| /* |
| * Copyright 2013 Google Inc. |
| * |
| * Use of this source code is governed by a BSD-style license that can be |
| * found in the LICENSE file. |
| */ |
| |
| #include "GrOvalRenderer.h" |
| |
| #include "GrEffect.h" |
| #include "gl/GrGLEffect.h" |
| #include "gl/GrGLSL.h" |
| #include "GrTBackendEffectFactory.h" |
| |
| #include "GrDrawState.h" |
| #include "GrDrawTarget.h" |
| #include "SkStrokeRec.h" |
| |
| SK_DEFINE_INST_COUNT(GrOvalRenderer) |
| |
| namespace { |
| |
| struct CircleVertex { |
| GrPoint fPos; |
| GrPoint fOffset; |
| SkScalar fOuterRadius; |
| SkScalar fInnerRadius; |
| }; |
| |
| struct EllipseVertex { |
| GrPoint fPos; |
| SkScalar fOuterXRadius; |
| SkScalar fInnerXRadius; |
| GrPoint fOuterOffset; |
| GrPoint fInnerOffset; |
| }; |
| |
| inline bool circle_stays_circle(const SkMatrix& m) { |
| return m.isSimilarity(); |
| } |
| |
| } |
| |
| /////////////////////////////////////////////////////////////////////////////// |
| |
| /** |
| * The output of this effect is a modulation of the input color and coverage for a circle, |
| * specified as offset_x, offset_y (both from center point), outer radius and inner radius. |
| */ |
| |
| class CircleEdgeEffect : public GrEffect { |
| public: |
| static GrEffectRef* Create(bool stroke) { |
| // we go through this so we only have one copy of each effect (stroked/filled) |
| static SkAutoTUnref<GrEffectRef> gCircleStrokeEdgeEffectRef( |
| CreateEffectRef(AutoEffectUnref(SkNEW_ARGS(CircleEdgeEffect, (true))))); |
| static SkAutoTUnref<GrEffectRef> gCircleFillEdgeEffectRef( |
| CreateEffectRef(AutoEffectUnref(SkNEW_ARGS(CircleEdgeEffect, (false))))); |
| |
| if (stroke) { |
| gCircleStrokeEdgeEffectRef.get()->ref(); |
| return gCircleStrokeEdgeEffectRef; |
| } else { |
| gCircleFillEdgeEffectRef.get()->ref(); |
| return gCircleFillEdgeEffectRef; |
| } |
| } |
| |
| virtual void getConstantColorComponents(GrColor* color, |
| uint32_t* validFlags) const SK_OVERRIDE { |
| *validFlags = 0; |
| } |
| |
| virtual const GrBackendEffectFactory& getFactory() const SK_OVERRIDE { |
| return GrTBackendEffectFactory<CircleEdgeEffect>::getInstance(); |
| } |
| |
| virtual ~CircleEdgeEffect() {} |
| |
| static const char* Name() { return "CircleEdge"; } |
| |
| inline bool isStroked() const { return fStroke; } |
| |
| class GLEffect : public GrGLEffect { |
| public: |
| GLEffect(const GrBackendEffectFactory& factory, const GrDrawEffect&) |
| : INHERITED (factory) {} |
| |
| virtual void emitCode(GrGLShaderBuilder* builder, |
| const GrDrawEffect& drawEffect, |
| EffectKey key, |
| const char* outputColor, |
| const char* inputColor, |
| const TextureSamplerArray& samplers) SK_OVERRIDE { |
| const CircleEdgeEffect& circleEffect = drawEffect.castEffect<CircleEdgeEffect>(); |
| const char *vsName, *fsName; |
| builder->addVarying(kVec4f_GrSLType, "CircleEdge", &vsName, &fsName); |
| |
| const SkString* attrName = |
| builder->getEffectAttributeName(drawEffect.getVertexAttribIndices()[0]); |
| builder->vsCodeAppendf("\t%s = %s;\n", vsName, attrName->c_str()); |
| |
| builder->fsCodeAppendf("\tfloat d = length(%s.xy);\n", fsName); |
