| /* |
| * Copyright 2006 The Android Open Source Project |
| * |
| * Use of this source code is governed by a BSD-style license that can be |
| * found in the LICENSE file. |
| */ |
| |
| #ifndef SkBlurMask_DEFINED |
| #define SkBlurMask_DEFINED |
| |
| #include "include/core/SkBlurTypes.h" |
| #include "include/core/SkRRect.h" |
| #include "include/core/SkShader.h" |
| #include "src/core/SkMask.h" |
| |
| class SkBlurMask { |
| public: |
| static bool SK_WARN_UNUSED_RESULT BlurRect(SkScalar sigma, SkMask *dst, const SkRect &src, |
| SkBlurStyle, SkIPoint *margin = nullptr, |
| SkMask::CreateMode createMode = |
| SkMask::kComputeBoundsAndRenderImage_CreateMode); |
| static bool SK_WARN_UNUSED_RESULT BlurRRect(SkScalar sigma, SkMask *dst, const SkRRect &src, |
| SkBlurStyle, SkIPoint *margin = nullptr, |
| SkMask::CreateMode createMode = |
| SkMask::kComputeBoundsAndRenderImage_CreateMode); |
| |
| // forceQuality will prevent BoxBlur from falling back to the low quality approach when sigma |
| // is very small -- this can be used predict the margin bump ahead of time without completely |
| // replicating the internal logic. This permits not only simpler caching of blurred results, |
| // but also being able to predict precisely at what pixels the blurred profile of e.g. a |
| // rectangle will lie. |
| // |
| // Calling details: |
| // * calculate margin - if src.fImage is null, then this call only calculates the border. |
| // * failure - if src.fImage is not null, failure is signal with dst->fImage being |
| // null. |
| |
| static bool SK_WARN_UNUSED_RESULT BoxBlur(SkMask* dst, const SkMask& src, |
| SkScalar sigma, SkBlurStyle style, |
| SkIPoint* margin = nullptr); |
| |
| // the "ground truth" blur does a gaussian convolution; it's slow |
| // but useful for comparison purposes. |
| static bool SK_WARN_UNUSED_RESULT BlurGroundTruth(SkScalar sigma, SkMask* dst, |
| const SkMask& src, |
| SkBlurStyle, SkIPoint* margin = nullptr); |
| |
| // If radius > 0, return the corresponding sigma, else return 0 |
| static SkScalar SK_API ConvertRadiusToSigma(SkScalar radius); |
| // If sigma > 0.5, return the corresponding radius, else return 0 |
| static SkScalar SK_API ConvertSigmaToRadius(SkScalar sigma); |
| |
| /* Helper functions for analytic rectangle blurs */ |
| |
| /** Look up the intensity of the (one dimnensional) blurred half-plane. |
| @param profile The precomputed 1D blur profile; initialized by ComputeBlurProfile below. |
| @param loc the location to look up; The lookup will clamp invalid inputs, but |
| meaningful data are available between 0 and blurred_width |
| @param blurred_width The width of the final, blurred rectangle |
| @param sharp_width The width of the original, unblurred rectangle. |
| */ |
| static uint8_t ProfileLookup(const uint8_t* profile, int loc, int blurredWidth, int sharpWidth); |
| |
| /** Populate the profile of a 1D blurred halfplane. |
| @param profile The 1D table to fill in |
| @param size Should be 6*sigma bytes |
| @param sigma The standard deviation of the gaussian blur kernel |
| */ |
| static void ComputeBlurProfile(uint8_t* profile, int size, SkScalar sigma); |
| |
| /** Compute an entire scanline of a blurred step function. This is a 1D helper that |
| will produce both the horizontal and vertical profiles of the blurry rectangle. |
| @param pixels Location to store the resulting pixel data; allocated and managed by caller |
| @param profile Precomputed blur profile computed by ComputeBlurProfile above. |
| @param width Size of the pixels array. |
| @param sigma Standard deviation of the gaussian blur kernel used to compute the profile; |
| this implicitly gives the size of the pixels array. |
| */ |
| |
| static void ComputeBlurredScanline(uint8_t* pixels, const uint8_t* profile, |
| unsigned int width, SkScalar sigma); |
| |
| |
| |
| }; |
| |
| #endif |