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

 /*
  * Copyright 2018 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */

 #include "gm/gm.h"
 #include "include/core/SkBlendMode.h"
 #include "include/core/SkCanvas.h"
 #include "include/core/SkColor.h"
 #include "include/core/SkColorFilter.h"
 #include "include/core/SkImage.h"
 #include "include/core/SkImageInfo.h"
 #include "include/core/SkMatrix.h"
 #include "include/core/SkPaint.h"
 #include "include/core/SkPoint.h"
 #include "include/core/SkRect.h"
 #include "include/core/SkRefCnt.h"
 #include "include/core/SkScalar.h"
 #include "include/core/SkShader.h"
 #include "include/core/SkSize.h"
 #include "include/core/SkString.h"
 #include "include/core/SkSurface.h"
 #include "include/core/SkTileMode.h"
 #include "include/core/SkTypes.h"
 #include "include/effects/SkGradientShader.h"
 #include "tools/ToolUtils.h"

 #include <algorithm>
 #include <initializer_list>
 #include <utility>

 // Makes a set of m x n tiled images to be drawn with SkCanvas::experimental_drawImageSetV1().
 static void make_image_tiles(int tileW, int tileH, int m, int n, const SkColor colors[4],
                              SkCanvas::ImageSetEntry set[], const SkColor bgColor=SK_ColorLTGRAY) {
     const int w = tileW * m;
     const int h = tileH * n;
     auto surf = SkSurface::MakeRaster(
             SkImageInfo::Make(w, h, kRGBA_8888_SkColorType, kPremul_SkAlphaType));
     surf->getCanvas()->clear(bgColor);

     static constexpr SkScalar kStripeW = 10;
     static constexpr SkScalar kStripeSpacing = 30;
     SkPaint paint;

     SkPoint pts1[] = {{0.f, 0.f}, {(SkScalar)w, (SkScalar)h}};
     auto grad = SkGradientShader::MakeLinear(pts1, colors, nullptr, 2, SkTileMode::kClamp);
     paint.setShader(std::move(grad));
     paint.setAntiAlias(true);
     paint.setStyle(SkPaint::kStroke_Style);
     paint.setStrokeWidth(kStripeW);
     SkPoint stripePts[] = {{-w - kStripeW, -kStripeW}, {kStripeW, h + kStripeW}};
     while (stripePts[0].fX <= w) {
         surf->getCanvas()->drawPoints(SkCanvas::kLines_PointMode, 2, stripePts, paint);
         stripePts[0].fX += kStripeSpacing;
         stripePts[1].fX += kStripeSpacing;
     }

     SkPoint pts2[] = {{0.f, (SkScalar)h}, {(SkScalar)w, 0.f}};
     grad = SkGradientShader::MakeLinear(pts2, colors + 2, nullptr, 2, SkTileMode::kClamp);
     paint.setShader(std::move(grad));
     paint.setBlendMode(SkBlendMode::kMultiply);
     stripePts[0] = {-w - kStripeW, h + kStripeW};
     stripePts[1] = {kStripeW, -kStripeW};
     while (stripePts[0].fX <= w) {
         surf->getCanvas()->drawPoints(SkCanvas::kLines_PointMode, 2, stripePts, paint);
         stripePts[0].fX += kStripeSpacing;
         stripePts[1].fX += kStripeSpacing;
     }
     auto fullImage = surf->makeImageSnapshot();
     for (int y = 0; y < n; ++y) {
         for (int x = 0; x < m; ++x) {
             // Images will have 1 pixel of overlap at interior seams for filtering continuity.
             SkIRect subset = SkIRect::MakeXYWH(x * tileW - 1, y * tileH - 1, tileW + 2, tileH + 2);
             set[y * m + x].fAAFlags = SkCanvas::kNone_QuadAAFlags;
             if (x == 0) {
                 subset.fLeft = 0;
                 set[y * m + x].fAAFlags |= SkCanvas::kLeft_QuadAAFlag;
             }
             if (x == m - 1) {
                 subset.fRight = w;
                 set[y * m + x].fAAFlags |= SkCanvas::kRight_QuadAAFlag;
             }
             if (y == 0) {
                 subset.fTop = 0;
                 set[y * m + x].fAAFlags |= SkCanvas::kTop_QuadAAFlag;
             }
             if (y == n - 1) {
                 subset.fBottom = h;
                 set[y * m + x].fAAFlags |= SkCanvas::kBottom_QuadAAFlag;
             }
             set[y * m + x].fImage = fullImage->makeSubset(subset);
             set[y * m + x].fSrcRect =
                     SkRect::MakeXYWH(x == 0 ? 0 : 1, y == 0 ? 0 : 1, tileW, tileH);
             set[y * m + x].fDstRect = SkRect::MakeXYWH(x * tileW, y * tileH, tileW, tileH);
             set[y * m + x].fAlpha = 1.f;
             SkASSERT(set[y * m + x].fImage);
         }
     }
 }

