Support COLRv1 color fonts
Implement support for COLRv1 color gradient vector forms. COLR v1 is an
extension to the OpenType COLR tables that introduces support for
gradients, transforms and compositing. [1]
COLRv1 fonts contain an OpenType COLR table with format v1. In a COLR v1
table, glyphs are defined by a directed, acyclic graph of Paint
operations. The task for the Skia implementation is to extract the COLR
v1 information from the font using FreeType's COLRv1 API, then traverse
the glyph graph and translate information from the font into Skia
operations on SkCanvas.
Care needs to be taken for transformations to work correctly. FreeType
sends a top level transform that includes the scaling from font units to
actual glyph size, as well as optional transforms configured on FreeType
using FT_Set_Transform. This is set up as the starting transform at the
beginning of drawing a COLRv1 glyph. At the stage of setting a clip for
a PaintGlyph operation, the glyph outline is retrieved from FreeType
unscaled and untransformed. Since the starting transformation is applied
to the SkCanvas, the unscaled glyph is properly scaled and positioned.
Similarly, computing the initial bounding box for the COLRv1 glyph needs
to consider transformations. COLRv1 glyphs have a base glyph entry in
the glyf table which can use a minimum of two points for defining a
bounding box. This bounding box is an imaged rectangle enclosing those
two points at the identity transform. We need to compute the bounding
box scaled, but at identity transform, then make a rectangle from it,
that we then transform so that we get a large enough area to paint
in. If those two points from the glyf table would be transformed first,
then we would compute the bounding box, the resulting bounding box ends
up too small.
As a test font, add a version of the samples-glyf_colr_1.ttf from [2]
with one glyph added for testing PaintColrGlyph functionality and
compositions.
Add a basic GM test that produces color glyphs untransformed, with
skew and with rotation and combinations of those.
[1] https://github.com/googlefonts/colr-gradients-spec/
[2] https://github.com/googlefonts/color-fonts
Bug: skia:11264
Change-Id: I8357cd0c7ac0039bb2eac18f21fa343bf61871eb
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/300558
Commit-Queue: Dominik Röttsches <drott@chromium.org>
Commit-Queue: Ben Wagner <bungeman@google.com>
Auto-Submit: Dominik Röttsches <drott@chromium.org>
Reviewed-by: Ben Wagner <bungeman@google.com>
2021-02-11 19:08:44 +00:00
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/*
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2021-11-01 15:54:47 +00:00
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* Copyright 2021 Google Inc.
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Support COLRv1 color fonts
Implement support for COLRv1 color gradient vector forms. COLR v1 is an
extension to the OpenType COLR tables that introduces support for
gradients, transforms and compositing. [1]
COLRv1 fonts contain an OpenType COLR table with format v1. In a COLR v1
table, glyphs are defined by a directed, acyclic graph of Paint
operations. The task for the Skia implementation is to extract the COLR
v1 information from the font using FreeType's COLRv1 API, then traverse
the glyph graph and translate information from the font into Skia
operations on SkCanvas.
Care needs to be taken for transformations to work correctly. FreeType
sends a top level transform that includes the scaling from font units to
actual glyph size, as well as optional transforms configured on FreeType
using FT_Set_Transform. This is set up as the starting transform at the
beginning of drawing a COLRv1 glyph. At the stage of setting a clip for
a PaintGlyph operation, the glyph outline is retrieved from FreeType
unscaled and untransformed. Since the starting transformation is applied
to the SkCanvas, the unscaled glyph is properly scaled and positioned.
Similarly, computing the initial bounding box for the COLRv1 glyph needs
to consider transformations. COLRv1 glyphs have a base glyph entry in
the glyf table which can use a minimum of two points for defining a
bounding box. This bounding box is an imaged rectangle enclosing those
two points at the identity transform. We need to compute the bounding
box scaled, but at identity transform, then make a rectangle from it,
that we then transform so that we get a large enough area to paint
in. If those two points from the glyf table would be transformed first,
then we would compute the bounding box, the resulting bounding box ends
up too small.
As a test font, add a version of the samples-glyf_colr_1.ttf from [2]
with one glyph added for testing PaintColrGlyph functionality and
compositions.
Add a basic GM test that produces color glyphs untransformed, with
skew and with rotation and combinations of those.
[1] https://github.com/googlefonts/colr-gradients-spec/
[2] https://github.com/googlefonts/color-fonts
Bug: skia:11264
Change-Id: I8357cd0c7ac0039bb2eac18f21fa343bf61871eb
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/300558
Commit-Queue: Dominik Röttsches <drott@chromium.org>
Commit-Queue: Ben Wagner <bungeman@google.com>
Auto-Submit: Dominik Röttsches <drott@chromium.org>
Reviewed-by: Ben Wagner <bungeman@google.com>
2021-02-11 19:08:44 +00:00
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*
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* Use of this source code is governed by a BSD-style license that can be
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* found in the LICENSE file.
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*/
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#include "gm/gm.h"
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#include "include/core/SkCanvas.h"
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#include "include/core/SkColor.h"
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#include "include/core/SkFont.h"
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#include "include/core/SkFontMetrics.h"
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#include "include/core/SkPaint.h"
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#include "include/core/SkRefCnt.h"
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#include "include/core/SkScalar.h"
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#include "include/core/SkSize.h"
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#include "include/core/SkString.h"
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#include "include/core/SkTypeface.h"
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#include "tools/Resources.h"
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#include "tools/ToolUtils.h"
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#include <string.h>
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#include <initializer_list>
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namespace skiagm {
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class ColrV1GM : public GM {
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public:
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[COLRv1] Map linear gradient extrema to [0, 1] range
Prepare data to Skia's linear gradient shader so that the extrema are
[0, 1] when the data in the font does not have them at these
positions. This is required for the shader to correctly compute repeat
modes.
Add the test font from the Google color fonts repo [1] with stops at [0,
1], [0.2, 0.8], [0, 1.5], [0.5, 1.5] respectively, compare[2].
[1] https://github.com/googlefonts/color-fonts/blob/main/fonts/more_samples-glyf_colr_1.ttf
[2] https://github.com/googlefonts/colr-gradients-spec/issues/281#issuecomment-828346428
Bug: skia:11922
Change-Id: Ic62a26911fa177af35ca16f183b5985d884237a5
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/405717
Commit-Queue: Dominik Röttsches <drott@google.com>
Reviewed-by: Ben Wagner <bungeman@google.com>
2021-05-11 12:59:43 +00:00
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// TODO(drott): Consolidate test fonts.
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2021-07-26 08:13:47 +00:00
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enum ColrV1TestType {
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[COLRv1] Map linear gradient extrema to [0, 1] range
Prepare data to Skia's linear gradient shader so that the extrema are
[0, 1] when the data in the font does not have them at these
positions. This is required for the shader to correctly compute repeat
modes.
