From 04d44e2e702c3082f02b6af0d7eb94d9972f5796 Mon Sep 17 00:00:00 2001 From: Anuj Verma Date: Mon, 17 Aug 2020 16:36:30 +0530 Subject: [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. --- ChangeLog | 9 +++ src/sdf/ftsdf.c | 199 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++ 2 files changed, 208 insertions(+) diff --git a/ChangeLog b/ChangeLog index 130b4fecf..0f1272e4e 100644 --- a/ChangeLog +++ b/ChangeLog @@ -1,3 +1,12 @@ +2020-08-17 Anuj Verma + + [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 [sdf] Structs, enums, macros, and functions for 'sdf' rasterizer. 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 */ -- cgit v1.2.1