 namespace skiagm {

 class DrawImageSetGM : public GM {
 private:
     SkString onShortName() override { return SkString("draw_image_set"); }
     SkISize onISize() override { return {1000, 725}; }
     void onOnceBeforeDraw() override {
         static constexpr SkColor kColors[] = {SK_ColorCYAN,    SK_ColorBLACK,
                                               SK_ColorMAGENTA, SK_ColorBLACK};
         make_image_tiles(kTileW, kTileH, kM, kN, kColors, fSet);
     }

     void onDraw(SkCanvas* canvas) override {
         SkScalar d = SkVector{kM * kTileW, kN * kTileH}.length();
         SkMatrix matrices[4];
         // rotation
         matrices[0].setRotate(30);
         matrices[0].postTranslate(d / 3, 0);
         // perespective
         SkPoint src[4];
         SkRect::MakeWH(kM * kTileW, kN * kTileH).toQuad(src);
         SkPoint dst[4] = {{0, 0},
                           {kM * kTileW + 10.f, -5.f},
                           {kM * kTileW - 28.f, kN * kTileH + 40.f},
                           {45.f, kN * kTileH - 25.f}};
         SkAssertResult(matrices[1].setPolyToPoly(src, dst, 4));
         matrices[1].postTranslate(d, 50.f);
         // skew
         matrices[2].setRotate(-60.f);
         matrices[2].postSkew(0.5f, -1.15f);
         matrices[2].postScale(0.6f, 1.05f);
         matrices[2].postTranslate(d, 2.6f * d);
         // perspective + mirror in x.
         dst[1] = {-.25 * kM * kTileW, 0};
         dst[0] = {5.f / 4.f * kM * kTileW, 0};
         dst[3] = {2.f / 3.f * kM * kTileW, 1 / 2.f * kN * kTileH};
         dst[2] = {1.f / 3.f * kM * kTileW, 1 / 2.f * kN * kTileH - 0.1f * kTileH};
         SkAssertResult(matrices[3].setPolyToPoly(src, dst, 4));
         matrices[3].postTranslate(100.f, d);
         for (auto fm : {SkFilterMode::kNearest, SkFilterMode::kLinear}) {
             SkPaint setPaint;
             setPaint.setBlendMode(SkBlendMode::kSrcOver);
             SkSamplingOptions sampling(fm);

             for (size_t m = 0; m < SK_ARRAY_COUNT(matrices); ++m) {
                 // Draw grid of red lines at interior tile boundaries.
                 static constexpr SkScalar kLineOutset = 10.f;
                 SkPaint paint;
                 paint.setAntiAlias(true);
                 paint.setColor(SK_ColorRED);
                 paint.setStyle(SkPaint::kStroke_Style);
                 paint.setStrokeWidth(0.f);
                 for (int x = 1; x < kM; ++x) {
                     SkPoint pts[] = {{x * kTileW, 0}, {x * kTileW, kN * kTileH}};
                     matrices[m].mapPoints(pts, 2);
                     SkVector v = pts[1] - pts[0];
                     v.setLength(v.length() + kLineOutset);
                     canvas->drawLine(pts[1] - v, pts[0] + v, paint);
                 }
                 for (int y = 1; y < kN; ++y) {
                     SkPoint pts[] = {{0, y * kTileH}, {kTileW * kM, y * kTileH}};
                     matrices[m].mapPoints(pts, 2);
                     SkVector v = pts[1] - pts[0];
                     v.setLength(v.length() + kLineOutset);
                     canvas->drawLine(pts[1] - v, pts[0] + v, paint);
                 }
                 canvas->save();
                 canvas->concat(matrices[m]);
                 canvas->experimental_DrawEdgeAAImageSet(fSet, kM * kN, nullptr, nullptr, sampling,
                                                         &setPaint,
                                                         SkCanvas::kFast_SrcRectConstraint);
                 canvas->restore();
             }
             // A more exotic case with an unusual blend mode, mixed aa flags set, and alpha,
             // subsets the image. And another with all the above plus a color filter.
             SkCanvas::ImageSetEntry entry;
             entry.fSrcRect = SkRect::MakeWH(kTileW, kTileH).makeInset(kTileW / 4.f, kTileH / 4.f);
             entry.fDstRect = SkRect::MakeWH(1.5 * kTileW, 1.5 * kTileH).makeOffset(d / 4, 2 * d);
             entry.fImage = fSet[0].fImage;
             entry.fAlpha = 0.7f;
             entry.fAAFlags = SkCanvas::kLeft_QuadAAFlag | SkCanvas::kTop_QuadAAFlag;
             canvas->save();
             canvas->rotate(3.f);

