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/*
* 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 "SkShader.h"
#include "SkMask.h"
class SkBlurMask {
public:
enum Style {
kNormal_Style, //!< fuzzy inside and outside
kSolid_Style, //!< solid inside, fuzzy outside
kOuter_Style, //!< nothing inside, fuzzy outside
kInner_Style, //!< fuzzy inside, nothing outside
kStyleCount
};
enum Quality {
kLow_Quality, //!< box blur
kHigh_Quality //!< three pass box blur (similar to gaussian)
};
static bool BlurRect(SkScalar sigma, SkMask *dst, const SkRect &src,
Style style,
SkIPoint *margin = NULL,
SkMask::CreateMode createMode =
SkMask::kComputeBoundsAndRenderImage_CreateMode);
static bool BoxBlur(SkMask* dst, const SkMask& src,
SkScalar sigma, Style style, Quality quality,
SkIPoint* margin = NULL);
// the "ground truth" blur does a gaussian convolution; it's slow
// but useful for comparison purposes.
static bool BlurGroundTruth(SkScalar sigma, SkMask* dst, const SkMask& src,
Style style,
SkIPoint* margin = NULL);
SK_ATTR_DEPRECATED("use sigma version")
static bool BlurRect(SkMask *dst, const SkRect &src,
SkScalar radius, Style style,
SkIPoint *margin = NULL,
SkMask::CreateMode createMode =
SkMask::kComputeBoundsAndRenderImage_CreateMode);
SK_ATTR_DEPRECATED("use sigma version")
static bool Blur(SkMask* dst, const SkMask& src,
SkScalar radius, Style style, Quality quality,
SkIPoint* margin = NULL);
SK_ATTR_DEPRECATED("use sigma version")
static bool BlurGroundTruth(SkMask* dst, const SkMask& src,
SkScalar radius, Style style,
SkIPoint* margin = NULL);
static SkScalar ConvertRadiusToSigma(SkScalar radius);
/* Helper functions for analytic rectangle blurs */
/** Look up the intensity of the (one dimnensional) blurred half-plane.
@param profile The precomputed 1D blur profile; memory allocated by and managed 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 blurred_width, int sharp_width);
/** Allocate memory for and populate the profile of a 1D blurred halfplane. The caller
must free the memory. The amount of memory allocated will be exactly 6*sigma bytes.
@param sigma The standard deviation of the gaussian blur kernel
@param profile_out The location to store the allocated profile curve
*/
static void ComputeBlurProfile(SkScalar sigma, uint8_t** profile_out);
/** 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
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