gm/hairlines.cpp - platform/external/skia - Gitiles

 /*
  * Copyright 2013 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 "SkCanvas.h"
 #include "SkPath.h"
 #include "SkTArray.h"

 namespace skiagm {

 class HairlinesGM : public GM {
 protected:


     SkString onShortName() override {
         return SkString("hairlines");
     }

     SkISize onISize() override { return SkISize::Make(1250, 1250); }

     void onOnceBeforeDraw() override {
         {
             SkPath* lineAnglesPath = &fPaths.push_back();
             enum {
                 kNumAngles = 15,
                 kRadius = 40,
             };
             for (int i = 0; i < kNumAngles; ++i) {
                 SkScalar angle = SK_ScalarPI * SkIntToScalar(i) / kNumAngles;
                 SkScalar x = kRadius * SkScalarCos(angle);
                 SkScalar y = kRadius * SkScalarSin(angle);
                 lineAnglesPath->moveTo(x, y);
                 lineAnglesPath->lineTo(-x, -y);
             }
         }

         {
             SkPath* kindaTightQuad = &fPaths.push_back();
             kindaTightQuad->moveTo(0, -10 * SK_Scalar1);
             kindaTightQuad->quadTo(SkIntToScalar(100), SkIntToScalar(100), -10 * SK_Scalar1, 0);
         }

         {
             SkPath* tightQuad = &fPaths.push_back();
             tightQuad->moveTo(0, -5 * SK_Scalar1);
             tightQuad->quadTo(SkIntToScalar(100), SkIntToScalar(100), -5 * SK_Scalar1, 0);
         }

         {
             SkPath* tighterQuad = &fPaths.push_back();
             tighterQuad->moveTo(0, -2 * SK_Scalar1);
             tighterQuad->quadTo(SkIntToScalar(100), SkIntToScalar(100), -2 * SK_Scalar1, 0);
         }

         {
             SkPath* unevenTighterQuad = &fPaths.push_back();
             unevenTighterQuad->moveTo(0, -1 * SK_Scalar1);
             SkPoint p;
             p.set(-2 * SK_Scalar1 + 3 * SkIntToScalar(102) / 4, SkIntToScalar(75));
             unevenTighterQuad->quadTo(SkIntToScalar(100), SkIntToScalar(100), p.fX, p.fY);
         }

         {
             SkPath* reallyTightQuad = &fPaths.push_back();
             reallyTightQuad->moveTo(0, -1 * SK_Scalar1);
             reallyTightQuad->quadTo(SkIntToScalar(100), SkIntToScalar(100), -1 * SK_Scalar1, 0);
         }

         {
             SkPath* closedQuad = &fPaths.push_back();
             closedQuad->moveTo(0, -0);
             closedQuad->quadTo(SkIntToScalar(100), SkIntToScalar(100), 0, 0);
         }

         {
             SkPath* unevenClosedQuad = &fPaths.push_back();
             unevenClosedQuad->moveTo(0, -0);
             unevenClosedQuad->quadTo(SkIntToScalar(100), SkIntToScalar(100),
                                      SkIntToScalar(75), SkIntToScalar(75));
         }

         // Two problem cases for gpu hairline renderer found by shapeops testing. These used
         // to assert that the computed bounding box didn't contain all the vertices.
         {
             SkPath* problem1 = &fPaths.push_back();
             problem1->moveTo(SkIntToScalar(4), SkIntToScalar(6));
             problem1->cubicTo(SkIntToScalar(5), SkIntToScalar(6),
                               SkIntToScalar(5), SkIntToScalar(4),
                               SkIntToScalar(4), SkIntToScalar(0));
             problem1->close();
         }

         {
             SkPath* problem2 = &fPaths.push_back();
             problem2->moveTo(SkIntToScalar(5), SkIntToScalar(1));
             problem2->lineTo(4.32787323f, 1.67212653f);
             problem2->cubicTo(2.75223875f, 3.24776125f,
                               3.00581908f, 4.51236057f,
                               3.7580452f, 4.37367964f);
             problem2->cubicTo(4.66472578f, 3.888381f,
                               5.f, 2.875f,
                               5.f, 1.f);
             problem2->close();
         }