Add the test font from the Google color fonts repo [1] with stops at [0,
1], [0.2, 0.8], [0, 1.5], [0.5, 1.5] respectively, compare[2].
[1] https://github.com/googlefonts/color-fonts/blob/main/fonts/more_samples-glyf_colr_1.ttf
[2] https://github.com/googlefonts/colr-gradients-spec/issues/281#issuecomment-828346428
Bug: skia:11922
Change-Id: Ic62a26911fa177af35ca16f183b5985d884237a5
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/405717
Commit-Queue: Dominik Röttsches <drott@google.com>
Reviewed-by: Ben Wagner <bungeman@google.com>
2021-05-11 12:59:43 +00:00
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kSkiaSampleFont,
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2021-07-26 08:13:47 +00:00
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kColorFontsRepoGradients,
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kColorFontsRepoScaling,
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kColorFontsRepoExtendMode,
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2021-07-29 08:37:33 +00:00
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kColorFontsRepoRotate,
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kColorFontsRepoSkew,
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2021-08-10 09:10:45 +00:00
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kColorFontsRepoTransform,
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2021-09-06 12:58:40 +00:00
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kColorFontsRepoClipBox,
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2021-11-09 14:13:19 +00:00
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kColorFontsRepoComposite,
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kColorFontsRepoForeground
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[COLRv1] Map linear gradient extrema to [0, 1] range
Prepare data to Skia's linear gradient shader so that the extrema are
[0, 1] when the data in the font does not have them at these
positions. This is required for the shader to correctly compute repeat
modes.
Add the test font from the Google color fonts repo [1] with stops at [0,
1], [0.2, 0.8], [0, 1.5], [0.5, 1.5] respectively, compare[2].
[1] https://github.com/googlefonts/color-fonts/blob/main/fonts/more_samples-glyf_colr_1.ttf
[2] https://github.com/googlefonts/colr-gradients-spec/issues/281#issuecomment-828346428
Bug: skia:11922
Change-Id: Ic62a26911fa177af35ca16f183b5985d884237a5
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/405717
Commit-Queue: Dominik Röttsches <drott@google.com>
Reviewed-by: Ben Wagner <bungeman@google.com>
2021-05-11 12:59:43 +00:00
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};
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2021-07-26 08:13:47 +00:00
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ColrV1GM(ColrV1TestType testType, SkScalar skewX, SkScalar rotateDeg)
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: fSkewX(skewX), fRotateDeg(rotateDeg), fTestType(testType) {}
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Support COLRv1 color fonts
Implement support for COLRv1 color gradient vector forms. COLR v1 is an
extension to the OpenType COLR tables that introduces support for
gradients, transforms and compositing. [1]
COLRv1 fonts contain an OpenType COLR table with format v1. In a COLR v1
table, glyphs are defined by a directed, acyclic graph of Paint
operations. The task for the Skia implementation is to extract the COLR
v1 information from the font using FreeType's COLRv1 API, then traverse
the glyph graph and translate information from the font into Skia
operations on SkCanvas.
Care needs to be taken for transformations to work correctly. FreeType
sends a top level transform that includes the scaling from font units to
actual glyph size, as well as optional transforms configured on FreeType
using FT_Set_Transform. This is set up as the starting transform at the
beginning of drawing a COLRv1 glyph. At the stage of setting a clip for
a PaintGlyph operation, the glyph outline is retrieved from FreeType
unscaled and untransformed. Since the starting transformation is applied
to the SkCanvas, the unscaled glyph is properly scaled and positioned.
Similarly, computing the initial bounding box for the COLRv1 glyph needs
to consider transformations. COLRv1 glyphs have a base glyph entry in
the glyf table which can use a minimum of two points for defining a
bounding box. This bounding box is an imaged rectangle enclosing those
two points at the identity transform. We need to compute the bounding
box scaled, but at identity transform, then make a rectangle from it,
that we then transform so that we get a large enough area to paint
in. If those two points from the glyf table would be transformed first,
then we would compute the bounding box, the resulting bounding box ends
up too small.
As a test font, add a version of the samples-glyf_colr_1.ttf from [2]
with one glyph added for testing PaintColrGlyph functionality and
compositions.
Add a basic GM test that produces color glyphs untransformed, with
skew and with rotation and combinations of those.
[1] https://github.com/googlefonts/colr-gradients-spec/
[2] https://github.com/googlefonts/color-fonts
Bug: skia:11264
Change-Id: I8357cd0c7ac0039bb2eac18f21fa343bf61871eb
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/300558
Commit-Queue: Dominik Röttsches <drott@chromium.org>
Commit-Queue: Ben Wagner <bungeman@google.com>
Auto-Submit: Dominik Röttsches <drott@chromium.org>
Reviewed-by: Ben Wagner <bungeman@google.com>
2021-02-11 19:08:44 +00:00
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protected:
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2021-07-26 08:13:47 +00:00
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static SkString testTypeToString(ColrV1TestType testType) {
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switch (testType) {
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case kSkiaSampleFont:
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return SkString("skia");
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case kColorFontsRepoGradients:
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return SkString("gradients");
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case kColorFontsRepoScaling:
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return SkString("scaling");
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case kColorFontsRepoExtendMode:
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return SkString("extend_mode");
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2021-07-29 08:37:33 +00:00
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case kColorFontsRepoRotate:
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return SkString("rotate");
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case kColorFontsRepoSkew:
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return SkString("skew");
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case kColorFontsRepoTransform:
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return SkString("transform");
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2021-08-10 09:10:45 +00:00
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case kColorFontsRepoClipBox:
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return SkString("clipbox");
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2021-09-06 12:58:40 +00:00
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case kColorFontsRepoComposite:
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return SkString("composite");
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2021-11-09 14:13:19 +00:00
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case kColorFontsRepoForeground:
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return SkString("foreground");
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2021-07-26 08:13:47 +00:00
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}
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SkASSERT(false); /* not reached */
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return SkString();
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}
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|
Support COLRv1 color fonts
Implement support for COLRv1 color gradient vector forms. COLR v1 is an
extension to the OpenType COLR tables that introduces support for
gradients, transforms and compositing. [1]
COLRv1 fonts contain an OpenType COLR table with format v1. In a COLR v1
table, glyphs are defined by a directed, acyclic graph of Paint
operations. The task for the Skia implementation is to extract the COLR
v1 information from the font using FreeType's COLRv1 API, then traverse
the glyph graph and translate information from the font into Skia
operations on SkCanvas.