| builder->fsCodeAppendf("\tfloat edgeAlpha = clamp(%s.z - d, 0.0, 1.0);\n", fsName); |
| if (circleEffect.isStroked()) { |
| builder->fsCodeAppendf("\tfloat innerAlpha = clamp(d - %s.w, 0.0, 1.0);\n", fsName); |
| builder->fsCodeAppend("\tedgeAlpha *= innerAlpha;\n"); |
| } |
| |
| SkString modulate; |
| GrGLSLModulate4f(&modulate, inputColor, "edgeAlpha"); |
| builder->fsCodeAppendf("\t%s = %s;\n", outputColor, modulate.c_str()); |
| } |
| |
| static inline EffectKey GenKey(const GrDrawEffect& drawEffect, const GrGLCaps&) { |
| const CircleEdgeEffect& circleEffect = drawEffect.castEffect<CircleEdgeEffect>(); |
| |
| return circleEffect.isStroked() ? 0x1 : 0x0; |
| } |
| |
| virtual void setData(const GrGLUniformManager&, const GrDrawEffect&) SK_OVERRIDE {} |
| |
| private: |
| typedef GrGLEffect INHERITED; |
| }; |
| |
| |
| private: |
| CircleEdgeEffect(bool stroke) : GrEffect() { |
| this->addVertexAttrib(kVec4f_GrSLType); |
| fStroke = stroke; |
| } |
| |
| virtual bool onIsEqual(const GrEffect& other) const SK_OVERRIDE { |
| const CircleEdgeEffect& cee = CastEffect<CircleEdgeEffect>(other); |
| return cee.fStroke == fStroke; |
| } |
| |
| bool fStroke; |
| |
| GR_DECLARE_EFFECT_TEST; |
| |
| typedef GrEffect INHERITED; |
| }; |
| |
| GR_DEFINE_EFFECT_TEST(CircleEdgeEffect); |
| |
| GrEffectRef* CircleEdgeEffect::TestCreate(SkMWCRandom* random, |
| GrContext* context, |
| const GrDrawTargetCaps&, |
| GrTexture* textures[]) { |
| return CircleEdgeEffect::Create(random->nextBool()); |
| } |
| |
| /////////////////////////////////////////////////////////////////////////////// |
| |
| /** |
| * The output of this effect is a modulation of the input color and coverage for an axis-aligned |
| * ellipse, specified as outer and inner radii, and outer and inner offsets from center. |
| */ |
| |
| class EllipseEdgeEffect : public GrEffect { |
| public: |
| static GrEffectRef* Create(bool stroke) { |
| // we go through this so we only have one copy of each effect (stroked/filled) |
| static SkAutoTUnref<GrEffectRef> gEllipseStrokeEdgeEffectRef( |
| CreateEffectRef(AutoEffectUnref(SkNEW_ARGS(EllipseEdgeEffect, (true))))); |
| static SkAutoTUnref<GrEffectRef> gEllipseFillEdgeEffectRef( |
| CreateEffectRef(AutoEffectUnref(SkNEW_ARGS(EllipseEdgeEffect, (false))))); |
| |
| if (stroke) { |
| gEllipseStrokeEdgeEffectRef.get()->ref(); |
| return gEllipseStrokeEdgeEffectRef; |
| } else { |
| gEllipseFillEdgeEffectRef.get()->ref(); |
| return gEllipseFillEdgeEffectRef; |
| } |
| } |
| |
| virtual void getConstantColorComponents(GrColor* color, |
| uint32_t* validFlags) const SK_OVERRIDE { |
| *validFlags = 0; |
| } |
| |
| virtual const GrBackendEffectFactory& getFactory() const SK_OVERRIDE { |
| return GrTBackendEffectFactory<EllipseEdgeEffect>::getInstance(); |
| } |
| |
| virtual ~EllipseEdgeEffect() {} |
| |
| static const char* Name() { return "EllipseEdge"; } |
| |
| inline bool isStroked() const { return fStroke; } |
| |
| class GLEffect : public GrGLEffect { |
| public: |
| GLEffect(const GrBackendEffectFactory& factory, const GrDrawEffect&) |
| : INHERITED (factory) {} |
| |
| virtual void emitCode(GrGLShaderBuilder* builder, |
