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

 /*
  * Copyright 2017 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 "SkResourceCache.h"
 #include "SkShadowUtils.h"

 void draw_shadow(SkCanvas* canvas, const SkPath& path, SkScalar height, SkColor color,
                  SkPoint3 lightPos, SkScalar lightR, bool isAmbient, uint32_t flags) {
     SkScalar ambientAlpha = isAmbient ? .5f : 0.f;
     SkScalar spotAlpha = isAmbient ? 0.f : .5f;
     SkColor ambientColor = SkColorSetARGB(ambientAlpha*SkColorGetA(color), SkColorGetR(color),
                                           SkColorGetG(color), SkColorGetB(color));
     SkColor spotColor = SkColorSetARGB(spotAlpha*SkColorGetA(color), SkColorGetR(color),
                                        SkColorGetG(color), SkColorGetB(color));
     SkShadowUtils::DrawShadow(canvas, path, SkPoint3{ 0, 0, height}, lightPos, lightR,
                               ambientColor, spotColor, flags);
 }

 static constexpr int kW = 800;
 static constexpr int kH = 960;

 enum ShadowMode {
     kDebugColorNoOccluders,
     kDebugColorOccluders,
     kGrayscale
 };

 void draw_paths(SkCanvas* canvas, ShadowMode mode) {
     SkTArray<SkPath> paths;
     paths.push_back().addRoundRect(SkRect::MakeWH(50, 50), 10, 10);
     SkRRect oddRRect;
     oddRRect.setNinePatch(SkRect::MakeWH(50, 50), 9, 13, 6, 16);
     paths.push_back().addRRect(oddRRect);
     paths.push_back().addRect(SkRect::MakeWH(50, 50));
     paths.push_back().addCircle(25, 25, 25);
     paths.push_back().cubicTo(100, 50, 20, 100, 0, 0);
     paths.push_back().addOval(SkRect::MakeWH(20, 60));

     // star
     SkTArray<SkPath> concavePaths;
     concavePaths.push_back().moveTo(0.0f, -33.3333f);
     concavePaths.back().lineTo(9.62f, -16.6667f);
     concavePaths.back().lineTo(28.867f, -16.6667f);
     concavePaths.back().lineTo(19.24f, 0.0f);
     concavePaths.back().lineTo(28.867f, 16.6667f);
     concavePaths.back().lineTo(9.62f, 16.6667f);
     concavePaths.back().lineTo(0.0f, 33.3333f);
     concavePaths.back().lineTo(-9.62f, 16.6667f);
     concavePaths.back().lineTo(-28.867f, 16.6667f);
     concavePaths.back().lineTo(-19.24f, 0.0f);
     concavePaths.back().lineTo(-28.867f, -16.6667f);
     concavePaths.back().lineTo(-9.62f, -16.6667f);
     concavePaths.back().close();

     // dumbbell
     concavePaths.push_back().moveTo(50, 0);
     concavePaths.back().cubicTo(100, 25, 60, 50, 50, 0);
     concavePaths.back().cubicTo(0, -25, 40, -50, 50, 0);

     static constexpr SkScalar kPad = 15.f;
     static constexpr SkScalar kLightR = 100.f;
     static constexpr SkScalar kHeight = 50.f;

     // transform light position relative to canvas to handle tiling
     SkPoint lightXY = canvas->getTotalMatrix().mapXY(250, 400);
     SkPoint3 lightPos = { lightXY.fX, lightXY.fY, 500 };

     canvas->translate(3 * kPad, 3 * kPad);
     canvas->save();
     SkScalar x = 0;
     SkScalar dy = 0;
     SkTDArray<SkMatrix> matrices;
     matrices.push()->reset();
     SkMatrix* m = matrices.push();
     m->setRotate(33.f, 25.f, 25.f);
     m->postScale(1.2f, 0.8f, 25.f, 25.f);
     for (auto& m : matrices) {
         for (int flags : { kNone_ShadowFlag, kTransparentOccluder_ShadowFlag }) {
             for (const auto& path : paths) {
                 SkRect postMBounds = path.getBounds();
                 m.mapRect(&postMBounds);
                 SkScalar w = postMBounds.width() + kHeight;
                 SkScalar dx = w + kPad;
                 if (x + dx > kW - 3 * kPad) {
                     canvas->restore();
                     canvas->translate(0, dy);
                     canvas->save();
                     x = 0;
                     dy = 0;
                 }

                 canvas->save();
                 canvas->concat(m);

                 if (kDebugColorNoOccluders == mode || kDebugColorOccluders == mode) {
                     draw_shadow(canvas, path, kHeight, SK_ColorRED, lightPos, kLightR,
                                 true, flags);
                     draw_shadow(canvas, path, kHeight, SK_ColorBLUE, lightPos, kLightR,
                                 false, flags);
                 } else if (kGrayscale == mode) {
                     SkColor ambientColor = SkColorSetARGB(0.1f * 255, 0, 0, 0);
                     SkColor spotColor = SkColorSetARGB(0.25f * 255, 0, 0, 0);
                     SkShadowUtils::DrawShadow(canvas, path, SkPoint3{0, 0, kHeight}, lightPos,
                                               kLightR, ambientColor, spotColor, flags);
                 }