Care needs to be taken for transformations to work correctly. FreeType
sends a top level transform that includes the scaling from font units to
actual glyph size, as well as optional transforms configured on FreeType
using FT_Set_Transform. This is set up as the starting transform at the
beginning of drawing a COLRv1 glyph. At the stage of setting a clip for
a PaintGlyph operation, the glyph outline is retrieved from FreeType
unscaled and untransformed. Since the starting transformation is applied
to the SkCanvas, the unscaled glyph is properly scaled and positioned.
Similarly, computing the initial bounding box for the COLRv1 glyph needs
to consider transformations. COLRv1 glyphs have a base glyph entry in
the glyf table which can use a minimum of two points for defining a
bounding box. This bounding box is an imaged rectangle enclosing those
two points at the identity transform. We need to compute the bounding
box scaled, but at identity transform, then make a rectangle from it,
that we then transform so that we get a large enough area to paint
in. If those two points from the glyf table would be transformed first,
then we would compute the bounding box, the resulting bounding box ends
up too small.
As a test font, add a version of the samples-glyf_colr_1.ttf from [2]
with one glyph added for testing PaintColrGlyph functionality and
compositions.
Add a basic GM test that produces color glyphs untransformed, with
skew and with rotation and combinations of those.
[1] https://github.com/googlefonts/colr-gradients-spec/
[2] https://github.com/googlefonts/color-fonts
Bug: skia:11264
Change-Id: I8357cd0c7ac0039bb2eac18f21fa343bf61871eb
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/300558
Commit-Queue: Dominik Röttsches <drott@chromium.org>
Commit-Queue: Ben Wagner <bungeman@google.com>
Auto-Submit: Dominik Röttsches <drott@chromium.org>
Reviewed-by: Ben Wagner <bungeman@google.com>
2021-02-11 19:08:44 +00:00
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struct EmojiFont {
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sk_sp<SkTypeface> fTypeface;
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[COLRv1] Map linear gradient extrema to [0, 1] range
Prepare data to Skia's linear gradient shader so that the extrema are
[0, 1] when the data in the font does not have them at these
positions. This is required for the shader to correctly compute repeat
modes.
Add the test font from the Google color fonts repo [1] with stops at [0,
1], [0.2, 0.8], [0, 1.5], [0.5, 1.5] respectively, compare[2].
[1] https://github.com/googlefonts/color-fonts/blob/main/fonts/more_samples-glyf_colr_1.ttf
[2] https://github.com/googlefonts/colr-gradients-spec/issues/281#issuecomment-828346428
Bug: skia:11922
Change-Id: Ic62a26911fa177af35ca16f183b5985d884237a5
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/405717
Commit-Queue: Dominik Röttsches <drott@google.com>
Reviewed-by: Ben Wagner <bungeman@google.com>
2021-05-11 12:59:43 +00:00
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std::vector<uint16_t> fGlyphs;
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size_t bytesize() { return fGlyphs.size() * sizeof(uint16_t); }
|
Support COLRv1 color fonts
Implement support for COLRv1 color gradient vector forms. COLR v1 is an
extension to the OpenType COLR tables that introduces support for
gradients, transforms and compositing. [1]
COLRv1 fonts contain an OpenType COLR table with format v1. In a COLR v1
table, glyphs are defined by a directed, acyclic graph of Paint
operations. The task for the Skia implementation is to extract the COLR
v1 information from the font using FreeType's COLRv1 API, then traverse
the glyph graph and translate information from the font into Skia
operations on SkCanvas.
Care needs to be taken for transformations to work correctly. FreeType
sends a top level transform that includes the scaling from font units to
actual glyph size, as well as optional transforms configured on FreeType
using FT_Set_Transform. This is set up as the starting transform at the
beginning of drawing a COLRv1 glyph. At the stage of setting a clip for
a PaintGlyph operation, the glyph outline is retrieved from FreeType
unscaled and untransformed. Since the starting transformation is applied
to the SkCanvas, the unscaled glyph is properly scaled and positioned.
Similarly, computing the initial bounding box for the COLRv1 glyph needs
to consider transformations. COLRv1 glyphs have a base glyph entry in
the glyf table which can use a minimum of two points for defining a
bounding box. This bounding box is an imaged rectangle enclosing those
two points at the identity transform. We need to compute the bounding
box scaled, but at identity transform, then make a rectangle from it,
that we then transform so that we get a large enough area to paint
in. If those two points from the glyf table would be transformed first,
then we would compute the bounding box, the resulting bounding box ends
up too small.
As a test font, add a version of the samples-glyf_colr_1.ttf from [2]
with one glyph added for testing PaintColrGlyph functionality and
compositions.
Add a basic GM test that produces color glyphs untransformed, with
skew and with rotation and combinations of those.
[1] https://github.com/googlefonts/colr-gradients-spec/
[2] https://github.com/googlefonts/color-fonts
Bug: skia:11264
Change-Id: I8357cd0c7ac0039bb2eac18f21fa343bf61871eb
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/300558
Commit-Queue: Dominik Röttsches <drott@chromium.org>
Commit-Queue: Ben Wagner <bungeman@google.com>
Auto-Submit: Dominik Röttsches <drott@chromium.org>
Reviewed-by: Ben Wagner <bungeman@google.com>
2021-02-11 19:08:44 +00:00
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} fEmojiFont;
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void onOnceBeforeDraw() override {
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2021-07-26 08:13:47 +00:00
|
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if (fTestType == kSkiaSampleFont) {
|
[COLRv1] Map linear gradient extrema to [0, 1] range
Prepare data to Skia's linear gradient shader so that the extrema are
[0, 1] when the data in the font does not have them at these
positions. This is required for the shader to correctly compute repeat
modes.
Add the test font from the Google color fonts repo [1] with stops at [0,
1], [0.2, 0.8], [0, 1.5], [0.5, 1.5] respectively, compare[2].