| const GrDrawEffect& drawEffect, |
| EffectKey key, |
| const char* outputColor, |
| const char* inputColor, |
| const TextureSamplerArray& samplers) SK_OVERRIDE { |
| const EllipseEdgeEffect& ellipseEffect = drawEffect.castEffect<EllipseEdgeEffect>(); |
| |
| const char *vsRadiiName, *fsRadiiName; |
| const char *vsOffsetsName, *fsOffsetsName; |
| |
| builder->addVarying(kVec2f_GrSLType, "EllipseRadii", &vsRadiiName, &fsRadiiName); |
| const SkString* attr0Name = |
| builder->getEffectAttributeName(drawEffect.getVertexAttribIndices()[0]); |
| builder->vsCodeAppendf("\t%s = %s;\n", vsRadiiName, attr0Name->c_str()); |
| |
| builder->addVarying(kVec4f_GrSLType, "EllipseOffsets", &vsOffsetsName, &fsOffsetsName); |
| const SkString* attr1Name = |
| builder->getEffectAttributeName(drawEffect.getVertexAttribIndices()[1]); |
| builder->vsCodeAppendf("\t%s = %s;\n", vsOffsetsName, attr1Name->c_str()); |
| |
| // get length of offset |
| builder->fsCodeAppendf("\tfloat dOuter = length(%s.xy);\n", fsOffsetsName); |
| // compare outer lengths against xOuterRadius |
| builder->fsCodeAppendf("\tfloat edgeAlpha = clamp(%s.x-dOuter, 0.0, 1.0);\n", |
| fsRadiiName); |
| |
| if (ellipseEffect.isStroked()) { |
| builder->fsCodeAppendf("\tfloat dInner = length(%s.zw);\n", fsOffsetsName); |
| |
| // compare inner lengths against xInnerRadius |
| builder->fsCodeAppendf("\tfloat innerAlpha = clamp(dInner-%s.y, 0.0, 1.0);\n", |
| fsRadiiName); |
| builder->fsCodeAppend("\tedgeAlpha *= innerAlpha;\n"); |
| } |
| |
| SkString modulate; |
| GrGLSLModulate4f(&modulate, inputColor, "edgeAlpha"); |
| builder->fsCodeAppendf("\t%s = %s;\n", outputColor, modulate.c_str()); |
| } |
| |
| static inline EffectKey GenKey(const GrDrawEffect& drawEffect, const GrGLCaps&) { |
| const EllipseEdgeEffect& ellipseEffect = drawEffect.castEffect<EllipseEdgeEffect>(); |
| |
| return ellipseEffect.isStroked() ? 0x1 : 0x0; |
| } |
| |
| virtual void setData(const GrGLUniformManager&, const GrDrawEffect&) SK_OVERRIDE { |
| } |
| |
| private: |
| typedef GrGLEffect INHERITED; |
| }; |
| |
| private: |
| EllipseEdgeEffect(bool stroke) : GrEffect() { |
| this->addVertexAttrib(kVec2f_GrSLType); |
| this->addVertexAttrib(kVec4f_GrSLType); |
| fStroke = stroke; |
| } |
| |
| virtual bool onIsEqual(const GrEffect& other) const SK_OVERRIDE { |
| const EllipseEdgeEffect& eee = CastEffect<EllipseEdgeEffect>(other); |
| return eee.fStroke == fStroke; |
| } |
| |
| bool fStroke; |
| |
| GR_DECLARE_EFFECT_TEST; |
| |
| typedef GrEffect INHERITED; |
| }; |
| |
| GR_DEFINE_EFFECT_TEST(EllipseEdgeEffect); |
| |
| GrEffectRef* EllipseEdgeEffect::TestCreate(SkMWCRandom* random, |
| GrContext* context, |
| const GrDrawTargetCaps&, |
| GrTexture* textures[]) { |
| return EllipseEdgeEffect::Create(random->nextBool()); |
| } |
| |
| /////////////////////////////////////////////////////////////////////////////// |
| |
| bool GrOvalRenderer::drawOval(GrDrawTarget* target, const GrContext* context, const GrPaint& paint, |
| const GrRect& oval, const SkStrokeRec& stroke) |
| { |
| if (!paint.isAntiAlias()) { |
| return false; |
| } |
| |
| const SkMatrix& vm = context->getMatrix(); |
