/*
* Copyright 2014 Google Inc.
*
* Use of this source code is governed by a BSD-style license that can be
* found in the LICENSE file.
*/
#include "GrRRectEffect.h"
#include "gl/GrGLEffect.h"
#include "gl/GrGLSL.h"
#include "GrConvexPolyEffect.h"
#include "GrOvalEffect.h"
#include "GrTBackendEffectFactory.h"
#include "SkRRect.h"
// The effects defined here only handle rrect radii >= kRadiusMin.
static const SkScalar kRadiusMin = SK_ScalarHalf;
//////////////////////////////////////////////////////////////////////////////
class GLCircularRRectEffect;
class CircularRRectEffect : public GrEffect {
public:
enum CornerFlags {
kTopLeft_CornerFlag = (1 << SkRRect::kUpperLeft_Corner),
kTopRight_CornerFlag = (1 << SkRRect::kUpperRight_Corner),
kBottomRight_CornerFlag = (1 << SkRRect::kLowerRight_Corner),
kBottomLeft_CornerFlag = (1 << SkRRect::kLowerLeft_Corner),
kLeft_CornerFlags = kTopLeft_CornerFlag | kBottomLeft_CornerFlag,
kTop_CornerFlags = kTopLeft_CornerFlag | kTopRight_CornerFlag,
kRight_CornerFlags = kTopRight_CornerFlag | kBottomRight_CornerFlag,
kBottom_CornerFlags = kBottomLeft_CornerFlag | kBottomRight_CornerFlag,
kAll_CornerFlags = kTopLeft_CornerFlag | kTopRight_CornerFlag |
kBottomLeft_CornerFlag | kBottomRight_CornerFlag,
kNone_CornerFlags = 0
};
// The flags are used to indicate which corners are circluar (unflagged corners are assumed to
// be square).
static GrEffectRef* Create(GrEffectEdgeType, uint32_t circularCornerFlags, const SkRRect&);
virtual ~CircularRRectEffect() {};
static const char* Name() { return "CircularRRect"; }
const SkRRect& getRRect() const { return fRRect; }
uint32_t getCircularCornerFlags() const { return fCircularCornerFlags; }
GrEffectEdgeType getEdgeType() const { return fEdgeType; }
typedef GLCircularRRectEffect GLEffect;
virtual void getConstantColorComponents(GrColor* color, uint32_t* validFlags) const SK_OVERRIDE;
virtual const GrBackendEffectFactory& getFactory() const SK_OVERRIDE;
private:
CircularRRectEffect(GrEffectEdgeType, uint32_t circularCornerFlags, const SkRRect&);
virtual bool onIsEqual(const GrEffect& other) const SK_OVERRIDE;
SkRRect fRRect;
GrEffectEdgeType fEdgeType;
uint32_t fCircularCornerFlags;
GR_DECLARE_EFFECT_TEST;
typedef GrEffect INHERITED;
};
GrEffectRef* CircularRRectEffect::Create(GrEffectEdgeType edgeType,
uint32_t circularCornerFlags,
const SkRRect& rrect) {
if (kFillAA_GrEffectEdgeType != edgeType && kInverseFillAA_GrEffectEdgeType != edgeType) {
return NULL;
}
return CreateEffectRef(AutoEffectUnref(SkNEW_ARGS(CircularRRectEffect,
(edgeType, circularCornerFlags, rrect))));
}
void CircularRRectEffect::getConstantColorComponents(GrColor* color, uint32_t* validFlags) const {
*validFlags = 0;
}
const GrBackendEffectFactory& CircularRRectEffect::getFactory() const {
return GrTBackendEffectFactory<CircularRRectEffect>::getInstance();
}
CircularRRectEffect::CircularRRectEffect(GrEffectEdgeType edgeType, uint32_t circularCornerFlags,
const SkRRect& rrect)
: fRRect(rrect)
, fEdgeType(edgeType)
, fCircularCornerFlags(circularCornerFlags) {
this->setWillReadFragmentPosition();
}
bool CircularRRectEffect::onIsEqual(const GrEffect& other) const {
const CircularRRectEffect& crre = CastEffect<CircularRRectEffect>(other);
// The corner flags are derived from fRRect, so no need to check them.