         // Three paths that show the same bug (missing end caps)
         {
             // A caret (crbug.com/131770)
             SkPath* bug0 = &fPaths.push_back();
             bug0->moveTo(6.5f,5.5f);
             bug0->lineTo(3.5f,0.5f);
             bug0->moveTo(0.5f,5.5f);
             bug0->lineTo(3.5f,0.5f);
         }

         {
             // An X (crbug.com/137317)
             SkPath* bug1 = &fPaths.push_back();

             bug1->moveTo(1, 1);
             bug1->lineTo(6, 6);
             bug1->moveTo(1, 6);
             bug1->lineTo(6, 1);
         }

         {
             // A right angle (crbug.com/137465 and crbug.com/256776)
             SkPath* bug2 = &fPaths.push_back();

             bug2->moveTo(5.5f, 5.5f);
             bug2->lineTo(5.5f, 0.5f);
             bug2->lineTo(0.5f, 0.5f);
         }

         {
             // Arc example to test imperfect truncation bug (crbug.com/295626)
             constexpr SkScalar kRad = SkIntToScalar(2000);
             constexpr SkScalar kStartAngle = 262.59717f;
             constexpr SkScalar kSweepAngle = SkScalarHalf(17.188717f);

             SkPath* bug = &fPaths.push_back();

             // Add a circular arc
             SkRect circle = SkRect::MakeLTRB(-kRad, -kRad, kRad, kRad);
             bug->addArc(circle, kStartAngle, kSweepAngle);

             // Now add the chord that should cap the circular arc
             SkScalar cosV, sinV = SkScalarSinCos(SkDegreesToRadians(kStartAngle), &cosV);

             SkPoint p0 = SkPoint::Make(kRad * cosV, kRad * sinV);

             sinV = SkScalarSinCos(SkDegreesToRadians(kStartAngle + kSweepAngle), &cosV);

             SkPoint p1 = SkPoint::Make(kRad * cosV, kRad * sinV);

             bug->moveTo(p0);
             bug->lineTo(p1);
         }
     }

     void onDraw(SkCanvas* canvas) override {
         constexpr SkAlpha kAlphaValue[] = { 0xFF, 0x40 };
         constexpr SkScalar kWidths[] = { 0, 0.5f, 1.5f };

         enum {
             kMargin = 5,
         };
         int wrapX = 1250 - kMargin;

         SkScalar maxH = 0;
         canvas->translate(SkIntToScalar(kMargin), SkIntToScalar(kMargin));
         canvas->save();

         SkScalar x = SkIntToScalar(kMargin);
         for (int p = 0; p < fPaths.count(); ++p) {
             for (size_t a = 0; a < SK_ARRAY_COUNT(kAlphaValue); ++a) {
                 for (int aa = 0; aa < 2; ++aa) {
                     for (size_t w = 0; w < SK_ARRAY_COUNT(kWidths); w++) {
                         const SkRect& bounds = fPaths[p].getBounds();

                         if (x + bounds.width() > wrapX) {
                             canvas->restore();
                             canvas->translate(0, maxH + SkIntToScalar(kMargin));
                             canvas->save();
                             maxH = 0;
                             x = SkIntToScalar(kMargin);
                         }

                         SkPaint paint;
                         paint.setARGB(kAlphaValue[a], 0, 0, 0);
                         paint.setAntiAlias(SkToBool(aa));
                         paint.setStyle(SkPaint::kStroke_Style);
                         paint.setStrokeWidth(kWidths[w]);

                         canvas->save();
                         canvas->translate(-bounds.fLeft, -bounds.fTop);
                         canvas->drawPath(fPaths[p], paint);
                         canvas->restore();