                 SkPaint paint;
                 paint.setAntiAlias(true);
                 if (kDebugColorNoOccluders == mode) {
                     // Draw the path outline in green on top of the ambient and spot shadows.
                     if (SkToBool(flags & kTransparentOccluder_ShadowFlag)) {
                         paint.setColor(SK_ColorCYAN);
                     } else {
                         paint.setColor(SK_ColorGREEN);
                     }
                     paint.setStyle(SkPaint::kStroke_Style);
                     paint.setStrokeWidth(0);
                 } else {
                     paint.setColor(kDebugColorOccluders == mode ? SK_ColorLTGRAY : SK_ColorWHITE);
                     if (SkToBool(flags & kTransparentOccluder_ShadowFlag)) {
                         paint.setAlpha(128);
                     }
                     paint.setStyle(SkPaint::kFill_Style);
                 }
                 canvas->drawPath(path, paint);
                 canvas->restore();

                 canvas->translate(dx, 0);
                 x += dx;
                 dy = SkTMax(dy, postMBounds.height() + kPad + kHeight);
             }
         }
     }

     // concave paths
     canvas->restore();
     canvas->translate(kPad, dy);
     canvas->save();
     x = kPad;
     dy = 0;
     for (auto& m : matrices) {
         // for the concave paths we are not clipping, so transparent and opaque are the same
         for (const auto& path : concavePaths) {
             SkRect postMBounds = path.getBounds();
             m.mapRect(&postMBounds);
             SkScalar w = postMBounds.width() + kHeight;
             SkScalar dx = w + kPad;

             canvas->save();
             canvas->concat(m);

             if (kDebugColorNoOccluders == mode || kDebugColorOccluders == mode) {
                 draw_shadow(canvas, path, kHeight, SK_ColorRED, lightPos, kLightR,
                             true, kNone_ShadowFlag);
                 draw_shadow(canvas, path, kHeight, SK_ColorBLUE, lightPos, kLightR,
                             false, kNone_ShadowFlag);
             } else if (kGrayscale == mode) {
                 SkColor ambientColor = SkColorSetARGB(0.1f * 255, 0, 0, 0);
                 SkColor spotColor = SkColorSetARGB(0.25f * 255, 0, 0, 0);
                 SkShadowUtils::DrawShadow(canvas, path, SkPoint3{ 0, 0, kHeight }, lightPos,
                                           kLightR, ambientColor, spotColor, kNone_ShadowFlag);
             }

             SkPaint paint;
             paint.setAntiAlias(true);
             if (kDebugColorNoOccluders == mode) {
                 // Draw the path outline in green on top of the ambient and spot shadows.
                 paint.setColor(SK_ColorGREEN);
                 paint.setStyle(SkPaint::kStroke_Style);
                 paint.setStrokeWidth(0);
             } else {
                 paint.setColor(kDebugColorOccluders == mode ? SK_ColorLTGRAY : SK_ColorWHITE);
                 paint.setStyle(SkPaint::kFill_Style);
             }
             canvas->drawPath(path, paint);
             canvas->restore();

             canvas->translate(dx, 0);
             x += dx;
             dy = SkTMax(dy, postMBounds.height() + kPad + kHeight);
         }
     }

     // Show where the light is in x,y as a circle (specified in device space).
     SkMatrix invCanvasM = canvas->getTotalMatrix();
     if (invCanvasM.invert(&invCanvasM)) {
         canvas->save();
         canvas->concat(invCanvasM);
         SkPaint paint;
         paint.setColor(SK_ColorBLACK);
         paint.setAntiAlias(true);
         canvas->drawCircle(lightPos.fX, lightPos.fY, kLightR / 10.f, paint);
         canvas->restore();
     }
 }

 DEF_SIMPLE_GM(shadow_utils, canvas, kW, kH) {
     draw_paths(canvas, kDebugColorNoOccluders);
 }

 DEF_SIMPLE_GM(shadow_utils_occl, canvas, kW, kH) {
     draw_paths(canvas, kDebugColorOccluders);
 }

