34 lines
1.1 KiB
C++
34 lines
1.1 KiB
C++
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// Copyright 2020 Google LLC.
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// Use of this source code is governed by a BSD-style license that can be found in the LICENSE file.
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#include "tools/fiddle/examples.h"
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REG_FIDDLE_ANIMATED(pong, 256, 256, false, 0, 10) {
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static SkScalar PingPong(double t, SkScalar period, SkScalar phase,
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SkScalar ends, SkScalar mid) {
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double value = ::fmod(t + phase, period);
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double half = period / 2.0;
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double diff = ::fabs(value - half);
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return SkDoubleToScalar(ends + (1.0 - diff / half) * (mid - ends));
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}
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void draw(SkCanvas* canvas) {
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canvas->clear(SK_ColorBLACK);
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float ballX = PingPong(frame * duration, 2.5f, 0.0f, 0.0f, 1.0f);
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float ballY = PingPong(frame * duration, 2.0f, 0.4f, 0.0f, 1.0f);
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SkPaint p;
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p.setColor(SK_ColorWHITE);
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p.setAntiAlias(true);
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float bX = ballX * 472 + 20;
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float bY = ballY * 200 + 28;
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if (canvas->getGrContext()) {
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canvas->drawRect(SkRect::MakeXYWH(236, bY - 15, 10, 30), p);
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bX -= 256;
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} else {
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canvas->drawRect(SkRect::MakeXYWH(10, bY - 15, 10, 30), p);
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}
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canvas->drawCircle(bX, bY, 5, p);
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}
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} // END FIDDLE
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