| // facevisitor-colrv1.cpp |
| // |
| // Finds and traverses COLRv1 glyphs using FreeType's |
| // COLRv1 API. |
| // |
| // Copyright 2021 by |
| // Dominik Röttsches. |
| // |
| // 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. |
| |
| |
| #include "visitors/facevisitor-colrv1.h" |
| |
| #include <cassert> |
| #include <unordered_set> |
| |
| #include "utils/logging.h" |
| |
| #include <freetype/freetype.h> |
| #include <freetype/ftcolor.h> |
| |
| |
| template<> struct std::hash<FT_OpaquePaint> |
| { |
| |
| |
| std::size_t |
| operator()( const FT_OpaquePaint& p ) const |
| { |
| std::size_t h1 = std::hash<FT_Byte*>{}( p.p ); |
| std::size_t h2 = std::hash<FT_Bool>{}( p.insert_root_transform ); |
| |
| |
| return h1 ^ (h2 << 1); |
| } |
| }; |
| |
| |
| template<> struct std::equal_to<FT_OpaquePaint> |
| { |
| |
| |
| bool |
| operator()( const FT_OpaquePaint& lhs, |
| const FT_OpaquePaint& rhs ) const |
| { |
| return lhs.p == rhs.p && |
| lhs.insert_root_transform == rhs.insert_root_transform; |
| } |
| }; |
| |
| |
| namespace { |
| |
| |
| using VisitedSet = std::unordered_set<FT_OpaquePaint>; |
| |
| |
| constexpr unsigned long MAX_TRAVERSE_GLYPHS = 5; |
| |
| |
| class ScopedSetInserter |
| : private freetype::noncopyable |
| { |
| public: |
| |
| |
| ScopedSetInserter( VisitedSet& set, |
| FT_OpaquePaint paint) |
| : visited_set( set ), |
| p( paint ) |
| { |
| |
| |
| visited_set.insert(p); |
| } |
| |
| |
| ~ScopedSetInserter() |
| { |
| visited_set.erase(p); |
| } |
| |
| |
| private: |
| |
| |
| VisitedSet& visited_set; |
| FT_OpaquePaint p; |
| }; |
| |
| |
| bool colrv1_start_glyph( const FT_Face& ft_face, |
| uint16_t glyph_id, |
| FT_Color_Root_Transform root_transform ); |
| |
| |
| void iterate_color_stops ( FT_Face face, |
| FT_ColorStopIterator* color_stop_iterator ) |
| { |
| const FT_UInt num_color_stops = color_stop_iterator->num_color_stops; |
| FT_ColorStop color_stop; |
| long color_stop_index = 0; |
| |
| |
| while ( FT_Get_Colorline_Stops( face, |
| &color_stop, |
| color_stop_iterator ) ) |
| { |
| LOG( INFO ) << "Color stop " << color_stop_index |
| << "/" << num_color_stops - 1 |
| << " stop offset: " << color_stop.stop_offset |
| << " palette index: " << color_stop.color.palette_index |
| << " alpha: " << color_stop.color.alpha; |
| } |
| } |
| |
| |
| void colrv1_draw_paint( FT_Face face, |
| FT_COLR_Paint colrv1_paint ) |
| { |
| switch ( colrv1_paint.format ) |
| { |
| |
| case FT_COLR_PAINTFORMAT_GLYPH: |
| { |
| LOG( INFO ) << "PaintGlyph"; |
| break; |
| } |
| |
| case FT_COLR_PAINTFORMAT_SOLID: |
| { |
| LOG( INFO ) << "PaintSolid," |
| << " palette_index: " |
| << colrv1_paint.u.solid.color.palette_index |
| << " alpha: " << colrv1_paint.u.solid.color.alpha; |
| break; |
| } |
| |
| case FT_COLR_PAINTFORMAT_LINEAR_GRADIENT: |
| { |
| LOG( INFO ) << "PaintLinearGradient," |