             setPaint.setBlendMode(SkBlendMode::kExclusion);
             canvas->experimental_DrawEdgeAAImageSet(&entry, 1, nullptr, nullptr, sampling,
                                                     &setPaint, SkCanvas::kFast_SrcRectConstraint);
             canvas->translate(entry.fDstRect.width() + 8.f, 0);
             SkPaint cfPaint = setPaint;
             cfPaint.setColorFilter(SkColorFilters::LinearToSRGBGamma());
             canvas->experimental_DrawEdgeAAImageSet(&entry, 1, nullptr, nullptr, sampling,
                                                     &cfPaint, SkCanvas::kFast_SrcRectConstraint);
             canvas->restore();
             canvas->translate(2 * d, 0);
         }
     }
     static constexpr int kM = 4;
     static constexpr int kN = 3;
     static constexpr SkScalar kTileW = 30;
     static constexpr SkScalar kTileH = 60;
     SkCanvas::ImageSetEntry fSet[kM * kN];
 };

 // This GM exercises rect-stays-rect type matrices to test that filtering and antialiasing are not
 // incorrectly disabled.
 class DrawImageSetRectToRectGM : public GM {
 private:
     SkString onShortName() override { return SkString("draw_image_set_rect_to_rect"); }
     SkISize onISize() override { return {1250, 850}; }
     void onOnceBeforeDraw() override {
         static constexpr SkColor kColors[] = {SK_ColorBLUE, SK_ColorWHITE,
                                               SK_ColorRED,  SK_ColorWHITE};
         make_image_tiles(kTileW, kTileH, kM, kN, kColors, fSet);
     }

     void onDraw(SkCanvas* canvas) override {
         ToolUtils::draw_checkerboard(canvas, SK_ColorBLACK, SK_ColorWHITE, 50);
         static constexpr SkScalar kW = kM * kTileW;
         static constexpr SkScalar kH = kN * kTileH;
         SkMatrix matrices[5];
         // Identity
         matrices[0].reset();
         // 90 degree rotation
         matrices[1].setRotate(90, kW / 2.f, kH / 2.f);
         // Scaling
         matrices[2].setScale(2.f, 0.5f);
         // Mirror in x and y
         matrices[3].setScale(-1.f, -1.f);
         matrices[3].postTranslate(kW, kH);
         // Mirror in y, rotate, and scale.
         matrices[4].setScale(1.f, -1.f);
         matrices[4].postTranslate(0, kH);
         matrices[4].postRotate(90, kW / 2.f, kH / 2.f);
         matrices[4].postScale(2.f, 0.5f);

         SkPaint paint;
         paint.setBlendMode(SkBlendMode::kSrcOver);

