Revert of New GM that exercises gamma-correctness in various parts of the pipeline.

gm/gamma.cpp

-/*
- * 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 Xfermodes to work:
-    canvas->clear(SK_ColorTRANSPARENT);
-
-    // *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.
-    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();
-}