return fEdgeType == crre.fEdgeType && fRRect == crre.fRRect;
}
//////////////////////////////////////////////////////////////////////////////
GR_DEFINE_EFFECT_TEST(CircularRRectEffect);
GrEffectRef* CircularRRectEffect::TestCreate(SkRandom* random,
GrContext*,
const GrDrawTargetCaps& caps,
GrTexture*[]) {
SkScalar w = random->nextRangeScalar(20.f, 1000.f);
SkScalar h = random->nextRangeScalar(20.f, 1000.f);
SkScalar r = random->nextRangeF(kRadiusMin, 9.f);
SkRRect rrect;
rrect.setRectXY(SkRect::MakeWH(w, h), r, r);
GrEffectRef* effect;
do {
GrEffectEdgeType et = (GrEffectEdgeType)random->nextULessThan(kGrEffectEdgeTypeCnt);
effect = GrRRectEffect::Create(et, rrect);
} while (NULL == effect);
return effect;
}
//////////////////////////////////////////////////////////////////////////////
class GLCircularRRectEffect : public GrGLEffect {
public:
GLCircularRRectEffect(const GrBackendEffectFactory&, const GrDrawEffect&);
virtual void emitCode(GrGLShaderBuilder* builder,
const GrDrawEffect& drawEffect,
EffectKey key,
const char* outputColor,
const char* inputColor,
const TransformedCoordsArray&,
const TextureSamplerArray&) SK_OVERRIDE;
static inline EffectKey GenKey(const GrDrawEffect&, const GrGLCaps&);
virtual void setData(const GrGLUniformManager&, const GrDrawEffect&) SK_OVERRIDE;
private:
GrGLUniformManager::UniformHandle fInnerRectUniform;
GrGLUniformManager::UniformHandle fRadiusPlusHalfUniform;
SkRRect fPrevRRect;
typedef GrGLEffect INHERITED;
};
GLCircularRRectEffect::GLCircularRRectEffect(const GrBackendEffectFactory& factory,
const GrDrawEffect& drawEffect)
: INHERITED (factory) {
fPrevRRect.setEmpty();
}
void GLCircularRRectEffect::emitCode(GrGLShaderBuilder* builder,
const GrDrawEffect& drawEffect,
EffectKey key,
const char* outputColor,
const char* inputColor,
const TransformedCoordsArray&,
const TextureSamplerArray& samplers) {
const CircularRRectEffect& crre = drawEffect.castEffect<CircularRRectEffect>();
const char *rectName;
const char *radiusPlusHalfName;
// The inner rect is the rrect bounds inset by the radius. Its left, top, right, and bottom
// edges correspond to components x, y, z, and w, respectively. When a side of the rrect has
// only rectangular corners, that side's value corresponds to the rect edge's value outset by
// half a pixel.
fInnerRectUniform = builder->addUniform(GrGLShaderBuilder::kFragment_Visibility,
kVec4f_GrSLType,
"innerRect",
&rectName);
fRadiusPlusHalfUniform = builder->addUniform(GrGLShaderBuilder::kFragment_Visibility,
kFloat_GrSLType,
"radiusPlusHalf",
&radiusPlusHalfName);
const char* fragmentPos = builder->fragmentPosition();
// At each quarter-circle corner we compute a vector that is the offset of the fragment position
// from the circle center. The vector is pinned in x and y to be in the quarter-plane relevant
// to that corner. This means that points near the interior near the rrect top edge will have
// a vector that points straight up for both the TL left and TR corners. Computing an
// alpha from this vector at either the TR or TL corner will give the correct result. Similarly,
// fragments near the other three edges will get the correct AA. Fragments in the interior of
// the rrect will have a (0,0) vector at all four corners. So long as the radius > 0.5 they will
// correctly produce an alpha value of 1 at all four corners. We take the min of all the alphas.
// The code below is a simplified version of the above that performs maxs on the vector
// components before computing distances and alpha values so that only one distance computation
// need be computed to determine the min alpha.