         static constexpr SkScalar kTranslate = std::max(kW, kH) * 2.f + 10.f;
         canvas->translate(5.f, 5.f);
         canvas->save();
         for (SkScalar frac : {0.f, 0.5f}) {
             canvas->save();
             canvas->translate(frac, frac);
             for (size_t m = 0; m < SK_ARRAY_COUNT(matrices); ++m) {
                 canvas->save();
                 canvas->concat(matrices[m]);
                 canvas->experimental_DrawEdgeAAImageSet(fSet, kM * kN, nullptr, nullptr,
                                                         SkSamplingOptions(SkFilterMode::kLinear),
                                                         &paint, SkCanvas::kFast_SrcRectConstraint);
                 canvas->restore();
                 canvas->translate(kTranslate, 0);
             }
             canvas->restore();
             canvas->restore();
             canvas->translate(0, kTranslate);
             canvas->save();
         }
         for (SkVector scale : {SkVector{2.f, 0.5f}, SkVector{0.5, 2.f}}) {
             SkCanvas::ImageSetEntry scaledSet[kM * kN];
             std::copy_n(fSet, kM * kN, scaledSet);
             for (int i = 0; i < kM * kN; ++i) {
                 scaledSet[i].fDstRect.fLeft *= scale.fX;
                 scaledSet[i].fDstRect.fTop *= scale.fY;
                 scaledSet[i].fDstRect.fRight *= scale.fX;
                 scaledSet[i].fDstRect.fBottom *= scale.fY;
                 scaledSet[i].fAlpha = 0 == (i % 3) ? 0.4f : 1.f;
             }
             for (size_t m = 0; m < SK_ARRAY_COUNT(matrices); ++m) {
                 canvas->save();
                 canvas->concat(matrices[m]);
                 canvas->experimental_DrawEdgeAAImageSet(scaledSet, kM * kN, nullptr, nullptr,
                                                         SkSamplingOptions(SkFilterMode::kLinear),
                                                         &paint, SkCanvas::kFast_SrcRectConstraint);
                 canvas->restore();
                 canvas->translate(kTranslate, 0);
             }
             canvas->restore();
             canvas->translate(0, kTranslate);
             canvas->save();
         }
     }
     static constexpr int kM = 2;
     static constexpr int kN = 2;
     static constexpr int kTileW = 40;
     static constexpr int kTileH = 50;
     SkCanvas::ImageSetEntry fSet[kM * kN];
 };

 // This GM exercises alpha-only and color textures being combined correctly with the paint's color.
 class DrawImageSetAlphaOnlyGM : public GM {
 private:
     SkString onShortName() override { return SkString("draw_image_set_alpha_only"); }
     SkISize onISize() override { return {kM*kTileW, 2*kN*kTileH}; }

     DrawResult onGpuSetup(GrDirectContext* direct, SkString*) override {
         static constexpr SkColor kColors[] = {SK_ColorBLUE, SK_ColorTRANSPARENT,
                                               SK_ColorRED,  SK_ColorTRANSPARENT};
         static constexpr SkColor kBGColor = SkColorSetARGB(128, 128, 128, 128);
         make_image_tiles(kTileW, kTileH, kM, kN, kColors, fSet, kBGColor);

         // Modify the alpha of the entries, decreasing by column, and convert even rows to
         // alpha-only textures.
         sk_sp<SkColorSpace> alphaSpace = SkColorSpace::MakeSRGB();
         for (int y = 0; y < kN; ++y) {
             for (int x = 0; x < kM; ++x) {
                 int i = y * kM + x;
                 fSet[i].fAlpha = (kM - x) / (float) kM;
                 if (y % 2 == 0) {
                     fSet[i].fImage = fSet[i].fImage->makeColorTypeAndColorSpace(
                             kAlpha_8_SkColorType, alphaSpace, direct);
                 }
             }
         }
         return skiagm::DrawResult::kOk;
     }

     void onDraw(SkCanvas* canvas) override {
         ToolUtils::draw_checkerboard(canvas, SK_ColorGRAY, SK_ColorDKGRAY, 25);

         SkPaint paint;
         paint.setBlendMode(SkBlendMode::kSrcOver);
         paint.setColor4f({0.2f, 0.8f, 0.4f, 1.f}); // colorizes even rows, no effect on odd rows

         // Top rows use experimental edge set API
         canvas->experimental_DrawEdgeAAImageSet(fSet, kM * kN, nullptr, nullptr,
                                                 SkSamplingOptions(SkFilterMode::kLinear), &paint,
                                                 SkCanvas::kFast_SrcRectConstraint);

         canvas->translate(0.f, kN * kTileH);

         // Bottom rows draw each image from the set using the regular API
         for (int y = 0; y < kN; ++y) {
             for (int x = 0; x < kM; ++x) {
                 int i = y * kM + x;
                 SkPaint entryPaint = paint;
                 entryPaint.setAlphaf(fSet[i].fAlpha * paint.getAlphaf());
                 canvas->drawImageRect(fSet[i].fImage.get(), fSet[i].fSrcRect, fSet[i].fDstRect,
                                       SkSamplingOptions(), &entryPaint,
                                       SkCanvas::kFast_SrcRectConstraint);
             }
         }
     }

     static constexpr int kM = 4;
     static constexpr int kN = 4;
     static constexpr int kTileW = 50;
     static constexpr int kTileH = 50;
     SkCanvas::ImageSetEntry fSet[kM * kN];
 };

 DEF_GM(return new DrawImageSetGM();)
 DEF_GM(return new DrawImageSetRectToRectGM();)
 DEF_GM(return new DrawImageSetAlphaOnlyGM();)