| << " p0.x " << colrv1_paint.u.linear_gradient.p0.x |
| << " p0.y " << colrv1_paint.u.linear_gradient.p0.y |
| << " p1.x " << colrv1_paint.u.linear_gradient.p1.x |
| << " p1.y " << colrv1_paint.u.linear_gradient.p1.y |
| << " p2.x " << colrv1_paint.u.linear_gradient.p2.x |
| << " p2.y " << colrv1_paint.u.linear_gradient.p2.y; |
| |
| iterate_color_stops( |
| face, |
| &colrv1_paint.u.linear_gradient.colorline.color_stop_iterator ); |
| |
| break; |
| } |
| |
| case FT_COLR_PAINTFORMAT_RADIAL_GRADIENT: |
| { |
| LOG( INFO ) << "PaintRadialGradient," |
| << " c0.x " << colrv1_paint.u.radial_gradient.c0.x |
| << " c0.y " << colrv1_paint.u.radial_gradient.c0.y |
| << " c1.x " << colrv1_paint.u.radial_gradient.c1.x |
| << " c1.y " << colrv1_paint.u.radial_gradient.c1.y |
| << " r0 " << colrv1_paint.u.radial_gradient.r0 |
| << " r1 " << colrv1_paint.u.radial_gradient.r1; |
| |
| iterate_color_stops( |
| face, |
| &colrv1_paint.u.radial_gradient.colorline.color_stop_iterator ); |
| |
| break; |
| } |
| |
| case FT_COLR_PAINTFORMAT_SWEEP_GRADIENT: |
| { |
| LOG( INFO ) << "PaintSweepGradient," |
| << " center.x " << colrv1_paint.u.sweep_gradient.center.x |
| << " center.y " << colrv1_paint.u.sweep_gradient.center.y |
| << " start_angle " |
| << colrv1_paint.u.sweep_gradient.start_angle |
| << " end_angle " << colrv1_paint.u.sweep_gradient.end_angle; |
| |
| iterate_color_stops( |
| face, |
| &colrv1_paint.u.sweep_gradient.colorline.color_stop_iterator ); |
| |
| break; |
| } |
| |
| case FT_COLR_PAINTFORMAT_TRANSFORM: |
| { |
| LOG( INFO ) << "PaintTransformed," |
| << " xx " << colrv1_paint.u.transform.affine.xx |
| << " xy " << colrv1_paint.u.transform.affine.xy |
| << " yx " << colrv1_paint.u.transform.affine.yx |
| << " yy " << colrv1_paint.u.transform.affine.yy |
| << " dx " << colrv1_paint.u.transform.affine.dx |
| << " dy " << colrv1_paint.u.transform.affine.dy; |
| break; |
| } |
| |
| case FT_COLR_PAINTFORMAT_TRANSLATE: |
| { |
| LOG( INFO ) << "PaintTranslate," |
| << " dx " << colrv1_paint.u.translate.dx |
| << " dy " << colrv1_paint.u.translate.dy; |
| break; |
| } |
| |
| case FT_COLR_PAINTFORMAT_SCALE: |
| { |
| LOG( INFO ) << "PaintScale," |
| << " center.x " << colrv1_paint.u.scale.center_x |
| << " center.y " << colrv1_paint.u.scale.center_y |
| << " scale.x " << colrv1_paint.u.scale.scale_x |
| << " scale.y " << colrv1_paint.u.scale.scale_y; |
| break; |
| } |
| |
| case FT_COLR_PAINTFORMAT_ROTATE: |
| { |
| LOG( INFO ) << "PaintRotate," |
| << " center.x " << colrv1_paint.u.rotate.center_x |
| << " center.y " << colrv1_paint.u.rotate.center_y |
| << " angle " << colrv1_paint.u.rotate.angle; |
| break; |
| } |
| |
| case FT_COLR_PAINTFORMAT_SKEW: |
| { |
| LOG( INFO ) << "PaintSkew," |
| << " center.x " << colrv1_paint.u.skew.center_x |
| << " center.y " << colrv1_paint.u.skew.center_y |
| << " x_skew_angle " << colrv1_paint.u.skew.x_skew_angle |
