1 /* 2 * Copyright 2022 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/gm.h" 9 #include "include/core/SkCanvas.h" 10 #include "include/core/SkImage.h" 11 #include "include/core/SkPaint.h" 12 #include "include/core/SkPixmap.h" 13 #include "include/core/SkShader.h" 14 #include "include/core/SkSurface.h" 15 #include "include/core/SkTileMode.h" 16 17 /** 18 * Tests image shader mirror tile mode with scale factors of 1 and -1, with nearest and linear 19 * filtering, and with/without a half pixel offset between device and image space. The linear filter 20 * should only have an effect when there is a half pixel offset. We test mirror tile mode in x and 21 * in y separately. 22 */ 23 DEF_SIMPLE_GM_CAN_FAIL(mirror_tile, canvas, errorMsg, 140, 370) { 24 // We don't run this test on the GPU because we're at the driver/hw's mercy for how this 25 // is handled. We also don't test this on recording or vector canvases. 26 if (SkPixmap unused; !canvas->peekPixels(&unused)) { 27 *errorMsg = "Test only works with canvases backed by CPU pixels"; 28 return skiagm::DrawResult::kSkip; 29 } 30 31 uint32_t colors[] {0xFFFF0000, 0xFF00FF00, 0xFF0000FF}; 32 SkPixmap pmx(SkImageInfo::Make({std::size(colors), 1}, 33 kRGBA_8888_SkColorType, 34 kPremul_SkAlphaType), 35 colors, 36 sizeof(colors)); 37 auto imgx = SkImage::MakeRasterCopy(pmx); 38 39 SkPixmap pmy(SkImageInfo::Make({1, std::size(colors)}, 40 kRGBA_8888_SkColorType, 41 kPremul_SkAlphaType), 42 colors, 43 sizeof(colors[0])); 44 auto imgy = SkImage::MakeRasterCopy(pmy); 45 46 // We draw offscreen and then zoom that up to make the result clear. 47 auto surf = canvas->makeSurface(canvas->imageInfo().makeWH(80, 80)); 48 SkASSERT(surf); 49 auto* c = surf->getCanvas(); 50 c->clear(SK_ColorWHITE); 51 52 for (bool offset : {false, true}) { 53 for (SkFilterMode fm : {SkFilterMode::kNearest, SkFilterMode::kLinear}) { 54 SkPaint paint; 55 56 // Draw single row image with mirror tiling in x and clamped in y. 57 paint.setShader(imgx->makeShader(SkTileMode::kMirror, 58 SkTileMode::kClamp, 59 SkSamplingOptions{fm})); 60 c->save(); 61 c->translate(imgx->width(), 0); 62 if (offset) { 63 c->translate(0.5, 0); 64 } 65 c->drawRect(SkRect::MakeXYWH(-imgx->width(), 0, 3*imgx->width(), 5), paint); 66 c->restore(); 67 68 // Draw single column image with mirror tiling in y and clamped in x. 69 paint.setShader(imgy->makeShader(SkTileMode::kClamp, 70 SkTileMode::kMirror, 71 SkSamplingOptions{fm})); 72 c->save(); 73 c->translate(3*imgx->width() + 3, imgy->height()); 74 if (offset) { 75 c->translate(0, 0.5); 76 } 77 c->drawRect(SkRect::MakeXYWH(0, -imgy->height(), 5, 3*imgy->height()), paint); 78 c->restore(); 79 80 c->translate(0, 3*imgy->height() + 3); 81 } 82 } 83 84 canvas->scale(8, 8); 85 canvas->drawImage(surf->makeImageSnapshot(), 0, 0); 86 return skiagm::DrawResult::kOk; 87 } 88