/* * Copyright 2015 Google Inc. * * Use of this source code is governed by a BSD-style license that can be * found in the LICENSE file. */ #include "ToolUtils.h" #include "gm.h" #include "Resources.h" #include "SkBlendModePriv.h" #include "SkGradientShader.h" DEF_SIMPLE_GM(gamma, canvas, 850, 200) { SkPaint p; const SkScalar sz = 50.0f; const int szInt = SkScalarTruncToInt(sz); const SkScalar tx = sz + 15.0f; const SkRect r = SkRect::MakeXYWH(0, 0, sz, sz); SkShader::TileMode rpt = SkShader::kRepeat_TileMode; auto srgbColorSpace = SkColorSpace::MakeSRGB(); SkBitmap ditherBmp; ditherBmp.allocN32Pixels(2, 2); SkPMColor* pixels = reinterpret_cast(ditherBmp.getPixels()); pixels[0] = pixels[3] = SkPackARGB32(0xFF, 0xFF, 0xFF, 0xFF); pixels[1] = pixels[2] = SkPackARGB32(0xFF, 0, 0, 0); SkBitmap linearGreyBmp; SkImageInfo linearGreyInfo = SkImageInfo::MakeN32(szInt, szInt, kOpaque_SkAlphaType, nullptr); linearGreyBmp.allocPixels(linearGreyInfo); linearGreyBmp.eraseARGB(0xFF, 0x7F, 0x7F, 0x7F); SkBitmap srgbGreyBmp; SkImageInfo srgbGreyInfo = SkImageInfo::MakeN32(szInt, szInt, kOpaque_SkAlphaType, srgbColorSpace); srgbGreyBmp.allocPixels(srgbGreyInfo); // 0xBC = 255 * linear_to_srgb(0.5f) srgbGreyBmp.eraseARGB(0xFF, 0xBC, 0xBC, 0xBC); SkBitmap mipmapBmp; SkImageInfo mipmapInfo = SkImageInfo::Make(2, 2, kN32_SkColorType, kOpaque_SkAlphaType, srgbColorSpace); mipmapBmp.allocPixels(mipmapInfo); SkPMColor* mipmapPixels = reinterpret_cast(mipmapBmp.getPixels()); unsigned s25 = 0x89; // 255 * linear_to_srgb(0.25f) unsigned s75 = 0xE1; // 255 * linear_to_srgb(0.75f) mipmapPixels[0] = mipmapPixels[3] = SkPackARGB32(0xFF, s25, s25, s25); mipmapPixels[1] = mipmapPixels[2] = SkPackARGB32(0xFF, s75, s75, s75); SkFont font(ToolUtils::create_portable_typeface()); SkPaint textPaint; textPaint.setAntiAlias(true); textPaint.setColor(SK_ColorWHITE); // Helpers: auto advance = [&]() { canvas->translate(tx, 0); p.reset(); }; auto drawString = [&](const char str[], SkScalar x, SkScalar y) { canvas->drawSimpleText(str, strlen(str), kUTF8_SkTextEncoding, x, y, font, textPaint); }; auto nextRect = [&](const char* label, const char* label2) { canvas->drawRect(r, p); drawString(label, 0, sz + font.getSpacing()); if (label2) { drawString(label2, 0, sz + 2 * font.getSpacing()); } advance(); }; auto nextBitmap = [&](const SkBitmap& bmp, const char* label) { canvas->drawBitmap(bmp, 0, 0); drawString(label, 0, sz + font.getSpacing()); advance(); }; auto nextXferRect = [&](SkColor srcColor, SkBlendMode mode, SkColor dstColor) { p.setColor(dstColor); canvas->drawRect(r, p); p.setColor(srcColor); p.setBlendMode(mode); canvas->drawRect(r, p); SkString srcText = SkStringPrintf("%08X", srcColor); SkString dstText = SkStringPrintf("%08X", dstColor); drawString(srcText.c_str(), 0, sz + font.getSpacing()); const char* modeName = SkBlendMode_Name(mode); drawString(modeName, 0, sz + 2 * font.getSpacing()); drawString(dstText.c_str(), 0, sz + 3 * font.getSpacing()); advance(); }; // Necessary for certain Xfermode tests to work (ie some of them output white @ 50% alpha): canvas->clear(SK_ColorBLACK); // *Everything* should be perceptually 50% grey. Only the first rectangle // is guaranteed to draw that way, though. canvas->save(); // Black/white dither, pixel perfect. This is ground truth. p.setShader(SkShader::MakeBitmapShader(ditherBmp, rpt, rpt)); p.setFilterQuality(SkFilterQuality::kNone_SkFilterQuality); nextRect("Dither", "Reference"); // Black/white dither, sampled at half-texel offset. Tests bilerp. // NOTE: We need to apply a non-identity scale and/or rotation to trick // the raster pipeline into *not* snapping to nearest. SkMatrix offsetMatrix = SkMatrix::Concat( SkMatrix::MakeScale(-1.0f), SkMatrix::MakeTrans(0.5f, 