From e1a3bc67690886dbc72271f447dec073363fe84c Mon Sep 17 00:00:00 2001 From: jvanverth Date: Fri, 12 Aug 2016 10:40:38 -0700 Subject: Add Android Shadow sample BUG=skia: GOLD_TRYBOT_URL= https://gold.skia.org/search?issue=2245693002 Review-Url: https://codereview.chromium.org/2245693002 --- samplecode/SampleAndroidShadows.cpp | 251 ++++++++++++++++++++++++++++++++++++ 1 file changed, 251 insertions(+) create mode 100755 samplecode/SampleAndroidShadows.cpp (limited to 'samplecode/SampleAndroidShadows.cpp') diff --git a/samplecode/SampleAndroidShadows.cpp b/samplecode/SampleAndroidShadows.cpp new file mode 100755 index 0000000000..9ab69a670c --- /dev/null +++ b/samplecode/SampleAndroidShadows.cpp @@ -0,0 +1,251 @@ + +/* + * 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 "SampleCode.h" +#include "SkBlurMask.h" +#include "SkBlurMaskFilter.h" +#include "SkCanvas.h" +#include "SkPath.h" +#include "SkPoint3.h" +#include "SkUtils.h" +#include "SkView.h" +#include "sk_tool_utils.h" + +class ShadowsView : public SampleView { + SkPath fRectPath; + SkPath fRRPath; + SkPath fCirclePath; + SkPoint3 fLightPos; + + bool fShowAmbient; + bool fShowSpot; + bool fShowObject; + +public: + ShadowsView() + : fShowAmbient(true) + , fShowSpot(true) + , fShowObject(true) {} + +protected: + void onOnceBeforeDraw() override { + fCirclePath.addCircle(0, 0, 50); + fRectPath.addRect(SkRect::MakeXYWH(-100, -50, 200, 100)); + fRRPath.addRRect(SkRRect::MakeRectXY(SkRect::MakeXYWH(-100, -50, 200, 100), 4, 4)); + fLightPos = SkPoint3::Make(-220, -330, 150); + } + + // overrides from SkEventSink + bool onQuery(SkEvent* evt) override { + if (SampleCode::TitleQ(*evt)) { + SampleCode::TitleR(evt, "AndroidShadows"); + return true; + } + + SkUnichar uni; + if (SampleCode::CharQ(*evt, &uni)) { + switch (uni) { + case 'B': + fShowAmbient = !fShowAmbient; + break; + case 'S': + fShowSpot = !fShowSpot; + break; + case 'O': + fShowObject = !fShowObject; + break; + case '>': + fLightPos.fZ += 10; + break; + case '<': + fLightPos.fZ -= 10; + break; + default: + break; + } + this->inval(nullptr); + } + return this->INHERITED::onQuery(evt); + } + + void drawBG(SkCanvas* canvas) { + canvas->drawColor(0xFFDDDDDD); + } + + static void GetOcclRect(const SkPath& path, SkRect* occlRect) { + SkRect pathRect; + SkRRect pathRRect; + if (path.isOval(&pathRect)) { + *occlRect = sk_tool_utils::compute_central_occluder(SkRRect::MakeOval(pathRect)); + } else if (path.isRRect(&pathRRect)) { + *occlRect = sk_tool_utils::compute_central_occluder(pathRRect); + } else if (path.isRect(occlRect)) { + // the inverse transform for the spot shadow occluder doesn't always get us + // back to exactly the same position, so deducting a little slop + occlRect->inset(1, 1); + } else { + *occlRect = SkRect::MakeEmpty(); + } + } + + void drawAmbientShadow(SkCanvas* canvas, const SkPath& path, SkScalar zValue, + SkScalar ambientAlpha) { + + if (ambientAlpha <= 0) { + return; + } + + const SkScalar kHeightFactor = 1.f / 128.f; + const SkScalar kGeomFactor = 64; + + SkScalar umbraAlpha = 1 / (1 + SkMaxScalar(zValue*kHeightFactor, 0)); + SkScalar radius = zValue*kHeightFactor*kGeomFactor; + + // occlude blur + SkRect occlRect; + GetOcclRect(path, &occlRect); + sk_sp mf = SkBlurMaskFilter::Make(kNormal_SkBlurStyle, + SkBlurMask::ConvertRadiusToSigma(radius), + occlRect, + SkBlurMaskFilter::kNone_BlurFlag); + + SkPaint paint; + paint.setAntiAlias(true); + paint.setMaskFilter(std::move(mf)); + paint.setColor(SkColorSetARGB((unsigned char)(ambientAlpha*umbraAlpha*255.999f), 