[1] https://github.com/googlefonts/color-fonts/blob/main/fonts/more_samples-glyf_colr_1.ttf
[2] https://github.com/googlefonts/colr-gradients-spec/issues/281#issuecomment-828346428
Bug: skia:11922
Change-Id: Ic62a26911fa177af35ca16f183b5985d884237a5
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/405717
Commit-Queue: Dominik Röttsches <drott@google.com>
Reviewed-by: Ben Wagner <bungeman@google.com>
2021-05-11 12:59:43 +00:00
|
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fEmojiFont.fTypeface = MakeResourceAsTypeface("fonts/colrv1_samples.ttf");
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fEmojiFont.fGlyphs = {19, 33, 34, 35, 20, 21, 22, 23, 24, 25};
|
2021-07-29 08:37:33 +00:00
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return;
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}
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fEmojiFont.fTypeface = MakeResourceAsTypeface("fonts/more_samples-glyf_colr_1.ttf");
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switch (fTestType) {
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case kSkiaSampleFont:
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SkASSERT(false);
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break;
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case kColorFontsRepoGradients:
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2022-01-13 17:13:06 +00:00
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fEmojiFont.fGlyphs = {2, 5, 6, 7, 8, 55};
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2021-07-29 08:37:33 +00:00
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break;
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case kColorFontsRepoScaling:
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fEmojiFont.fGlyphs = {9, 10, 11, 12, 13, 14};
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break;
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case kColorFontsRepoExtendMode:
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fEmojiFont.fGlyphs = {15, 16, 17, 18, 19, 20};
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break;
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case kColorFontsRepoRotate:
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fEmojiFont.fGlyphs = {21, 22, 23, 24};
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break;
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case kColorFontsRepoSkew:
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fEmojiFont.fGlyphs = {25, 26, 27, 28, 29, 30};
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break;
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case kColorFontsRepoTransform:
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fEmojiFont.fGlyphs = {31, 32, 33, 34};
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break;
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2021-08-10 09:10:45 +00:00
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case kColorFontsRepoClipBox:
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fEmojiFont.fGlyphs = {35, 36, 37, 38, 39};
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break;
|
2021-09-06 12:58:40 +00:00
|
|
|
case kColorFontsRepoComposite:
|
|
|
|
fEmojiFont.fGlyphs = {40, 41, 42, 43, 44, 45, 46};
|
|
|
|
break;
|
2021-11-09 14:13:19 +00:00
|
|
|
case kColorFontsRepoForeground:
|
|
|
|
fEmojiFont.fGlyphs = {47, 48, 49, 50, 51, 52, 53, 54};
|
|
|
|
break;
|
[COLRv1] Map linear gradient extrema to [0, 1] range
Prepare data to Skia's linear gradient shader so that the extrema are
[0, 1] when the data in the font does not have them at these
positions. This is required for the shader to correctly compute repeat
modes.
Add the test font from the Google color fonts repo [1] with stops at [0,
1], [0.2, 0.8], [0, 1.5], [0.5, 1.5] respectively, compare[2].
[1] https://github.com/googlefonts/color-fonts/blob/main/fonts/more_samples-glyf_colr_1.ttf
[2] https://github.com/googlefonts/colr-gradients-spec/issues/281#issuecomment-828346428
Bug: skia:11922
Change-Id: Ic62a26911fa177af35ca16f183b5985d884237a5
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/405717
Commit-Queue: Dominik Röttsches <drott@google.com>
Reviewed-by: Ben Wagner <bungeman@google.com>
2021-05-11 12:59:43 +00:00
|
|
|
}
|
Support COLRv1 color fonts
Implement support for COLRv1 color gradient vector forms. COLR v1 is an
extension to the OpenType COLR tables that introduces support for
gradients, transforms and compositing. [1]
COLRv1 fonts contain an OpenType COLR table with format v1. In a COLR v1
table, glyphs are defined by a directed, acyclic graph of Paint
operations. The task for the Skia implementation is to extract the COLR
v1 information from the font using FreeType's COLRv1 API, then traverse
the glyph graph and translate information from the font into Skia
operations on SkCanvas.
Care needs to be taken for transformations to work correctly. FreeType
sends a top level transform that includes the scaling from font units to
actual glyph size, as well as optional transforms configured on FreeType
using FT_Set_Transform. This is set up as the starting transform at the
beginning of drawing a COLRv1 glyph. At the stage of setting a clip for
a PaintGlyph operation, the glyph outline is retrieved from FreeType
unscaled and untransformed. Since the starting transformation is applied
to the SkCanvas, the unscaled glyph is properly scaled and positioned.
Similarly, computing the initial bounding box for the COLRv1 glyph needs
to consider transformations. COLRv1 glyphs have a base glyph entry in
the glyf table which can use a minimum of two points for defining a
bounding box. This bounding box is an imaged rectangle enclosing those
two points at the identity transform. We need to compute the bounding
box scaled, but at identity transform, then make a rectangle from it,
that we then transform so that we get a large enough area to paint
in. If those two points from the glyf table would be transformed first,
then we would compute the bounding box, the resulting bounding box ends
up too small.
As a test font, add a version of the samples-glyf_colr_1.ttf from [2]
with one glyph added for testing PaintColrGlyph functionality and
compositions.
Add a basic GM test that produces color glyphs untransformed, with
skew and with rotation and combinations of those.
[1] https://github.com/googlefonts/colr-gradients-spec/
[2] https://github.com/googlefonts/color-fonts
Bug: skia:11264
Change-Id: I8357cd0c7ac0039bb2eac18f21fa343bf61871eb
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/300558
Commit-Queue: Dominik Röttsches <drott@chromium.org>
Commit-Queue: Ben Wagner <bungeman@google.com>
Auto-Submit: Dominik Röttsches <drott@chromium.org>
Reviewed-by: Ben Wagner <bungeman@google.com>
2021-02-11 19:08:44 +00:00
|
|
|
}
|
|
|
|
|
|
|
|
SkString onShortName() override {
|
[COLRv1] Map linear gradient extrema to [0, 1] range
Prepare data to Skia's linear gradient shader so that the extrema are
[0, 1] when the data in the font does not have them at these
positions. This is required for the shader to correctly compute repeat
modes.
Add the test font from the Google color fonts repo [1] with stops at [0,
1], [0.2, 0.8], [0, 1.5], [0.5, 1.5] respectively, compare[2].
[1] https://github.com/googlefonts/color-fonts/blob/main/fonts/more_samples-glyf_colr_1.ttf
[2] https://github.com/googlefonts/colr-gradients-spec/issues/281#issuecomment-828346428
Bug: skia:11922
Change-Id: Ic62a26911fa177af35ca16f183b5985d884237a5
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/405717
Commit-Queue: Dominik Röttsches <drott@google.com>
Reviewed-by: Ben Wagner <bungeman@google.com>
2021-05-11 12:59:43 +00:00
|
|
|
SkString gm_name = SkStringPrintf("colrv1_%s_samples",
|
2021-07-26 08:13:47 +00:00
|
|
|
testTypeToString(fTestType).c_str());
|
[COLRv1] Map linear gradient extrema to [0, 1] range
Prepare data to Skia's linear gradient shader so that the extrema are
[0, 1] when the data in the font does not have them at these
positions. This is required for the shader to correctly compute repeat
modes.
Add the test font from the Google color fonts repo [1] with stops at [0,
1], [0.2, 0.8], [0, 1.5], [0.5, 1.5] respectively, compare[2].
