forked from minhngoc25a/freetype2
481 lines
11 KiB
C
481 lines
11 KiB
C
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#include <freetype/internal/ftobjs.h>
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#include <freetype/internal/ftdebug.h>
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#include <freetype/ftlist.h>
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#include "ftsdf.h"
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#include "ftsdferrs.h"
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/**************************************************************************
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*
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* typedefs
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*
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*/
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typedef FT_Vector FT_26D6_Vec; /* with 26.6 fixed point components */
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typedef FT_Vector FT_16D16_Vec; /* with 16.16 fixed point components */
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/**************************************************************************
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*
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* structures and enums
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*
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*/
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typedef struct SDF_TRaster_
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{
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FT_Memory memory; /* used internally to allocate memory */
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} SDF_TRaster;
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/* enumeration of all the types of curve present in vector fonts */
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typedef enum SDF_Edge_Type_
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{
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SDF_EDGE_UNDEFINED = 0, /* undefined, used to initialize */
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SDF_EDGE_LINE = 1, /* straight line segment */
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SDF_EDGE_CONIC = 2, /* second order bezier curve */
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SDF_EDGE_CUBIC = 3 /* third order bezier curve */
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} SDF_Edge_Type;
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/* represent a single edge in a contour */
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typedef struct SDF_Edge_
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{
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FT_26D6_Vec start_pos; /* start position of the edge */
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FT_26D6_Vec end_pos; /* end position of the edge */
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FT_26D6_Vec control_a; /* first control point of a bezier curve */
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FT_26D6_Vec control_b; /* second control point of a bezier curve */
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SDF_Edge_Type edge_type; /* edge identifier */
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} SDF_Edge;
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/* A contour represent a set of edges which make a closed */
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/* loop. */
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typedef struct SDF_Contour_
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{
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FT_26D6_Vec last_pos; /* end position of the last edge */
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FT_List edges; /* list of all edges in the contour */
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} SDF_Contour;
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/* Represent a set a contours which makes up a complete */
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/* glyph outline. */
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typedef struct SDF_Shape_
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{
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FT_Memory memory; /* used internally to allocate memory */
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FT_List contours; /* list of all contours in the outline */
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} SDF_Shape;
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/**************************************************************************
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*
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* constants, initializer and destructor
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*
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*/
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static
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const FT_Vector zero_vector = { 0, 0 };
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static
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const SDF_Edge null_edge = { { 0, 0 }, { 0, 0 },
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{ 0, 0 }, { 0, 0 },
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SDF_EDGE_UNDEFINED };
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static
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const SDF_Contour null_contour = { { 0, 0 }, NULL };
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static
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const SDF_Shape null_shape = { NULL, NULL };
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static
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const FT_ListRec empty_list = { NULL, NULL };
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/* Creates a new `SDF_Edge' on the heap and assigns the `edge' */
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/* pointer to the newly allocated memory. */
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static FT_Error
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sdf_edge_new( FT_Memory memory,
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SDF_Edge** edge )
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{
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FT_Error error = FT_Err_Ok;
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SDF_Edge* ptr = NULL;
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if ( !memory || !edge )
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{
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error = FT_THROW( Invalid_Argument );
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goto Exit;
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}
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FT_QNEW( ptr );
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if ( error == FT_Err_Ok )
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{
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*ptr = null_edge;
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*edge = ptr;
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}
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Exit:
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return error;
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}
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/* Creates a new `SDF_Contour' on the heap and assigns the `contour' */
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/* pointer to the newly allocated memory. Note that the function also */
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/* allocate the `contour.edges' list variable and sets to empty list. */
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static FT_Error
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sdf_contour_new( FT_Memory memory,
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SDF_Contour** contour )
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{
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FT_Error error = FT_Err_Ok;
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SDF_Contour* ptr = NULL;
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if ( !memory || !contour )
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{
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error = FT_THROW( Invalid_Argument );
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goto Exit;
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}
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FT_QNEW( ptr );
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if ( error == FT_Err_Ok )
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{
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*ptr = null_contour;
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FT_QNEW( ptr->edges );
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if ( error == FT_Err_Ok )
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{
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*ptr->edges = empty_list;
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*contour = ptr;
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}
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}
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Exit:
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return error;
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}