| |
| // we can draw circles |
| if (SkScalarNearlyEqual(oval.width(), oval.height()) |
| && circle_stays_circle(vm)) { |
| drawCircle(target, paint, oval, stroke); |
| |
| // and axis-aligned ellipses only |
| } else if (vm.rectStaysRect()) { |
| return drawEllipse(target, paint, oval, stroke); |
| |
| } else { |
| return false; |
| } |
| |
| return true; |
| } |
| |
| void GrOvalRenderer::drawCircle(GrDrawTarget* target, |
| const GrPaint& paint, |
| const GrRect& circle, |
| const SkStrokeRec& stroke) |
| { |
| GrDrawState* drawState = target->drawState(); |
| |
| const SkMatrix& vm = drawState->getViewMatrix(); |
| GrPoint center = GrPoint::Make(circle.centerX(), circle.centerY()); |
| vm.mapPoints(¢er, 1); |
| SkScalar radius = vm.mapRadius(SkScalarHalf(circle.width())); |
| SkScalar strokeWidth = vm.mapRadius(stroke.getWidth()); |
| |
| GrDrawState::AutoDeviceCoordDraw adcd(drawState); |
| if (!adcd.succeeded()) { |
| return; |
| } |
| |
| // position + edge |
| static const GrVertexAttrib kVertexAttribs[] = { |
| {kVec2f_GrVertexAttribType, 0, kPosition_GrVertexAttribBinding}, |
| {kVec4f_GrVertexAttribType, sizeof(GrPoint), kEffect_GrVertexAttribBinding} |
| }; |
| drawState->setVertexAttribs(kVertexAttribs, SK_ARRAY_COUNT(kVertexAttribs)); |
| GrAssert(sizeof(CircleVertex) == drawState->getVertexSize()); |
| |
| GrDrawTarget::AutoReleaseGeometry geo(target, 4, 0); |
| if (!geo.succeeded()) { |
| GrPrintf("Failed to get space for vertices!\n"); |
| return; |
| } |
| |
| CircleVertex* verts = reinterpret_cast<CircleVertex*>(geo.vertices()); |
| |
| SkStrokeRec::Style style = stroke.getStyle(); |
| bool isStroked = (SkStrokeRec::kStroke_Style == style || SkStrokeRec::kHairline_Style == style); |
| enum { |
| // the edge effects share this stage with glyph rendering |
| // (kGlyphMaskStage in GrTextContext) && SW path rendering |
| // (kPathMaskStage in GrSWMaskHelper) |
| kEdgeEffectStage = GrPaint::kTotalStages, |
| }; |
| |
| GrEffectRef* effect = CircleEdgeEffect::Create(isStroked); |
| static const int kCircleEdgeAttrIndex = 1; |
| drawState->setEffect(kEdgeEffectStage, effect, kCircleEdgeAttrIndex)->unref(); |
| |
| SkScalar innerRadius = 0.0f; |
| SkScalar outerRadius = radius; |
| SkScalar halfWidth = 0; |
| if (style != SkStrokeRec::kFill_Style) { |
| if (SkScalarNearlyZero(strokeWidth)) { |
| halfWidth = SK_ScalarHalf; |
| } else { |
| halfWidth = SkScalarHalf(strokeWidth); |
| } |
| |
| outerRadius += halfWidth; |
| if (isStroked) { |
| innerRadius = SkMaxScalar(0, radius - halfWidth); |
| } |
| } |
| |
| // The radii are outset for two reasons. First, it allows the shader to simply perform |
| // clamp(distance-to-center - radius, 0, 1). Second, the outer radius is used to compute the |
| // verts of the bounding box that is rendered and the outset ensures the box will cover all |
| // pixels partially covered by the circle. |
| outerRadius += SK_ScalarHalf; |
| innerRadius -= SK_ScalarHalf; |
| |
| SkRect bounds = SkRect::MakeLTRB( |
| center.fX - outerRadius, |
| center.fY - outerRadius, |
| center.fX + outerRadius, |
| center.fY + outerRadius |
| ); |
| |
