skia2/include/gpu/effects/GrBlurredEdgeFragmentProcessor.h
Brian Salomon cb30bb2cb7 Remove GrFragmentProcessor::computeInvariantOutput
Change-Id: If475730103052c6097eb91be06808fb723b70bf8
Reviewed-on: https://skia-review.googlesource.com/8330
Reviewed-by: Greg Daniel <egdaniel@google.com>
Commit-Queue: Brian Salomon <bsalomon@google.com>
2017-02-13 15:32:00 +00:00

69 lines
2.0 KiB
C++

/*
* Copyright 2017 Google Inc.
*
* Use of this source code is governed by a BSD-style license that can be
* found in the LICENSE file.
*/
#ifndef GrBlurredEdgeFragmentProcessor_DEFINED
#define GrBlurredEdgeFragmentProcessor_DEFINED
#include "GrFragmentProcessor.h"
/**
* Shader for managing a blurred edge for a shadow.
*
* There are two blurring modes supported: Gaussian blur function and smoothstep function.
*
* If the primitive supports an implicit distance to the edge, the radius of the blur is specified
* by r & g values of the color in 14.2 fixed point. For spot shadows, we increase the stroke width
* to set the shadow against the shape. This pad is specified by b, also in 6.2 fixed point.
* The a value represents the max final alpha.
*
* When not using implicit distance, then b in the input color represents the input to the
* blur function, and r the max final alpha.
*
*/
class GrBlurredEdgeFP : public GrFragmentProcessor {
public:
enum Mode {
kGaussian_Mode,
kSmoothstep_Mode,
kLastMode = kSmoothstep_Mode
};
static const int kModeCnt = kLastMode + 1;
static sk_sp<GrFragmentProcessor> Make(Mode mode = kGaussian_Mode) {
return sk_sp<GrFragmentProcessor>(new GrBlurredEdgeFP(mode));
}
const char* name() const override { return "BlurredEdge"; }
Mode mode() const { return fMode; }
private:
GrBlurredEdgeFP(Mode mode)
: INHERITED(kNone_OptimizationFlags)
, fMode(mode) {
// enable output of distance information for shape
this->setWillUseDistanceVectorField();
this->initClassID<GrBlurredEdgeFP>();
}
GrGLSLFragmentProcessor* onCreateGLSLInstance() const override;
void onGetGLSLProcessorKey(const GrShaderCaps&, GrProcessorKeyBuilder*) const override;
bool onIsEqual(const GrFragmentProcessor&) const override;
GR_DECLARE_FRAGMENT_PROCESSOR_TEST;
Mode fMode;
typedef GrFragmentProcessor INHERITED;
};
#endif