit:
return error;
Invalid_Outline:
return -1;
}
/*************************************************************************/
/* */
/* <Function> */
/* FT_Outline_New */
/* */
/* <Description> */
/* Creates a new outline of a given size. */
/* */
/* <Input> */
/* library :: A handle to the library object from where the */
/* outline is allocated. Note however that the new */
/* outline will NOT necessarily be FREED when */
/* destroying the library, by FT_Done_FreeType(). */
/* */
/* numPoints :: The maximum number of points within the outline. */
/* */
/* numContours :: The maximum number of contours within the outline. */
/* */
/* <Output> */
/* outline :: A handle to the new outline. NULL in case of */
/* error. */
/* */
/* <Return> */
/* FreeType error code. 0 means success. */
/* */
/* <MT-Note> */
/* No. */
/* */
/* <Note> */
/* The reason why this function takes a `library' parameter is simply */
/* to use the library's memory allocator. You can copy the source */
/* code of this function, replacing allocations with `malloc()' if */
/* you want to control where the objects go. */
/* */
BASE_FUNC
FT_Error FT_Outline_New( FT_Library library,
FT_UInt numPoints,
FT_Int numContours,
FT_Outline* outline )
{
FT_Error error;
FT_Memory memory;
if ( !outline )
return FT_Err_Invalid_Argument;
*outline = null_outline;
memory = library->memory;
if ( ALLOC_ARRAY( outline->points, numPoints * 2L, FT_Pos ) ||
ALLOC_ARRAY( outline->tags, numPoints, FT_Byte ) ||
ALLOC_ARRAY( outline->contours, numContours, FT_UShort ) )
goto Fail;
outline->n_points = (FT_UShort)numPoints;
outline->n_contours = (FT_Short)numContours;
outline->flags |= ft_outline_owner;
return FT_Err_Ok;
Fail:
outline->flags |= ft_outline_owner;
FT_Outline_Done( library, outline );
return error;
}
/*************************************************************************/
/* */
/* <Function> */
/* FT_Outline_Done */
/* */
/* <Description> */
/* Destroys an outline created with FT_Outline_New(). */
/* */
/* <Input> */
/* library :: A handle of the library object used to allocate the */
/* outline. */
/* */
/* outline :: A pointer to the outline object to be discarded. */
/* */
/* <Return> */
/* FreeType error code. 0 means success. */
/* */
/* <MT-Note> */
/* No. */
/* */
/* <Note> */
/* If the outline's `owner' field is not set, only the outline */
/* descriptor will be released. */
/* */
/* The reason why this function takes an `outline' parameter is */
/* simply to use FT_Alloc()/FT_Free(). You can copy the source code */
/* of this function, replacing allocations with `malloc()' in your */
/* application if you want something simpler. */
/* */
BASE_FUNC
FT_Error FT_Outline_Done( FT_Library library,
FT_Outline* outline )
{
FT_Memory memory = library->memory;
if ( outline )
{
if ( outline->flags & ft_outline_owner )
{
FREE( outline->points );
FREE( outline->tags );
FREE( outline->contours );
}
*outline = null_outline;
return FT_Err_Ok;
}
else
return FT_Err_Invalid_Argument;
}
/*************************************************************************/
/* */
/* <Function> */
/* FT_Outline_Get_CBox */
/* */
/* <Description> */
/* Returns an outline's `control box'. The control box encloses all */
/* the outline's points, including Bezier control points. Though it */
/* coincides with the exact bounding box for most glyphs, it can be */
/* slightly larger in some situations (like when rotating an outline */
/* which contains Bezier outside arcs). */
/* */
