robertphillips | a408c8f | 2016-07-28 09:20:33 -0700 | [diff] [blame] | 1 | /* |
| 2 | * Copyright 2016 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 "SkGammaColorFilter.h" |
| 10 | #include "SkImage.h" |
| 11 | |
| 12 | // Fill a width x height block with a horizontal ramp from 0 to 255 |
| 13 | static void draw_grey_ramp(SkCanvas* canvas, int width, int height, int numSteps) { |
| 14 | int greyPerStep = SkScalarRoundToInt(255.0f / numSteps); |
| 15 | int widthPerStep = SkScalarRoundToInt(width / SkIntToScalar(numSteps)); |
| 16 | |
| 17 | SkIRect rect = SkIRect::MakeWH(widthPerStep, height); |
| 18 | |
| 19 | SkPaint paint; |
| 20 | int grey = 0; |
| 21 | int x = 0; |
| 22 | for (int i = 0; i < numSteps-1; ++i) { |
| 23 | paint.setColor(SkColorSetARGB(255, grey, grey, grey)); |
| 24 | |
| 25 | rect.offsetTo(x, 0); |
| 26 | canvas->drawRect(SkRect::Make(rect), paint); |
| 27 | |
| 28 | x += widthPerStep; |
| 29 | grey += greyPerStep; |
| 30 | } |
| 31 | |
| 32 | paint.setColor(SK_ColorWHITE); |
| 33 | rect.setLTRB(x, 0, width, height); |
| 34 | canvas->drawRect(SkRect::Make(rect), paint); |
| 35 | } |
| 36 | |
| 37 | static sk_sp<SkImage> create_grey_ramp(int width, int height, int numSteps) { |
| 38 | SkBitmap bm; |
| 39 | bm.allocN32Pixels(width, height); |
| 40 | SkCanvas canvas(bm); |
| 41 | canvas.clear(0x0); |
| 42 | |
| 43 | draw_grey_ramp(&canvas, width, height, numSteps); |
| 44 | |
| 45 | return SkImage::MakeFromBitmap(bm); |
| 46 | } |
| 47 | |
| 48 | namespace skiagm { |
| 49 | |
| 50 | class GammaColorFilterGM : public GM { |
| 51 | public: |
| 52 | GammaColorFilterGM() { |
| 53 | this->setBGColor(SK_ColorBLACK); |
| 54 | } |
| 55 | |
| 56 | protected: |
| 57 | |
| 58 | SkString onShortName() override { |
| 59 | return SkString("gammacolorfilter"); |
| 60 | } |
| 61 | |
| 62 | SkISize onISize() override { |
| 63 | return SkISize::Make(4 * kCellWidth, kCellHeight); |
| 64 | } |
| 65 | |
| 66 | void onDraw(SkCanvas* canvas) override { |
Brian Osman | 1105224 | 2016-10-27 14:47:55 -0400 | [diff] [blame] | 67 | GrRenderTargetContext* renderTargetContext = |
| 68 | canvas->internal_private_accessTopLayerRenderTargetContext(); |
| 69 | if (!renderTargetContext) { |
robertphillips | a408c8f | 2016-07-28 09:20:33 -0700 | [diff] [blame] | 70 | skiagm::GM::DrawGpuOnlyMessage(canvas); |
| 71 | return; |
| 72 | } |
| 73 | |
| 74 | sk_sp<SkImage> image(create_grey_ramp(kCellWidth, kCellHeight/2, kNumGreySteps)); |
| 75 | |
| 76 | // Leftmost is a non-gamma pair |
| 77 | draw_grey_ramp(canvas, kCellWidth, kCellHeight/2, kNumGreySteps); |
| 78 | canvas->drawImage(image, 0, kCellHeight/2); |
| 79 | canvas->translate(SkIntToScalar(image->width()), 0); |
| 80 | |
| 81 | for (auto gamma : { 1.0f, 1.0f / 1.8f, 1.0f / 2.2f }) { |
| 82 | SkPaint paint; |
| 83 | paint.setColorFilter(SkGammaColorFilter::Make(gamma)); |
| 84 | |
| 85 | draw_grey_ramp(canvas, kCellWidth, kCellHeight/2, kNumGreySteps); |
| 86 | canvas->drawImage(image, 0, kCellHeight/2, &paint); |
| 87 | canvas->translate(SkIntToScalar(image->width()), 0); |
| 88 | } |
| 89 | } |
| 90 | |
| 91 | private: |
mtklein | dbfd7ab | 2016-09-01 11:24:54 -0700 | [diff] [blame] | 92 | static constexpr int kCellWidth = 64; |
| 93 | static constexpr int kCellHeight = 64; |
| 94 | static constexpr int kNumGreySteps = 16; |
robertphillips | a408c8f | 2016-07-28 09:20:33 -0700 | [diff] [blame] | 95 | |
| 96 | typedef GM INHERITED; |
| 97 | }; |
| 98 | |
| 99 | ////////////////////////////////////////////////////////////////////////////// |
| 100 | |
| 101 | DEF_GM(return new GammaColorFilterGM;) |
| 102 | } |