skia2/gm/drawglyphs.cpp
Brian Osman a5842bc903 Move SkSpan to include/, for use in public API
Change-Id: I674f038600afd6d49316c1ece515941ee5579068
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/406939
Reviewed-by: Herb Derby <herb@google.com>
Commit-Queue: Brian Osman <brianosman@google.com>
2021-05-12 13:19:32 +00:00

90 lines
3.0 KiB
C++

/*
* Copyright 2021 Google Inc.
*
* Use of this source code is governed by a BSD-style license that can be
* found in the LICENSE file.
*/
#include "gm/gm.h"
#include "include/core/SkCanvas.h"
#include "include/core/SkFont.h"
#include "include/core/SkPaint.h"
#include "include/core/SkRSXform.h"
#include "include/core/SkSpan.h"
#include "include/private/SkTDArray.h"
#include "src/core/SkZip.h"
#include "tools/ToolUtils.h"
static const char gText[] = "Call me Ishmael. Some years ago—never mind how long precisely";
class DrawGlyphsGM : public skiagm::GM {
public:
void onOnceBeforeDraw() override {
fTypeface = ToolUtils::create_portable_typeface("serif", SkFontStyle());
fFont = SkFont(fTypeface);
fFont.setSubpixel(true);
fFont.setSize(18);
const size_t txtLen = strlen(gText);
fGlyphCount = fFont.countText(gText, txtLen, SkTextEncoding::kUTF8);
fGlyphs.append(fGlyphCount);
fFont.textToGlyphs(gText, txtLen, SkTextEncoding::kUTF8, fGlyphs.begin(), fGlyphCount);
fPositions.append(fGlyphCount);
fFont.getPos(fGlyphs.begin(), fGlyphCount, fPositions.begin());
auto positions = SkMakeSpan(fPositions.begin(), fGlyphCount);
fLength = positions.back().x() - positions.front().x();
fRadius = fLength / SK_FloatPI;
fXforms.append(fGlyphCount);
for (auto [xform, pos] : SkMakeZip(fXforms.begin(), positions)) {
const SkScalar lengthToGlyph = pos.x() - positions.front().x();
const SkScalar angle = SK_FloatPI * (fLength - lengthToGlyph) / fLength;
const SkScalar cos = std::cos(angle);
const SkScalar sin = std::sin(angle);
xform = SkRSXform::Make(sin, cos, fRadius*cos, -fRadius*sin);
}
}
SkString onShortName() override {
return SkString("drawglyphs");
}
SkISize onISize() override {
return SkISize::Make(640, 480);
}
void onDraw(SkCanvas* canvas) override {
canvas->drawGlyphs(fGlyphCount, fGlyphs.begin(), fPositions.begin(), {50, 100}, fFont,
SkPaint{});
canvas->drawGlyphs(fGlyphCount, fGlyphs.begin(), fPositions.begin(), {50, 120}, fFont,
SkPaint{});
// Check bounding box calculation.
for (auto& pos : fPositions) {
pos += {0, -500};
}
canvas->drawGlyphs(fGlyphCount, fGlyphs.begin(), fPositions.begin(), {50, 640}, fFont,
SkPaint{});
canvas->drawGlyphs(fGlyphCount, fGlyphs.begin(), fXforms.begin(),
{50 + fLength / 2, 160 + fRadius}, fFont, SkPaint{});
// TODO: add tests for cluster versions of drawGlyphs.
}
private:
sk_sp<SkTypeface> fTypeface;
SkFont fFont;
SkTDArray<SkGlyphID> fGlyphs;
SkTDArray<SkPoint> fPositions;
SkTDArray<SkRSXform> fXforms;
int fGlyphCount;
SkScalar fRadius;
SkScalar fLength;
};
DEF_GM(return new DrawGlyphsGM{};)