/* Computing the control box is very fast, while getting the bounding */
/* box can take much more time as it needs to walk over all segments */
/* and arcs in the outline. To get the latter, you can use the */
/* `ftbbox' component which is dedicated to this single task. */
/* */
/* <Input> */
/* outline :: A pointer to the source outline descriptor. */
/* */
/* <Output> */
/* cbox :: The outline's control box. */
/* */
/* <MT-Note> */
/* Yes. */
/* */
BASE_FUNC
void FT_Outline_Get_CBox( FT_Outline* outline,
FT_BBox* cbox )
{
FT_Pos xMin, yMin, xMax, yMax;
if ( outline && cbox )
{
if ( outline->n_points == 0 )
{
xMin = 0;
yMin = 0;
xMax = 0;
yMax = 0;
}
else
{
FT_Vector* vec = outline->points;
FT_Vector* limit = vec + outline->n_points;
xMin = xMax = vec->x;
yMin = yMax = vec->y;
vec++;
for ( ; vec < limit; vec++ )
{
FT_Pos x, y;
x = vec->x;
if ( x < xMin ) xMin = x;
if ( x > xMax ) xMax = x;
y = vec->y;
if ( y < yMin ) yMin = y;
if ( y > yMax ) yMax = y;
}
}
cbox->xMin = xMin;
cbox->xMax = xMax;
cbox->yMin = yMin;
cbox->yMax = yMax;
}
}
/*************************************************************************/
/* */
/* <Function> */
/* FT_Outline_Translate */
/* */
/* <Description> */
/* Applies a simple translation to the points of an outline. */
/* */
/* <Input> */
/* outline :: A pointer to the target outline descriptor. */
/* xOffset :: The horizontal offset. */
/* yOffset :: The vertical offset. */
/* */
/* <MT-Note> */
/* Yes. */
/* */
BASE_FUNC
void FT_Outline_Translate( FT_Outline* outline,
FT_Pos xOffset,
FT_Pos yOffset )
{
FT_UShort n;
FT_Vector* vec = outline->points;
for ( n = 0; n < outline->n_points; n++ )
{
vec->x += xOffset;
vec->y += yOffset;
vec++;
}
}
/*************************************************************************/
/* */
/* <Function> */
/* FT_Outline_Reverse */
/* */
/* <Description> */
/* Reverse the drawing direction of an outline. This is used to */
/* ensure consistent fill conventions for mirrored glyphs.. */
/* */
/* <Input> */
/* outline :: A pointer to the target outline descriptor. */
/* */
/* <Note> */
/* This functions toggles the bit flag ft_outline_reverse_fill in */
/* the outline's "flags" field.. */
/* */
BASE_FUNC
void FT_Outline_Reverse( FT_Outline* outline )
{
FT_UShort n;
FT_Int first, last;
first = 0;
for ( n = 0; n < outline->n_contours; n++ )
{
last = outline->contours[n];
/* reverse point table */
{
FT_Vector* p = outline->points + first;
FT_Vector* q = outline->points + last;
FT_Vector swap;
while (p < q)
{
swap = *p;
*p = *q;
*q = swap;
p++;
q--;
}
}
/* reverse tags table */
{
char* p = outline->tags + first;
char* q = outline->tags + last;
char swap;
while (p < q)
{
swap = *p;
*p = *q;
*q = swap;
p++;
q--;
}
}
first = last+1;
}
outline->flags ^= ft_outline_reverse_fill;
}
/*************************************************************************/
/* */
/* <Function> */
/* FT_Done_GlyphZone */
/* */
/* <Description> */
/* Deallocates a glyph zone. */
/* */
/* <Input> */
/* zone :: pointer to the target glyph zone. */
/* */
BASE_FUNC
void FT_Done_GlyphZone( FT_GlyphZone* zone )
{
FT_Memory memory = zone->memory;
FREE( zone->contours );
FREE( zone->tags );
FREE( zone->cur );
FREE( zone->org );
zone->max_points = zone->n_points = 0;
zone->max_contours = zone->n_contours = 0;
}
/*************************************************************************/
/* */
/* <Function> */
/* FT_New_GlyphZone */
/* */
/* <Description> */
/* Allocates a new glyph zone. */
