add new readPixels with direct memory parameters

bench/PremulAndUnpremulAlphaOpsBench.cpp

-/*
- * Copyright 2013 Google Inc.
- *
- * Use of this source code is governed by a BSD-style license that can be
- * found in the LICENSE file.
- */
-
-#include "SkBenchmark.h"
-#include "SkCanvas.h"
-#include "SkConfig8888.h"
-#include "SkString.h"
-#include "sk_tool_utils.h"
-
-class PremulAndUnpremulAlphaOpsBench : public SkBenchmark {

[bsalomon, 2014/03/17 18:19:47]

Removing this benchmark scares me a little bit. The GrContext read/write pixel
code that makes this fast is really tricky and easy to regress.

[reed1, 2014/03/17 18:47:09]

Restored and updated

-public:
-    PremulAndUnpremulAlphaOpsBench(SkCanvas::Config8888 config) {
-        fUnPremulConfig = config;
-        fName.printf("premul_and_unpremul_alpha_%s",
-                     (config ==  SkCanvas::kRGBA_Unpremul_Config8888) ?
-                     "RGBA8888" : "Native8888");
-    }
-
-protected:
-    virtual const char* onGetName() SK_OVERRIDE {
-        return fName.c_str();
-    }
-
-    virtual void onDraw(const int loops, SkCanvas* canvas) SK_OVERRIDE {
-        canvas->clear(SK_ColorBLACK);
-        SkISize size = canvas->getDeviceSize();
-
-        SkBitmap bmp1;
-        bmp1.setConfig(SkBitmap::kARGB_8888_Config, size.width(),
-                       size.height());
-        bmp1.allocPixels();
-        SkAutoLockPixels alp(bmp1);
-        uint32_t* pixels = reinterpret_cast<uint32_t*>(bmp1.getPixels());
-        for (int h = 0; h < size.height(); ++h) {
-            for (int w = 0; w < size.width(); ++w)
-                pixels[h * size.width() + w] = SkPackConfig8888(fUnPremulConfig,
-                    h & 0xFF, w & 0xFF, w & 0xFF, w & 0xFF);
-        }
-
-        SkBitmap bmp2;
-        bmp2.setConfig(SkBitmap::kARGB_8888_Config, size.width(),
-                       size.height());
-
-        SkColorType ct;
-        SkAlphaType at;
-        sk_tool_utils::config8888_to_imagetypes(fUnPremulConfig, &ct, &at);
-        if (bmp1.isOpaque()) {
-            at = kOpaque_SkAlphaType;
-        }
-
-        for (int loop = 0; loop < loops; ++loop) {
-            // Unpremul -> Premul
-            sk_tool_utils::write_pixels(canvas, bmp1, 0, 0, ct, at);
-            // Premul -> Unpremul
-            canvas->readPixels(&bmp2, 0, 0, fUnPremulConfig);
-        }
-    }
-
-private:
-    SkCanvas::Config8888 fUnPremulConfig;
-    SkString fName;
-    typedef SkBenchmark INHERITED;
-};
-
-
-DEF_BENCH(return new PremulAndUnpremulAlphaOpsBench(SkCanvas::kRGBA_Unpremul_Config8888));
-DEF_BENCH(return new PremulAndUnpremulAlphaOpsBench(SkCanvas::kNative_Unpremul_Config8888));