/* * 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 "gm.h" #include "Resources.h" #include "SkGradientShader.h" DEF_SIMPLE_GM(gamma, canvas, 500, 200) { SkPaint p; const SkScalar sz = 50.0f; const int szInt = SkScalarTruncToInt(sz); const SkScalar tx = sz + 5.0f; const SkRect r = SkRect::MakeXYWH(0, 0, sz, sz); SkShader::TileMode rpt = SkShader::kRepeat_TileMode; SkBitmap ditherBmp; ditherBmp.allocN32Pixels(2, 2); SkPMColor* pixels = reinterpret_cast<SkPMColor*>(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, kLinear_SkColorProfileType); linearGreyBmp.allocPixels(linearGreyInfo); linearGreyBmp.eraseARGB(0xFF, 0x7F, 0x7F, 0x7F); SkBitmap srgbGreyBmp; SkImageInfo srgbGreyInfo = SkImageInfo::MakeN32(szInt, szInt, kOpaque_SkAlphaType, kSRGB_SkColorProfileType); srgbGreyBmp.allocPixels(srgbGreyInfo); srgbGreyBmp.eraseARGB(0xFF, 0xBC, 0xBC, 0xBC); SkPaint textPaint; textPaint.setColor(SK_ColorWHITE); // Helpers: auto advance = [&]() { canvas->translate(tx, 0); p.reset(); }; auto nextRect = [&](const char* label, const char* label2) { canvas->drawRect(r, p); canvas->drawText(label, strlen(label), 0, sz + textPaint.getFontSpacing(), textPaint); if (label2) { canvas->drawText(label2, strlen(label2), 0, sz + 2 * textPaint.getFontSpacing(), textPaint); } advance(); }; auto nextBitmap = [&](const SkBitmap& bmp, const char* label) { canvas->drawBitmap(bmp, 0, 0); canvas->drawText(label, strlen(label), 0, sz + textPaint.getFontSpacing(), textPaint); advance(); }; auto nextXferRect = [&](SkColor srcColor, SkXfermode::Mode mode, SkColor dstColor) { p.setColor(dstColor); canvas->drawRect(r, p); p.setColor(srcColor); p.setXfermodeMode(mode); canvas->drawRect(r, p); SkString srcText = SkStringPrintf("%08X", srcColor); SkString dstText = SkStringPrintf("%08X", dstColor); canvas->drawText(srcText.c_str(), srcText.size(), 0, sz + textPaint.getFontSpacing(), textPaint); const char* modeName = SkXfermode::ModeName(mode); canvas->drawText(modeName, strlen(modeName), 0, sz + 2 * textPaint.getFontSpacing(), textPaint); canvas->drawText(dstText.c_str(), dstText.size(), 0, sz + 3 * textPaint.getFontSpacing(), textPaint); 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::CreateBitmapShader( ditherBmp, rpt, rpt))->unref(); 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::CreateBitmapShader( ditherBmp, rpt, rpt, &offsetMatrix))->unref(); 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::CreateBitmapShader( ditherBmp, rpt, rpt, &scaleMatrix))->unref(); p.setFilterQuality(SkFilterQuality::kMedium_SkFilterQuality); nextRect("Dither", "Scale"); // 50% grey via paint color. p.setColor(0xff7f7f7f); nextRect("Color", 0); // 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::CreateLinear( points, colors, nullptr, 2, SkShader::kClamp_TileMode))->unref(); nextRect("Gradient", 0); // 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::CreateBitmapShader(linearGreyBmp, rpt, rpt))->unref(); p.setFilterQuality(SkFilterQuality::kMedium_SkFilterQuality); nextRect("Lnr BMP", "Shader"); // Bitmap wrapped in a shader (sRGB): p.setShader(SkShader::CreateBitmapShader(srgbGreyBmp, rpt, rpt))->unref(); p.setFilterQuality(SkFilterQuality::kMedium_SkFilterQuality); nextRect("sRGB BMP", "Shader"); // Carriage return. canvas->restore(); canvas->translate(0, 2 * sz); const U8CPU sqrtHalf = 0xB4; const SkColor sqrtHalfAlpha = SkColorSetARGB(sqrtHalf, 0, 0, 0); const SkColor sqrtHalfWhite = SkColorSetARGB(0xFF, sqrtHalf, sqrtHalf, sqrtHalf); // Xfermode tests, all done off-screen so certain modes work... canvas->saveLayer(nullptr, nullptr); nextXferRect(0x7fffffff, SkXfermode::kSrcOver_Mode, SK_ColorBLACK); nextXferRect(0x7f000000, SkXfermode::kSrcOver_Mode, SK_ColorWHITE); nextXferRect(SK_ColorBLACK, SkXfermode::kDstOver_Mode, 0x7fffffff); nextXferRect(SK_ColorWHITE, SkXfermode::kSrcIn_Mode, 0x7fff00ff); nextXferRect(0x7fff00ff, SkXfermode::kDstIn_Mode, SK_ColorWHITE); nextXferRect(sqrtHalfWhite, SkXfermode::kSrcIn_Mode, sqrtHalfAlpha); nextXferRect(sqrtHalfAlpha, SkXfermode::kDstIn_Mode, sqrtHalfWhite); nextXferRect(0xff3f3f3f, SkXfermode::kPlus_Mode, 0xff3f3f3f); nextXferRect(sqrtHalfWhite, SkXfermode::kModulate_Mode, sqrtHalfWhite); canvas->restore(); canvas->restore(); }