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/* Creates a new `SDF_Shape' on the heap and assigns the `shape' */
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/* pointer to the newly allocated memory. Note that the function also */
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/* allocate the `shape.contours' list variable and sets to empty list. */
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static void
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sdf_shape_new( FT_Memory memory,
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SDF_Shape** shape )
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{
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FT_Error error = FT_Err_Ok;
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SDF_Shape* ptr = NULL;
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if ( !memory || !shape )
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{
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error = FT_THROW( Invalid_Argument );
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goto Exit;
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}
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FT_QNEW( ptr );
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if ( error == FT_Err_Ok )
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{
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*ptr = null_shape;
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FT_QNEW( ptr->contours );
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if ( error == FT_Err_Ok )
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{
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*ptr->contours = empty_list;
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ptr->memory = memory;
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*shape = ptr;
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}
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}
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Exit:
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return error;
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}
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/**************************************************************************
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*
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* shape decomposition functions
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*
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*/
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static FT_Error
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sdf_move_to( const FT_26D6_Vec* to,
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void* user )
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{
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/* This function is called when walking along a new contour */
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/* so add a new contour to the shape's list. */
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SDF_Shape* shape = ( SDF_Shape* )user;
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SDF_Contour* contour = NULL;
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FT_ListNode node = NULL;
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FT_Error error = FT_Err_Ok;
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FT_Memory memory = shape->memory;
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if ( !to || !user )
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{
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error = FT_THROW( Invalid_Argument );
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goto Exit;
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}
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error = sdf_contour_new( memory, &contour );
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if ( error != FT_Err_Ok )
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goto Exit;
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FT_QNEW( node );
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if ( error != FT_Err_Ok )
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goto Exit;
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contour->last_pos = *to;
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node->data = contour;
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FT_List_Add( shape->contours, node );
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Exit:
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return error;
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}
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static FT_Error
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sdf_line_to( const FT_26D6_Vec* to,
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void* user )
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{
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SDF_Shape* shape = ( SDF_Shape* )user;
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SDF_Edge* edge = NULL;
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SDF_Contour* contour = NULL;
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FT_ListNode node = NULL;
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FT_Error error = FT_Err_Ok;
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FT_Memory memory = shape->memory;
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if ( !to || !user )
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{
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error = FT_THROW( Invalid_Argument );
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goto Exit;
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}
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contour = ( SDF_Contour* )shape->contours->tail->data;
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if ( contour->last_pos.x == to->x &&
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contour->last_pos.y == to->y )
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goto Exit;
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error = sdf_edge_new( memory, &edge );
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if ( error != FT_Err_Ok )
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goto Exit;
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FT_QNEW( node );
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if ( error != FT_Err_Ok )
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goto Exit;
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edge->edge_type = SDF_EDGE_LINE;
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edge->start_pos = contour->last_pos;
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edge->end_pos = *to;
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contour->last_pos = *to;
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node->data = edge;
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FT_List_Add( contour->edges, node );
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Exit:
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return error;
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}
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static FT_Error
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sdf_conic_to( const FT_26D6_Vec* control_1,
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const FT_26D6_Vec* to,
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void* user )
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{
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SDF_Shape* shape = ( SDF_Shape* )user;
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SDF_Edge* edge = NULL;
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SDF_Contour* contour = NULL;
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FT_ListNode node = NULL;
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FT_Error error = FT_Err_Ok;
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FT_Memory memory = shape->memory;
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if ( !control_1 || !to || !user )
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{
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error = FT_THROW( Invalid_Argument );
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goto Exit;
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}
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contour = ( SDF_Contour* )shape->contours->tail->data;
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error = sdf_edge_new( memory, &edge );
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if ( error != FT_Err_Ok )
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goto Exit;
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FT_QNEW( node );
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if ( error != FT_Err_Ok )
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goto Exit;
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edge->edge_type = SDF_EDGE_CONIC;
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edge->start_pos = contour->last_pos;
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edge->control_a = *control_1;
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edge->end_pos = *to;
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contour->last_pos = *to;
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node->data = edge;
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FT_List_Add( contour->edges, node );