//
// For the cases where one half of the rrect is rectangular we drop one of the x or y
// computations, compute a separate rect edge alpha for the rect side, and mul the two computed
// alphas together.
switch (crre.getCircularCornerFlags()) {
case CircularRRectEffect::kAll_CornerFlags:
builder->fsCodeAppendf("\t\tvec2 dxy0 = %s.xy - %s;\n", rectName, fragmentPos);
builder->fsCodeAppendf("\t\tvec2 dxy1 = %s - %s.zw;\n", fragmentPos, rectName);
builder->fsCodeAppend("\t\tvec2 dxy = max(max(dxy0, dxy1), 0.0);\n");
builder->fsCodeAppendf("\t\tfloat alpha = clamp(%s - length(dxy), 0.0, 1.0);\n",
radiusPlusHalfName);
break;
case CircularRRectEffect::kTopLeft_CornerFlag:
builder->fsCodeAppendf("\t\tvec2 dxy = max(%s.xy - %s.xy, 0.0);\n",
rectName, fragmentPos);
builder->fsCodeAppendf("\t\tfloat rightAlpha = clamp(%s.z - %s.x, 0.0, 1.0);\n",
rectName, fragmentPos);
builder->fsCodeAppendf("\t\tfloat bottomAlpha = clamp(%s.w - %s.y, 0.0, 1.0);\n",
rectName, fragmentPos);
builder->fsCodeAppendf("\t\tfloat alpha = bottomAlpha * rightAlpha * clamp(%s - length(dxy), 0.0, 1.0);\n",
radiusPlusHalfName);
break;
case CircularRRectEffect::kTopRight_CornerFlag:
builder->fsCodeAppendf("\t\tvec2 dxy = max(vec2(%s.x - %s.z, %s.y - %s.y), 0.0);\n",
fragmentPos, rectName, rectName, fragmentPos);
builder->fsCodeAppendf("\t\tfloat leftAlpha = clamp(%s.x - %s.x, 0.0, 1.0);\n",
fragmentPos, rectName);
builder->fsCodeAppendf("\t\tfloat bottomAlpha = clamp(%s.w - %s.y, 0.0, 1.0);\n",
rectName, fragmentPos);
builder->fsCodeAppendf("\t\tfloat alpha = bottomAlpha * leftAlpha * clamp(%s - length(dxy), 0.0, 1.0);\n",
radiusPlusHalfName);
break;
case CircularRRectEffect::kBottomRight_CornerFlag:
builder->fsCodeAppendf("\t\tvec2 dxy = max(%s.xy - %s.zw, 0.0);\n",
fragmentPos, rectName);
builder->fsCodeAppendf("\t\tfloat leftAlpha = clamp(%s.x - %s.x, 0.0, 1.0);\n",
fragmentPos, rectName);
builder->fsCodeAppendf("\t\tfloat topAlpha = clamp(%s.y - %s.y, 0.0, 1.0);\n",
fragmentPos, rectName);
builder->fsCodeAppendf("\t\tfloat alpha = topAlpha * leftAlpha * clamp(%s - length(dxy), 0.0, 1.0);\n",
radiusPlusHalfName);
break;
case CircularRRectEffect::kBottomLeft_CornerFlag:
builder->fsCodeAppendf("\t\tvec2 dxy = max(vec2(%s.x - %s.x, %s.y - %s.w), 0.0);\n",
rectName, fragmentPos, fragmentPos, rectName);
builder->fsCodeAppendf("\t\tfloat rightAlpha = clamp(%s.z - %s.x, 0.0, 1.0);\n",
rectName, fragmentPos);
builder->fsCodeAppendf("\t\tfloat topAlpha = clamp(%s.y - %s.y, 0.0, 1.0);\n",
fragmentPos, rectName);
builder->fsCodeAppendf("\t\tfloat alpha = topAlpha * rightAlpha * clamp(%s - length(dxy), 0.0, 1.0);\n",
radiusPlusHalfName);
break;
case CircularRRectEffect::kLeft_CornerFlags:
builder->fsCodeAppendf("\t\tvec2 dxy0 = %s.xy - %s.xy;\n", rectName, fragmentPos);
builder->fsCodeAppendf("\t\tfloat dy1 = %s.y - %s.w;\n", fragmentPos, rectName);
builder->fsCodeAppend("\t\tvec2 dxy = max(vec2(dxy0.x, max(dxy0.y, dy1)), 0.0);\n");
builder->fsCodeAppendf("\t\tfloat rightAlpha = clamp(%s.z - %s.x, 0.0, 1.0);\n",
rectName, fragmentPos);
builder->fsCodeAppendf("\t\tfloat alpha = rightAlpha * clamp(%s - length(dxy), 0.0, 1.0);\n",
radiusPlusHalfName);
break;
case CircularRRectEffect::kTop_CornerFlags:
builder->fsCodeAppendf("\t\tvec2 dxy0 = %s.xy - %s.xy;\n", rectName, fragmentPos);
builder->fsCodeAppendf("\t\tfloat dx1 = %s.x - %s.z;\n", fragmentPos, rectName);
