skia2/docs/examples/Canvas_accessTopLayerPixels_b.cpp
Mike Klein c0bd9f9fe5 rewrite includes to not need so much -Ifoo
Current strategy: everything from the top

Things to look at first are the manual changes:

   - added tools/rewrite_includes.py
   - removed -Idirectives from BUILD.gn
   - various compile.sh simplifications
   - tweak tools/embed_resources.py
   - update gn/find_headers.py to write paths from the top
   - update gn/gn_to_bp.py SkUserConfig.h layout
     so that #include "include/config/SkUserConfig.h" always
     gets the header we want.

No-Presubmit: true
Change-Id: I73a4b181654e0e38d229bc456c0d0854bae3363e
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/209706
Commit-Queue: Mike Klein <mtklein@google.com>
Reviewed-by: Hal Canary <halcanary@google.com>
Reviewed-by: Brian Osman <brianosman@google.com>
Reviewed-by: Florin Malita <fmalita@chromium.org>
2019-04-24 16:27:11 +00:00

41 lines
1.3 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=a7ac9c21bbabcdeeca00f72a61cd0f3e
REG_FIDDLE(Canvas_accessTopLayerPixels_b, 256, 256, false, 0) {
void draw(SkCanvas* canvas) {
SkPaint paint;
SkFont font(nullptr, 100);
canvas->drawString("ABC", 20, 160, font, paint);
SkRect layerBounds = SkRect::MakeXYWH(32, 32, 192, 192);
canvas->saveLayerAlpha(&layerBounds, 128);
canvas->clear(SK_ColorWHITE);
canvas->drawString("DEF", 20, 160, font, paint);
SkImageInfo imageInfo;
size_t rowBytes;
SkIPoint origin;
uint32_t* access = (uint32_t*) canvas->accessTopLayerPixels(&imageInfo, &rowBytes, &origin);
if (access) {
int h = imageInfo.height();
int v = imageInfo.width();
int rowWords = rowBytes / sizeof(uint32_t);
for (int y = 0; y < h; ++y) {
int newY = (y - h / 2) * 2 + h / 2;
if (newY < 0 || newY >= h) {
continue;
}
for (int x = 0; x < v; ++x) {
int newX = (x - v / 2) * 2 + v / 2;
if (newX < 0 || newX >= v) {
continue;
}
if (access[y * rowWords + x] == SK_ColorBLACK) {
access[newY * rowWords + newX] = SK_ColorGRAY;
}
}
}
}
canvas->restore();
}
} // END FIDDLE