| << " y_skew_angle " << colrv1_paint.u.skew.y_skew_angle; |
| break; |
| } |
| |
| case FT_COLR_PAINTFORMAT_COLR_GLYPH: |
| case FT_COLR_PAINTFORMAT_COLR_LAYERS: |
| case FT_COLR_PAINTFORMAT_COMPOSITE: |
| case FT_COLR_PAINT_FORMAT_MAX: |
| case FT_COLR_PAINTFORMAT_UNSUPPORTED: |
| { |
| // No action for these paint format types in drawing. |
| break; |
| } |
| } |
| } |
| |
| |
| bool colrv1_traverse_paint( FT_Face face, |
| FT_OpaquePaint opaque_paint, |
| VisitedSet& visited_set ) |
| { |
| FT_COLR_Paint paint; |
| |
| bool traverse_result = true; |
| |
| |
| if ( visited_set.find( opaque_paint ) != visited_set.end() ) |
| { |
| LOG( ERROR ) << "Paint cycle detected, aborting."; |
| return false; |
| } |
| |
| |
| ScopedSetInserter scoped_set_inserter( visited_set, opaque_paint ); |
| |
| |
| if ( !FT_Get_Paint( face, opaque_paint, &paint ) ) |
| { |
| LOG( ERROR ) << "FT_Get_Paint failed."; |
| return false; |
| } |
| |
| // Keep track of failures to retrieve the FT_COLR_Paint from FreeType in the |
| // recursion, cancel recursion when a paint retrieval fails. |
| switch ( paint.format ) |
| { |
| |
| case FT_COLR_PAINTFORMAT_COLR_LAYERS: |
| { |
| FT_LayerIterator& layer_iterator = paint.u.colr_layers.layer_iterator; |
| FT_OpaquePaint opaque_paint_fetch; |
| |
| LOG( INFO ) << "PaintColrLayers," |
| << " num_layers " << layer_iterator.num_layers; |
| |
| opaque_paint_fetch.p = nullptr; |
| while ( FT_Get_Paint_Layers( face, |
| &layer_iterator, |
| &opaque_paint_fetch ) ) |
| colrv1_traverse_paint( face, |
| opaque_paint_fetch, |
| visited_set ); |
| |
| break; |
| } |
| |
| case FT_COLR_PAINTFORMAT_GLYPH: |
| colrv1_draw_paint( face, paint ); |
| traverse_result = colrv1_traverse_paint( face, |
| paint.u.glyph.paint, |
| visited_set ); |
| break; |
| |
| case FT_COLR_PAINTFORMAT_COLR_GLYPH: |
| |
| LOG( INFO ) << "PaintColrGlyph," |
| << " glyphId " << paint.u.colr_glyph.glyphID; |
| |
| traverse_result = colrv1_start_glyph( face, |
| paint.u.colr_glyph.glyphID, |
| FT_COLOR_NO_ROOT_TRANSFORM ); |
| break; |
| |
| case FT_COLR_PAINTFORMAT_TRANSFORM: |
| colrv1_draw_paint( face, paint ); |
| traverse_result = colrv1_traverse_paint( face, |
| paint.u.transform.paint, |
| visited_set ); |
| break; |
| |
| case FT_COLR_PAINTFORMAT_TRANSLATE: |
| colrv1_draw_paint( face, paint ); |
| traverse_result = colrv1_traverse_paint( face, |
| paint.u.translate.paint, |
| visited_set ); |
| break; |
| |
| case FT_COLR_PAINTFORMAT_SCALE: |
| colrv1_draw_paint( face, paint ); |
| traverse_result = colrv1_traverse_paint( face, |
| paint.u.scale.paint, |
| visited_set ); |
| break; |
| |
| case FT_COLR_PAINTFORMAT_ROTATE: |
| colrv1_draw_paint( face, paint ); |
| traverse_result = colrv1_traverse_paint( face, |
| paint.u.rotate.paint, |
| visited_set ); |
| break; |
| |
| case FT_COLR_PAINTFORMAT_SKEW: |
| colrv1_draw_paint( face, paint ); |
| traverse_result = colrv1_traverse_paint( face, |
