skia2/docs/examples/pong2.cpp
Herb Derby 5623d9e36f Replace SK_ARRAY_COUNT with std::size() for skia/docs
Change-Id: I9569ba4760546be6302c24658e64cb58c7db86e5
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/550697
Reviewed-by: John Stiles <johnstiles@google.com>
Commit-Queue: Herb Derby <herb@google.com>
2022-06-16 20:09:58 +00:00

32 lines
1.1 KiB
C++

// Copyright 2020 Google LLC.
// Use of this source code is governed by a BSD-style license that can be found in the LICENSE file.
#include "tools/fiddle/examples.h"
REG_FIDDLE_ANIMATED(pong2, 512, 256, false, 0, 10) {
static SkScalar PingPong(double t, SkScalar period, SkScalar phase,
SkScalar ends, SkScalar mid) {
double value = ::fmod(t + phase, period);
double half = period / 2.0;
double diff = ::fabs(value - half);
return SkDoubleToScalar(ends + (1.0 - diff / half) * (mid - ends));
}
void draw(SkCanvas* canvas) {
float bX = PingPong(frame * duration, 2.5f, 0.0f, 0, 1) * 472 + 20;
float bY = PingPong(frame * duration, 2.0f, 0.4f, 0, 1) * 200 + 28;
SkPaint p;
p.setColor(SK_ColorWHITE);
p.setAntiAlias(true);
canvas->clear(SK_ColorBLACK);
canvas->drawRect(SkRect::MakeXYWH(492, bY - 15, 10, 30), p);
canvas->drawRect(SkRect::MakeXYWH(10, bY - 15, 10, 30), p);
canvas->drawCircle(bX, bY, 5, p);
const float intervals[] = { 12, 6 };
p.setStrokeWidth(5);
p.setPathEffect(SkDashPathEffect::Make(intervals, std::size(intervals), 0));
canvas->drawLine({256,0}, {256, 256}, p);
}
} // END FIDDLE