1 /*
2 * Copyright 2014 Google Inc.
3 *
4 * Use of this source code is governed by a BSD-style license that can be
5 * found in the LICENSE file.
6 */
7
8 #include "GrPathRendering.h"
9 #include "SkDescriptor.h"
10 #include "SkGlyph.h"
11 #include "SkMatrix.h"
12 #include "SkTypeface.h"
13 #include "GrPathRange.h"
14
15 class GlyphGenerator : public GrPathRange::PathGenerator {
16 public:
GlyphGenerator(const SkTypeface & typeface,const SkDescriptor & desc)17 GlyphGenerator(const SkTypeface& typeface, const SkDescriptor& desc)
18 : fDesc(desc.copy()),
19 fScalerContext(typeface.createScalerContext(fDesc)) {
20 fFlipMatrix.setScale(1, -1);
21 }
22
~GlyphGenerator()23 virtual ~GlyphGenerator() {
24 SkDescriptor::Free(fDesc);
25 }
26
getNumPaths()27 int getNumPaths() override {
28 return fScalerContext->getGlyphCount();
29 }
30
generatePath(int glyphID,SkPath * out)31 void generatePath(int glyphID, SkPath* out) override {
32 SkGlyph skGlyph;
33 skGlyph.initWithGlyphID(glyphID);
34 fScalerContext->getMetrics(&skGlyph);
35
36 fScalerContext->getPath(skGlyph, out);
37 out->transform(fFlipMatrix); // Load glyphs with the inverted y-direction.
38 }
39
isEqualTo(const SkDescriptor & desc) const40 bool isEqualTo(const SkDescriptor& desc) const override {
41 return fDesc->equals(desc);
42 }
43
44 private:
45 SkDescriptor* const fDesc;
46 const SkAutoTDelete<SkScalerContext> fScalerContext;
47 SkMatrix fFlipMatrix;
48 };
49
createGlyphs(const SkTypeface * typeface,const SkDescriptor * desc,const SkStrokeRec & stroke)50 GrPathRange* GrPathRendering::createGlyphs(const SkTypeface* typeface,
51 const SkDescriptor* desc,
52 const SkStrokeRec& stroke) {
53 if (NULL == typeface) {
54 typeface = SkTypeface::GetDefaultTypeface();
55 SkASSERT(NULL != typeface);
56 }
57
58 if (desc) {
59 SkAutoTUnref<GlyphGenerator> generator(SkNEW_ARGS(GlyphGenerator, (*typeface, *desc)));
60 return this->createPathRange(generator, stroke);
61 }
62
63 SkScalerContextRec rec;
64 memset(&rec, 0, sizeof(rec));
65 rec.fFontID = typeface->uniqueID();
66 rec.fTextSize = SkPaint::kCanonicalTextSizeForPaths;
67 rec.fPreScaleX = rec.fPost2x2[0][0] = rec.fPost2x2[1][1] = SK_Scalar1;
68 // Don't bake stroke information into the glyphs, we'll let the GPU do the stroking.
69
70 SkAutoDescriptor ad(sizeof(rec) + SkDescriptor::ComputeOverhead(1));
71 SkDescriptor* genericDesc = ad.getDesc();
72
73 genericDesc->init();
74 genericDesc->addEntry(kRec_SkDescriptorTag, sizeof(rec), &rec);
75 genericDesc->computeChecksum();
76
77 SkAutoTUnref<GlyphGenerator> generator(SkNEW_ARGS(GlyphGenerator, (*typeface, *genericDesc)));
78 return this->createPathRange(generator, stroke);
79 }
80