/* */
/* <Input> */
/* memory :: A handle to the current memory object. */
/* */
/* maxPoints :: The capacity of glyph zone in points. */
/* */
/* maxContours :: The capacity of glyph zone in contours. */
/* */
/* <Output> */
/* zone :: A pointer to the target glyph zone record. */
/* */
/* <Return> */
/* FreeType error code. 0 means success. */
/* */
BASE_FUNC
FT_Error FT_New_GlyphZone( FT_Memory memory,
FT_UShort maxPoints,
FT_Short maxContours,
FT_GlyphZone* zone )
{
FT_Error error;
if (maxPoints > 0)
maxPoints += 2;
MEM_Set( zone, 0, sizeof(*zone) );
zone->memory = memory;
if ( ALLOC_ARRAY( zone->org, maxPoints*2, FT_F26Dot6 ) ||
ALLOC_ARRAY( zone->cur, maxPoints*2, FT_F26Dot6 ) ||
ALLOC_ARRAY( zone->tags, maxPoints, FT_Byte ) ||
ALLOC_ARRAY( zone->contours, maxContours, FT_UShort ) )
{
FT_Done_GlyphZone(zone);
}
return error;
}
/*************************************************************************/
/* */
/* <Function> */
/* FT_Update_GlyphZone */
/* */
/* <Description> */
/* Checks the size of a zone and reallocates it if necessary. */
/* */
/* <Input> */
/* newPoints :: The new capacity for points. We add two slots for */
/* phantom points. */
/* */
/* newContours :: The new capacity for contours. */
/* */
/* <InOut> */
/* zone :: The address of the target zone. */
/* */
/* maxPoints :: The address of the zone's current capacity for */
/* points. */
/* */
/* maxContours :: The address of the zone's current capacity for */
/* contours. */
/* */
BASE_FUNC
FT_Error FT_Update_GlyphZone( FT_GlyphZone* zone,
FT_UShort newPoints,
FT_Short newContours )
{
FT_Error error = FT_Err_Ok;
FT_Memory memory = zone->memory;
newPoints += 2;
if ( zone->max_points < newPoints )
{
/* reallocate the points arrays */
if ( REALLOC_ARRAY( zone->org, zone->max_points*2, newPoints*2, FT_F26Dot6 ) ||
REALLOC_ARRAY( zone->cur, zone->max_points*2, newPoints*2, FT_F26Dot6 ) ||
REALLOC_ARRAY( zone->tags, zone->max_points*2, newPoints, FT_Byte ) )
goto Exit;
zone->max_points = newPoints;
}
if ( zone->max_contours < newContours )
{
/* reallocate the contours array */
if ( REALLOC_ARRAY( zone->contours, zone->max_contours, newContours, FT_UShort ) )
goto Exit;
zone->max_contours = newContours;
}
Exit:
return error;
}
/*************************************************************************/
/* */
/* <Function> */
/* FT_Outline_Get_Bitmap */
/* */
/* <Description> */
/* Renders an outline within a bitmap. The outline's image is simply */
/* or-ed to the target bitmap. */
/* */
/* */
/* <Input> */
/* library :: A handle to a FreeType library object. */
/* outline :: A pointer to the source outline descriptor. */
/* map :: A pointer to the target bitmap descriptor. */
/* */
/* <Return> */
/* FreeType error code. 0 means success. */
/* */
/* <MT-Note> */
/* YES. Rendering is synchronized, so that concurrent calls to the */
/* scan-line converter will be serialized. */
/* */
/* <Note> */
/* This function does NOT CREATE the bitmap, it only renders an */
/* outline image within the one you pass to it! */
/* */
/* It will use the raster correponding to the default glyph format. */
/* */
EXPORT_FUNC
FT_Error FT_Outline_Get_Bitmap( FT_Library library,
FT_Outline* outline,
FT_Bitmap* map )
{
FT_Error error;
FT_Raster raster;
FT_Raster_Funcs funcs;
FT_Raster_Params params;
error = FT_Err_Invalid_Glyph_Format;
raster = FT_Get_Raster( library, ft_glyph_format_outline, &funcs );
if (!raster) goto Exit;
params.target = map;
params.source = outline;