builder->fsCodeAppend("\t\tvec2 dxy = max(vec2(max(dxy0.x, dx1), dxy0.y), 0.0);\n");
builder->fsCodeAppendf("\t\tfloat bottomAlpha = clamp(%s.w - %s.y, 0.0, 1.0);\n",
rectName, fragmentPos);
builder->fsCodeAppendf("\t\tfloat alpha = bottomAlpha * clamp(%s - length(dxy), 0.0, 1.0);\n",
radiusPlusHalfName);
break;
case CircularRRectEffect::kRight_CornerFlags:
builder->fsCodeAppendf("\t\tfloat dy0 = %s.y - %s.y;\n", rectName, fragmentPos);
builder->fsCodeAppendf("\t\tvec2 dxy1 = %s.xy - %s.zw;\n", fragmentPos, rectName);
builder->fsCodeAppend("\t\tvec2 dxy = max(vec2(dxy1.x, max(dy0, dxy1.y)), 0.0);\n");
builder->fsCodeAppendf("\t\tfloat leftAlpha = clamp(%s.x - %s.x, 0.0, 1.0);\n",
fragmentPos, rectName);
builder->fsCodeAppendf("\t\tfloat alpha = leftAlpha * clamp(%s - length(dxy), 0.0, 1.0);\n",
radiusPlusHalfName);
break;
case CircularRRectEffect::kBottom_CornerFlags:
builder->fsCodeAppendf("\t\tfloat dx0 = %s.x - %s.x;\n", rectName, fragmentPos);
builder->fsCodeAppendf("\t\tvec2 dxy1 = %s.xy - %s.zw;\n", fragmentPos, rectName);
builder->fsCodeAppend("\t\tvec2 dxy = max(vec2(max(dx0, dxy1.x), dxy1.y), 0.0);\n");
builder->fsCodeAppendf("\t\tfloat topAlpha = clamp(%s.y - %s.y, 0.0, 1.0);\n",
fragmentPos, rectName);
builder->fsCodeAppendf("\t\tfloat alpha = topAlpha * clamp(%s - length(dxy), 0.0, 1.0);\n",
radiusPlusHalfName);
break;
}
if (kInverseFillAA_GrEffectEdgeType == crre.getEdgeType()) {
builder->fsCodeAppend("\t\talpha = 1.0 - alpha;\n");
}
builder->fsCodeAppendf("\t\t%s = %s;\n", outputColor,
(GrGLSLExpr4(inputColor) * GrGLSLExpr1("alpha")).c_str());
}
GrGLEffect::EffectKey GLCircularRRectEffect::GenKey(const GrDrawEffect& drawEffect,
const GrGLCaps&) {
const CircularRRectEffect& crre = drawEffect.castEffect<CircularRRectEffect>();
GR_STATIC_ASSERT(kGrEffectEdgeTypeCnt <= 8);
return (crre.getCircularCornerFlags() << 3) | crre.getEdgeType();
}
void GLCircularRRectEffect::setData(const GrGLUniformManager& uman,
const GrDrawEffect& drawEffect) {
const CircularRRectEffect& crre = drawEffect.castEffect<CircularRRectEffect>();
const SkRRect& rrect = crre.getRRect();
if (rrect != fPrevRRect) {
SkRect rect = rrect.getBounds();
SkScalar radius = 0;
switch (crre.getCircularCornerFlags()) {
case CircularRRectEffect::kAll_CornerFlags:
SkASSERT(rrect.isSimpleCircular());
radius = rrect.getSimpleRadii().fX;
SkASSERT(radius >= kRadiusMin);
rect.inset(radius, radius);
break;
case CircularRRectEffect::kTopLeft_CornerFlag:
radius = rrect.radii(SkRRect::kUpperLeft_Corner).fX;
rect.fLeft += radius;
rect.fTop += radius;
rect.fRight += 0.5f;
rect.fBottom += 0.5f;
break;
case CircularRRectEffect::kTopRight_CornerFlag:
radius = rrect.radii(SkRRect::kUpperRight_Corner).fX;
rect.fLeft -= 0.5f;
rect.fTop += radius;
rect.fRight -= radius;
rect.fBottom += 0.5f;
break;
case CircularRRectEffect::kBottomRight_CornerFlag:
radius = rrect.radii(SkRRect::kLowerRight_Corner).fX;
rect.fLeft -= 0.5f;
rect.fTop -= 0.5f;
rect.fRight -= radius;
rect.fBottom -= radius;
break;
case CircularRRectEffect::kBottomLeft_CornerFlag:
radius = rrect.radii(SkRRect::kLowerLeft_Corner).fX;
rect.fLeft += radius;
rect.fTop -= 0.5f;
rect.fRight += 0.5f;
rect.fBottom -= radius;
break;
case CircularRRectEffect::kLeft_CornerFlags:
radius = rrect.radii(SkRRect::kUpperLeft_Corner).fX;
rect.fLeft += radius;
rect.fTop += radius;
rect.fRight += 0.5f;