 }  // namespace skiagm
	/*
	* Copyright 2018 Google Inc.
	*
	* Use of this source code is governed by a BSD-style license that can be
	* found in the LICENSE file.
	*/

	#include "gm/gm.h"
	#include "include/core/SkBlendMode.h"
	#include "include/core/SkCanvas.h"
	#include "include/core/SkColor.h"
	#include "include/core/SkColorFilter.h"
	#include "include/core/SkImage.h"
	#include "include/core/SkImageInfo.h"
	#include "include/core/SkMatrix.h"
	#include "include/core/SkPaint.h"
	#include "include/core/SkPoint.h"
	#include "include/core/SkRect.h"
	#include "include/core/SkRefCnt.h"
	#include "include/core/SkScalar.h"
	#include "include/core/SkShader.h"
	#include "include/core/SkSize.h"
	#include "include/core/SkString.h"
	#include "include/core/SkSurface.h"
	#include "include/core/SkTileMode.h"
	#include "include/core/SkTypes.h"
	#include "include/effects/SkGradientShader.h"
	#include "tools/ToolUtils.h"

	#include <algorithm>
	#include <initializer_list>
	#include <utility>

	// Makes a set of m x n tiled images to be drawn with SkCanvas::experimental_drawImageSetV1().
	static void make_image_tiles(int tileW, int tileH, int m, int n, const SkColor colors[4],
	SkCanvas::ImageSetEntry set[], const SkColor bgColor=SK_ColorLTGRAY) {
	const int w = tileW * m;
	const int h = tileH * n;
	auto surf = SkSurface::MakeRaster(
	SkImageInfo::Make(w, h, kRGBA_8888_SkColorType, kPremul_SkAlphaType));
	surf->getCanvas()->clear(bgColor);

	static constexpr SkScalar kStripeW = 10;
	static constexpr SkScalar kStripeSpacing = 30;
	SkPaint paint;

	SkPoint pts1[] = {{0.f, 0.f}, {(SkScalar)w, (SkScalar)h}};
	auto grad = SkGradientShader::MakeLinear(pts1, colors, nullptr, 2, SkTileMode::kClamp);
	paint.setShader(std::move(grad));
	paint.setAntiAlias(true);
	paint.setStyle(SkPaint::kStroke_Style);
	paint.setStrokeWidth(kStripeW);
	SkPoint stripePts[] = {{-w - kStripeW, -kStripeW}, {kStripeW, h + kStripeW}};
	while (stripePts[0].fX <= w) {
	surf->getCanvas()->drawPoints(SkCanvas::kLines_PointMode, 2, stripePts, paint);
	stripePts[0].fX += kStripeSpacing;
	stripePts[1].fX += kStripeSpacing;
	}

	SkPoint pts2[] = {{0.f, (SkScalar)h}, {(SkScalar)w, 0.f}};
	grad = SkGradientShader::MakeLinear(pts2, colors + 2, nullptr, 2, SkTileMode::kClamp);
	paint.setShader(std::move(grad));
	paint.setBlendMode(SkBlendMode::kMultiply);
	stripePts[0] = {-w - kStripeW, h + kStripeW};
	stripePts[1] = {kStripeW, -kStripeW};
	while (stripePts[0].fX <= w) {
	surf->getCanvas()->drawPoints(SkCanvas::kLines_PointMode, 2, stripePts, paint);
	stripePts[0].fX += kStripeSpacing;
	stripePts[1].fX += kStripeSpacing;
	}
	auto fullImage = surf->makeImageSnapshot();
	for (int y = 0; y < n; ++y) {
	for (int x = 0; x < m; ++x) {
	// Images will have 1 pixel of overlap at interior seams for filtering continuity.
	SkIRect subset = SkIRect::MakeXYWH(x * tileW - 1, y * tileH - 1, tileW + 2, tileH + 2);
	set[y * m + x].fAAFlags = SkCanvas::kNone_QuadAAFlags;
	if (x == 0) {
	subset.fLeft = 0;
	set[y * m + x].fAAFlags \|= SkCanvas::kLeft_QuadAAFlag;
	}
	if (x == m - 1) {
	subset.fRight = w;
	set[y * m + x].fAAFlags \|= SkCanvas::kRight_QuadAAFlag;
	}
	if (y == 0) {
	subset.fTop = 0;
	set[y * m + x].fAAFlags \|= SkCanvas::kTop_QuadAAFlag;
	}
	if (y == n - 1) {
	subset.fBottom = h;
	set[y * m + x].fAAFlags \|= SkCanvas::kBottom_QuadAAFlag;
	}
	set[y * m + x].fImage = fullImage->makeSubset(subset);
	set[y * m + x].fSrcRect =
	SkRect::MakeXYWH(x == 0 ? 0 : 1, y == 0 ? 0 : 1, tileW, tileH);
	set[y * m + x].fDstRect = SkRect::MakeXYWH(x * tileW, y * tileH, tileW, tileH);
	set[y * m + x].fAlpha = 1.f;
	SkASSERT(set[y * m + x].fImage);
	}
	}
	}

