1 /*
2  * Copyright 2013 Google Inc.
3  *
4  * Use of this source code is governed by a BSD-style license that can be
5  * found in the LICENSE file.
6  */
7 
8 #ifndef SkGpuBlurUtils_DEFINED
9 #define SkGpuBlurUtils_DEFINED
10 
11 #if SK_SUPPORT_GPU
12 #include "GrRenderTargetContext.h"
13 #include "effects/GrTextureDomain.h"
14 
15 class GrContext;
16 class GrTexture;
17 
18 struct SkRect;
19 
20 namespace SkGpuBlurUtils {
21   /**
22     * Applies a 2D Gaussian blur to a given texture. The blurred result is returned
23     * as a renderTargetContext in case the caller wishes to future draw into the result.
24     * Note: one of sigmaX and sigmaY should be non-zero!
25     * @param context         The GPU context
26     * @param src             The source to be blurred.
27     * @param colorSpace      Color space of the source (used for the renderTargetContext result,
28     *                        too).
29     * @param dstBounds       The destination bounds, relative to the source texture.
30     * @param srcBounds       The source bounds, relative to the source texture. If non-null,
31     *                        no pixels will be sampled outside of this rectangle.
32     * @param sigmaX          The blur's standard deviation in X.
33     * @param sigmaY          The blur's standard deviation in Y.
34     * @param mode            The mode to handle samples outside bounds.
35     * @param fit             backing fit for the returned render target context
36     * @return                The renderTargetContext containing the blurred result.
37     */
38     sk_sp<GrRenderTargetContext> GaussianBlur(
39             GrRecordingContext* context,
40             sk_sp<GrTextureProxy> src,
41             sk_sp<SkColorSpace> colorSpace,
42             const SkIRect& dstBounds,
43             const SkIRect& srcBounds,
44             float sigmaX,
45             float sigmaY,
46             GrTextureDomain::Mode mode,
47             SkAlphaType at,
48             SkBackingFit fit = SkBackingFit::kApprox);
49 };
50 
51 #endif
52 #endif
53