| paint.u.skew.paint, |
| visited_set ); |
| break; |
| |
| case FT_COLR_PAINTFORMAT_COMPOSITE: |
| { |
| LOG( INFO ) << "PaintComposite," |
| << " composite_mode " << paint.u.composite.composite_mode; |
| |
| traverse_result = colrv1_traverse_paint( face, |
| paint.u.composite.backdrop_paint, |
| visited_set ); |
| traverse_result = |
| traverse_result && colrv1_traverse_paint( face, |
| paint.u.composite.source_paint, |
| visited_set ); |
| break; |
| } |
| |
| case FT_COLR_PAINTFORMAT_SOLID: |
| case FT_COLR_PAINTFORMAT_LINEAR_GRADIENT: |
| case FT_COLR_PAINTFORMAT_RADIAL_GRADIENT: |
| case FT_COLR_PAINTFORMAT_SWEEP_GRADIENT: |
| { |
| colrv1_draw_paint( face, paint ); |
| break; |
| } |
| |
| case FT_COLR_PAINT_FORMAT_MAX: |
| case FT_COLR_PAINTFORMAT_UNSUPPORTED: |
| LOG ( INFO ) << "Invalid paint format."; |
| break; |
| } |
| |
| return traverse_result; |
| } |
| |
| |
| bool colrv1_start_glyph( const FT_Face& ft_face, |
| uint16_t glyph_id, |
| FT_Color_Root_Transform root_transform ) |
| { |
| FT_OpaquePaint opaque_paint; |
| bool has_colrv1_layers = false; |
| |
| |
| opaque_paint.p = nullptr; |
| |
| if ( FT_Get_Color_Glyph_Paint( ft_face, |
| glyph_id, |
| root_transform, |
| &opaque_paint ) ) |
| { |
| FT_ClipBox colr_glyph_clip_box; |
| FT_Get_Color_Glyph_ClipBox( ft_face, glyph_id, &colr_glyph_clip_box ); |
| LOG( INFO ) << "ClipBox," |
| << " glyph_id " << glyph_id |
| << " bottom_left (" |
| << colr_glyph_clip_box.bottom_left.x << ", " |
| << colr_glyph_clip_box.bottom_left.y << ")" |
| << " top_left (" |
| << colr_glyph_clip_box.top_left.x << ", " |
| << colr_glyph_clip_box.top_left.y << ")" |
| << " top_right (" |
| << colr_glyph_clip_box.top_right.x << ", " |
| << colr_glyph_clip_box.top_right.y << ")" |
| << " bottom_right (" |
| << colr_glyph_clip_box.bottom_right.x << ", " |
| << colr_glyph_clip_box.bottom_right.y << ")"; |
| |
| VisitedSet visited_set; |
| has_colrv1_layers = true; |
| colrv1_traverse_paint( ft_face, opaque_paint, visited_set ); |
| } |
| |
| return has_colrv1_layers; |
| } |
| } |
| |
| |
| void |
| freetype::FaceVisitorColrV1:: |
| run( Unique_FT_Face face ) |
| { |
| FT_OpaquePaint opaque_paint; |
| unsigned long num_glyphs; |
| |
| |
| assert( face != nullptr ); |
| |
| num_glyphs = face->num_glyphs; |
| |
| LOG( INFO ) << "Starting COLR v1 traversal."; |
| |
| opaque_paint.p = nullptr; |
| |
| for ( uint16_t glyph_id = 0; |
| glyph_id < num_glyphs; |
| glyph_id++ ) |
| { |
| if ( num_traversed_glyphs >= MAX_TRAVERSE_GLYPHS ) |
| { |
| LOG( INFO ) << "Finished with this font after " |
| << MAX_TRAVERSE_GLYPHS |
| << " traversed glyphs."; |
| return; |
| } |
| |
| if ( !colrv1_start_glyph( face.get(), |
| glyph_id, |
| FT_COLOR_INCLUDE_ROOT_TRANSFORM ) ) |
| { |
| LOG( INFO ) << "No COLRv1 glyph for glyph id " << glyph_id << "."; |
| continue; |
| } |
| |
| num_traversed_glyphs++; |
| } |
| } |