params.flags = 0;
if (map->pixel_mode == ft_pixel_mode_grays)
params.flags |= ft_raster_flag_aa;
error = funcs.raster_render( raster, ¶ms );
Exit:
return error;
}
/*************************************************************************/
/* */
/* <Function> */
/* FT_Outline_Render */
/* */
/* <Description> */
/* Renders an outline within a bitmap using the current scan-convert */
/* This functions uses a FT_Raster_Params as argument, allowing */
/* advanced features like direct composition/translucency, etc.. */
/* */
/* <Input> */
/* library :: A handle to a FreeType library object. */
/* outline :: A pointer to the source outline descriptor. */
/* params :: A pointer to a FT_Raster_Params used to describe */
/* the rendering operation */
/* */
/* <Return> */
/* FreeType error code. 0 means success. */
/* */
/* <MT-Note> */
/* YES. Rendering is synchronized, so that concurrent calls to the */
/* scan-line converter will be serialized. */
/* */
/* <Note> */
/* You should know what you're doing and the role of FT_Raster_Params */
/* to use this function. */
/* */
/* the field "params.source" will be set to "outline" before the */
/* scan converter is called, which means that the value you give it */
/* is actually ignored.. */
/* */
EXPORT_FUNC
FT_Error FT_Outline_Render( FT_Library library,
FT_Outline* outline,
FT_Raster_Params* params )
{
FT_Error error;
FT_Raster raster;
FT_Raster_Funcs funcs;
error = FT_Err_Invalid_Glyph_Format;
raster = FT_Get_Raster( library, ft_glyph_format_outline, &funcs );
if (!raster) goto Exit;
params->source = (void*)outline;
error = funcs.raster_render( raster, params );
Exit:
return error;
}
/*************************************************************************/
/*************************************************************************/
/*************************************************************************/
/**** ****/
/**** The following functions are not used by the font drivers ****/
/**** but they are provided as a convenience for client apps. ****/
/**** ****/
/**** Note that they will not be compiled if the configuration ****/
/**** macro FT_CONFIG_OPTION_NO_CONVENIENCE_FUNCS is defined ****/
/**** ****/
/*************************************************************************/
/*************************************************************************/
/*************************************************************************/
#ifndef FT_CONFIG_OPTION_NO_CONVENIENCE_FUNCS
/*************************************************************************/
/* */
/* <Function> */
/* FT_Outline_Copy */
/* */
/* <Description> */
/* Copies an outline into another one. Both objects must have the */
/* same sizes (number of points & number of contours) when this */
/* function is called. */
/* */
/* <Input> */
/* source :: A handle to the source outline. */
/* target :: A handle to the target outline. */
/* */
/* <Return> */
/* FreeType error code. 0 means success. */
/* */
BASE_FUNC
FT_Error FT_Outline_Copy( FT_Outline* source,
FT_Outline* target )
{
FT_Int is_owner;
if ( !source || !target ||
source->n_points != target->n_points ||
source->n_contours != target->n_contours )
return FT_Err_Invalid_Argument;
MEM_Copy( target->points, source->points,
source->n_points * 2 * sizeof ( FT_Pos ) );
MEM_Copy( target->tags, source->tags,
source->n_points * sizeof ( FT_Byte ) );
MEM_Copy( target->contours, source->contours,
source->n_contours * sizeof ( FT_Short ) );
