skia2/gm/addarc.cpp

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/*
* Copyright 2015 Google Inc.
*
* Use of this source code is governed by a BSD-style license that can be
* found in the LICENSE file.
*/
#include "gm.h"
#include "SkAnimTimer.h"
#include "SkCanvas.h"
#include "SkPathMeasure.h"
#include "SkRandom.h"
class AddArcGM : public skiagm::GM {
public:
AddArcGM() : fRotate(0) {}
protected:
SkString onShortName() override { return SkString("addarc"); }
SkISize onISize() override { return SkISize::Make(1040, 1040); }
void onDraw(SkCanvas* canvas) override {
canvas->translate(20, 20);
SkRect r = SkRect::MakeWH(1000, 1000);
SkPaint paint;
paint.setAntiAlias(true);
paint.setStyle(SkPaint::kStroke_Style);
paint.setStrokeWidth(15);
const SkScalar inset = paint.getStrokeWidth() + 4;
const SkScalar sweepAngle = 345;
SkRandom rand;
SkScalar sign = 1;
while (r.width() > paint.getStrokeWidth() * 3) {
paint.setColor(sk_tool_utils::color_to_565(rand.nextU() | (0xFF << 24)));
SkScalar startAngle = rand.nextUScalar1() * 360;
SkScalar speed = SkScalarSqrt(16 / r.width()) * 0.5f;
startAngle += fRotate * 360 * speed * sign;
SkPath path;
path.addArc(r, startAngle, sweepAngle);
canvas->drawPath(path, paint);
r.inset(inset, inset);
sign = -sign;
}
}
bool onAnimate(const SkAnimTimer& timer) override {
fRotate = timer.scaled(1, 360);
return true;
}
private:
SkScalar fRotate;
typedef skiagm::GM INHERITED;
};
DEF_GM( return new AddArcGM; )
///////////////////////////////////////////////////
#define R 400
class AddArcMeasGM : public skiagm::GM {
public:
AddArcMeasGM() {}
protected:
SkString onShortName() override { return SkString("addarc_meas"); }
SkISize onISize() override { return SkISize::Make(2*R + 40, 2*R + 40); }
void onDraw(SkCanvas* canvas) override {
canvas->translate(R + 20, R + 20);
SkPaint paint;
paint.setAntiAlias(true);
paint.setStyle(SkPaint::kStroke_Style);
SkPaint measPaint;
measPaint.setAntiAlias(true);
measPaint.setColor(SK_ColorRED);
const SkRect oval = SkRect::MakeLTRB(-R, -R, R, R);
canvas->drawOval(oval, paint);
for (SkScalar deg = 0; deg < 360; deg += 10) {
const SkScalar rad = SkDegreesToRadians(deg);
SkScalar rx = SkScalarCos(rad) * R;
SkScalar ry = SkScalarSin(rad) * R;
canvas->drawLine(0, 0, rx, ry, paint);
SkPath path;
path.addArc(oval, 0, deg);
SkPathMeasure meas(path, false);
SkScalar arcLen = rad * R;
SkPoint pos;
if (meas.getPosTan(arcLen, &pos, nullptr)) {
canvas->drawLine(0, 0, pos.x(), pos.y(), measPaint);
}
}
}
private:
typedef skiagm::GM INHERITED;
};
DEF_GM( return new AddArcMeasGM; )
///////////////////////////////////////////////////
// Emphasize drawing a stroked oval (containing conics) and then scaling the results up,
// to ensure that we compute the stroke taking the CTM into account
//
class StrokeCircleGM : public skiagm::GM {
public:
StrokeCircleGM() : fRotate(0) {}
protected:
SkString onShortName() override { return SkString("strokecircle"); }
SkISize onISize() override { return SkISize::Make(520, 520); }
void onDraw(SkCanvas* canvas) override {
canvas->scale(20, 20);
canvas->translate(13, 13);
SkPaint paint;
paint.setAntiAlias(true);
paint.setStyle(SkPaint::kStroke_Style);
paint.setStrokeWidth(SK_Scalar1 / 2);
const SkScalar delta = paint.getStrokeWidth() * 3 / 2;
SkRect r = SkRect::MakeXYWH(-12, -12, 24, 24);
SkRandom rand;
SkScalar sign = 1;
while (r.width() > paint.getStrokeWidth() * 2) {
SkAutoCanvasRestore acr(canvas, true);
canvas->rotate(fRotate * sign);
paint.setColor(sk_tool_utils::color_to_565(rand.nextU() | (0xFF << 24)));
canvas->drawOval(r, paint);
r.inset(delta, delta);
sign = -sign;
}
}
bool onAnimate(const SkAnimTimer& timer) override {
fRotate = timer.scaled(60, 360);
return true;
}
private:
SkScalar fRotate;
typedef skiagm::GM INHERITED;
};
DEF_GM( return new StrokeCircleGM; )
//////////////////////
static void html_canvas_arc(SkPath* path, SkScalar x, SkScalar y, SkScalar r, SkScalar start,
SkScalar end, bool ccw) {
SkRect bounds = { x - r, y - r, x + r, y + r };
SkScalar sweep = ccw ? end - start : start - end;
path->arcTo(bounds, start, sweep, false);
}
// Lifted from canvas-arc-circumference-fill-diffs.html
class ManyArcsGM : public skiagm::GM {
public:
ManyArcsGM() {}
protected:
SkString onShortName() override { return SkString("manyarcs"); }
SkISize onISize() override { return SkISize::Make(620, 330); }
void onDraw(SkCanvas* canvas) override {
SkPaint paint;
paint.setAntiAlias(true);
paint.setStyle(SkPaint::kStroke_Style);
canvas->translate(10, 10);
// 20 angles.
SkScalar sweepAngles[] = {
-123.7f, -2.3f, -2, -1, -0.3f, -0.000001f, 0, 0.000001f, 0.3f, 0.7f,
1, 1.3f, 1.5f, 1.7f, 1.99999f, 2, 2.00001f, 2.3f, 4.3f, 3934723942837.3f
};
for (size_t i = 0; i < SK_ARRAY_COUNT(sweepAngles); ++i) {
sweepAngles[i] *= 180;
}
SkScalar startAngles[] = { -1, -0.5f, 0, 0.5f };
for (size_t i = 0; i < SK_ARRAY_COUNT(startAngles); ++i) {
startAngles[i] *= 180;
}
bool anticlockwise = false;
SkScalar sign = 1;
for (size_t i = 0; i < SK_ARRAY_COUNT(startAngles) * 2; ++i) {
if (i == SK_ARRAY_COUNT(startAngles)) {
anticlockwise = true;
sign = -1;
}
SkScalar startAngle = startAngles[i % SK_ARRAY_COUNT(startAngles)] * sign;
canvas->save();
for (size_t j = 0; j < SK_ARRAY_COUNT(sweepAngles); ++j) {
SkPath path;
path.moveTo(0, 2);
html_canvas_arc(&path, 18, 15, 10, startAngle, startAngle + (sweepAngles[j] * sign),
anticlockwise);
path.lineTo(0, 28);
canvas->drawPath(path, paint);
canvas->translate(30, 0);
}
canvas->restore();
canvas->translate(0, 40);
}
}
private:
typedef skiagm::GM INHERITED;
};
DEF_GM( return new ManyArcsGM; )