skia2/gm/circulararcs.cpp

236 lines
8.0 KiB
C++

/*
* 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 "SkDashPathEffect.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[] = {1.f, 45.f, 90.f, 130.f, 180.f, 184.f, 300.f, 355.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);
}
DEF_ARC_GM(stroke_and_fill_butt) {
auto setStroke = [] (SkPaint* p) {
p->setStyle(SkPaint::kStrokeAndFill_Style);
p->setStrokeCap(SkPaint::kButt_Cap);
};
draw_arcs(canvas, setStroke);
}
DEF_ARC_GM(stroke_and_fill_square) {
auto setStroke = [] (SkPaint* p) {
p->setStyle(SkPaint::kStrokeAndFill_Style);
p->setStrokeCap(SkPaint::kSquare_Cap);
};
draw_arcs(canvas, setStroke);
}
DEF_ARC_GM(stroke_and_fill_round) {
auto setStroke = [] (SkPaint* p) {
p->setStyle(SkPaint::kStrokeAndFill_Style);
p->setStrokeCap(SkPaint::kRound_Cap);
};
draw_arcs(canvas, setStroke);
}
DEF_SIMPLE_GM(circular_arcs_weird, canvas, 1000, 400) {
static constexpr SkScalar kS = 50;
struct Arc {
SkRect fOval;
SkScalar fStart;
SkScalar fSweep;
};
static const Arc noDrawArcs[] = {
// no sweep
{SkRect::MakeWH(kS, kS), 0, 0},
// empty rect in x
{SkRect::MakeWH(-kS, kS), 0, 90},
// empty rect in y
{SkRect::MakeWH(kS, -kS), 0, 90},
// empty rect in x and y
{SkRect::MakeWH( 0, 0), 0, 90},
};
static const Arc arcs[] = {
// large start
{SkRect::MakeWH(kS, kS), 810.f, 90.f},
// large negative start
{SkRect::MakeWH(kS, kS), -810.f, 90.f},
// exactly 360 sweep
{SkRect::MakeWH(kS, kS), 0.f, 360.f},
// exactly -360 sweep
{SkRect::MakeWH(kS, kS), 0.f, -360.f},
// exactly 540 sweep
{SkRect::MakeWH(kS, kS), 0.f, 540.f},
// exactly -540 sweep
{SkRect::MakeWH(kS, kS), 0.f, -540.f},
// generic large sweep and large start
{SkRect::MakeWH(kS, kS), 1125.f, 990.f},
};
SkTArray<SkPaint> paints;
// fill
paints.push_back();
// stroke
paints.push_back().setStyle(SkPaint::kStroke_Style);
paints.back().setStrokeWidth(kS / 6.f);
// hairline
paints.push_back().setStyle(SkPaint::kStroke_Style);
paints.back().setStrokeWidth(0.f);
// stroke and fill
paints.push_back().setStyle(SkPaint::kStrokeAndFill_Style);
paints.back().setStrokeWidth(kS / 6.f);
// dash effect
paints.push_back().setStyle(SkPaint::kStroke_Style);
paints.back().setStrokeWidth(kS / 6.f);
static constexpr SkScalar kDashIntervals[] = {kS / 15, 2 * kS / 15};
paints.back().setPathEffect(SkDashPathEffect::Make(kDashIntervals, 2, 0.f));
canvas->translate(kPad, kPad);
// This loop should draw nothing.
for (auto arc : noDrawArcs) {
for (auto paint : paints) {
paint.setAntiAlias(true);
canvas->drawArc(arc.fOval, arc.fStart, arc.fSweep, false, paint);
canvas->drawArc(arc.fOval, arc.fStart, arc.fSweep, true, paint);
}
}
SkPaint linePaint;
linePaint.setAntiAlias(true);
linePaint.setColor(SK_ColorRED);
SkScalar midX = SK_ARRAY_COUNT(arcs) * (kS + kPad) - kPad/2.f;
SkScalar height = paints.count() * (kS + kPad);
canvas->drawLine(midX, -kPad, midX, height, linePaint);
for (auto paint : paints) {
paint.setAntiAlias(true);
canvas->save();
for (auto arc : arcs) {
canvas->drawArc(arc.fOval, arc.fStart, arc.fSweep, false, paint);
canvas->translate(kS + kPad, 0.f);
}
for (auto arc : arcs) {
canvas->drawArc(arc.fOval, arc.fStart, arc.fSweep, true, paint);
canvas->translate(kS + kPad, 0.f);
}
canvas->restore();
canvas->translate(0, kS + kPad);
}
}
DEF_SIMPLE_GM(onebadarc, canvas, 100, 100) {
SkPath path;
path.moveTo(SkBits2Float(0x41a00000), SkBits2Float(0x41a00000)); // 20, 20
path.lineTo(SkBits2Float(0x4208918c), SkBits2Float(0x4208918c)); // 34.1421f, 34.1421f
path.conicTo(SkBits2Float(0x41a00000), SkBits2Float(0x42412318), // 20, 48.2843f
SkBits2Float(0x40bb73a0), SkBits2Float(0x4208918c), // 5.85786f, 34.1421f
SkBits2Float(0x3f3504f3)); // 0.707107f
path.quadTo(SkBits2Float(0x40bb73a0), SkBits2Float(0x4208918c), // 5.85786f, 34.1421f
SkBits2Float(0x40bb73a2), SkBits2Float(0x4208918c)); // 5.85787f, 34.1421f
path.lineTo(SkBits2Float(0x41a00000), SkBits2Float(0x41a00000)); // 20, 20
path.close();
SkPaint p0;
p0.setColor(SK_ColorRED);
p0.setStrokeWidth(15.f);
p0.setStyle(SkPaint::kStroke_Style);
p0.setAlpha(100);
canvas->translate(20, 0);
canvas->drawPath(path, p0);
SkRect kRect = { 60, 0, 100, 40};
canvas->drawArc(kRect, 45, 90, true, p0);
}