rect.fBottom -= radius;
break;
case CircularRRectEffect::kTop_CornerFlags:
radius = rrect.radii(SkRRect::kUpperLeft_Corner).fX;
rect.fLeft += radius;
rect.fTop += radius;
rect.fRight -= radius;
rect.fBottom += 0.5f;
break;
case CircularRRectEffect::kRight_CornerFlags:
radius = rrect.radii(SkRRect::kUpperRight_Corner).fX;
rect.fLeft -= 0.5f;
rect.fTop += radius;
rect.fRight -= radius;
rect.fBottom -= radius;
break;
case CircularRRectEffect::kBottom_CornerFlags:
radius = rrect.radii(SkRRect::kLowerLeft_Corner).fX;
rect.fLeft += radius;
rect.fTop -= 0.5f;
rect.fRight -= radius;
rect.fBottom -= radius;
break;
default:
SkFAIL("Should have been one of the above cases.");
}
uman.set4f(fInnerRectUniform, rect.fLeft, rect.fTop, rect.fRight, rect.fBottom);
uman.set1f(fRadiusPlusHalfUniform, radius + 0.5f);
fPrevRRect = rrect;
}
}
//////////////////////////////////////////////////////////////////////////////
class GLEllipticalRRectEffect;
class EllipticalRRectEffect : public GrEffect {
public:
static GrEffectRef* Create(GrEffectEdgeType, const SkRRect&);
virtual ~EllipticalRRectEffect() {};
static const char* Name() { return "EllipticalRRect"; }
const SkRRect& getRRect() const { return fRRect; }
GrEffectEdgeType getEdgeType() const { return fEdgeType; }
typedef GLEllipticalRRectEffect GLEffect;
virtual void getConstantColorComponents(GrColor* color, uint32_t* validFlags) const SK_OVERRIDE;
virtual const GrBackendEffectFactory& getFactory() const SK_OVERRIDE;
private:
EllipticalRRectEffect(GrEffectEdgeType, const SkRRect&);
virtual bool onIsEqual(const GrEffect& other) const SK_OVERRIDE;
SkRRect fRRect;
GrEffectEdgeType fEdgeType;
GR_DECLARE_EFFECT_TEST;
typedef GrEffect INHERITED;
};
GrEffectRef* EllipticalRRectEffect::Create(GrEffectEdgeType edgeType, const SkRRect& rrect) {
if (kFillAA_GrEffectEdgeType != edgeType && kInverseFillAA_GrEffectEdgeType != edgeType) {
return NULL;
}
return CreateEffectRef(AutoEffectUnref(SkNEW_ARGS(EllipticalRRectEffect, (edgeType, rrect))));
}
void EllipticalRRectEffect::getConstantColorComponents(GrColor* color, uint32_t* validFlags) const {
*validFlags = 0;
}
const GrBackendEffectFactory& EllipticalRRectEffect::getFactory() const {
return GrTBackendEffectFactory<EllipticalRRectEffect>::getInstance();
}
EllipticalRRectEffect::EllipticalRRectEffect(GrEffectEdgeType edgeType, const SkRRect& rrect)
: fRRect(rrect)
, fEdgeType(edgeType){
this->setWillReadFragmentPosition();
}
bool EllipticalRRectEffect::onIsEqual(const GrEffect& other) const {
const EllipticalRRectEffect& erre = CastEffect<EllipticalRRectEffect>(other);
return fEdgeType == erre.fEdgeType && fRRect == erre.fRRect;
}
//////////////////////////////////////////////////////////////////////////////
GR_DEFINE_EFFECT_TEST(EllipticalRRectEffect);
GrEffectRef* EllipticalRRectEffect::TestCreate(SkRandom* random,
GrContext*,
const GrDrawTargetCaps& caps,
GrTexture*[]) {
SkScalar w = random->nextRangeScalar(20.f, 1000.f);
SkScalar h = random->nextRangeScalar(20.f, 1000.f);
SkVector r[4];
r[SkRRect::kUpperLeft_Corner].fX = random->nextRangeF(kRadiusMin, 9.f);
// ensure at least one corner really is elliptical
do {
r[SkRRect::kUpperLeft_Corner].fY = random->nextRangeF(kRadiusMin, 9.f);
} while (r[SkRRect::kUpperLeft_Corner].fY == r[SkRRect::kUpperLeft_Corner].fX);
SkRRect rrect;
if (random->nextBool()) {
// half the time create a four-radii rrect.
