robertphillips@google.com | 4157085 | 2013-06-03 17:13:25 +0000 | [diff] [blame] | 1 | /* |
| 2 | * Copyright 2013 Google Inc. |
| 3 | * |
| 4 | * Use of this source code is governed by a BSD-style license that can be |
| 5 | * found in the LICENSE file. |
| 6 | */ |
| 7 | |
| 8 | #include "gm.h" |
| 9 | #include "SkCanvas.h" |
| 10 | #include "SkBlurMaskFilter.h" |
| 11 | #include "SkLayerDrawLooper.h" |
| 12 | #include "SkColorFilter.h" |
| 13 | |
| 14 | // This GM tests 3 different ways of drawing four shadows around a square: |
| 15 | // just using 4 blurred rects |
| 16 | // using 4 1-level draw loopers |
| 17 | // using 1 4-level draw looper |
| 18 | // They all produce exactly the same pixels |
| 19 | class MegaLooperGM : public skiagm::GM { |
| 20 | public: |
| 21 | // The types define "<# of loopers> x <# of stages per looper>" |
| 22 | enum Type { |
| 23 | k0x0_Type, // draw without loopers at all |
| 24 | k4x1_Type, // a looper for each shadow |
| 25 | k1x4_Type, // all four shadows in one looper |
| 26 | }; |
| 27 | |
| 28 | MegaLooperGM(Type type) : fType(type) {} |
| 29 | |
| 30 | protected: |
| 31 | virtual SkString onShortName() { |
| 32 | switch (fType) { |
| 33 | case k0x0_Type: |
| 34 | return SkString("megalooper_0x0"); |
| 35 | break; |
| 36 | case k4x1_Type: |
| 37 | return SkString("megalooper_4x1"); |
| 38 | break; |
| 39 | case k1x4_Type: // fall through |
| 40 | default: |
| 41 | return SkString("megalooper_1x4"); |
| 42 | break; |
| 43 | } |
| 44 | } |
| 45 | |
| 46 | virtual SkISize onISize() { |
| 47 | return SkISize::Make(kWidth, kHeight); |
| 48 | } |
| 49 | |
| 50 | virtual void onDraw(SkCanvas* canvas) { |
| 51 | for (int y = 100; y < kHeight; y += 200) { |
| 52 | for (int x = 100; x < kWidth; x += 200) { |
| 53 | switch (fType) { |
| 54 | case k0x0_Type: |
| 55 | draw0x0(canvas, SkIntToScalar(x), SkIntToScalar(y)); |
| 56 | break; |
| 57 | case k4x1_Type: |
| 58 | draw4x1(canvas, SkIntToScalar(x), SkIntToScalar(y)); |
| 59 | break; |
| 60 | case k1x4_Type: // fall through |
| 61 | default: |
| 62 | draw1x4(canvas, SkIntToScalar(x), SkIntToScalar(y)); |
| 63 | break; |
| 64 | } |
| 65 | } |
| 66 | } |
| 67 | } |
| 68 | |
| 69 | private: |
| 70 | static const int kWidth = 800; |
| 71 | static const int kHeight = 800; |
| 72 | static const int kHalfOuterClipSize = 100; |
| 73 | static const int kHalfSquareSize = 50; |
| 74 | static const int kOffsetToOutsideClip = kHalfSquareSize + kHalfOuterClipSize + 1; |
| 75 | |
| 76 | static const SkPoint gBlurOffsets[4]; |
| 77 | static const SkColor gColors[4]; |
| 78 | Type fType; |
| 79 | |
| 80 | // Just draw a blurred rect at each of the four corners of a square (centered at x,y). |
| 81 | // Use two clips to define a rectori where we want pixels to appear. |
| 82 | void draw0x0(SkCanvas* canvas, SkScalar x, SkScalar y) { |
| 83 | SkRect innerClip = { -kHalfSquareSize, -kHalfSquareSize, kHalfSquareSize, kHalfSquareSize }; |
| 84 | innerClip.offset(x, y); |
| 85 | |
skia.committer@gmail.com | 11f2b44 | 2013-06-04 07:00:53 +0000 | [diff] [blame] | 86 | SkRect outerClip = { |
| 87 | -kHalfOuterClipSize-kHalfSquareSize, -kHalfOuterClipSize-kHalfSquareSize, |
robertphillips@google.com | 4157085 | 2013-06-03 17:13:25 +0000 | [diff] [blame] | 88 | kHalfOuterClipSize+kHalfSquareSize, kHalfOuterClipSize+kHalfSquareSize |
| 89 | }; |
| 90 | outerClip.offset(x, y); |
| 91 | |
| 92 | canvas->save(); |
| 93 | canvas->clipRect(outerClip, SkRegion::kIntersect_Op); |
| 94 | canvas->clipRect(innerClip, SkRegion::kDifference_Op); |
| 95 | |
| 96 | SkPaint paint; |
| 97 | paint.setAntiAlias(true); |