0.0f)); p.setShader(SkShader::MakeBitmapShader(ditherBmp, rpt, rpt, &offsetMatrix)); p.setFilterQuality(SkFilterQuality::kMedium_SkFilterQuality); nextRect("Dither", "Bilerp"); // Black/white dither, scaled down by 2x. Tests minification. SkMatrix scaleMatrix = SkMatrix::MakeScale(0.5f); p.setShader(SkShader::MakeBitmapShader(ditherBmp, rpt, rpt, &scaleMatrix)); p.setFilterQuality(SkFilterQuality::kMedium_SkFilterQuality); nextRect("Dither", "Scale"); // 25%/75% dither, scaled down by 2x. Tests ALL aspects of minification. Specifically, are // sRGB sources decoded to linear before computing mipmaps? p.setShader(SkShader::MakeBitmapShader(mipmapBmp, rpt, rpt, &scaleMatrix)); p.setFilterQuality(SkFilterQuality::kMedium_SkFilterQuality); nextRect("MipMaps", nullptr); // 50% grey via paint color. Paint color (SkColor) is specified to be sRGB! p.setColor(0xffbcbcbc); nextRect("Color", nullptr); { // Black -> White gradient, scaled to sample just the middle. // Tests gradient interpolation. SkPoint points[2] = { SkPoint::Make(0 - (sz * 10), 0), SkPoint::Make(sz + (sz * 10), 0) }; SkColor colors[2] = { SK_ColorBLACK, SK_ColorWHITE }; p.setShader(SkGradientShader::MakeLinear(points, colors, nullptr, 2, SkShader::kClamp_TileMode)); nextRect("Gradient", "Interpolation"); } { // Shallow gradient around 50% (perceptual) gray. Endpoints are SkColor, so sRGB. // Tests gamma-correction of gradient stops before interpolation in two-stop case SkPoint points[2] = { SkPoint::Make(0, 0), SkPoint::Make(sz, 0) }; SkColor colors[2] = { 0xffbbbbbb, 0xffbdbdbd }; p.setShader(SkGradientShader::MakeLinear(points, colors, nullptr, 2, SkShader::kClamp_TileMode)); nextRect("Gradient", "Endpoints"); } { // Shallow 3-stop gradient around 50% (perceptual) gray. Endpoints are SkColor, so sRGB. // Tests gamma-correction of gradient stops before interpolation in three-stop case SkPoint points[2] = { SkPoint::Make(0, 0), SkPoint::Make(sz, 0) }; SkColor colors[3] = { 0xffbbbbbb, 0xffbdbdbd, 0xffbbbbbb }; p.setShader(SkGradientShader::MakeLinear(points, colors, nullptr, 3, SkShader::kClamp_TileMode)); nextRect("Gradient", "3-Stop"); } { // Shallow N-stop gradient around 50% (perceptual) gray. Endpoints are SkColor, so sRGB. // Tests gamma-correction of gradient stops before interpolation in texture implementation SkPoint points[2] = { SkPoint::Make(0, 0), SkPoint::Make(sz, 0) }; SkColor colors[5] = { 0xffbbbbbb, 0xffbdbdbd, 0xffbbbbbb, 0xffbdbdbd, 0xffbbbbbb }; p.setShader(SkGradientShader::MakeLinear(points, colors, nullptr, 5, SkShader::kClamp_TileMode)); nextRect("Gradient", "Texture"); } // 50% grey from linear bitmap, with drawBitmap nextBitmap(linearGreyBmp, "Lnr BMP"); // 50% grey from sRGB bitmap, with drawBitmap nextBitmap(srgbGreyBmp, "sRGB BMP"); // Bitmap wrapped in a shader (linear): p.setShader(SkShader::MakeBitmapShader(linearGreyBmp, rpt, rpt)); p.setFilterQuality(SkFilterQuality::kMedium_SkFilterQuality); nextRect("Lnr BMP", "Shader"); // Bitmap wrapped in a shader (sRGB): p.setShader(SkShader::MakeBitmapShader(srgbGreyBmp, rpt, rpt)); p.setFilterQuality(SkFilterQuality::kMedium_SkFilterQuality); nextRect("sRGB BMP", "Shader"); // Carriage return. canvas->restore(); canvas->translate(0, 2 * sz); // Xfermode tests, all done off-screen so certain modes work... canvas->saveLayer(nullptr, nullptr); nextXferRect(0x7fffffff, SkBlendMode::kSrcOver, SK_ColorBLACK); nextXferRect(0x7f000000, SkBlendMode::kSrcOver, SK_ColorWHITE); nextXferRect(SK_ColorBLACK, SkBlendMode::kDstOver, 0x7fffffff); nextXferRect(SK_ColorWHITE, SkBlendMode::kSrcIn, 0x7fff00ff); nextXferRect(0x7fff00ff, SkBlendMode::kDstIn, SK_ColorWHITE); // 0x89 = 255 * linear_to_srgb(0.25) nextXferRect(0xff898989, SkBlendMode::kPlus, 0xff898989); // 0xDB = 255 * linear_to_srgb(sqrt(0.5)) nextXferRect(0xffdbdbdb, SkBlendMode::kModulate, 0xffdbdbdb); canvas->restore(); }