 DEF_SIMPLE_GM(shadow_utils_gray, canvas, kW, kH) {
     draw_paths(canvas, kGrayscale);
 }
	/*
	* Copyright 2017 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 "SkResourceCache.h"
	#include "SkShadowUtils.h"

	void draw_shadow(SkCanvas* canvas, const SkPath& path, SkScalar height, SkColor color,
	SkPoint3 lightPos, SkScalar lightR, bool isAmbient, uint32_t flags) {
	SkScalar ambientAlpha = isAmbient ? .5f : 0.f;
	SkScalar spotAlpha = isAmbient ? 0.f : .5f;
	SkColor ambientColor = SkColorSetARGB(ambientAlpha*SkColorGetA(color), SkColorGetR(color),
	SkColorGetG(color), SkColorGetB(color));
	SkColor spotColor = SkColorSetARGB(spotAlpha*SkColorGetA(color), SkColorGetR(color),
	SkColorGetG(color), SkColorGetB(color));
	SkShadowUtils::DrawShadow(canvas, path, SkPoint3{ 0, 0, height}, lightPos, lightR,
	ambientColor, spotColor, flags);
	}

	static constexpr int kW = 800;
	static constexpr int kH = 960;

	enum ShadowMode {
	kDebugColorNoOccluders,
	kDebugColorOccluders,
	kGrayscale
	};

	void draw_paths(SkCanvas* canvas, ShadowMode mode) {
	SkTArray<SkPath> paths;
	paths.push_back().addRoundRect(SkRect::MakeWH(50, 50), 10, 10);
	SkRRect oddRRect;
	oddRRect.setNinePatch(SkRect::MakeWH(50, 50), 9, 13, 6, 16);
	paths.push_back().addRRect(oddRRect);
	paths.push_back().addRect(SkRect::MakeWH(50, 50));
	paths.push_back().addCircle(25, 25, 25);
	paths.push_back().cubicTo(100, 50, 20, 100, 0, 0);
	paths.push_back().addOval(SkRect::MakeWH(20, 60));

	// star
	SkTArray<SkPath> concavePaths;
	concavePaths.push_back().moveTo(0.0f, -33.3333f);
	concavePaths.back().lineTo(9.62f, -16.6667f);
	concavePaths.back().lineTo(28.867f, -16.6667f);
	concavePaths.back().lineTo(19.24f, 0.0f);
	concavePaths.back().lineTo(28.867f, 16.6667f);
	concavePaths.back().lineTo(9.62f, 16.6667f);
	concavePaths.back().lineTo(0.0f, 33.3333f);
	concavePaths.back().lineTo(-9.62f, 16.6667f);
	concavePaths.back().lineTo(-28.867f, 16.6667f);
	concavePaths.back().lineTo(-19.24f, 0.0f);
	concavePaths.back().lineTo(-28.867f, -16.6667f);
	concavePaths.back().lineTo(-9.62f, -16.6667f);
	concavePaths.back().close();

	// dumbbell
	concavePaths.push_back().moveTo(50, 0);
	concavePaths.back().cubicTo(100, 25, 60, 50, 50, 0);
	concavePaths.back().cubicTo(0, -25, 40, -50, 50, 0);

	static constexpr SkScalar kPad = 15.f;
	static constexpr SkScalar kLightR = 100.f;
	static constexpr SkScalar kHeight = 50.f;

	// transform light position relative to canvas to handle tiling
	SkPoint lightXY = canvas->getTotalMatrix().mapXY(250, 400);
	SkPoint3 lightPos = { lightXY.fX, lightXY.fY, 500 };

	canvas->translate(3 * kPad, 3 * kPad);
	canvas->save();
	SkScalar x = 0;
	SkScalar dy = 0;
	SkTDArray<SkMatrix> matrices;
	matrices.push()->reset();
	SkMatrix* m = matrices.push();
	m->setRotate(33.f, 25.f, 25.f);
	m->postScale(1.2f, 0.8f, 25.f, 25.f);
	for (auto& m : matrices) {
	for (int flags : { kNone_ShadowFlag, kTransparentOccluder_ShadowFlag }) {
	for (const auto& path : paths) {
	SkRect postMBounds = path.getBounds();
	m.mapRect(&postMBounds);
	SkScalar w = postMBounds.width() + kHeight;
	SkScalar dx = w + kPad;
	if (x + dx > kW - 3 * kPad) {
	canvas->restore();
	canvas->translate(0, dy);
	canvas->save();
	x = 0;
	dy = 0;
	}

	canvas->save();
	canvas->concat(m);

	if (kDebugColorNoOccluders == mode \|\| kDebugColorOccluders == mode) {
	draw_shadow(canvas, path, kHeight, SK_ColorRED, lightPos, kLightR,
	true, flags);
	draw_shadow(canvas, path, kHeight, SK_ColorBLUE, lightPos, kLightR,
	false, flags);
	} else if (kGrayscale == mode) {
	SkColor ambientColor = SkColorSetARGB(0.1f * 255, 0, 0, 0);
	SkColor spotColor = SkColorSetARGB(0.25f * 255, 0, 0, 0);
	SkShadowUtils::DrawShadow(canvas, path, SkPoint3{0, 0, kHeight}, lightPos,
	kLightR, ambientColor, spotColor, flags);
	}