                         maxH = SkMaxScalar(maxH, bounds.height());

                         SkScalar dx = bounds.width() + SkIntToScalar(kMargin);
                         x += dx;
                         canvas->translate(dx, 0);
                     }
                 }
             }
         }
         canvas->restore();
     }

 private:
     SkTArray<SkPath> fPaths;
     typedef GM INHERITED;
 };

 static void draw_squarehair_tests(SkCanvas* canvas, SkScalar width, SkPaint::Cap cap, bool aa) {
     SkPaint paint;
     paint.setStrokeCap(cap);
     paint.setStrokeWidth(width);
     paint.setAntiAlias(aa);
     paint.setStyle(SkPaint::kStroke_Style);
     canvas->drawLine(10, 10, 20, 10, paint);
     canvas->drawLine(30, 10, 30, 20, paint);
     canvas->drawLine(40, 10, 50, 20, paint);
     SkPath path;
     path.moveTo(60, 10);
     path.quadTo(60, 20, 70, 20);
     path.conicTo(70, 10, 80, 10, 0.707f);
     canvas->drawPath(path, paint);
     path.reset();
     path.moveTo(90, 10);
     path.cubicTo(90, 20, 100, 20, 100, 10);
     path.lineTo(110, 10);
     canvas->drawPath(path, paint);
     canvas->translate(0, 30);
 }

 DEF_SIMPLE_GM(squarehair, canvas, 240, 360) {
     const bool aliases[] = { false, true };
     const SkScalar widths[] = { 0, 0.999f, 1, 1.001f };
     const SkPaint::Cap caps[] = { SkPaint::kButt_Cap, SkPaint::kSquare_Cap, SkPaint::kRound_Cap };
     for (auto alias : aliases) {
         canvas->save();
         for (auto width : widths) {
             for (auto cap : caps) {
                 draw_squarehair_tests(canvas, width, cap, alias);
             }
         }
         canvas->restore();
         canvas->translate(120, 0);
     }
 }

 //////////////////////////////////////////////////////////////////////////////

 DEF_GM( return new HairlinesGM; )

 }
	/*
	* Copyright 2013 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 "SkCanvas.h"
	#include "SkPath.h"
	#include "SkTArray.h"

	namespace skiagm {

	class HairlinesGM : public GM {
	protected:


	SkString onShortName() override {
	return SkString("hairlines");
	}

	SkISize onISize() override { return SkISize::Make(1250, 1250); }

	void onOnceBeforeDraw() override {
	{
	SkPath* lineAnglesPath = &fPaths.push_back();
	enum {
	kNumAngles = 15,
	kRadius = 40,
	};
	for (int i = 0; i < kNumAngles; ++i) {
	SkScalar angle = SK_ScalarPI * SkIntToScalar(i) / kNumAngles;
	SkScalar x = kRadius * SkScalarCos(angle);
	SkScalar y = kRadius * SkScalarSin(angle);
	lineAnglesPath->moveTo(x, y);
	lineAnglesPath->lineTo(-x, -y);
	}
	}

	{
	SkPath* kindaTightQuad = &fPaths.push_back();
	kindaTightQuad->moveTo(0, -10 * SK_Scalar1);
	kindaTightQuad->quadTo(SkIntToScalar(100), SkIntToScalar(100), -10 * SK_Scalar1, 0);
	}

	{
	SkPath* tightQuad = &fPaths.push_back();
	tightQuad->moveTo(0, -5 * SK_Scalar1);
	tightQuad->quadTo(SkIntToScalar(100), SkIntToScalar(100), -5 * SK_Scalar1, 0);
	}

	{
	SkPath* tighterQuad = &fPaths.push_back();
	tighterQuad->moveTo(0, -2 * SK_Scalar1);
	tighterQuad->quadTo(SkIntToScalar(100), SkIntToScalar(100), -2 * SK_Scalar1, 0);
	}

