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67 lines
2.3 KiB
67 lines
2.3 KiB
/* |
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* Copyright 2016 Google Inc. |
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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 "SkShaper.h" |
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#include "SkStream.h" |
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#include "SkTextBlob.h" |
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#include "SkTypeface.h" |
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struct SkShaper::Impl { |
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sk_sp<SkTypeface> fTypeface; |
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}; |
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SkShaper::SkShaper(sk_sp<SkTypeface> tf) : fImpl(new Impl) { |
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fImpl->fTypeface = tf ? std::move(tf) : SkTypeface::MakeDefault(); |
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} |
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SkShaper::~SkShaper() {} |
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bool SkShaper::good() const { return true; } |
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// This example only uses public API, so we don't use SkUTF8_NextUnichar. |
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unsigned utf8_lead_byte_to_count(const char* ptr) { |
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uint8_t c = *(const uint8_t*)ptr; |
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SkASSERT(c <= 0xF7); |
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SkASSERT((c & 0xC0) != 0x80); |
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return (((0xE5 << 24) >> ((unsigned)c >> 4 << 1)) & 3) + 1; |
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} |
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SkScalar SkShaper::shape(SkTextBlobBuilder* builder, |
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const SkPaint& srcPaint, |
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const char* utf8text, |
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size_t textBytes, |
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SkPoint point) const { |
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SkPaint paint(srcPaint); |
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paint.setTypeface(fImpl->fTypeface); |
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paint.setTextEncoding(SkPaint::kUTF8_TextEncoding); |
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int glyphCount = paint.countText(utf8text, textBytes); |
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if (glyphCount <= 0) { |
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return 0; |
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} |
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SkRect bounds; |
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(void)paint.measureText(utf8text, textBytes, &bounds); |
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paint.setTextEncoding(SkPaint::kGlyphID_TextEncoding); |
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const SkTextBlobBuilder::RunBuffer& runBuffer = |
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builder->allocRunTextPosH(paint, glyphCount, point.y(), textBytes, SkString(), &bounds); |
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memcpy(runBuffer.utf8text, utf8text, textBytes); |
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const char* txtPtr = utf8text; |
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for (int i = 0; i < glyphCount; ++i) { |
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// Each charater maps to exactly one glyph via SkGlyphCache::unicharToGlyph(). |
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runBuffer.clusters[i] = SkToU32(txtPtr - utf8text); |
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txtPtr += utf8_lead_byte_to_count(txtPtr); |
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SkASSERT(txtPtr <= utf8text + textBytes); |
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} |
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paint.setTextEncoding(SkPaint::kUTF8_TextEncoding); |
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(void)paint.textToGlyphs(utf8text, textBytes, runBuffer.glyphs); |
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(void)paint.getTextWidths(utf8text, textBytes, runBuffer.pos); |
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SkScalar x = point.x(); |
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for (int i = 0; i < glyphCount; ++i) { |
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SkScalar w = runBuffer.pos[i]; |
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runBuffer.pos[i] = x; |
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x += w; |
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} |
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return (SkScalar)x; |
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}
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