r[SkRRect::kLowerRight_Corner].fX = random->nextRangeF(kRadiusMin, 9.f);
r[SkRRect::kLowerRight_Corner].fY = random->nextRangeF(kRadiusMin, 9.f);
r[SkRRect::kUpperRight_Corner].fX = r[SkRRect::kLowerRight_Corner].fX;
r[SkRRect::kUpperRight_Corner].fY = r[SkRRect::kUpperLeft_Corner].fY;
r[SkRRect::kLowerLeft_Corner].fX = r[SkRRect::kUpperLeft_Corner].fX;
r[SkRRect::kLowerLeft_Corner].fY = r[SkRRect::kLowerRight_Corner].fY;
rrect.setRectRadii(SkRect::MakeWH(w, h), r);
} else {
rrect.setRectXY(SkRect::MakeWH(w, h), r[SkRRect::kUpperLeft_Corner].fX,
r[SkRRect::kUpperLeft_Corner].fY);
}
GrEffectRef* effect;
do {
GrEffectEdgeType et = (GrEffectEdgeType)random->nextULessThan(kGrEffectEdgeTypeCnt);
effect = GrRRectEffect::Create(et, rrect);
} while (NULL == effect);
return effect;
}
//////////////////////////////////////////////////////////////////////////////
class GLEllipticalRRectEffect : public GrGLEffect {
public:
GLEllipticalRRectEffect(const GrBackendEffectFactory&, const GrDrawEffect&);
virtual void emitCode(GrGLShaderBuilder* builder,
const GrDrawEffect& drawEffect,
EffectKey key,
const char* outputColor,
const char* inputColor,
const TransformedCoordsArray&,
const TextureSamplerArray&) SK_OVERRIDE;
static inline EffectKey GenKey(const GrDrawEffect&, const GrGLCaps&);
virtual void setData(const GrGLUniformManager&, const GrDrawEffect&) SK_OVERRIDE;
private:
GrGLUniformManager::UniformHandle fInnerRectUniform;
GrGLUniformManager::UniformHandle fInvRadiiSqdUniform;
SkRRect fPrevRRect;
typedef GrGLEffect INHERITED;
};
GLEllipticalRRectEffect::GLEllipticalRRectEffect(const GrBackendEffectFactory& factory,
const GrDrawEffect& drawEffect)
: INHERITED (factory) {
fPrevRRect.setEmpty();
}
void GLEllipticalRRectEffect::emitCode(GrGLShaderBuilder* builder,
const GrDrawEffect& drawEffect,
EffectKey key,
const char* outputColor,
const char* inputColor,
const TransformedCoordsArray&,
const TextureSamplerArray& samplers) {
const EllipticalRRectEffect& erre = drawEffect.castEffect<EllipticalRRectEffect>();
const char *rectName;
// The inner rect is the rrect bounds inset by the x/y radii
fInnerRectUniform = builder->addUniform(GrGLShaderBuilder::kFragment_Visibility,
kVec4f_GrSLType,
"innerRect",
&rectName);
const char* fragmentPos = builder->fragmentPosition();
// At each quarter-ellipse corner we compute a vector that is the offset of the fragment pos
// to the ellipse center. The vector is pinned in x and y to be in the quarter-plane relevant
// to that corner. This means that points near the interior near the rrect top edge will have
// a vector that points straight up for both the TL left and TR corners. Computing an
// alpha from this vector at either the TR or TL corner will give the correct result. Similarly,
// fragments near the other three edges will get the correct AA. Fragments in the interior of
// the rrect will have a (0,0) vector at all four corners. So long as the radii > 0.5 they will
// correctly produce an alpha value of 1 at all four corners. We take the min of all the alphas.