[1] https://github.com/googlefonts/color-fonts/blob/main/fonts/more_samples-glyf_colr_1.ttf
[2] https://github.com/googlefonts/colr-gradients-spec/issues/281#issuecomment-828346428
Bug: skia:11922
Change-Id: Ic62a26911fa177af35ca16f183b5985d884237a5
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/405717
Commit-Queue: Dominik Röttsches <drott@google.com>
Reviewed-by: Ben Wagner <bungeman@google.com>
2021-05-11 12:59:43 +00:00
|
|
|
if (fSkewX) {
|
|
|
|
gm_name.append("_skew");
|
|
|
|
}
|
|
|
|
|
|
|
|
if (fRotateDeg) {
|
|
|
|
gm_name.append("_rotate");
|
Support COLRv1 color fonts
Implement support for COLRv1 color gradient vector forms. COLR v1 is an
extension to the OpenType COLR tables that introduces support for
gradients, transforms and compositing. [1]
COLRv1 fonts contain an OpenType COLR table with format v1. In a COLR v1
table, glyphs are defined by a directed, acyclic graph of Paint
operations. The task for the Skia implementation is to extract the COLR
v1 information from the font using FreeType's COLRv1 API, then traverse
the glyph graph and translate information from the font into Skia
operations on SkCanvas.
Care needs to be taken for transformations to work correctly. FreeType
sends a top level transform that includes the scaling from font units to
actual glyph size, as well as optional transforms configured on FreeType
using FT_Set_Transform. This is set up as the starting transform at the
beginning of drawing a COLRv1 glyph. At the stage of setting a clip for
a PaintGlyph operation, the glyph outline is retrieved from FreeType
unscaled and untransformed. Since the starting transformation is applied
to the SkCanvas, the unscaled glyph is properly scaled and positioned.
Similarly, computing the initial bounding box for the COLRv1 glyph needs
to consider transformations. COLRv1 glyphs have a base glyph entry in
the glyf table which can use a minimum of two points for defining a
bounding box. This bounding box is an imaged rectangle enclosing those
two points at the identity transform. We need to compute the bounding
box scaled, but at identity transform, then make a rectangle from it,
that we then transform so that we get a large enough area to paint
in. If those two points from the glyf table would be transformed first,
then we would compute the bounding box, the resulting bounding box ends
up too small.
As a test font, add a version of the samples-glyf_colr_1.ttf from [2]
with one glyph added for testing PaintColrGlyph functionality and
compositions.
Add a basic GM test that produces color glyphs untransformed, with
skew and with rotation and combinations of those.
[1] https://github.com/googlefonts/colr-gradients-spec/
[2] https://github.com/googlefonts/color-fonts
Bug: skia:11264
Change-Id: I8357cd0c7ac0039bb2eac18f21fa343bf61871eb
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/300558
Commit-Queue: Dominik Röttsches <drott@chromium.org>
Commit-Queue: Ben Wagner <bungeman@google.com>
Auto-Submit: Dominik Röttsches <drott@chromium.org>
Reviewed-by: Ben Wagner <bungeman@google.com>
2021-02-11 19:08:44 +00:00
|
|
|
}
|
[COLRv1] Map linear gradient extrema to [0, 1] range
Prepare data to Skia's linear gradient shader so that the extrema are
[0, 1] when the data in the font does not have them at these
positions. This is required for the shader to correctly compute repeat
modes.
Add the test font from the Google color fonts repo [1] with stops at [0,
1], [0.2, 0.8], [0, 1.5], [0.5, 1.5] respectively, compare[2].
[1] https://github.com/googlefonts/color-fonts/blob/main/fonts/more_samples-glyf_colr_1.ttf
[2] https://github.com/googlefonts/colr-gradients-spec/issues/281#issuecomment-828346428
Bug: skia:11922
Change-Id: Ic62a26911fa177af35ca16f183b5985d884237a5
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/405717
Commit-Queue: Dominik Röttsches <drott@google.com>
Reviewed-by: Ben Wagner <bungeman@google.com>
2021-05-11 12:59:43 +00:00
|
|
|
return gm_name;
|
Support COLRv1 color fonts
Implement support for COLRv1 color gradient vector forms. COLR v1 is an
extension to the OpenType COLR tables that introduces support for
gradients, transforms and compositing. [1]
COLRv1 fonts contain an OpenType COLR table with format v1. In a COLR v1
table, glyphs are defined by a directed, acyclic graph of Paint
operations. The task for the Skia implementation is to extract the COLR
v1 information from the font using FreeType's COLRv1 API, then traverse
the glyph graph and translate information from the font into Skia
operations on SkCanvas.
Care needs to be taken for transformations to work correctly. FreeType
sends a top level transform that includes the scaling from font units to
actual glyph size, as well as optional transforms configured on FreeType
using FT_Set_Transform. This is set up as the starting transform at the
beginning of drawing a COLRv1 glyph. At the stage of setting a clip for
a PaintGlyph operation, the glyph outline is retrieved from FreeType
unscaled and untransformed. Since the starting transformation is applied
to the SkCanvas, the unscaled glyph is properly scaled and positioned.
Similarly, computing the initial bounding box for the COLRv1 glyph needs
to consider transformations. COLRv1 glyphs have a base glyph entry in
the glyf table which can use a minimum of two points for defining a
bounding box. This bounding box is an imaged rectangle enclosing those
two points at the identity transform. We need to compute the bounding
box scaled, but at identity transform, then make a rectangle from it,
that we then transform so that we get a large enough area to paint
in. If those two points from the glyf table would be transformed first,
then we would compute the bounding box, the resulting bounding box ends
up too small.
As a test font, add a version of the samples-glyf_colr_1.ttf from [2]
with one glyph added for testing PaintColrGlyph functionality and
compositions.
Add a basic GM test that produces color glyphs untransformed, with
skew and with rotation and combinations of those.
[1] https://github.com/googlefonts/colr-gradients-spec/
[2] https://github.com/googlefonts/color-fonts
Bug: skia:11264
Change-Id: I8357cd0c7ac0039bb2eac18f21fa343bf61871eb
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/300558
Commit-Queue: Dominik Röttsches <drott@chromium.org>
Commit-Queue: Ben Wagner <bungeman@google.com>
Auto-Submit: Dominik Röttsches <drott@chromium.org>
Reviewed-by: Ben Wagner <bungeman@google.com>
2021-02-11 19:08:44 +00:00
|
|
|
}
|
|
|
|
|
2021-03-25 14:13:46 +00:00
|
|
|
SkISize onISize() override { return SkISize::Make(1400, 600); }
|
Support COLRv1 color fonts
Implement support for COLRv1 color gradient vector forms. COLR v1 is an
extension to the OpenType COLR tables that introduces support for
gradients, transforms and compositing. [1]
COLRv1 fonts contain an OpenType COLR table with format v1. In a COLR v1
table, glyphs are defined by a directed, acyclic graph of Paint
operations. The task for the Skia implementation is to extract the COLR
v1 information from the font using FreeType's COLRv1 API, then traverse
the glyph graph and translate information from the font into Skia
operations on SkCanvas.