| verts[0].fPos = SkPoint::Make(bounds.fLeft, bounds.fTop); |
| verts[0].fOffset = SkPoint::Make(-outerRadius, -outerRadius); |
| verts[0].fOuterRadius = outerRadius; |
| verts[0].fInnerRadius = innerRadius; |
| |
| verts[1].fPos = SkPoint::Make(bounds.fRight, bounds.fTop); |
| verts[1].fOffset = SkPoint::Make(outerRadius, -outerRadius); |
| verts[1].fOuterRadius = outerRadius; |
| verts[1].fInnerRadius = innerRadius; |
| |
| verts[2].fPos = SkPoint::Make(bounds.fLeft, bounds.fBottom); |
| verts[2].fOffset = SkPoint::Make(-outerRadius, outerRadius); |
| verts[2].fOuterRadius = outerRadius; |
| verts[2].fInnerRadius = innerRadius; |
| |
| verts[3].fPos = SkPoint::Make(bounds.fRight, bounds.fBottom); |
| verts[3].fOffset = SkPoint::Make(outerRadius, outerRadius); |
| verts[3].fOuterRadius = outerRadius; |
| verts[3].fInnerRadius = innerRadius; |
| |
| target->drawNonIndexed(kTriangleStrip_GrPrimitiveType, 0, 4, &bounds); |
| } |
| |
| bool GrOvalRenderer::drawEllipse(GrDrawTarget* target, |
| const GrPaint& paint, |
| const GrRect& ellipse, |
| const SkStrokeRec& stroke) |
| { |
| GrDrawState* drawState = target->drawState(); |
| #ifdef SK_DEBUG |
| { |
| // we should have checked for this previously |
| bool isAxisAlignedEllipse = drawState->getViewMatrix().rectStaysRect(); |
| SkASSERT(paint.isAntiAlias() && isAxisAlignedEllipse); |
| } |
| #endif |
| |
| const SkMatrix& vm = drawState->getViewMatrix(); |
| GrPoint center = GrPoint::Make(ellipse.centerX(), ellipse.centerY()); |
| vm.mapPoints(¢er, 1); |
| SkRect xformedRect; |
| vm.mapRect(&xformedRect, ellipse); |
| SkScalar xRadius = SkScalarHalf(xformedRect.width()); |
| SkScalar yRadius = SkScalarHalf(xformedRect.height()); |
| if (SkScalarDiv(xRadius, yRadius) > 2 || SkScalarDiv(yRadius, xRadius) > 2) { |
| return false; |
| } |
| |
| GrDrawState::AutoDeviceCoordDraw adcd(drawState); |
| if (!adcd.succeeded()) { |
| return false; |
| } |
| |
| // position + edge |
| static const GrVertexAttrib kVertexAttribs[] = { |
| {kVec2f_GrVertexAttribType, 0, kPosition_GrVertexAttribBinding}, |
| {kVec2f_GrVertexAttribType, sizeof(GrPoint), kEffect_GrVertexAttribBinding}, |
| {kVec4f_GrVertexAttribType, 2*sizeof(GrPoint), kEffect_GrVertexAttribBinding} |
| }; |
| drawState->setVertexAttribs(kVertexAttribs, SK_ARRAY_COUNT(kVertexAttribs)); |
| GrAssert(sizeof(EllipseVertex) == drawState->getVertexSize()); |
| |
| GrDrawTarget::AutoReleaseGeometry geo(target, 4, 0); |
| if (!geo.succeeded()) { |
| GrPrintf("Failed to get space for vertices!\n"); |
| return false; |
| } |
| |
| EllipseVertex* verts = reinterpret_cast<EllipseVertex*>(geo.vertices()); |
| |
| SkStrokeRec::Style style = stroke.getStyle(); |
| bool isStroked = (SkStrokeRec::kStroke_Style == style || SkStrokeRec::kHairline_Style == style); |
| enum { |
| // the edge effects share this stage with glyph rendering |
| // (kGlyphMaskStage in GrTextContext) && SW path rendering |
| // (kPathMaskStage in GrSWMaskHelper) |
| kEdgeEffectStage = GrPaint::kTotalStages, |
| }; |
| |
| GrEffectRef* effect = EllipseEdgeEffect::Create(isStroked); |
| static const int kEllipseCenterAttrIndex = 1; |
| static const int kEllipseEdgeAttrIndex = 2; |
