The Tor Browser: gfx/skia/trunk/src/gpu/effects/GrBezierEffect.h@129ffea94266 (annotated)

gfx/skia/trunk/src/gpu/effects/GrBezierEffect.h@129ffea94266 (annotated)

gfx/skia/trunk/src/gpu/effects/GrBezierEffect.h

Sat, 03 Jan 2015 20:18:00 +0100

author: Michael Schloh von Bennewitz <michael@schloh.com>
date: Sat, 03 Jan 2015 20:18:00 +0100
branch: TOR_BUG_3246
changeset 7: 129ffea94266
permissions: -rw-r--r--

Conditionally enable double key logic according to:
private browsing mode or privacy.thirdparty.isolate preference and
implement in GetCookieStringCommon and FindCookie where it counts...
With some reservations of how to convince FindCookie users to test
condition and pass a nullptr when disabling double key logic.

 /*
  * Copyright 2013 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 #ifndef GrBezierEffect_DEFINED
 #define GrBezierEffect_DEFINED
 #include "GrDrawTargetCaps.h"
 #include "GrEffect.h"
 #include "GrVertexEffect.h"
 #include "GrTypesPriv.h"
 /**
  * Shader is based off of Loop-Blinn Quadratic GPU Rendering
  * The output of this effect is a hairline edge for conics.
  * Conics specified by implicit equation K^2 - LM.
  * K, L, and M, are the first three values of the vertex attribute,
  * the fourth value is not used. Distance is calculated using a
  * first order approximation from the taylor series.
  * Coverage for AA is max(0, 1-distance).
  *
  * Test were also run using a second order distance approximation.
  * There were two versions of the second order approx. The first version
  * is of roughly the form:
  * f(q) = |f(p)| - ||f'(p)||*||q-p|| - ||f''(p)||*||q-p||^2.
  * The second is similar:
  * f(q) = |f(p)| + ||f'(p)||*||q-p|| + ||f''(p)||*||q-p||^2.
  * The exact version of the equations can be found in the paper
  * "Distance Approximations for Rasterizing Implicit Curves" by Gabriel Taubin
  *
  * In both versions we solve the quadratic for ||q-p||.
  * Version 1:
  * gFM is magnitude of first partials and gFM2 is magnitude of 2nd partials (as derived from paper)
  * builder->fsCodeAppend("\t\tedgeAlpha = (sqrt(gFM*gFM+4.0*func*gF2M) - gFM)/(2.0*gF2M);\n");
  * Version 2:
  * builder->fsCodeAppend("\t\tedgeAlpha = (gFM - sqrt(gFM*gFM-4.0*func*gF2M))/(2.0*gF2M);\n");
  *
  * Also note that 2nd partials of k,l,m are zero
  *
  * When comparing the two second order approximations to the first order approximations,
  * the following results were found. Version 1 tends to underestimate the distances, thus it
  * basically increases all the error that we were already seeing in the first order
  * approx. So this version is not the one to use. Version 2 has the opposite effect
  * and tends to overestimate the distances. This is much closer to what we are
  * looking for. It is able to render ellipses (even thin ones) without the need to chop.
  * However, it can not handle thin hyperbolas well and thus would still rely on
  * chopping to tighten the clipping. Another side effect of the overestimating is
  * that the curves become much thinner and "ropey". If all that was ever rendered
  * were "not too thin" curves and ellipses then 2nd order may have an advantage since
  * only one geometry would need to be rendered. However no benches were run comparing
  * chopped first order and non chopped 2nd order.
  */
 class GrGLConicEffect;
 class GrConicEffect : public GrVertexEffect {
 public:
     static GrEffectRef* Create(const GrEffectEdgeType edgeType, const GrDrawTargetCaps& caps) {
         GR_CREATE_STATIC_EFFECT(gConicFillAA, GrConicEffect, (kFillAA_GrEffectEdgeType));
         GR_CREATE_STATIC_EFFECT(gConicHairAA, GrConicEffect, (kHairlineAA_GrEffectEdgeType));
         GR_CREATE_STATIC_EFFECT(gConicFillBW, GrConicEffect, (kFillBW_GrEffectEdgeType));
         switch (edgeType) {
             case kFillAA_GrEffectEdgeType:
                 if (!caps.shaderDerivativeSupport()) {
                     return NULL;
                 }
                 gConicFillAA->ref();
                 return gConicFillAA;
             case kHairlineAA_GrEffectEdgeType:
                 if (!caps.shaderDerivativeSupport()) {
                     return NULL;
                 }
                 gConicHairAA->ref();
                 return gConicHairAA;
             case kFillBW_GrEffectEdgeType:
                 gConicFillBW->ref();
                 return gConicFillBW;
             default:
                 return NULL;
         }
     }
     virtual ~GrConicEffect();
     static const char* Name() { return "Conic"; }
     inline bool isAntiAliased() const { return GrEffectEdgeTypeIsAA(fEdgeType); }
     inline bool isFilled() const { return GrEffectEdgeTypeIsFill(fEdgeType); }
     inline GrEffectEdgeType getEdgeType() const { return fEdgeType; }
     typedef GrGLConicEffect GLEffect;
     virtual void getConstantColorComponents(GrColor* color,
                                             uint32_t* validFlags) const SK_OVERRIDE {
         *validFlags = 0;
     }
     virtual const GrBackendEffectFactory& getFactory() const SK_OVERRIDE;
 private:
     GrConicEffect(GrEffectEdgeType);
     virtual bool onIsEqual(const GrEffect& other) const SK_OVERRIDE;
     GrEffectEdgeType fEdgeType;
     GR_DECLARE_EFFECT_TEST;