	namespace skiagm {

	class DrawImageSetGM : public GM {
	private:
	SkString onShortName() override { return SkString("draw_image_set"); }
	SkISize onISize() override { return {1000, 725}; }
	void onOnceBeforeDraw() override {
	static constexpr SkColor kColors[] = {SK_ColorCYAN, SK_ColorBLACK,
	SK_ColorMAGENTA, SK_ColorBLACK};
	make_image_tiles(kTileW, kTileH, kM, kN, kColors, fSet);
	}

	void onDraw(SkCanvas* canvas) override {
	SkScalar d = SkVector{kM * kTileW, kN * kTileH}.length();
	SkMatrix matrices[4];
	// rotation
	matrices[0].setRotate(30);
	matrices[0].postTranslate(d / 3, 0);
	// perespective
	SkPoint src[4];
	SkRect::MakeWH(kM * kTileW, kN * kTileH).toQuad(src);
	SkPoint dst[4] = {{0, 0},
	{kM * kTileW + 10.f, -5.f},
	{kM * kTileW - 28.f, kN * kTileH + 40.f},
	{45.f, kN * kTileH - 25.f}};
	SkAssertResult(matrices[1].setPolyToPoly(src, dst, 4));
	matrices[1].postTranslate(d, 50.f);
	// skew
	matrices[2].setRotate(-60.f);
	matrices[2].postSkew(0.5f, -1.15f);
	matrices[2].postScale(0.6f, 1.05f);
	matrices[2].postTranslate(d, 2.6f * d);
	// perspective + mirror in x.
	dst[1] = {-.25 * kM * kTileW, 0};
	dst[0] = {5.f / 4.f * kM * kTileW, 0};
	dst[3] = {2.f / 3.f * kM * kTileW, 1 / 2.f * kN * kTileH};
	dst[2] = {1.f / 3.f * kM * kTileW, 1 / 2.f * kN * kTileH - 0.1f * kTileH};
	SkAssertResult(matrices[3].setPolyToPoly(src, dst, 4));
	matrices[3].postTranslate(100.f, d);
	for (auto fm : {SkFilterMode::kNearest, SkFilterMode::kLinear}) {
	SkPaint setPaint;
	setPaint.setBlendMode(SkBlendMode::kSrcOver);
	SkSamplingOptions sampling(fm);

	for (size_t m = 0; m < SK_ARRAY_COUNT(matrices); ++m) {
	// Draw grid of red lines at interior tile boundaries.
	static constexpr SkScalar kLineOutset = 10.f;
	SkPaint paint;
	paint.setAntiAlias(true);
	paint.setColor(SK_ColorRED);
	paint.setStyle(SkPaint::kStroke_Style);
	paint.setStrokeWidth(0.f);
	for (int x = 1; x < kM; ++x) {
	SkPoint pts[] = {{x * kTileW, 0}, {x * kTileW, kN * kTileH}};
	matrices[m].mapPoints(pts, 2);
	SkVector v = pts[1] - pts[0];
	v.setLength(v.length() + kLineOutset);
	canvas->drawLine(pts[1] - v, pts[0] + v, paint);
	}
	for (int y = 1; y < kN; ++y) {
	SkPoint pts[] = {{0, y * kTileH}, {kTileW * kM, y * kTileH}};
	matrices[m].mapPoints(pts, 2);
	SkVector v = pts[1] - pts[0];
	v.setLength(v.length() + kLineOutset);
	canvas->drawLine(pts[1] - v, pts[0] + v, paint);
	}
	canvas->save();
	canvas->concat(matrices[m]);
	canvas->experimental_DrawEdgeAAImageSet(fSet, kM * kN, nullptr, nullptr, sampling,
	&setPaint,
	SkCanvas::kFast_SrcRectConstraint);
	canvas->restore();
	}
	// A more exotic case with an unusual blend mode, mixed aa flags set, and alpha,
	// subsets the image. And another with all the above plus a color filter.
	SkCanvas::ImageSetEntry entry;
	entry.fSrcRect = SkRect::MakeWH(kTileW, kTileH).makeInset(kTileW / 4.f, kTileH / 4.f);
	entry.fDstRect = SkRect::MakeWH(1.5 * kTileW, 1.5 * kTileH).makeOffset(d / 4, 2 * d);
	entry.fImage = fSet[0].fImage;
	entry.fAlpha = 0.7f;
	entry.fAAFlags = SkCanvas::kLeft_QuadAAFlag \| SkCanvas::kTop_QuadAAFlag;
	canvas->save();
	canvas->rotate(3.f);

