1.1 --- /dev/null Thu Jan 01 00:00:00 1970 +0000
1.2 +++ b/gfx/skia/trunk/src/effects/SkBlurMask.h Wed Dec 31 06:09:35 2014 +0100
1.3 @@ -0,0 +1,91 @@
1.4 +
1.5 +/*
1.6 + * Copyright 2006 The Android Open Source Project
1.7 + *
1.8 + * Use of this source code is governed by a BSD-style license that can be
1.9 + * found in the LICENSE file.
1.10 + */
1.11 +
1.12 +
1.13 +#ifndef SkBlurMask_DEFINED
1.14 +#define SkBlurMask_DEFINED
1.15 +
1.16 +#include "SkShader.h"
1.17 +#include "SkMask.h"
1.18 +#include "SkRRect.h"
1.19 +
1.20 +class SkBlurMask {
1.21 +public:
1.22 + enum Style {
1.23 + kNormal_Style, //!< fuzzy inside and outside
1.24 + kSolid_Style, //!< solid inside, fuzzy outside
1.25 + kOuter_Style, //!< nothing inside, fuzzy outside
1.26 + kInner_Style, //!< fuzzy inside, nothing outside
1.27 +
1.28 + kStyleCount
1.29 + };
1.30 +
1.31 + enum Quality {
1.32 + kLow_Quality, //!< box blur
1.33 + kHigh_Quality //!< three pass box blur (similar to gaussian)
1.34 + };
1.35 +
1.36 + static bool BlurRect(SkScalar sigma, SkMask *dst, const SkRect &src,
1.37 + Style style,
1.38 + SkIPoint *margin = NULL,
1.39 + SkMask::CreateMode createMode =
1.40 + SkMask::kComputeBoundsAndRenderImage_CreateMode);
1.41 + static bool BlurRRect(SkScalar sigma, SkMask *dst, const SkRRect &src,
1.42 + Style style,
1.43 + SkIPoint *margin = NULL,
1.44 + SkMask::CreateMode createMode =
1.45 + SkMask::kComputeBoundsAndRenderImage_CreateMode);
1.46 + static bool BoxBlur(SkMask* dst, const SkMask& src,
1.47 + SkScalar sigma, Style style, Quality quality,
1.48 + SkIPoint* margin = NULL);
1.49 +
1.50 + // the "ground truth" blur does a gaussian convolution; it's slow
1.51 + // but useful for comparison purposes.
1.52 + static bool BlurGroundTruth(SkScalar sigma, SkMask* dst, const SkMask& src,
1.53 + Style style,
1.54 + SkIPoint* margin = NULL);
1.55 +
1.56 + static SkScalar ConvertRadiusToSigma(SkScalar radius);
1.57 +
1.58 + /* Helper functions for analytic rectangle blurs */
1.59 +
1.60 + /** Look up the intensity of the (one dimnensional) blurred half-plane.
1.61 + @param profile The precomputed 1D blur profile; memory allocated by and managed by
1.62 + ComputeBlurProfile below.
1.63 + @param loc the location to look up; The lookup will clamp invalid inputs, but
1.64 + meaningful data are available between 0 and blurred_width
1.65 + @param blurred_width The width of the final, blurred rectangle
1.66 + @param sharp_width The width of the original, unblurred rectangle.
1.67 + */
1.68 + static uint8_t ProfileLookup(const uint8_t* profile, int loc, int blurred_width, int sharp_width);
1.69 +
1.70 + /** Allocate memory for and populate the profile of a 1D blurred halfplane. The caller
1.71 + must free the memory. The amount of memory allocated will be exactly 6*sigma bytes.
1.72 + @param sigma The standard deviation of the gaussian blur kernel
1.73 + @param profile_out The location to store the allocated profile curve
1.74 + */
1.75 +
1.76 + static void ComputeBlurProfile(SkScalar sigma, uint8_t** profile_out);
1.77 +
1.78 + /** Compute an entire scanline of a blurred step function. This is a 1D helper that
1.79 + will produce both the horizontal and vertical profiles of the blurry rectangle.
1.80 + @param pixels Location to store the resulting pixel data; allocated and managed by caller
1.81 + @param profile Precomputed blur profile computed by ComputeBlurProfile above.
1.82 + @param width Size of the pixels array.
1.83 + @param sigma Standard deviation of the gaussian blur kernel used to compute the profile;
1.84 + this implicitly gives the size of the pixels array.
1.85 + */
1.86 +
1.87 + static void ComputeBlurredScanline(uint8_t* pixels, const uint8_t* profile,
1.88 + unsigned int width, SkScalar sigma);
1.89 +
1.90 +
1.91 +
1.92 +};
1.93 +
1.94 +#endif