Care needs to be taken for transformations to work correctly. FreeType
sends a top level transform that includes the scaling from font units to
actual glyph size, as well as optional transforms configured on FreeType
using FT_Set_Transform. This is set up as the starting transform at the
beginning of drawing a COLRv1 glyph. At the stage of setting a clip for
a PaintGlyph operation, the glyph outline is retrieved from FreeType
unscaled and untransformed. Since the starting transformation is applied
to the SkCanvas, the unscaled glyph is properly scaled and positioned.
Similarly, computing the initial bounding box for the COLRv1 glyph needs
to consider transformations. COLRv1 glyphs have a base glyph entry in
the glyf table which can use a minimum of two points for defining a
bounding box. This bounding box is an imaged rectangle enclosing those
two points at the identity transform. We need to compute the bounding
box scaled, but at identity transform, then make a rectangle from it,
that we then transform so that we get a large enough area to paint
in. If those two points from the glyf table would be transformed first,
then we would compute the bounding box, the resulting bounding box ends
up too small.
As a test font, add a version of the samples-glyf_colr_1.ttf from [2]
with one glyph added for testing PaintColrGlyph functionality and
compositions.
Add a basic GM test that produces color glyphs untransformed, with
skew and with rotation and combinations of those.
[1] https://github.com/googlefonts/colr-gradients-spec/
[2] https://github.com/googlefonts/color-fonts
Bug: skia:11264
Change-Id: I8357cd0c7ac0039bb2eac18f21fa343bf61871eb
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/300558
Commit-Queue: Dominik Röttsches <drott@chromium.org>
Commit-Queue: Ben Wagner <bungeman@google.com>
Auto-Submit: Dominik Röttsches <drott@chromium.org>
Reviewed-by: Ben Wagner <bungeman@google.com>
2021-02-11 19:08:44 +00:00
|
|
|
|
|
|
|
DrawResult onDraw(SkCanvas* canvas, SkString* errorMsg) override {
|
|
|
|
canvas->drawColor(SK_ColorWHITE);
|
|
|
|
SkPaint paint;
|
|
|
|
|
|
|
|
canvas->translate(200, 20);
|
|
|
|
|
|
|
|
if (!fEmojiFont.fTypeface) {
|
|
|
|
*errorMsg = "Did not recognize COLR v1 font format.";
|
|
|
|
return DrawResult::kSkip;
|
|
|
|
}
|
|
|
|
|
|
|
|
canvas->rotate(fRotateDeg);
|
|
|
|
canvas->skew(fSkewX, 0);
|
|
|
|
|
|
|
|
SkFont font(fEmojiFont.fTypeface);
|
|
|
|
|
|
|
|
SkFontMetrics metrics;
|
|
|
|
SkScalar y = 0;
|
2021-11-09 14:13:19 +00:00
|
|
|
std::vector<SkColor> paint_colors = {
|
|
|
|
SK_ColorBLACK, SK_ColorGREEN, SK_ColorRED, SK_ColorBLUE};
|
|
|
|
auto paint_color_iterator = paint_colors.begin();
|
Support COLRv1 color fonts
Implement support for COLRv1 color gradient vector forms. COLR v1 is an
extension to the OpenType COLR tables that introduces support for
gradients, transforms and compositing. [1]
COLRv1 fonts contain an OpenType COLR table with format v1. In a COLR v1
table, glyphs are defined by a directed, acyclic graph of Paint
operations. The task for the Skia implementation is to extract the COLR
v1 information from the font using FreeType's COLRv1 API, then traverse
the glyph graph and translate information from the font into Skia
operations on SkCanvas.
Care needs to be taken for transformations to work correctly. FreeType
sends a top level transform that includes the scaling from font units to
actual glyph size, as well as optional transforms configured on FreeType
using FT_Set_Transform. This is set up as the starting transform at the
beginning of drawing a COLRv1 glyph. At the stage of setting a clip for
a PaintGlyph operation, the glyph outline is retrieved from FreeType
unscaled and untransformed. Since the starting transformation is applied
to the SkCanvas, the unscaled glyph is properly scaled and positioned.
Similarly, computing the initial bounding box for the COLRv1 glyph needs
to consider transformations. COLRv1 glyphs have a base glyph entry in
the glyf table which can use a minimum of two points for defining a
bounding box. This bounding box is an imaged rectangle enclosing those
two points at the identity transform. We need to compute the bounding
box scaled, but at identity transform, then make a rectangle from it,
that we then transform so that we get a large enough area to paint
in. If those two points from the glyf table would be transformed first,
then we would compute the bounding box, the resulting bounding box ends
up too small.
As a test font, add a version of the samples-glyf_colr_1.ttf from [2]
with one glyph added for testing PaintColrGlyph functionality and
compositions.
Add a basic GM test that produces color glyphs untransformed, with
skew and with rotation and combinations of those.
[1] https://github.com/googlefonts/colr-gradients-spec/
[2] https://github.com/googlefonts/color-fonts
Bug: skia:11264
Change-Id: I8357cd0c7ac0039bb2eac18f21fa343bf61871eb
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/300558
Commit-Queue: Dominik Röttsches <drott@chromium.org>
Commit-Queue: Ben Wagner <bungeman@google.com>
Auto-Submit: Dominik Röttsches <drott@chromium.org>
Reviewed-by: Ben Wagner <bungeman@google.com>
2021-02-11 19:08:44 +00:00
|
|
|
for (SkScalar textSize : { 12, 18, 30, 120 }) {
|
|
|
|
font.setSize(textSize);
|
|
|
|
font.getMetrics(&metrics);
|
|
|
|
y += -metrics.fAscent;
|
2021-11-09 14:13:19 +00:00
|
|
|
paint.setColor(*paint_color_iterator);
|
[COLRv1] Map linear gradient extrema to [0, 1] range
Prepare data to Skia's linear gradient shader so that the extrema are
[0, 1] when the data in the font does not have them at these
positions. This is required for the shader to correctly compute repeat
modes.
Add the test font from the Google color fonts repo [1] with stops at [0,
1], [0.2, 0.8], [0, 1.5], [0.5, 1.5] respectively, compare[2].