	setPaint.setBlendMode(SkBlendMode::kExclusion);
	canvas->experimental_DrawEdgeAAImageSet(&entry, 1, nullptr, nullptr, sampling,
	&setPaint, SkCanvas::kFast_SrcRectConstraint);
	canvas->translate(entry.fDstRect.width() + 8.f, 0);
	SkPaint cfPaint = setPaint;
	cfPaint.setColorFilter(SkColorFilters::LinearToSRGBGamma());
	canvas->experimental_DrawEdgeAAImageSet(&entry, 1, nullptr, nullptr, sampling,
	&cfPaint, SkCanvas::kFast_SrcRectConstraint);
	canvas->restore();
	canvas->translate(2 * d, 0);
	}
	}
	static constexpr int kM = 4;
	static constexpr int kN = 3;
	static constexpr SkScalar kTileW = 30;
	static constexpr SkScalar kTileH = 60;
	SkCanvas::ImageSetEntry fSet[kM * kN];
	};

	// This GM exercises rect-stays-rect type matrices to test that filtering and antialiasing are not
	// incorrectly disabled.
	class DrawImageSetRectToRectGM : public GM {
	private:
	SkString onShortName() override { return SkString("draw_image_set_rect_to_rect"); }
	SkISize onISize() override { return {1250, 850}; }
	void onOnceBeforeDraw() override {
	static constexpr SkColor kColors[] = {SK_ColorBLUE, SK_ColorWHITE,
	SK_ColorRED, SK_ColorWHITE};
	make_image_tiles(kTileW, kTileH, kM, kN, kColors, fSet);
	}

	void onDraw(SkCanvas* canvas) override {
	ToolUtils::draw_checkerboard(canvas, SK_ColorBLACK, SK_ColorWHITE, 50);
	static constexpr SkScalar kW = kM * kTileW;
	static constexpr SkScalar kH = kN * kTileH;
	SkMatrix matrices[5];
	// Identity
	matrices[0].reset();
	// 90 degree rotation
	matrices[1].setRotate(90, kW / 2.f, kH / 2.f);
	// Scaling
	matrices[2].setScale(2.f, 0.5f);
	// Mirror in x and y
	matrices[3].setScale(-1.f, -1.f);
	matrices[3].postTranslate(kW, kH);
	// Mirror in y, rotate, and scale.
	matrices[4].setScale(1.f, -1.f);
	matrices[4].postTranslate(0, kH);
	matrices[4].postRotate(90, kW / 2.f, kH / 2.f);
	matrices[4].postScale(2.f, 0.5f);

	SkPaint paint;
	paint.setBlendMode(SkBlendMode::kSrcOver);

