diff options
author | Anuj Verma <anujv@iitbhilai.ac.in> | 2020-08-17 16:36:30 +0530 |
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committer | Werner Lemberg <wl@gnu.org> | 2020-12-22 09:03:26 +0100 |
commit | 04d44e2e702c3082f02b6af0d7eb94d9972f5796 (patch) | |
tree | b1de89d7fc49e24f7d41053aead89f23370ce8b5 | |
parent | 328a994ae23d7fefcabb9a2322e52b580425e7b2 (diff) | |
download | freetype2-04d44e2e702c3082f02b6af0d7eb94d9972f5796.tar.gz |
[sdf] Add functions to decompose `FT_Outline`.
* src/sdf/ftsdf.c (sdf_move_to, sdf_line_to, sdf_conic_to,
sdf_cubic_to): New auxiliary decomposition functions.
(sdf_compose_funcs): New structure.
(sdf_outline_decompose): New function.
-rw-r--r-- | ChangeLog | 9 | ||||
-rw-r--r-- | src/sdf/ftsdf.c | 199 |
2 files changed, 208 insertions, 0 deletions
@@ -1,5 +1,14 @@ 2020-08-17 Anuj Verma <anujv@iitbhilai.ac.in> + [sdf] Add functions to decompose `FT_Outline`. + + * src/sdf/ftsdf.c (sdf_move_to, sdf_line_to, sdf_conic_to, + sdf_cubic_to): New auxiliary decomposition functions. + (sdf_compose_funcs): New structure. + (sdf_outline_decompose): New function. + +2020-08-17 Anuj Verma <anujv@iitbhilai.ac.in> + [sdf] Structs, enums, macros, and functions for 'sdf' rasterizer. * src/sdf/ftsdf.c (FT_DEBUG_INNER, FT_ASSIGNP_INNER) diff --git a/src/sdf/ftsdf.c b/src/sdf/ftsdf.c index be7c2b411..4967ed401 100644 --- a/src/sdf/ftsdf.c +++ b/src/sdf/ftsdf.c @@ -643,4 +643,203 @@ SDF_FREE( *shape ); } + + /************************************************************************** + * + * shape decomposition functions + * + */ + + /* This function is called when starting a new contour at `to`, */ + /* which gets added to the shape's list. */ + static FT_Error + sdf_move_to( const FT_26D6_Vec* to, + void* user ) + { + SDF_Shape* shape = ( SDF_Shape* )user; + SDF_Contour* contour = NULL; + + FT_Error error = FT_Err_Ok; + FT_Memory memory = shape->memory; + + + if ( !to || !user ) + { + error = FT_THROW( Invalid_Argument ); + goto Exit; + } + + FT_CALL( sdf_contour_new( memory, &contour ) ); + + contour->last_pos = *to; + contour->next = shape->contours; + shape->contours = contour; + + Exit: + return error; + } + + + /* This function is called when there is a line in the */ + /* contour. The line starts at the previous edge point and */ + /* stops at `to`. */ + static FT_Error + sdf_line_to( const FT_26D6_Vec* to, + void* user ) + { + SDF_Shape* shape = ( SDF_Shape* )user; + SDF_Edge* edge = NULL; + SDF_Contour* contour = NULL; + + FT_Error error = FT_Err_Ok; + FT_Memory memory = shape->memory; + + + if ( !to || !user ) + { + error = FT_THROW( Invalid_Argument ); + goto Exit; + } + + contour = shape->contours; + + if ( contour->last_pos.x == to->x && + contour->last_pos.y == to->y ) + goto Exit; + + FT_CALL( sdf_edge_new( memory, &edge ) ); + + edge->edge_type = SDF_EDGE_LINE; + edge->start_pos = contour->last_pos; + edge->end_pos = *to; + + edge->next = contour->edges; + contour->edges = edge; + contour->last_pos = *to; + + Exit: + return error; + } + + + /* This function is called when there is a conic Bezier curve */ + /* in the contour. The curve starts at the previous edge point */ + /* and stops at `to`, with control point `control_1`. */ + static FT_Error + sdf_conic_to( const FT_26D6_Vec* control_1, + const FT_26D6_Vec* to, + void* user ) + { + SDF_Shape* shape = ( SDF_Shape* )user; + SDF_Edge* edge = NULL; + SDF_Contour* contour = NULL; + + FT_Error error = FT_Err_Ok; + FT_Memory memory = shape->memory; + + + if ( !control_1 || !to || !user ) + { + error = FT_THROW( Invalid_Argument ); + goto Exit; + } + + contour = shape->contours; + + FT_CALL( sdf_edge_new( memory, &edge ) ); + + edge->edge_type = SDF_EDGE_CONIC; + edge->start_pos = contour->last_pos; + edge->control_a = *control_1; + edge->end_pos = *to; + + edge->next = contour->edges; + contour->edges = edge; + contour->last_pos = *to; + + Exit: + return error; + } + + + /* This function is called when there is a cubic Bezier curve */ + /* in the contour. The curve starts at the previous edge point */ + /* and stops at `to`, with two control points `control_1` and */ + /* `control_2`. */ + static FT_Error + sdf_cubic_to( const FT_26D6_Vec* control_1, + const FT_26D6_Vec* control_2, + const FT_26D6_Vec* to, + void* user ) + { + SDF_Shape* shape = ( SDF_Shape* )user; + SDF_Edge* edge = NULL; + SDF_Contour* contour = NULL; + + FT_Error error = FT_Err_Ok; + FT_Memory memory = shape->memory; + + + if ( !control_2 || !control_1 || !to || !user ) + { + error = FT_THROW( Invalid_Argument ); + goto Exit; + } + + contour = shape->contours; + + FT_CALL( sdf_edge_new( memory, &edge ) ); + + edge->edge_type = SDF_EDGE_CUBIC; + edge->start_pos = contour->last_pos; + edge->control_a = *control_1; + edge->control_b = *control_2; + edge->end_pos = *to; + + edge->next = contour->edges; + contour->edges = edge; + contour->last_pos = *to; + + Exit: + return error; + } + + + /* Construct the structure to hold all four outline */ + /* decomposition functions. */ + FT_DEFINE_OUTLINE_FUNCS( + sdf_decompose_funcs, + + (FT_Outline_MoveTo_Func) sdf_move_to, /* move_to */ + (FT_Outline_LineTo_Func) sdf_line_to, /* line_to */ + (FT_Outline_ConicTo_Func)sdf_conic_to, /* conic_to */ + (FT_Outline_CubicTo_Func)sdf_cubic_to, /* cubic_to */ + + 0, /* shift */ + 0 /* delta */ + ) + + + /* Decompose `outline` and put it into the `shape` structure. */ + static FT_Error + sdf_outline_decompose( FT_Outline* outline, + SDF_Shape* shape ) + { + FT_Error error = FT_Err_Ok; + + + if ( !outline || !shape ) + { + error = FT_THROW( Invalid_Argument ); + goto Exit; + } + + error = FT_Outline_Decompose( outline, + &sdf_decompose_funcs, + (void*)shape ); + + Exit: + return error; + } + /* END */ |