[1] https://github.com/googlefonts/color-fonts/blob/main/fonts/more_samples-glyf_colr_1.ttf
[2] https://github.com/googlefonts/colr-gradients-spec/issues/281#issuecomment-828346428
Bug: skia:11922
Change-Id: Ic62a26911fa177af35ca16f183b5985d884237a5
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/405717
Commit-Queue: Dominik Röttsches <drott@google.com>
Reviewed-by: Ben Wagner <bungeman@google.com>
2021-05-11 12:59:43 +00:00
|
|
|
canvas->drawSimpleText(fEmojiFont.fGlyphs.data(),
|
|
|
|
fEmojiFont.bytesize(),
|
Support COLRv1 color fonts
Implement support for COLRv1 color gradient vector forms. COLR v1 is an
extension to the OpenType COLR tables that introduces support for
gradients, transforms and compositing. [1]
COLRv1 fonts contain an OpenType COLR table with format v1. In a COLR v1
table, glyphs are defined by a directed, acyclic graph of Paint
operations. The task for the Skia implementation is to extract the COLR
v1 information from the font using FreeType's COLRv1 API, then traverse
the glyph graph and translate information from the font into Skia
operations on SkCanvas.
Care needs to be taken for transformations to work correctly. FreeType
sends a top level transform that includes the scaling from font units to
actual glyph size, as well as optional transforms configured on FreeType
using FT_Set_Transform. This is set up as the starting transform at the
beginning of drawing a COLRv1 glyph. At the stage of setting a clip for
a PaintGlyph operation, the glyph outline is retrieved from FreeType
unscaled and untransformed. Since the starting transformation is applied
to the SkCanvas, the unscaled glyph is properly scaled and positioned.
Similarly, computing the initial bounding box for the COLRv1 glyph needs
to consider transformations. COLRv1 glyphs have a base glyph entry in
the glyf table which can use a minimum of two points for defining a
bounding box. This bounding box is an imaged rectangle enclosing those
two points at the identity transform. We need to compute the bounding
box scaled, but at identity transform, then make a rectangle from it,
that we then transform so that we get a large enough area to paint
in. If those two points from the glyf table would be transformed first,
then we would compute the bounding box, the resulting bounding box ends
up too small.
As a test font, add a version of the samples-glyf_colr_1.ttf from [2]
with one glyph added for testing PaintColrGlyph functionality and
compositions.
Add a basic GM test that produces color glyphs untransformed, with
skew and with rotation and combinations of those.
[1] https://github.com/googlefonts/colr-gradients-spec/
[2] https://github.com/googlefonts/color-fonts
Bug: skia:11264
Change-Id: I8357cd0c7ac0039bb2eac18f21fa343bf61871eb
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/300558
Commit-Queue: Dominik Röttsches <drott@chromium.org>
Commit-Queue: Ben Wagner <bungeman@google.com>
Auto-Submit: Dominik Röttsches <drott@chromium.org>
Reviewed-by: Ben Wagner <bungeman@google.com>
2021-02-11 19:08:44 +00:00
|
|
|
SkTextEncoding::kGlyphID,
|
|
|
|
10, y, font, paint);
|
|
|
|
y += metrics.fDescent + metrics.fLeading;
|
2021-11-09 14:13:19 +00:00
|
|
|
paint_color_iterator++;
|
Support COLRv1 color fonts
Implement support for COLRv1 color gradient vector forms. COLR v1 is an
extension to the OpenType COLR tables that introduces support for
gradients, transforms and compositing. [1]
COLRv1 fonts contain an OpenType COLR table with format v1. In a COLR v1
table, glyphs are defined by a directed, acyclic graph of Paint
operations. The task for the Skia implementation is to extract the COLR
v1 information from the font using FreeType's COLRv1 API, then traverse
the glyph graph and translate information from the font into Skia
operations on SkCanvas.
Care needs to be taken for transformations to work correctly. FreeType
sends a top level transform that includes the scaling from font units to
actual glyph size, as well as optional transforms configured on FreeType
using FT_Set_Transform. This is set up as the starting transform at the
beginning of drawing a COLRv1 glyph. At the stage of setting a clip for
a PaintGlyph operation, the glyph outline is retrieved from FreeType
unscaled and untransformed. Since the starting transformation is applied
to the SkCanvas, the unscaled glyph is properly scaled and positioned.
Similarly, computing the initial bounding box for the COLRv1 glyph needs
to consider transformations. COLRv1 glyphs have a base glyph entry in
the glyf table which can use a minimum of two points for defining a
bounding box. This bounding box is an imaged rectangle enclosing those
two points at the identity transform. We need to compute the bounding
box scaled, but at identity transform, then make a rectangle from it,
that we then transform so that we get a large enough area to paint
in. If those two points from the glyf table would be transformed first,
then we would compute the bounding box, the resulting bounding box ends
up too small.
As a test font, add a version of the samples-glyf_colr_1.ttf from [2]
with one glyph added for testing PaintColrGlyph functionality and
compositions.
Add a basic GM test that produces color glyphs untransformed, with
skew and with rotation and combinations of those.
[1] https://github.com/googlefonts/colr-gradients-spec/
[2] https://github.com/googlefonts/color-fonts
Bug: skia:11264
Change-Id: I8357cd0c7ac0039bb2eac18f21fa343bf61871eb
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/300558
Commit-Queue: Dominik Röttsches <drott@chromium.org>
Commit-Queue: Ben Wagner <bungeman@google.com>
Auto-Submit: Dominik Röttsches <drott@chromium.org>
Reviewed-by: Ben Wagner <bungeman@google.com>
2021-02-11 19:08:44 +00:00
|
|
|
}
|
|
|
|
return DrawResult::kOk;
|
|
|
|
}
|
|
|
|
|
|
|
|
private:
|
|
|
|
using INHERITED = GM;
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SkScalar fSkewX;
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SkScalar fRotateDeg;
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2021-07-26 08:13:47 +00:00
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ColrV1TestType fTestType;
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Support COLRv1 color fonts
Implement support for COLRv1 color gradient vector forms. COLR v1 is an
extension to the OpenType COLR tables that introduces support for
gradients, transforms and compositing. [1]
COLRv1 fonts contain an OpenType COLR table with format v1. In a COLR v1
table, glyphs are defined by a directed, acyclic graph of Paint
operations. The task for the Skia implementation is to extract the COLR
v1 information from the font using FreeType's COLRv1 API, then traverse
the glyph graph and translate information from the font into Skia
operations on SkCanvas.
Care needs to be taken for transformations to work correctly. FreeType
sends a top level transform that includes the scaling from font units to
actual glyph size, as well as optional transforms configured on FreeType
using FT_Set_Transform. This is set up as the starting transform at the
beginning of drawing a COLRv1 glyph. At the stage of setting a clip for
a PaintGlyph operation, the glyph outline is retrieved from FreeType
unscaled and untransformed. Since the starting transformation is applied
to the SkCanvas, the unscaled glyph is properly scaled and positioned.