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Exit:
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return error;
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}
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static FT_Error
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sdf_cubic_to( const FT_26D6_Vec* control_1,
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const FT_26D6_Vec* control_2,
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const FT_26D6_Vec* to,
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void* user )
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{
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SDF_Shape* shape = ( SDF_Shape* )user;
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SDF_Edge* edge = NULL;
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SDF_Contour* contour = NULL;
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FT_ListNode node = NULL;
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FT_Error error = FT_Err_Ok;
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FT_Memory memory = shape->memory;
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if ( !control_2 || !control_1 || !to || !user )
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{
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error = FT_THROW( Invalid_Argument );
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goto Exit;
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}
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contour = ( SDF_Contour* )shape->contours->tail->data;
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error = sdf_edge_new( memory, &edge );
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if ( error != FT_Err_Ok )
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goto Exit;
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FT_QNEW( node );
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if ( error != FT_Err_Ok )
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goto Exit;
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edge->edge_type = SDF_EDGE_CUBIC;
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edge->start_pos = contour->last_pos;
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edge->control_a = *control_1;
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edge->control_b = *control_2;
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edge->end_pos = *to;
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contour->last_pos = *to;
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node->data = edge;
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FT_List_Add( contour->edges, node );
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Exit:
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return error;
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}
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FT_DEFINE_OUTLINE_FUNCS(
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sdf_decompose_funcs,
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(FT_Outline_MoveTo_Func) sdf_move_to, /* move_to */
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(FT_Outline_LineTo_Func) sdf_line_to, /* line_to */
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(FT_Outline_ConicTo_Func) sdf_conic_to, /* conic_to */
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(FT_Outline_CubicTo_Func) sdf_cubic_to, /* cubic_to */
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0, /* shift */
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0 /* delta */
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)
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/* function decomposes the outline and puts it into the `shape' object */
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static FT_Error
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sdf_outline_decompose( FT_Outline* outline,
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SDF_Shape* shape )
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{
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FT_Error error = FT_Err_Ok;
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if ( !outline || !shape )
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{
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error = FT_THROW( Invalid_Argument );
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goto Exit;
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}
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error = FT_Outline_Decompose( outline, &sdf_decompose_funcs, (void*)shape );
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Exit:
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return error;
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}
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/**************************************************************************
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*
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* interface functions
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*
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*/
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static FT_Error
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sdf_raster_new( FT_Memory memory,
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FT_Raster* araster)
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{
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FT_Error error = FT_Err_Ok;
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SDF_TRaster* raster = NULL;
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*araster = 0;
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if ( !FT_ALLOC( raster, sizeof( SDF_TRaster ) ) )
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{
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raster->memory = memory;
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*araster = (FT_Raster)raster;
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}
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return error;
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}
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static void
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sdf_raster_reset( FT_Raster raster,
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unsigned char* pool_base,
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unsigned long pool_size )
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{
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/* no use of this function */
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FT_UNUSED( raster );
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FT_UNUSED( pool_base );
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FT_UNUSED( pool_size );
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}
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static FT_Error
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sdf_raster_set_mode( FT_Raster raster,
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unsigned long mode,
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void* args )
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{
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FT_UNUSED( raster );
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FT_UNUSED( mode );
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FT_UNUSED( args );
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return FT_Err_Ok;
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}
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static FT_Error
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sdf_raster_render( FT_Raster raster,
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const FT_Raster_Params* params )
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{
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FT_UNUSED( raster );
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FT_UNUSED( params );
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return FT_THROW( Unimplemented_Feature );
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}
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static void
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sdf_raster_done( FT_Raster raster )
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{
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FT_Memory memory = (FT_Memory)((SDF_TRaster*)raster)->memory;
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FT_FREE( raster );
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}
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FT_DEFINE_RASTER_FUNCS(
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ft_sdf_raster,
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FT_GLYPH_FORMAT_OUTLINE,
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(FT_Raster_New_Func) sdf_raster_new, /* raster_new */
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(FT_Raster_Reset_Func) sdf_raster_reset, /* raster_reset */
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(FT_Raster_Set_Mode_Func) sdf_raster_set_mode, /* raster_set_mode */
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(FT_Raster_Render_Func) sdf_raster_render, /* raster_render */
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(FT_Raster_Done_Func) sdf_raster_done /* raster_done */
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)
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/* END */
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