skia2/docs/examples/Alpha_Constants_b.cpp
Mike Reed 34a0c97f5e don't use drawBitmap
Bug: skia:11216
Change-Id: I89a40e330f27f30c461f2b6012bf26c082b66094
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/359076
Reviewed-by: Mike Reed <reed@google.com>
Commit-Queue: Mike Reed <reed@google.com>
2021-01-26 02:24:21 +00:00

24 lines
1.0 KiB
C++

// Copyright 2019 Google LLC.
// Use of this source code is governed by a BSD-style license that can be found in the LICENSE file.
#include "tools/fiddle/examples.h"
// HASH=0424f67ebc2858e8fd04ae3367b115ff
REG_FIDDLE(Alpha_Constants_b, 256, 128, false, 1) {
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 < source.height(); ++y) {
for (int x = 0; x < source.width(); ++x) {
SkPMColor pixel = srcPixels[y * source.width() + x];
const SkColor color = SkUnPreMultiply::PMColorToColor(pixel);
if (SkColorGetA(color) == SK_AlphaOPAQUE) {
srcPixels[y * source.width() + x] = SK_ColorGREEN;
}
}
}
canvas->drawImage(SkImage::MakeRasterCopy(pixmap), 0, 0);
}
} // END FIDDLE