     typedef GrVertexEffect INHERITED;
 };
 ///////////////////////////////////////////////////////////////////////////////
 /**
  * The output of this effect is a hairline edge for quadratics.
  * Quadratic specified by 0=u^2-v canonical coords. u and v are the first
  * two components of the vertex attribute. At the three control points that define
  * the Quadratic, u, v have the values {0,0}, {1/2, 0}, and {1, 1} respectively.
  * Coverage for AA is min(0, 1-distance). 3rd & 4th cimponent unused.
  * Requires shader derivative instruction support.
  */
 class GrGLQuadEffect;
 class GrQuadEffect : public GrVertexEffect {
 public:
     static GrEffectRef* Create(const GrEffectEdgeType edgeType, const GrDrawTargetCaps& caps) {
         GR_CREATE_STATIC_EFFECT(gQuadFillAA, GrQuadEffect, (kFillAA_GrEffectEdgeType));
         GR_CREATE_STATIC_EFFECT(gQuadHairAA, GrQuadEffect, (kHairlineAA_GrEffectEdgeType));
         GR_CREATE_STATIC_EFFECT(gQuadFillBW, GrQuadEffect, (kFillBW_GrEffectEdgeType));
         switch (edgeType) {
             case kFillAA_GrEffectEdgeType:
                 if (!caps.shaderDerivativeSupport()) {
                     return NULL;
                 }
                 gQuadFillAA->ref();
                 return gQuadFillAA;
             case kHairlineAA_GrEffectEdgeType:
                 if (!caps.shaderDerivativeSupport()) {
                     return NULL;
                 }
                 gQuadHairAA->ref();
                 return gQuadHairAA;
             case kFillBW_GrEffectEdgeType:
                 gQuadFillBW->ref();
                 return gQuadFillBW;
             default:
                 return NULL;
         }
     }
     virtual ~GrQuadEffect();
     static const char* Name() { return "Quad"; }
     inline bool isAntiAliased() const { return GrEffectEdgeTypeIsAA(fEdgeType); }
     inline bool isFilled() const { return GrEffectEdgeTypeIsFill(fEdgeType); }
     inline GrEffectEdgeType getEdgeType() const { return fEdgeType; }
     typedef GrGLQuadEffect GLEffect;
     virtual void getConstantColorComponents(GrColor* color,
                                             uint32_t* validFlags) const SK_OVERRIDE {
         *validFlags = 0;
     }
     virtual const GrBackendEffectFactory& getFactory() const SK_OVERRIDE;
 private:
     GrQuadEffect(GrEffectEdgeType);
     virtual bool onIsEqual(const GrEffect& other) const SK_OVERRIDE;
     GrEffectEdgeType fEdgeType;
     GR_DECLARE_EFFECT_TEST;
     typedef GrVertexEffect INHERITED;
 };
 //////////////////////////////////////////////////////////////////////////////
 /**
  * Shader is based off of "Resolution Independent Curve Rendering using
  * Programmable Graphics Hardware" by Loop and Blinn.
  * The output of this effect is a hairline edge for non rational cubics.
  * Cubics are specified by implicit equation K^3 - LM.
  * K, L, and M, are the first three values of the vertex attribute,
  * the fourth value is not used. Distance is calculated using a
  * first order approximation from the taylor series.
  * Coverage for AA is max(0, 1-distance).
  */
 class GrGLCubicEffect;
 class GrCubicEffect : public GrVertexEffect {
 public:
     static GrEffectRef* Create(const GrEffectEdgeType edgeType, const GrDrawTargetCaps& caps) {
         GR_CREATE_STATIC_EFFECT(gCubicFillAA, GrCubicEffect, (kFillAA_GrEffectEdgeType));
         GR_CREATE_STATIC_EFFECT(gCubicHairAA, GrCubicEffect, (kHairlineAA_GrEffectEdgeType));
         GR_CREATE_STATIC_EFFECT(gCubicFillBW, GrCubicEffect, (kFillBW_GrEffectEdgeType));
         switch (edgeType) {
             case kFillAA_GrEffectEdgeType:
                 if (!caps.shaderDerivativeSupport()) {
                     return NULL;
                 }
                 gCubicFillAA->ref();
                 return gCubicFillAA;
             case kHairlineAA_GrEffectEdgeType:
                 if (!caps.shaderDerivativeSupport()) {
                     return NULL;
                 }
                 gCubicHairAA->ref();
                 return gCubicHairAA;
             case kFillBW_GrEffectEdgeType:
                 gCubicFillBW->ref();
                 return gCubicFillBW;
             default:
                 return NULL;
         }
     }
     virtual ~GrCubicEffect();
     static const char* Name() { return "Cubic"; }
     inline bool isAntiAliased() const { return GrEffectEdgeTypeIsAA(fEdgeType); }
     inline bool isFilled() const { return GrEffectEdgeTypeIsFill(fEdgeType); }
     inline GrEffectEdgeType getEdgeType() const { return fEdgeType; }
     typedef GrGLCubicEffect GLEffect;
     virtual void getConstantColorComponents(GrColor* color,
                                             uint32_t* validFlags) const SK_OVERRIDE {
         *validFlags = 0;
     }
     virtual const GrBackendEffectFactory& getFactory() const SK_OVERRIDE;
 private:
     GrCubicEffect(GrEffectEdgeType);
     virtual bool onIsEqual(const GrEffect& other) const SK_OVERRIDE;
     GrEffectEdgeType fEdgeType;
     GR_DECLARE_EFFECT_TEST;
     typedef GrVertexEffect INHERITED;
 };
 #endif

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gfx/skia/trunk/src/gpu/effects/GrBezierEffect.h@129ffea94266 (annotated)

gfx/skia/trunk/src/gpu/effects/GrBezierEffect.h