	{
	SkPath* unevenTighterQuad = &fPaths.push_back();
	unevenTighterQuad->moveTo(0, -1 * SK_Scalar1);
	SkPoint p;
	p.set(-2 * SK_Scalar1 + 3 * SkIntToScalar(102) / 4, SkIntToScalar(75));
	unevenTighterQuad->quadTo(SkIntToScalar(100), SkIntToScalar(100), p.fX, p.fY);
	}

	{
	SkPath* reallyTightQuad = &fPaths.push_back();
	reallyTightQuad->moveTo(0, -1 * SK_Scalar1);
	reallyTightQuad->quadTo(SkIntToScalar(100), SkIntToScalar(100), -1 * SK_Scalar1, 0);
	}

	{
	SkPath* closedQuad = &fPaths.push_back();
	closedQuad->moveTo(0, -0);
	closedQuad->quadTo(SkIntToScalar(100), SkIntToScalar(100), 0, 0);
	}

	{
	SkPath* unevenClosedQuad = &fPaths.push_back();
	unevenClosedQuad->moveTo(0, -0);
	unevenClosedQuad->quadTo(SkIntToScalar(100), SkIntToScalar(100),
	SkIntToScalar(75), SkIntToScalar(75));
	}

	// Two problem cases for gpu hairline renderer found by shapeops testing. These used
	// to assert that the computed bounding box didn't contain all the vertices.
	{
	SkPath* problem1 = &fPaths.push_back();
	problem1->moveTo(SkIntToScalar(4), SkIntToScalar(6));
	problem1->cubicTo(SkIntToScalar(5), SkIntToScalar(6),
	SkIntToScalar(5), SkIntToScalar(4),
	SkIntToScalar(4), SkIntToScalar(0));
	problem1->close();
	}

	{
	SkPath* problem2 = &fPaths.push_back();
	problem2->moveTo(SkIntToScalar(5), SkIntToScalar(1));
	problem2->lineTo(4.32787323f, 1.67212653f);
	problem2->cubicTo(2.75223875f, 3.24776125f,
	3.00581908f, 4.51236057f,
	3.7580452f, 4.37367964f);
	problem2->cubicTo(4.66472578f, 3.888381f,
	5.f, 2.875f,
	5.f, 1.f);
	problem2->close();
	}

	// Three paths that show the same bug (missing end caps)
	{
	// A caret (crbug.com/131770)
	SkPath* bug0 = &fPaths.push_back();
	bug0->moveTo(6.5f,5.5f);
	bug0->lineTo(3.5f,0.5f);
	bug0->moveTo(0.5f,5.5f);
	bug0->lineTo(3.5f,0.5f);
	}

	{
	// An X (crbug.com/137317)
	SkPath* bug1 = &fPaths.push_back();

	bug1->moveTo(1, 1);
	bug1->lineTo(6, 6);
	bug1->moveTo(1, 6);
	bug1->lineTo(6, 1);
	}

	{
	// A right angle (crbug.com/137465 and crbug.com/256776)
	SkPath* bug2 = &fPaths.push_back();

	bug2->moveTo(5.5f, 5.5f);
	bug2->lineTo(5.5f, 0.5f);
	bug2->lineTo(0.5f, 0.5f);
	}

	{
	// Arc example to test imperfect truncation bug (crbug.com/295626)
	constexpr SkScalar kRad = SkIntToScalar(2000);
	constexpr SkScalar kStartAngle = 262.59717f;
	constexpr SkScalar kSweepAngle = SkScalarHalf(17.188717f);

	SkPath* bug = &fPaths.push_back();

	// Add a circular arc
	SkRect circle = SkRect::MakeLTRB(-kRad, -kRad, kRad, kRad);
	bug->addArc(circle, kStartAngle, kSweepAngle);

	// Now add the chord that should cap the circular arc
	SkScalar cosV, sinV = SkScalarSinCos(SkDegreesToRadians(kStartAngle), &cosV);

