skia2/samplecode/SampleGlyphTransform.cpp
Hal Canary 8a027312cd Samples: add name() virtual
Change-Id: I9b6e39bc7e35346bb73dfe014de1c8daa5a92f2a
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/225428
Auto-Submit: Hal Canary <halcanary@google.com>
Commit-Queue: Ben Wagner <bungeman@google.com>
Reviewed-by: Ben Wagner <bungeman@google.com>
2019-07-03 17:41:16 +00:00

84 lines
2.4 KiB
C++

/*
* Copyright 2018 Google Inc.
*
* Use of this source code is governed by a BSD-style license that can be
* found in the LICENSE file.
*/
#include "samplecode/Sample.h"
#include "tools/ToolUtils.h"
#include "include/core/SkCanvas.h"
#include "include/core/SkPath.h"
#include "include/core/SkRRect.h"
#include "include/core/SkTypeface.h"
#include "include/utils/SkRandom.h"
#include "tools/timer/AnimTimer.h"
#include <cmath>
// Implementation in C++ of Animated Emoji
// See https://t.d3fc.io/status/705212795936247808
// See https://crbug.com/848616
class GlyphTransformView : public Sample {
public:
GlyphTransformView() {}
protected:
void onOnceBeforeDraw() override {
fEmojiFont.fTypeface = ToolUtils::emoji_typeface();
fEmojiFont.fText = ToolUtils::emoji_sample_text();
}
SkString name() override { return SkString("Glyph Transform"); }
void onDrawContent(SkCanvas* canvas) override {
SkPaint paint;
SkFont font(fEmojiFont.fTypeface);
const char* text = fEmojiFont.fText;
double baseline = this->height() / 2;
canvas->drawLine(0, baseline, this->width(), baseline, paint);
SkMatrix ctm;
ctm.setRotate(fRotate); // d3 rotate takes degrees
ctm.postScale(fScale * 4, fScale * 4);
ctm.postTranslate(fTranslate.fX + this->width() * 0.8, fTranslate.fY + baseline);
canvas->concat(ctm);
// d3 by default anchors text around the middle
SkRect bounds;
font.measureText(text, strlen(text), SkTextEncoding::kUTF8, &bounds);
canvas->drawSimpleText(text, strlen(text), SkTextEncoding::kUTF8, -bounds.centerX(), -bounds.centerY(),
font, paint);
}
bool onAnimate(const AnimTimer& timer) override {
constexpr SkScalar maxt = 100000;
double t = timer.pingPong(20, 0, 0, maxt); // d3 t is in milliseconds
fTranslate.set(sin(t / 3000) - t * this->width() * 0.7 / maxt, sin(t / 999) / t);
fScale = 4.5 - std::sqrt(t) / 99;
fRotate = sin(t / 734);
return true;
}
private:
struct EmojiFont {
sk_sp<SkTypeface> fTypeface;
const char* fText;
} fEmojiFont;
SkVector fTranslate;
SkScalar fScale;
SkScalar fRotate;
typedef Sample INHERITED;
};
//////////////////////////////////////////////////////////////////////////////
DEF_SAMPLE( return new GlyphTransformView(); )