| // 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=092739b4cd5d732a27c07ced8ef45f01 |
| REG_FIDDLE(Bitmap_extractAlpha_2, 256, 160, false, 0) { |
| void draw(SkCanvas* canvas) { |
| auto radiusToSigma = [](SkScalar radius) -> SkScalar { |
| static const SkScalar kBLUR_SIGMA_SCALE = 0.57735f; |
| return radius > 0 ? kBLUR_SIGMA_SCALE * radius + 0.5f : 0.0f; |
| }; |
| SkBitmap alpha, bitmap; |
| bitmap.allocN32Pixels(100, 100); |
| SkCanvas offscreen(bitmap); |
| offscreen.clear(0); |
| SkPaint paint; |
| paint.setAntiAlias(true); |
| paint.setColor(SK_ColorBLUE); |
| paint.setStyle(SkPaint::kStroke_Style); |
| paint.setStrokeWidth(20); |
| offscreen.drawCircle(50, 50, 39, paint); |
| paint.setMaskFilter(SkMaskFilter::MakeBlur(kNormal_SkBlurStyle, radiusToSigma(25))); |
| SkIPoint offset; |
| bitmap.extractAlpha(&alpha, &paint, &offset); |
| paint.setColor(SK_ColorRED); |
| canvas->drawImage(bitmap.asImage(), 0, -offset.fY, SkSamplingOptions(), &paint); |
| canvas->drawImage(alpha.asImage(), 100 + offset.fX, 0, SkSamplingOptions(), &paint); |
| } |
| } // END FIDDLE |