skia2/samplecode/SampleGlyphTransform.cpp
Mike Klein cd5104e942 SkAnimTimer -> AnimTimer
Change-Id: I700b7c0461475062ac66712cc29070f150cf777d
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/202315
Commit-Queue: Mike Klein <mtklein@google.com>
Reviewed-by: Brian Osman <brianosman@google.com>
2019-03-20 18:26:35 +00:00

90 lines
2.5 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 "Sample.h"
#include "ToolUtils.h"
#include "AnimTimer.h"
#include "SkCanvas.h"
#include "SkPath.h"
#include "SkRRect.h"
#include "SkRandom.h"
#include "SkTypeface.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();
}
bool onQuery(Sample::Event* evt) override {
if (Sample::TitleQ(*evt)) {
Sample::TitleR(evt, "Glyph Transform");
return true;
}
return this->INHERITED::onQuery(evt);
}
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), kUTF8_SkTextEncoding, &bounds);
canvas->drawSimpleText(text, strlen(text), kUTF8_SkTextEncoding, -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(); )