Index: gm/gamma.cpp |
diff --git a/gm/gamma.cpp b/gm/gamma.cpp |
new file mode 100644 |
index 0000000000000000000000000000000000000000..003061baebff4e66760e36c46b97f2676d626df5 |
--- /dev/null |
+++ b/gm/gamma.cpp |
@@ -0,0 +1,171 @@ |
+/* |
+ * 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(); |
+} |