// The code below is a simplified version of the above that performs maxs on the vector
// components before computing distances and alpha values so that only one distance computation
// need be computed to determine the min alpha.
builder->fsCodeAppendf("\t\tvec2 dxy0 = %s.xy - %s;\n", rectName, fragmentPos);
builder->fsCodeAppendf("\t\tvec2 dxy1 = %s - %s.zw;\n", fragmentPos, rectName);
switch (erre.getRRect().getType()) {
case SkRRect::kSimple_Type: {
const char *invRadiiXYSqdName;
fInvRadiiSqdUniform = builder->addUniform(GrGLShaderBuilder::kFragment_Visibility,
kVec2f_GrSLType,
"invRadiiXY",
&invRadiiXYSqdName);
builder->fsCodeAppend("\t\tvec2 dxy = max(max(dxy0, dxy1), 0.0);\n");
// Z is the x/y offsets divided by squared radii.
builder->fsCodeAppendf("\t\tvec2 Z = dxy * %s;\n", invRadiiXYSqdName);
break;
}
case SkRRect::kNinePatch_Type: {
const char *invRadiiLTRBSqdName;
fInvRadiiSqdUniform = builder->addUniform(GrGLShaderBuilder::kFragment_Visibility,
kVec4f_GrSLType,
"invRadiiLTRB",
&invRadiiLTRBSqdName);
builder->fsCodeAppend("\t\tvec2 dxy = max(max(dxy0, dxy1), 0.0);\n");
// Z is the x/y offsets divided by squared radii. We only care about the (at most) one
// corner where both the x and y offsets are positive, hence the maxes. (The inverse
// squared radii will always be positive.)
builder->fsCodeAppendf("\t\tvec2 Z = max(max(dxy0 * %s.xy, dxy1 * %s.zw), 0.0);\n",
invRadiiLTRBSqdName, invRadiiLTRBSqdName);
break;
}
default:
SkFAIL("RRect should always be simple or nine-patch.");
}
// implicit is the evaluation of (x/a)^2 + (y/b)^2 - 1.
builder->fsCodeAppend("\t\tfloat implicit = dot(Z, dxy) - 1.0;\n");
// grad_dot is the squared length of the gradient of the implicit.
builder->fsCodeAppendf("\t\tfloat grad_dot = 4.0 * dot(Z, Z);\n");
// avoid calling inversesqrt on zero.
builder->fsCodeAppend("\t\tgrad_dot = max(grad_dot, 1.0e-4);\n");
builder->fsCodeAppendf("\t\tfloat approx_dist = implicit * inversesqrt(grad_dot);\n");
if (kFillAA_GrEffectEdgeType == erre.getEdgeType()) {
builder->fsCodeAppend("\t\tfloat alpha = clamp(0.5 - approx_dist, 0.0, 1.0);\n");
} else {
builder->fsCodeAppend("\t\tfloat alpha = clamp(0.5 + approx_dist, 0.0, 1.0);\n");
}
builder->fsCodeAppendf("\t\t%s = %s;\n", outputColor,
(GrGLSLExpr4(inputColor) * GrGLSLExpr1("alpha")).c_str());
}
GrGLEffect::EffectKey GLEllipticalRRectEffect::GenKey(const GrDrawEffect& drawEffect,
const GrGLCaps&) {
const EllipticalRRectEffect& erre = drawEffect.castEffect<EllipticalRRectEffect>();
GR_STATIC_ASSERT(kLast_GrEffectEdgeType < (1 << 3));
return erre.getRRect().getType() | erre.getEdgeType() << 3;
}
void GLEllipticalRRectEffect::setData(const GrGLUniformManager& uman,
const GrDrawEffect& drawEffect) {
const EllipticalRRectEffect& erre = drawEffect.castEffect<EllipticalRRectEffect>();
const SkRRect& rrect = erre.getRRect();
if (rrect != fPrevRRect) {
SkRect rect = rrect.getBounds();
const SkVector& r0 = rrect.radii(SkRRect::kUpperLeft_Corner);
SkASSERT(r0.fX >= kRadiusMin);
SkASSERT(r0.fY >= kRadiusMin);
switch (erre.getRRect().getType()) {
case SkRRect::kSimple_Type:
rect.inset(r0.fX, r0.fY);
uman.set2f(fInvRadiiSqdUniform, 1.f / (r0.fX * r0.fX),
1.f / (r0.fY * r0.fY));
break;
case SkRRect::kNinePatch_Type: {
const SkVector& r1 = rrect.radii(SkRRect::kLowerRight_Corner);
SkASSERT(r1.fX >= kRadiusMin);