Similarly, computing the initial bounding box for the COLRv1 glyph needs
to consider transformations. COLRv1 glyphs have a base glyph entry in
the glyf table which can use a minimum of two points for defining a
bounding box. This bounding box is an imaged rectangle enclosing those
two points at the identity transform. We need to compute the bounding
box scaled, but at identity transform, then make a rectangle from it,
that we then transform so that we get a large enough area to paint
in. If those two points from the glyf table would be transformed first,
then we would compute the bounding box, the resulting bounding box ends
up too small.
As a test font, add a version of the samples-glyf_colr_1.ttf from [2]
with one glyph added for testing PaintColrGlyph functionality and
compositions.
Add a basic GM test that produces color glyphs untransformed, with
skew and with rotation and combinations of those.
[1] https://github.com/googlefonts/colr-gradients-spec/
[2] https://github.com/googlefonts/color-fonts
Bug: skia:11264
Change-Id: I8357cd0c7ac0039bb2eac18f21fa343bf61871eb
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/300558
Commit-Queue: Dominik Röttsches <drott@chromium.org>
Commit-Queue: Ben Wagner <bungeman@google.com>
Auto-Submit: Dominik Röttsches <drott@chromium.org>
Reviewed-by: Ben Wagner <bungeman@google.com>
2021-02-11 19:08:44 +00:00
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};
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[COLRv1] Map linear gradient extrema to [0, 1] range
Prepare data to Skia's linear gradient shader so that the extrema are
[0, 1] when the data in the font does not have them at these
positions. This is required for the shader to correctly compute repeat
modes.
Add the test font from the Google color fonts repo [1] with stops at [0,
1], [0.2, 0.8], [0, 1.5], [0.5, 1.5] respectively, compare[2].
[1] https://github.com/googlefonts/color-fonts/blob/main/fonts/more_samples-glyf_colr_1.ttf
[2] https://github.com/googlefonts/colr-gradients-spec/issues/281#issuecomment-828346428
Bug: skia:11922
Change-Id: Ic62a26911fa177af35ca16f183b5985d884237a5
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/405717
Commit-Queue: Dominik Röttsches <drott@google.com>
Reviewed-by: Ben Wagner <bungeman@google.com>
2021-05-11 12:59:43 +00:00
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DEF_GM(return new ColrV1GM(ColrV1GM::kSkiaSampleFont, 0.f, 0.f);)
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DEF_GM(return new ColrV1GM(ColrV1GM::kSkiaSampleFont, -0.5f, 0.f);)
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DEF_GM(return new ColrV1GM(ColrV1GM::kSkiaSampleFont, 0.f, 20.f);)
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DEF_GM(return new ColrV1GM(ColrV1GM::kSkiaSampleFont, -0.5f, 20.f);)
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2021-07-26 08:13:47 +00:00
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DEF_GM(return new ColrV1GM(ColrV1GM::kColorFontsRepoGradients, 0.f, 0.f);)
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DEF_GM(return new ColrV1GM(ColrV1GM::kColorFontsRepoScaling, 0.f, 0.f);)
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DEF_GM(return new ColrV1GM(ColrV1GM::kColorFontsRepoExtendMode, 0.f, 0.f);)
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2021-07-29 08:37:33 +00:00
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DEF_GM(return new ColrV1GM(ColrV1GM::kColorFontsRepoRotate, 0.f, 0.f);)
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DEF_GM(return new ColrV1GM(ColrV1GM::kColorFontsRepoSkew, 0.f, 0.f);)
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DEF_GM(return new ColrV1GM(ColrV1GM::kColorFontsRepoTransform, 0.f, 0.f);)
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2021-08-10 09:10:45 +00:00
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DEF_GM(return new ColrV1GM(ColrV1GM::kColorFontsRepoClipBox, 0.f, 0.f);)
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DEF_GM(return new ColrV1GM(ColrV1GM::kColorFontsRepoClipBox, -0.5f, 20.f);)
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2021-09-06 12:58:40 +00:00
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DEF_GM(return new ColrV1GM(ColrV1GM::kColorFontsRepoComposite, 0.f, 0.f);)
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2021-11-09 14:13:19 +00:00
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DEF_GM(return new ColrV1GM(ColrV1GM::kColorFontsRepoForeground, 0.f, 0.f);)
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Support COLRv1 color fonts
Implement support for COLRv1 color gradient vector forms. COLR v1 is an
extension to the OpenType COLR tables that introduces support for
gradients, transforms and compositing. [1]
COLRv1 fonts contain an OpenType COLR table with format v1. In a COLR v1
table, glyphs are defined by a directed, acyclic graph of Paint
operations. The task for the Skia implementation is to extract the COLR
v1 information from the font using FreeType's COLRv1 API, then traverse
the glyph graph and translate information from the font into Skia
operations on SkCanvas.
Care needs to be taken for transformations to work correctly. FreeType
sends a top level transform that includes the scaling from font units to
actual glyph size, as well as optional transforms configured on FreeType
using FT_Set_Transform. This is set up as the starting transform at the
beginning of drawing a COLRv1 glyph. At the stage of setting a clip for
a PaintGlyph operation, the glyph outline is retrieved from FreeType
unscaled and untransformed. Since the starting transformation is applied
to the SkCanvas, the unscaled glyph is properly scaled and positioned.
Similarly, computing the initial bounding box for the COLRv1 glyph needs
to consider transformations. COLRv1 glyphs have a base glyph entry in
the glyf table which can use a minimum of two points for defining a
bounding box. This bounding box is an imaged rectangle enclosing those
two points at the identity transform. We need to compute the bounding
box scaled, but at identity transform, then make a rectangle from it,
that we then transform so that we get a large enough area to paint
in. If those two points from the glyf table would be transformed first,
then we would compute the bounding box, the resulting bounding box ends
up too small.
As a test font, add a version of the samples-glyf_colr_1.ttf from [2]
with one glyph added for testing PaintColrGlyph functionality and
compositions.
Add a basic GM test that produces color glyphs untransformed, with
skew and with rotation and combinations of those.
[1] https://github.com/googlefonts/colr-gradients-spec/
[2] https://github.com/googlefonts/color-fonts
Bug: skia:11264
Change-Id: I8357cd0c7ac0039bb2eac18f21fa343bf61871eb
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/300558
Commit-Queue: Dominik Röttsches <drott@chromium.org>
Commit-Queue: Ben Wagner <bungeman@google.com>
Auto-Submit: Dominik Röttsches <drott@chromium.org>
Reviewed-by: Ben Wagner <bungeman@google.com>
2021-02-11 19:08:44 +00:00
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} // namespace skiagm
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