| 98 | paint.setMaskFilter(createBlur())->unref(); |
| 99 | |
| 100 | for (int i = 0; i < 4; ++i) { |
| 101 | paint.setColor(gColors[i]); |
| 102 | |
| 103 | SkRect rect = { -kHalfSquareSize, -kHalfSquareSize, kHalfSquareSize, kHalfSquareSize }; |
| 104 | rect.offset(gBlurOffsets[i]); |
| 105 | rect.offset(x, y); |
| 106 | canvas->drawRect(rect, paint); |
| 107 | } |
| 108 | |
| 109 | canvas->restore(); |
| 110 | } |
| 111 | |
| 112 | SkMaskFilter* createBlur() { |
| 113 | static const SkScalar kBlurRadius = 25.0f; |
| 114 | |
| 115 | return SkBlurMaskFilter::Create(kBlurRadius, |
| 116 | SkBlurMaskFilter::kNormal_BlurStyle, |
| 117 | SkBlurMaskFilter::kHighQuality_BlurFlag); |
| 118 | } |
| 119 | |
| 120 | // This draws 4 blurred shadows around a single square (centered at x, y). |
| 121 | // Each blur is offset +/- half the square's side in x & y from the original |
| 122 | // (so each blurred rect is centered at one of the corners of the original). |
| 123 | // For each blur a large outer clip is centered around the blurred rect |
| 124 | // while a difference clip stays at the location of the original rect. |
| 125 | // Each blurred rect is drawn with a draw looper where the original (non- |
| 126 | // blurred rect) is offset to reside outside of the large outer clip (so |
skia.committer@gmail.com | 11f2b44 | 2013-06-04 07:00:53 +0000 | [diff] [blame] | 127 | // it never appears) but the offset in the draw looper is used to translate |
robertphillips@google.com | 4157085 | 2013-06-03 17:13:25 +0000 | [diff] [blame] | 128 | // the blurred version back into the clip. |
| 129 | void draw4x1(SkCanvas* canvas, SkScalar x, SkScalar y) { |
| 130 | |
| 131 | for (int i = 0; i < 4; ++i) { |
| 132 | SkPaint loopPaint; |
| 133 | |
commit-bot@chromium.org | ef284a8 | 2013-07-11 22:29:29 +0000 | [diff] [blame^] | 134 | loopPaint.setLooper(create1Looper(-kOffsetToOutsideClip, 0, gColors[i]))->unref(); |
robertphillips@google.com | 4157085 | 2013-06-03 17:13:25 +0000 | [diff] [blame] | 135 | loopPaint.setAntiAlias(true); |
| 136 | |
skia.committer@gmail.com | 11f2b44 | 2013-06-04 07:00:53 +0000 | [diff] [blame] | 137 | SkRect outerClip = { |
| 138 | -kHalfOuterClipSize, -kHalfOuterClipSize, |
| 139 | kHalfOuterClipSize, kHalfOuterClipSize |
robertphillips@google.com | 4157085 | 2013-06-03 17:13:25 +0000 | [diff] [blame] | 140 | }; |
| 141 | outerClip.offset(x, y); |
| 142 | // center it on the blurred rect |
| 143 | outerClip.offset(gBlurOffsets[i]); |
| 144 | |
| 145 | SkRect rect = { -kHalfSquareSize, -kHalfSquareSize, kHalfSquareSize, kHalfSquareSize }; |
| 146 | rect.offset(x, y); |
| 147 | |
| 148 | canvas->save(); |
| 149 | canvas->clipRect(outerClip, SkRegion::kIntersect_Op); |
| 150 | canvas->clipRect(rect, SkRegion::kDifference_Op); |
| 151 | |
| 152 | // move the rect to where we want the blur to appear |
| 153 | rect.offset(gBlurOffsets[i]); |
| 154 | // then move it outside the clip (the blur stage of the draw |
| 155 | // looper will undo this translation) |
| 156 | rect.offset(SkIntToScalar(kOffsetToOutsideClip), 0); |
| 157 | |
| 158 | canvas->drawRect(rect, loopPaint); |
| 159 | canvas->restore(); |
| 160 | } |
| 161 | } |
| 162 | |
skia.committer@gmail.com | 11f2b44 | 2013-06-04 07:00:53 +0000 | [diff] [blame] | 163 | // Create a 1-tier drawlooper |
robertphillips@google.com | 4157085 | 2013-06-03 17:13:25 +0000 | [diff] [blame] | 164 | SkLayerDrawLooper* create1Looper(SkScalar xOff, SkScalar yOff, SkColor color) { |
| 165 | SkLayerDrawLooper* looper = new SkLayerDrawLooper; |
| 166 | SkLayerDrawLooper::LayerInfo info; |
| 167 | |
| 168 | info.fFlagsMask = 0; |
