Alpha_Constants_a.cpp File Reference

#include "tools/fiddle/examples.h"

Go to the source code of this file.

Functions
	REG_FIDDLE (Alpha_Constants_a, 256, 128, false, 1)

Function Documentation

REG_FIDDLE()

REG_FIDDLE	(	Alpha_Constants_a	,
		256	,
		128	,
		false	,
		1
	)

Definition at line 4 of file Alpha_Constants_a.cpp.

                                                  {
void draw(SkCanvas* canvas) {
    std::vector<int32_t> srcPixels;
    srcPixels.resize(source.height() * source.rowBytes());
    SkPixmap pixmap(SkImageInfo::MakeN32Premul(source.width(), source.height()),
                    &srcPixels.front(), source.rowBytes());
    source.readPixels(pixmap, 0, 0);
    for (int y = 0; y < 16; ++y) {
        for (int x = 0; x < 16; ++x) {
            int32_t* blockStart = &srcPixels.front() + y * source.width() * 16 + x * 16;
            size_t transparentCount = 0;
            for (int fillY = 0; fillY < source.height() / 16; ++fillY) {
                for (int fillX = 0; fillX < source.width() / 16; ++fillX) {
                    const SkColor color = SkUnPreMultiply::PMColorToColor(blockStart[fillX]);
                    transparentCount += SkColorGetA(color) == SK_AlphaTRANSPARENT;
                }
                blockStart += source.width();
            }
            if (transparentCount > 200) {
                blockStart = &srcPixels.front() + y * source.width() * 16 + x * 16;
                for (int fillY = 0; fillY < source.height() / 16; ++fillY) {
                    for (int fillX = 0; fillX < source.width() / 16; ++fillX) {
                        blockStart[fillX] = SK_ColorRED;
                    }
                    blockStart += source.width();
                }
            }
        }
    }
    canvas->drawImage(SkImages::RasterFromPixmapCopy(pixmap), 0, 0);
}
}  // END FIDDLE