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epoger@google.comec3ed6a2011-07-28 14:26:00 +00001/*
2 * Copyright 2006 The Android Open Source Project
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
reed@android.com8a1c16f2008-12-17 15:59:43 +00008#ifndef SkBlurMask_DEFINED
9#define SkBlurMask_DEFINED
10
commit-bot@chromium.orge3964552014-04-28 16:25:35 +000011#include "SkBlurTypes.h"
reed@android.com8a1c16f2008-12-17 15:59:43 +000012#include "SkShader.h"
humper@google.com7c5d7b72013-03-11 20:16:28 +000013#include "SkMask.h"
commit-bot@chromium.orga4771542014-03-10 21:42:06 +000014#include "SkRRect.h"
reed@android.com8a1c16f2008-12-17 15:59:43 +000015
16class SkBlurMask {
17public:
commit-bot@chromium.orge3964552014-04-28 16:25:35 +000018 static bool BlurRect(SkScalar sigma, SkMask *dst, const SkRect &src, SkBlurStyle,
skia.committer@gmail.com2e71f162013-03-12 07:12:32 +000019 SkIPoint *margin = NULL,
robertphillips@google.com7ce661d2013-08-27 16:14:03 +000020 SkMask::CreateMode createMode =
21 SkMask::kComputeBoundsAndRenderImage_CreateMode);
commit-bot@chromium.orge3964552014-04-28 16:25:35 +000022 static bool BlurRRect(SkScalar sigma, SkMask *dst, const SkRRect &src, SkBlurStyle,
commit-bot@chromium.orga4771542014-03-10 21:42:06 +000023 SkIPoint *margin = NULL,
24 SkMask::CreateMode createMode =
25 SkMask::kComputeBoundsAndRenderImage_CreateMode);
robertphillips@google.com7ce661d2013-08-27 16:14:03 +000026 static bool BoxBlur(SkMask* dst, const SkMask& src,
commit-bot@chromium.orge3964552014-04-28 16:25:35 +000027 SkScalar sigma, SkBlurStyle style, SkBlurQuality quality,
commit-bot@chromium.org55aec082014-04-28 18:21:24 +000028 SkIPoint* margin = NULL);
humper@google.coma99a92c2013-02-20 16:42:06 +000029
30 // the "ground truth" blur does a gaussian convolution; it's slow
31 // but useful for comparison purposes.
commit-bot@chromium.orge3964552014-04-28 16:25:35 +000032 static bool BlurGroundTruth(SkScalar sigma, SkMask* dst, const SkMask& src, SkBlurStyle,
robertphillips@google.com7ce661d2013-08-27 16:14:03 +000033 SkIPoint* margin = NULL);
humper@google.coma99a92c2013-02-20 16:42:06 +000034
robertphillips@google.com7ce661d2013-08-27 16:14:03 +000035 static SkScalar ConvertRadiusToSigma(SkScalar radius);
skia.committer@gmail.com4c18e9f2014-01-31 03:01:59 +000036
commit-bot@chromium.orgcf34bc02014-01-30 15:34:43 +000037 /* Helper functions for analytic rectangle blurs */
skia.committer@gmail.com4c18e9f2014-01-31 03:01:59 +000038
commit-bot@chromium.orgcf34bc02014-01-30 15:34:43 +000039 /** Look up the intensity of the (one dimnensional) blurred half-plane.
40 @param profile The precomputed 1D blur profile; memory allocated by and managed by
41 ComputeBlurProfile below.
skia.committer@gmail.com4c18e9f2014-01-31 03:01:59 +000042 @param loc the location to look up; The lookup will clamp invalid inputs, but
commit-bot@chromium.orgcf34bc02014-01-30 15:34:43 +000043 meaningful data are available between 0 and blurred_width
44 @param blurred_width The width of the final, blurred rectangle
45 @param sharp_width The width of the original, unblurred rectangle.
skia.committer@gmail.com4c18e9f2014-01-31 03:01:59 +000046 */
commit-bot@chromium.orgcf34bc02014-01-30 15:34:43 +000047 static uint8_t ProfileLookup(const uint8_t* profile, int loc, int blurred_width, int sharp_width);
skia.committer@gmail.com4c18e9f2014-01-31 03:01:59 +000048
commit-bot@chromium.orgcf34bc02014-01-30 15:34:43 +000049 /** Allocate memory for and populate the profile of a 1D blurred halfplane. The caller
50 must free the memory. The amount of memory allocated will be exactly 6*sigma bytes.
51 @param sigma The standard deviation of the gaussian blur kernel
52 @param profile_out The location to store the allocated profile curve
53 */
skia.committer@gmail.com4c18e9f2014-01-31 03:01:59 +000054
commit-bot@chromium.orgcf34bc02014-01-30 15:34:43 +000055 static void ComputeBlurProfile(SkScalar sigma, uint8_t** profile_out);
skia.committer@gmail.com4c18e9f2014-01-31 03:01:59 +000056
commit-bot@chromium.orgcf34bc02014-01-30 15:34:43 +000057 /** Compute an entire scanline of a blurred step function. This is a 1D helper that
58 will produce both the horizontal and vertical profiles of the blurry rectangle.
59 @param pixels Location to store the resulting pixel data; allocated and managed by caller
60 @param profile Precomputed blur profile computed by ComputeBlurProfile above.
61 @param width Size of the pixels array.
62 @param sigma Standard deviation of the gaussian blur kernel used to compute the profile;
63 this implicitly gives the size of the pixels array.
64 */
skia.committer@gmail.com4c18e9f2014-01-31 03:01:59 +000065
commit-bot@chromium.orgcf34bc02014-01-30 15:34:43 +000066 static void ComputeBlurredScanline(uint8_t* pixels, const uint8_t* profile,
67 unsigned int width, SkScalar sigma);
skia.committer@gmail.com4c18e9f2014-01-31 03:01:59 +000068
69
70
reed@android.com8a1c16f2008-12-17 15:59:43 +000071};
72
73#endif