| /* |
| * Copyright 2014 Google Inc. |
| * |
| * Use of this source code is governed by a BSD-style license that can be |
| * found in the LICENSE file. |
| */ |
| |
| #include "gm/gm.h" |
| #include "include/core/SkCanvas.h" |
| #include "include/core/SkColor.h" |
| #include "include/core/SkFont.h" |
| #include "include/core/SkFontStyle.h" |
| #include "include/core/SkImage.h" |
| #include "include/core/SkPaint.h" |
| #include "include/core/SkRefCnt.h" |
| #include "include/core/SkScalar.h" |
| #include "include/core/SkTypeface.h" |
| #include "include/core/SkTypes.h" |
| #include "tools/Resources.h" |
| #include "tools/ToolUtils.h" |
| |
| static void draw_image(SkCanvas* canvas, const char* resource, int x, int y) { |
| sk_sp<SkImage> image(GetResourceAsImage(resource)); |
| if (image) { |
| canvas->drawImage(image, SkIntToScalar(x), SkIntToScalar(y)); |
| } else { |
| SkDebugf("\nCould not decode file '%s'. Did you forget" |
| " to set the resourcePath?\n", resource); |
| } |
| } |
| |
| /* |
| This GM tests whether the image decoders properly decode each color |
| channel. Four copies of the same image should appear in the GM, and |
| the letter R should be red, B should be blue, G green, C cyan, M |
| magenta, Y yellow, and K black. In all but the JPEG version of the |
| image, the letters should be on a white disc on a transparent |
| background (rendered as a checkerboard). The JPEG image has a grey |
| background and compression artifacts. |
| */ |
| DEF_SIMPLE_GM(colorwheel, canvas, 256, 256) { |
| ToolUtils::draw_checkerboard(canvas); |
| draw_image(canvas, "images/color_wheel.png", 0, 0); // top left |
| draw_image(canvas, "images/color_wheel.gif", 128, 0); // top right |
| draw_image(canvas, "images/color_wheel.webp", 0, 128); // bottom left |
| draw_image(canvas, "images/color_wheel.jpg", 128, 128); // bottom right |
| } |
| |
| DEF_SIMPLE_GM(colorwheelnative, canvas, 128, 28) { |
| SkFont font(ToolUtils::create_portable_typeface("sans-serif", SkFontStyle::Bold()), 18); |
| font.setEdging(SkFont::Edging::kAlias); |
| |
| canvas->clear(SK_ColorLTGRAY); |
| canvas->drawString("R", 8.0f, 20.0f, font, SkPaint(SkColors::kRed)); |
| canvas->drawString("G", 24.0f, 20.0f, font, SkPaint(SkColors::kGreen)); |
| canvas->drawString("B", 40.0f, 20.0f, font, SkPaint(SkColors::kBlue)); |
| canvas->drawString("C", 56.0f, 20.0f, font, SkPaint(SkColors::kCyan)); |
| canvas->drawString("M", 72.0f, 20.0f, font, SkPaint(SkColors::kMagenta)); |
| canvas->drawString("Y", 88.0f, 20.0f, font, SkPaint(SkColors::kYellow)); |
| canvas->drawString("K", 104.0f, 20.0f, font, SkPaint(SkColors::kBlack)); |
| } |
| |
| /** |
| * This GM tests decoding images with non-default (overridden) alpha types. |
| */ |
| DEF_SIMPLE_GM(colorwheel_alphatypes, canvas, 256, 128) { |
| canvas->clear(SK_ColorWHITE); |
| |
| sk_sp<SkData> imgData = GetResourceAsData("images/color_wheel.png"); |
| |
| auto pmImg = ToolUtils::MakeTextureImage( |
| canvas, SkImages::DeferredFromEncodedData(imgData, kPremul_SkAlphaType)); |
| auto upmImg = ToolUtils::MakeTextureImage( |
| canvas, SkImages::DeferredFromEncodedData(imgData, kUnpremul_SkAlphaType)); |
| |
| SkSamplingOptions linear{SkFilterMode::kLinear}; |
| |
| // We draw a tiny (8x8) section of the image that falls right on the edge of transparency, |
| // and blow it up so we can really see the impact of filtering in premul or unpremul. |
| SkRect srcRect = SkRect::MakeXYWH(12, 102, 8, 8); |
| SkRect dstRect = SkRect::MakeLTRB(0, 0, 128, 128); |
| |
| // First, we draw the normal (premul-then-filter) image, which looks good. The yellow image |
| // transitions to the white background like you'd expect. |
| canvas->drawImageRect(pmImg, srcRect, dstRect, |
| linear, nullptr, SkCanvas::kFast_SrcRectConstraint); |
| // Next, we draw the unpremul (filter-then-premul) image, which looks bad. Filtering in unpremul |
| // causes the implicit black of the transparent pixels to be bleed into the filtered edge, |
| // creating a dark "fringe" at the boundary between the yellow image and white background. |
| canvas->drawImageRect(upmImg, srcRect, dstRect.makeOffset(128, 0), |
| linear, nullptr, SkCanvas::kFast_SrcRectConstraint); |
| } |