	static constexpr SkScalar kTranslate = std::max(kW, kH) * 2.f + 10.f;
	canvas->translate(5.f, 5.f);
	canvas->save();
	for (SkScalar frac : {0.f, 0.5f}) {
	canvas->save();
	canvas->translate(frac, frac);
	for (size_t m = 0; m < SK_ARRAY_COUNT(matrices); ++m) {
	canvas->save();
	canvas->concat(matrices[m]);
	canvas->experimental_DrawEdgeAAImageSet(fSet, kM * kN, nullptr, nullptr,
	SkSamplingOptions(SkFilterMode::kLinear),
	&paint, SkCanvas::kFast_SrcRectConstraint);
	canvas->restore();
	canvas->translate(kTranslate, 0);
	}
	canvas->restore();
	canvas->restore();
	canvas->translate(0, kTranslate);
	canvas->save();
	}
	for (SkVector scale : {SkVector{2.f, 0.5f}, SkVector{0.5, 2.f}}) {
	SkCanvas::ImageSetEntry scaledSet[kM * kN];
	std::copy_n(fSet, kM * kN, scaledSet);
	for (int i = 0; i < kM * kN; ++i) {
	scaledSet[i].fDstRect.fLeft *= scale.fX;
	scaledSet[i].fDstRect.fTop *= scale.fY;
	scaledSet[i].fDstRect.fRight *= scale.fX;
	scaledSet[i].fDstRect.fBottom *= scale.fY;
	scaledSet[i].fAlpha = 0 == (i % 3) ? 0.4f : 1.f;
	}
	for (size_t m = 0; m < SK_ARRAY_COUNT(matrices); ++m) {
	canvas->save();
	canvas->concat(matrices[m]);
	canvas->experimental_DrawEdgeAAImageSet(scaledSet, kM * kN, nullptr, nullptr,
	SkSamplingOptions(SkFilterMode::kLinear),
	&paint, SkCanvas::kFast_SrcRectConstraint);
	canvas->restore();
	canvas->translate(kTranslate, 0);
	}
	canvas->restore();
	canvas->translate(0, kTranslate);
	canvas->save();
	}
	}
	static constexpr int kM = 2;
	static constexpr int kN = 2;
	static constexpr int kTileW = 40;
	static constexpr int kTileH = 50;
	SkCanvas::ImageSetEntry fSet[kM * kN];
	};

	// This GM exercises alpha-only and color textures being combined correctly with the paint's color.
	class DrawImageSetAlphaOnlyGM : public GM {
	private:
	SkString onShortName() override { return SkString("draw_image_set_alpha_only"); }
	SkISize onISize() override { return {kMkTileW, 2kN*kTileH}; }

	DrawResult onGpuSetup(GrDirectContext* direct, SkString*) override {
	static constexpr SkColor kColors[] = {SK_ColorBLUE, SK_ColorTRANSPARENT,
	SK_ColorRED, SK_ColorTRANSPARENT};
	static constexpr SkColor kBGColor = SkColorSetARGB(128, 128, 128, 128);
	make_image_tiles(kTileW, kTileH, kM, kN, kColors, fSet, kBGColor);

	// Modify the alpha of the entries, decreasing by column, and convert even rows to
	// alpha-only textures.
	sk_sp<SkColorSpace> alphaSpace = SkColorSpace::MakeSRGB();
	for (int y = 0; y < kN; ++y) {
	for (int x = 0; x < kM; ++x) {
	int i = y * kM + x;
	fSet[i].fAlpha = (kM - x) / (float) kM;
	if (y % 2 == 0) {
	fSet[i].fImage = fSet[i].fImage->makeColorTypeAndColorSpace(
	kAlpha_8_SkColorType, alphaSpace, direct);
	}
	}
	}
	return skiagm::DrawResult::kOk;
	}

	void onDraw(SkCanvas* canvas) override {
	ToolUtils::draw_checkerboard(canvas, SK_ColorGRAY, SK_ColorDKGRAY, 25);

	SkPaint paint;
	paint.setBlendMode(SkBlendMode::kSrcOver);
	paint.setColor4f({0.2f, 0.8f, 0.4f, 1.f}); // colorizes even rows, no effect on odd rows

	// Top rows use experimental edge set API
	canvas->experimental_DrawEdgeAAImageSet(fSet, kM * kN, nullptr, nullptr,
	SkSamplingOptions(SkFilterMode::kLinear), &paint,
	SkCanvas::kFast_SrcRectConstraint);

	canvas->translate(0.f, kN * kTileH);

	// Bottom rows draw each image from the set using the regular API
	for (int y = 0; y < kN; ++y) {
	for (int x = 0; x < kM; ++x) {
	int i = y * kM + x;
	SkPaint entryPaint = paint;
	entryPaint.setAlphaf(fSet[i].fAlpha * paint.getAlphaf());
	canvas->drawImageRect(fSet[i].fImage.get(), fSet[i].fSrcRect, fSet[i].fDstRect,
	SkSamplingOptions(), &entryPaint,
	SkCanvas::kFast_SrcRectConstraint);
	}
	}
	}

	static constexpr int kM = 4;
	static constexpr int kN = 4;
	static constexpr int kTileW = 50;
	static constexpr int kTileH = 50;
	SkCanvas::ImageSetEntry fSet[kM * kN];
	};

	DEF_GM(return new DrawImageSetGM();)
	DEF_GM(return new DrawImageSetRectToRectGM();)
	DEF_GM(return new DrawImageSetAlphaOnlyGM();)

	} // namespace skiagm