| drawState->setEffect(kEdgeEffectStage, effect, |
| kEllipseCenterAttrIndex, kEllipseEdgeAttrIndex)->unref(); |
| |
| SkScalar innerXRadius = 0.0f; |
| SkScalar innerRatio = 1.0f; |
| |
| if (SkStrokeRec::kFill_Style != style) { |
| SkScalar strokeWidth = stroke.getWidth(); |
| |
| // do (potentially) anisotropic mapping |
| SkVector scaledStroke; |
| scaledStroke.set(strokeWidth, strokeWidth); |
| vm.mapVectors(&scaledStroke, 1); |
| |
| if (SkScalarNearlyZero(scaledStroke.length())) { |
| scaledStroke.set(SK_ScalarHalf, SK_ScalarHalf); |
| } else { |
| scaledStroke.scale(0.5f); |
| } |
| |
| // this is legit only if scale & translation (which should be the case at the moment) |
| if (SkStrokeRec::kStroke_Style == style || SkStrokeRec::kHairline_Style == style) { |
| SkScalar innerYRadius = SkMaxScalar(0, yRadius - scaledStroke.fY); |
| if (innerYRadius > SK_ScalarNearlyZero) { |
| innerXRadius = SkMaxScalar(0, xRadius - scaledStroke.fX); |
| innerRatio = innerXRadius/innerYRadius; |
| } |
| } |
| xRadius += scaledStroke.fX; |
| yRadius += scaledStroke.fY; |
| } |
| |
| SkScalar outerRatio = SkScalarDiv(xRadius, yRadius); |
| |
| // We've extended the outer x radius out half a pixel to antialias. |
| // This will also expand the rect so all the pixels will be captured. |
| xRadius += SK_ScalarHalf; |
| yRadius += SK_ScalarHalf; |
| innerXRadius -= SK_ScalarHalf; |
| |
| SkRect bounds = SkRect::MakeLTRB( |
| center.fX - xRadius, |
| center.fY - yRadius, |
| center.fX + xRadius, |
| center.fY + yRadius |
| ); |
| |
| // The offsets are created by scaling the y radius by the appropriate ratio. This way we end up |
| // with a circle equation which can be checked quickly in the shader. We need one offset for |
| // outer and one for inner because they have different scale factors -- otherwise we end up with |
| // non-uniform strokes. |
| verts[0].fPos = SkPoint::Make(bounds.fLeft, bounds.fTop); |
| verts[0].fOuterXRadius = xRadius; |
| verts[0].fInnerXRadius = innerXRadius; |
| verts[0].fOuterOffset = SkPoint::Make(-xRadius, -outerRatio*yRadius); |
| verts[0].fInnerOffset = SkPoint::Make(-xRadius, -innerRatio*yRadius); |
| |
| verts[1].fPos = SkPoint::Make(bounds.fRight, bounds.fTop); |
| verts[1].fOuterXRadius = xRadius; |
| verts[1].fInnerXRadius = innerXRadius; |
| verts[1].fOuterOffset = SkPoint::Make(xRadius, -outerRatio*yRadius); |
| verts[1].fInnerOffset = SkPoint::Make(xRadius, -innerRatio*yRadius); |
| |
| verts[2].fPos = SkPoint::Make(bounds.fLeft, bounds.fBottom); |
| verts[2].fOuterXRadius = xRadius; |
| verts[2].fInnerXRadius = innerXRadius; |
| verts[2].fOuterOffset = SkPoint::Make(-xRadius, outerRatio*yRadius); |
| verts[2].fInnerOffset = SkPoint::Make(-xRadius, innerRatio*yRadius); |
| |
| verts[3].fPos = SkPoint::Make(bounds.fRight, bounds.fBottom); |
| verts[3].fOuterXRadius = xRadius; |
| verts[3].fInnerXRadius = innerXRadius; |
| verts[3].fOuterOffset = SkPoint::Make(xRadius, outerRatio*yRadius); |
| verts[3].fInnerOffset = SkPoint::Make(xRadius, innerRatio*yRadius); |
| |
| target->drawNonIndexed(kTriangleStrip_GrPrimitiveType, 0, 4, &bounds); |
| |
| return true; |
| } |