/* copy all flags, except the "ft_outline_owner" one */
is_owner = target->flags & ft_outline_owner;
target->flags = source->flags;
target->flags &= ~ft_outline_owner;
target->flags |= is_owner;
return FT_Err_Ok;
}
/*************************************************************************/
/* */
/* <Function> */
/* FT_Outline_Transform */
/* */
/* <Description> */
/* Applies a simple 2x2 matrix to all of an outline's points. Useful */
/* for applying rotations, slanting, flipping, etc. */
/* */
/* <Input> */
/* outline :: A pointer to the target outline descriptor. */
/* matrix :: A pointer to the transformation matrix. */
/* */
/* <MT-Note> */
/* Yes. */
/* */
/* <Note> */
/* You can use FT_Outline_Translate() if you need to translate the */
/* outline's points. */
/* */
BASE_FUNC
void FT_Outline_Transform( FT_Outline* outline,
FT_Matrix* matrix )
{
FT_UShort n;
FT_Vector* vec;
vec = outline->points;
for ( n = 0; n < outline->n_points; n++ )
{
FT_Pos x, y;
x = FT_MulFix( vec->x, matrix->xx ) +
FT_MulFix( vec->y, matrix->xy );
y = FT_MulFix( vec->x, matrix->yx ) +
FT_MulFix( vec->y, matrix->yy );
vec->x = x;
vec->y = y;
vec++;
}
}
/*************************************************************************/
/* */
/* <Function> */
/* FT_Vector_Transform */
/* */
/* <Description> */
/* Transforms a single vector through a 2x2 matrix. */
/* */
/* <InOut> */
/* vector :: The target vector to transform */
/* */
/* <Input> */
/* matrix :: A pointer to the source 2x2 matrix. */
/* */
/* <MT-Note> */
/* Yes. */
/* */
EXPORT_DEF
void FT_Vector_Transform( FT_Vector* vector,
FT_Matrix* matrix )
{
FT_Pos xz, yz;
xz = FT_MulFix( vector->x, matrix->xx ) +
FT_MulFix( vector->y, matrix->xy );
yz = FT_MulFix( vector->x, matrix->yx ) +
FT_MulFix( vector->y, matrix->yy );
vector->x = xz;
vector->y = yz;
}
/*************************************************************************/
/* */
/* <Function> */
/* FT_Matrix_Multiply */
/* */
/* <Description> */
/* Performs the matrix operation `b = a*b'. */
/* */
/* <Input> */
/* a :: A pointer to matrix `a'. */
/* */
/* <InOut> */
/* b :: A pointer to matrix `b'. */
/* */
/* <MT-Note> */
/* Yes. */
/* */
BASE_FUNC
void FT_Matrix_Multiply( FT_Matrix* a,
FT_Matrix* b )
{
FT_Fixed xx, xy, yx, yy;
xx = FT_MulFix( a->xx, b->xx ) + FT_MulFix( a->xy, b->yx );
xy = FT_MulFix( a->xx, b->xy ) + FT_MulFix( a->xy, b->yy );
yx = FT_MulFix( a->yx, b->xx ) + FT_MulFix( a->yy, b->yx );
yy = FT_MulFix( a->yx, b->xy ) + FT_MulFix( a->yy, b->yy );
b->xx = xx; b->xy = xy;
b->yx = yx; b->yy = yy;
}
/*************************************************************************/
/* */
/* <Function> */
/* FT_Matrix_Invert */
/* */
/* <Description> */
/* Inverts a 2x2 matrix. Returns an error if it can't be inverted. */
/* */
/* <InOut> */
/* matrix :: A pointer to the target matrix. Remains untouched in */
/* case of error. */
/* */
/* <Return> */
/* FreeType error code. 0 means success. */
/* */
/* <MT-Note> */
/* Yes. */
/* */
BASE_FUNC
FT_Error FT_Matrix_Invert( FT_Matrix* matrix )
{
FT_Pos delta, xx, yy;
/* compute discriminant */
delta = FT_MulFix( matrix->xx, matrix->yy ) -
FT_MulFix( matrix->xy, matrix->yx );
if ( !delta )
return FT_Err_Invalid_Argument; /* matrix can't be inverted */
matrix->xy = - FT_DivFix( matrix->xy, delta );
matrix->yx = - FT_DivFix( matrix->yx, delta );
xx = matrix->xx;
yy = matrix->yy;
matrix->xx = FT_DivFix( yy, delta );
matrix->yy = FT_DivFix( xx, delta );
return FT_Err_Ok;
}
#endif
/* END */