	SkPoint p0 = SkPoint::Make(kRad * cosV, kRad * sinV);

	sinV = SkScalarSinCos(SkDegreesToRadians(kStartAngle + kSweepAngle), &cosV);

	SkPoint p1 = SkPoint::Make(kRad * cosV, kRad * sinV);

	bug->moveTo(p0);
	bug->lineTo(p1);
	}
	}

	void onDraw(SkCanvas* canvas) override {
	constexpr SkAlpha kAlphaValue[] = { 0xFF, 0x40 };
	constexpr SkScalar kWidths[] = { 0, 0.5f, 1.5f };

	enum {
	kMargin = 5,
	};
	int wrapX = 1250 - kMargin;

	SkScalar maxH = 0;
	canvas->translate(SkIntToScalar(kMargin), SkIntToScalar(kMargin));
	canvas->save();

	SkScalar x = SkIntToScalar(kMargin);
	for (int p = 0; p < fPaths.count(); ++p) {
	for (size_t a = 0; a < SK_ARRAY_COUNT(kAlphaValue); ++a) {
	for (int aa = 0; aa < 2; ++aa) {
	for (size_t w = 0; w < SK_ARRAY_COUNT(kWidths); w++) {
	const SkRect& bounds = fPaths[p].getBounds();

	if (x + bounds.width() > wrapX) {
	canvas->restore();
	canvas->translate(0, maxH + SkIntToScalar(kMargin));
	canvas->save();
	maxH = 0;
	x = SkIntToScalar(kMargin);
	}

	SkPaint paint;
	paint.setARGB(kAlphaValue[a], 0, 0, 0);
	paint.setAntiAlias(SkToBool(aa));
	paint.setStyle(SkPaint::kStroke_Style);
	paint.setStrokeWidth(kWidths[w]);

	canvas->save();
	canvas->translate(-bounds.fLeft, -bounds.fTop);
	canvas->drawPath(fPaths[p], paint);
	canvas->restore();

	maxH = SkMaxScalar(maxH, bounds.height());

	SkScalar dx = bounds.width() + SkIntToScalar(kMargin);
	x += dx;
	canvas->translate(dx, 0);
	}
	}
	}
	}
	canvas->restore();
	}

	private:
	SkTArray<SkPath> fPaths;
	typedef GM INHERITED;
	};

	static void draw_squarehair_tests(SkCanvas* canvas, SkScalar width, SkPaint::Cap cap, bool aa) {
	SkPaint paint;
	paint.setStrokeCap(cap);
	paint.setStrokeWidth(width);
	paint.setAntiAlias(aa);
	paint.setStyle(SkPaint::kStroke_Style);
	canvas->drawLine(10, 10, 20, 10, paint);
	canvas->drawLine(30, 10, 30, 20, paint);
	canvas->drawLine(40, 10, 50, 20, paint);
	SkPath path;
	path.moveTo(60, 10);
	path.quadTo(60, 20, 70, 20);
	path.conicTo(70, 10, 80, 10, 0.707f);
	canvas->drawPath(path, paint);
	path.reset();
	path.moveTo(90, 10);
	path.cubicTo(90, 20, 100, 20, 100, 10);
	path.lineTo(110, 10);
	canvas->drawPath(path, paint);
	canvas->translate(0, 30);
	}

	DEF_SIMPLE_GM(squarehair, canvas, 240, 360) {
	const bool aliases[] = { false, true };
	const SkScalar widths[] = { 0, 0.999f, 1, 1.001f };
	const SkPaint::Cap caps[] = { SkPaint::kButt_Cap, SkPaint::kSquare_Cap, SkPaint::kRound_Cap };
	for (auto alias : aliases) {
	canvas->save();
	for (auto width : widths) {
	for (auto cap : caps) {
	draw_squarehair_tests(canvas, width, cap, alias);
	}
	}
	canvas->restore();
	canvas->translate(120, 0);
	}
	}

	//////////////////////////////////////////////////////////////////////////////

	DEF_GM( return new HairlinesGM; )

	}