1 // Copyright 2019 Google LLC.
2 // Use of this source code is governed by a BSD-style license that can be found in the LICENSE file.
3 #include "tools/fiddle/examples.h"
4 REG_FIDDLE(Canvas_accessTopLayerPixels_b, 256, 256, false, 0) {
draw(SkCanvas * canvas)5 void draw(SkCanvas* canvas) {
6 SkPaint paint;
7 SkFont font(fontMgr->matchFamilyStyle(nullptr, {}), 100);
8 canvas->drawString("ABC", 20, 160, font, paint);
9 SkRect layerBounds = SkRect::MakeXYWH(32, 32, 192, 192);
10 canvas->saveLayerAlpha(&layerBounds, 128);
11 canvas->clear(SK_ColorWHITE);
12 canvas->drawString("DEF", 20, 160, font, paint);
13 SkImageInfo imageInfo;
14 size_t rowBytes;
15 SkIPoint origin;
16 uint32_t* access = (uint32_t*) canvas->accessTopLayerPixels(&imageInfo, &rowBytes, &origin);
17 if (access) {
18 int h = imageInfo.height();
19 int v = imageInfo.width();
20 int rowWords = rowBytes / sizeof(uint32_t);
21 for (int y = 0; y < h; ++y) {
22 int newY = (y - h / 2) * 2 + h / 2;
23 if (newY < 0 || newY >= h) {
24 continue;
25 }
26 for (int x = 0; x < v; ++x) {
27 int newX = (x - v / 2) * 2 + v / 2;
28 if (newX < 0 || newX >= v) {
29 continue;
30 }
31 if (access[y * rowWords + x] == SK_ColorBLACK) {
32 access[newY * rowWords + newX] = SK_ColorGRAY;
33 }
34 }
35 }
36 }
37 canvas->restore();
38 }
39 } // END FIDDLE
40