0, 0, 0)); + canvas->drawPath(path, paint); + + // draw occlusion rect + SkPaint stroke; + stroke.setStyle(SkPaint::kStroke_Style); + stroke.setColor(SK_ColorBLUE); + canvas->drawRect(occlRect, stroke); + } + + void drawSpotShadow(SkCanvas* canvas, const SkPath& path, SkScalar zValue, + SkPoint3 lightPos, SkScalar lightWidth, SkScalar spotAlpha) { + if (spotAlpha <= 0) { + return; + } + + SkScalar zRatio = zValue / (lightPos.fZ - zValue); + if (zRatio < 0.0f) { + zRatio = 0.0f; + } else if (zRatio > 0.95f) { + zRatio = 0.95f; + } + SkScalar radius = lightWidth*zRatio; + + // compute the transformation params + SkPoint center = SkPoint::Make(path.getBounds().centerX(), path.getBounds().centerY()); + canvas->getTotalMatrix().mapPoints(¢er, 1); + SkPoint offset = SkPoint::Make(-zRatio*(lightPos.fX - center.fX), + -zRatio*(lightPos.fY - center.fY)); + SkScalar scale = lightPos.fZ / (lightPos.fZ - zValue); + if (scale < 1.0f) { + scale = 1.0f; + } else if (scale > 1024.f) { + scale = 1024.f; + } + + SkAutoCanvasRestore acr(canvas, true); + + SkRect occlRect; + GetOcclRect(path, &occlRect); + // apply inverse transform + occlRect.offset(-offset); + occlRect.fLeft /= scale; + occlRect.fRight /= scale; + occlRect.fTop /= scale; + occlRect.fBottom /= scale; + sk_sp mf = SkBlurMaskFilter::Make(kNormal_SkBlurStyle, + SkBlurMask::ConvertRadiusToSigma(radius), + occlRect, + SkBlurMaskFilter::kNone_BlurFlag); + + SkPaint paint; + paint.setAntiAlias(true); + paint.setMaskFilter(std::move(mf)); + paint.setColor(SkColorSetARGB((unsigned char)(spotAlpha*255.999f), 0, 0, 0)); + + // apply transformation to shadow + canvas->translate(offset.fX, offset.fY); + canvas->scale(scale, scale); + canvas->drawPath(path, paint); + + // draw occlusion rect + SkPaint stroke; + stroke.setStyle(SkPaint::kStroke_Style); + stroke.setColor(SK_ColorRED); + canvas->drawRect(occlRect, stroke); + } + + void drawShadowedPath(SkCanvas* canvas, const SkPath& path, SkScalar zValue, + const SkPaint& paint) { + const SkScalar kLightWidth = 3; + const SkScalar kAmbientAlpha = 0.25f; + const SkScalar kSpotAlpha = 0.25f; + + if (fShowAmbient) { + this->drawAmbientShadow(canvas, path, zValue, kAmbientAlpha); + } + if (fShowSpot) { + this->drawSpotShadow(canvas, path, zValue, fLightPos, kLightWidth, kSpotAlpha); + } + if (fShowObject) { + canvas->drawPath(path, paint); + } + } + + void onDrawContent(SkCanvas* canvas) override { + this->drawBG(canvas); + + SkPaint paint; + paint.setAntiAlias(true); + + paint.setColor(SK_ColorWHITE); + canvas->translate(200, 90); + this->drawShadowedPath(canvas, fRectPath, 5, paint); + + paint.setColor(SK_ColorRED); + canvas->translate(250, 0); + this->drawShadowedPath(canvas, fRRPath, 5, paint); + + paint.setColor(SK_ColorBLUE); + canvas->translate(-250, 110); + this->drawShadowedPath(canvas, fCirclePath, 5, paint); + } + +protected: + SkView::Click* onFindClickHandler(SkScalar x, SkScalar y, unsigned modi) override { + return new SkView::Click(this); + } + + bool onClick(Click *click) override { + SkScalar x = click->fCurr.fX; + SkScalar y = click->fCurr.fY; + + SkScalar dx = x - click->fPrev.fX; + SkScalar dy = y - click->fPrev.fY; + + if (dx != 0 || dy != 0) { + fLightPos.fX += dx; + fLightPos.fY += dy; + this->inval(nullptr); + } + + return true; + } + +private: + typedef SkView INHERITED; +}; + +////////////////////////////////////////////////////////////////////////////// + +static SkView* MyFactory() { return new ShadowsView; } +static SkViewRegister reg(MyFactory); -- cgit v1.2.3