| 169 | info.fPaintBits = SkLayerDrawLooper::kColorFilter_Bit | |
| 170 | SkLayerDrawLooper::kMaskFilter_Bit; |
| 171 | info.fColorMode = SkXfermode::kSrc_Mode; |
| 172 | info.fOffset.set(xOff, yOff); |
| 173 | info.fPostTranslate = false; |
| 174 | |
| 175 | SkPaint* paint = looper->addLayer(info); |
| 176 | |
| 177 | paint->setMaskFilter(this->createBlur())->unref(); |
| 178 | |
| 179 | SkColorFilter* cf = SkColorFilter::CreateModeFilter(color, SkXfermode::kSrcIn_Mode); |
| 180 | paint->setColorFilter(cf)->unref(); |
| 181 | |
| 182 | return looper; |
| 183 | } |
| 184 | |
| 185 | void draw1x4(SkCanvas* canvas, SkScalar x, SkScalar y) { |
| 186 | SkRect rect = { -kHalfSquareSize, -kHalfSquareSize, kHalfSquareSize, kHalfSquareSize }; |
| 187 | rect.offset(x, y); |
| 188 | |
skia.committer@gmail.com | 11f2b44 | 2013-06-04 07:00:53 +0000 | [diff] [blame] | 189 | SkRect outerClip = { |
| 190 | -kHalfOuterClipSize-kHalfSquareSize, -kHalfOuterClipSize-kHalfSquareSize, |
robertphillips@google.com | 4157085 | 2013-06-03 17:13:25 +0000 | [diff] [blame] | 191 | kHalfOuterClipSize+kHalfSquareSize, kHalfOuterClipSize+kHalfSquareSize |
| 192 | }; |
| 193 | outerClip.offset(x, y); |
| 194 | |
| 195 | SkPaint paint; |
| 196 | paint.setAntiAlias(true); |
commit-bot@chromium.org | ef284a8 | 2013-07-11 22:29:29 +0000 | [diff] [blame^] | 197 | paint.setLooper(create4Looper(-kOffsetToOutsideClip-kHalfSquareSize, 0))->unref(); |
robertphillips@google.com | 4157085 | 2013-06-03 17:13:25 +0000 | [diff] [blame] | 198 | |
| 199 | canvas->save(); |
| 200 | canvas->clipRect(outerClip, SkRegion::kIntersect_Op); |
| 201 | canvas->clipRect(rect, SkRegion::kDifference_Op); |
| 202 | |
| 203 | rect.offset(SkIntToScalar(kOffsetToOutsideClip+kHalfSquareSize), 0); |
| 204 | canvas->drawRect(rect, paint); |
| 205 | canvas->restore(); |
| 206 | } |
| 207 | |
| 208 | // Create a 4-tier draw looper |
| 209 | SkLayerDrawLooper* create4Looper(SkScalar xOff, SkScalar yOff) { |
| 210 | SkLayerDrawLooper* looper = new SkLayerDrawLooper; |
| 211 | SkLayerDrawLooper::LayerInfo info; |
| 212 | |
| 213 | info.fFlagsMask = 0; |
| 214 | info.fPaintBits = SkLayerDrawLooper::kColorFilter_Bit | |
| 215 | SkLayerDrawLooper::kMaskFilter_Bit; |
| 216 | info.fColorMode = SkXfermode::kSrc_Mode; |
| 217 | info.fPostTranslate = false; |
| 218 | |
| 219 | SkPaint* paint; |
| 220 | |
| 221 | for (int i = 3; i >= 0; --i) { |
| 222 | info.fOffset.set(xOff+gBlurOffsets[i].fX, yOff+gBlurOffsets[i].fY); |
| 223 | paint = looper->addLayer(info); |
| 224 | |
| 225 | paint->setMaskFilter(this->createBlur())->unref(); |
| 226 | |
| 227 | SkColorFilter* cf = SkColorFilter::CreateModeFilter(gColors[i], SkXfermode::kSrcIn_Mode); |
| 228 | paint->setColorFilter(cf)->unref(); |
| 229 | } |
| 230 | |
| 231 | return looper; |
| 232 | } |
| 233 | |
| 234 | typedef GM INHERITED; |
| 235 | }; |
| 236 | |
| 237 | const SkPoint MegaLooperGM::gBlurOffsets[4] = { |
skia.committer@gmail.com | 11f2b44 | 2013-06-04 07:00:53 +0000 | [diff] [blame] | 238 | { kHalfSquareSize, kHalfSquareSize }, |
| 239 | { -kHalfSquareSize, kHalfSquareSize }, |
| 240 | { kHalfSquareSize, -kHalfSquareSize }, |
robertphillips@google.com | 4157085 | 2013-06-03 17:13:25 +0000 | [diff] [blame] | 241 | { -kHalfSquareSize, -kHalfSquareSize } |
| 242 | }; |
| 243 | |
| 244 | const SkColor MegaLooperGM::gColors[4] = { |
| 245 | SK_ColorGREEN, SK_ColorYELLOW, SK_ColorBLUE, SK_ColorRED |
| 246 | }; |
| 247 | |
| 248 | DEF_GM( return new MegaLooperGM(MegaLooperGM::k0x0_Type); ) |
| 249 | DEF_GM( return new MegaLooperGM(MegaLooperGM::k4x1_Type); ) |
| 250 | DEF_GM( return new MegaLooperGM(MegaLooperGM::k1x4_Type); ) |