	SkPaint paint;
	paint.setAntiAlias(true);
	if (kDebugColorNoOccluders == mode) {
	// Draw the path outline in green on top of the ambient and spot shadows.
	if (SkToBool(flags & kTransparentOccluder_ShadowFlag)) {
	paint.setColor(SK_ColorCYAN);
	} else {
	paint.setColor(SK_ColorGREEN);
	}
	paint.setStyle(SkPaint::kStroke_Style);
	paint.setStrokeWidth(0);
	} else {
	paint.setColor(kDebugColorOccluders == mode ? SK_ColorLTGRAY : SK_ColorWHITE);
	if (SkToBool(flags & kTransparentOccluder_ShadowFlag)) {
	paint.setAlpha(128);
	}
	paint.setStyle(SkPaint::kFill_Style);
	}
	canvas->drawPath(path, paint);
	canvas->restore();

	canvas->translate(dx, 0);
	x += dx;
	dy = SkTMax(dy, postMBounds.height() + kPad + kHeight);
	}
	}
	}

	// concave paths
	canvas->restore();
	canvas->translate(kPad, dy);
	canvas->save();
	x = kPad;
	dy = 0;
	for (auto& m : matrices) {
	// for the concave paths we are not clipping, so transparent and opaque are the same
	for (const auto& path : concavePaths) {
	SkRect postMBounds = path.getBounds();
	m.mapRect(&postMBounds);
	SkScalar w = postMBounds.width() + kHeight;
	SkScalar dx = w + kPad;

	canvas->save();
	canvas->concat(m);

	if (kDebugColorNoOccluders == mode \|\| kDebugColorOccluders == mode) {
	draw_shadow(canvas, path, kHeight, SK_ColorRED, lightPos, kLightR,
	true, kNone_ShadowFlag);
	draw_shadow(canvas, path, kHeight, SK_ColorBLUE, lightPos, kLightR,
	false, kNone_ShadowFlag);
	} else if (kGrayscale == mode) {
	SkColor ambientColor = SkColorSetARGB(0.1f * 255, 0, 0, 0);
	SkColor spotColor = SkColorSetARGB(0.25f * 255, 0, 0, 0);
	SkShadowUtils::DrawShadow(canvas, path, SkPoint3{ 0, 0, kHeight }, lightPos,
	kLightR, ambientColor, spotColor, kNone_ShadowFlag);
	}

	SkPaint paint;
	paint.setAntiAlias(true);
	if (kDebugColorNoOccluders == mode) {
	// Draw the path outline in green on top of the ambient and spot shadows.
	paint.setColor(SK_ColorGREEN);
	paint.setStyle(SkPaint::kStroke_Style);
	paint.setStrokeWidth(0);
	} else {
	paint.setColor(kDebugColorOccluders == mode ? SK_ColorLTGRAY : SK_ColorWHITE);
	paint.setStyle(SkPaint::kFill_Style);
	}
	canvas->drawPath(path, paint);
	canvas->restore();

	canvas->translate(dx, 0);
	x += dx;
	dy = SkTMax(dy, postMBounds.height() + kPad + kHeight);
	}
	}

	// Show where the light is in x,y as a circle (specified in device space).
	SkMatrix invCanvasM = canvas->getTotalMatrix();
	if (invCanvasM.invert(&invCanvasM)) {
	canvas->save();
	canvas->concat(invCanvasM);
	SkPaint paint;
	paint.setColor(SK_ColorBLACK);
	paint.setAntiAlias(true);
	canvas->drawCircle(lightPos.fX, lightPos.fY, kLightR / 10.f, paint);
	canvas->restore();
	}
	}

	DEF_SIMPLE_GM(shadow_utils, canvas, kW, kH) {
	draw_paths(canvas, kDebugColorNoOccluders);
	}

	DEF_SIMPLE_GM(shadow_utils_occl, canvas, kW, kH) {
	draw_paths(canvas, kDebugColorOccluders);
	}

	DEF_SIMPLE_GM(shadow_utils_gray, canvas, kW, kH) {
	draw_paths(canvas, kGrayscale);
	}