SkASSERT(r1.fY >= kRadiusMin);
rect.fLeft += r0.fX;
rect.fTop += r0.fY;
rect.fRight -= r1.fX;
rect.fBottom -= r1.fY;
uman.set4f(fInvRadiiSqdUniform, 1.f / (r0.fX * r0.fX),
1.f / (r0.fY * r0.fY),
1.f / (r1.fX * r1.fX),
1.f / (r1.fY * r1.fY));
break;
}
default:
SkFAIL("RRect should always be simple or nine-patch.");
}
uman.set4f(fInnerRectUniform, rect.fLeft, rect.fTop, rect.fRight, rect.fBottom);
fPrevRRect = rrect;
}
}
//////////////////////////////////////////////////////////////////////////////
GrEffectRef* GrRRectEffect::Create(GrEffectEdgeType edgeType, const SkRRect& rrect) {
if (rrect.isRect()) {
return GrConvexPolyEffect::Create(edgeType, rrect.getBounds());
}
if (rrect.isOval()) {
return GrOvalEffect::Create(edgeType, rrect.getBounds());
}
if (rrect.isSimple()) {
if (rrect.getSimpleRadii().fX < kRadiusMin || rrect.getSimpleRadii().fY < kRadiusMin) {
// In this case the corners are extremely close to rectangular and we collapse the
// clip to a rectangular clip.
return GrConvexPolyEffect::Create(edgeType, rrect.getBounds());
}
if (rrect.getSimpleRadii().fX == rrect.getSimpleRadii().fY) {
return CircularRRectEffect::Create(edgeType, CircularRRectEffect::kAll_CornerFlags,
rrect);
} else {
return EllipticalRRectEffect::Create(edgeType, rrect);
}
}
if (rrect.isComplex() || rrect.isNinePatch()) {
// Check for the "tab" cases - two adjacent circular corners and two square corners.
SkScalar circularRadius = 0;
uint32_t cornerFlags = 0;
SkVector radii[4];
bool squashedRadii = false;
for (int c = 0; c < 4; ++c) {
radii[c] = rrect.radii((SkRRect::Corner)c);
SkASSERT((0 == radii[c].fX) == (0 == radii[c].fY));
if (0 == radii[c].fX) {
// The corner is square, so no need to squash or flag as circular.
continue;
}
if (radii[c].fX < kRadiusMin || radii[c].fY < kRadiusMin) {
radii[c].set(0, 0);
squashedRadii = true;
continue;
}
if (radii[c].fX != radii[c].fY) {
cornerFlags = ~0U;
break;
}
if (!cornerFlags) {
circularRadius = radii[c].fX;
cornerFlags = 1 << c;
} else {
if (radii[c].fX != circularRadius) {
cornerFlags = ~0U;
break;
}
cornerFlags |= 1 << c;
}
}
switch (cornerFlags) {
case CircularRRectEffect::kAll_CornerFlags:
// This rrect should have been caught in the simple case above. Though, it would
// be correctly handled in the fallthrough code.
SkASSERT(false);
case CircularRRectEffect::kTopLeft_CornerFlag:
case CircularRRectEffect::kTopRight_CornerFlag:
case CircularRRectEffect::kBottomRight_CornerFlag:
case CircularRRectEffect::kBottomLeft_CornerFlag:
case CircularRRectEffect::kLeft_CornerFlags:
case CircularRRectEffect::kTop_CornerFlags:
case CircularRRectEffect::kRight_CornerFlags:
case CircularRRectEffect::kBottom_CornerFlags: {
SkTCopyOnFirstWrite<SkRRect> rr(rrect);
if (squashedRadii) {
rr.writable()->setRectRadii(rrect.getBounds(), radii);
}
return CircularRRectEffect::Create(edgeType, cornerFlags, *rr);
}
case CircularRRectEffect::kNone_CornerFlags:
return GrConvexPolyEffect::Create(edgeType, rrect.getBounds());
default: {
if (squashedRadii) {
// If we got here then we squashed some but not all the radii to zero. (If all
// had been squashed cornerFlags would be 0.) The elliptical effect doesn't
// support some rounded and some square corners.
return NULL;
}
if (rrect.isNinePatch()) {
return EllipticalRRectEffect::Create(edgeType, rrect);
}
return NULL;
}
}
}
return NULL;
}