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/*
* Copyright 2016 Google Inc.
*
* Use of this source code is governed by a BSD-style license that can be
* found in the LICENSE file.
*/
#include <functional>
#include "SkCanvas.h"
#include "gm.h"
static constexpr SkScalar kStarts[] = {0.f, 10.f, 30.f, 45.f, 90.f, 165.f, 180.f, 270.f};
static constexpr SkScalar kSweeps[] = {45.f, 90.f, 165.f, 180.f, 220.f, 270.f, 300.f, 315.f};
static constexpr SkScalar kDiameter = 40.f;
static constexpr SkRect kRect = {0.f, 0.f, kDiameter, kDiameter};
static constexpr int kW = 1000;
static constexpr int kH = 1000;
static constexpr SkScalar kPad = 20.f;
void draw_arcs(SkCanvas* canvas, std::function<void(SkPaint*)> configureStyle) {
// Draws grid of arcs with different start/sweep angles in red and their complement arcs in
// blue.
auto drawGrid = [canvas, &configureStyle] (SkScalar x, SkScalar y, bool useCenter, bool aa) {
SkPaint p0;
p0.setColor(SK_ColorRED);
p0.setAntiAlias(aa);
// Set a reasonable stroke width that configureStyle can override.
p0.setStrokeWidth(15.f);
SkPaint p1 = p0;
p1.setColor(SK_ColorBLUE);
// Use alpha so we see magenta on overlap between arc and its complement.
p0.setAlpha(100);
p1.setAlpha(100);
configureStyle(&p0);
configureStyle(&p1);
canvas->save();
canvas->translate(kPad + x, kPad + y);
for (auto start : kStarts) {
canvas->save();
for (auto sweep : kSweeps) {
canvas->drawArc(kRect, start, sweep, useCenter, p0);
canvas->drawArc(kRect, start, -(360.f - sweep), useCenter, p1);
canvas->translate(kRect.width() + kPad, 0.f);
}
canvas->restore();
canvas->translate(0, kRect.height() + kPad);
}
canvas->restore();
};
// Draw a grids for combo of enabling/disabling aa and using center.
static constexpr SkScalar kGridW = kW / 2.f;
static constexpr SkScalar kGridH = kH / 2.f;
drawGrid(0.f , 0.f , false, false);
drawGrid(kGridW, 0.f , true , false);
drawGrid(0.f , kGridH, false, true );
drawGrid(kGridW, kGridH, true , true );
// Draw separators between the grids.
SkPaint linePaint;
linePaint.setAntiAlias(true);
linePaint.setColor(SK_ColorBLACK);
canvas->drawLine(kGridW, 0.f , kGridW, SkIntToScalar(kH), linePaint);
canvas->drawLine(0.f , kGridH, SkIntToScalar(kW), kGridH, linePaint);
}
#define DEF_ARC_GM(name) DEF_SIMPLE_GM(circular_arcs_##name, canvas, kW, kH)
DEF_ARC_GM(fill) {
auto setFill = [] (SkPaint*p) { p->setStyle(SkPaint::kFill_Style); };
draw_arcs(canvas, setFill);
}
DEF_ARC_GM(hairline) {
auto setHairline = [] (SkPaint* p) {
p->setStyle(SkPaint::kStroke_Style);
p->setStrokeWidth(0.f);
};
draw_arcs(canvas, setHairline);
}
DEF_ARC_GM(stroke_butt) {
auto setStroke = [](SkPaint* p) {
p->setStyle(SkPaint::kStroke_Style);
p->setStrokeCap(SkPaint::kButt_Cap);
};
draw_arcs(canvas, setStroke);
}
DEF_ARC_GM(stroke_square) {
auto setStroke = [] (SkPaint* p) {
p->setStyle(SkPaint::kStroke_Style);
p->setStrokeCap(SkPaint::kSquare_Cap);
};
draw_arcs(canvas, setStroke);
}
DEF_ARC_GM(stroke_round) {
auto setStroke = [] (SkPaint* p) {
p->setStyle(SkPaint::kStroke_Style);
p->setStrokeCap(SkPaint::kRound_Cap);
};
draw_arcs(canvas, setStroke);
}
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