| /* |
| * 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 "GrDashingEffect.h" |
| |
| #include "gl/GrGLEffect.h" |
| #include "gl/GrGLSL.h" |
| #include "GrContext.h" |
| #include "GrCoordTransform.h" |
| #include "GrDrawTargetCaps.h" |
| #include "GrEffect.h" |
| #include "GrTBackendEffectFactory.h" |
| #include "SkGr.h" |
| |
| /////////////////////////////////////////////////////////////////////////////// |
| |
| static void calc_dash_scaling(SkScalar* parallelScale, SkScalar* perpScale, |
| const SkMatrix& viewMatrix, const SkPoint pts[2]) { |
| SkVector vecSrc = pts[1] - pts[0]; |
| SkScalar magSrc = vecSrc.length(); |
| SkScalar invSrc = magSrc ? SkScalarInvert(magSrc) : 0; |
| vecSrc.scale(invSrc); |
| |
| SkVector vecSrcPerp; |
| vecSrc.rotateCW(&vecSrcPerp); |
| viewMatrix.mapVectors(&vecSrc, 1); |
| viewMatrix.mapVectors(&vecSrcPerp, 1); |
| |
| // parallelScale tells how much to scale along the line parallel to the dash line |
| // perpScale tells how much to scale in the direction perpendicular to the dash line |
| *parallelScale = vecSrc.length(); |
| *perpScale = vecSrcPerp.length(); |
| } |
| |
| // calculates the rotation needed to aligned pts to the x axis with pts[0] < pts[1] |
| // Stores the rotation matrix in rotMatrix, and the mapped points in ptsRot |
| static void align_to_x_axis(const SkPoint pts[2], SkMatrix* rotMatrix, SkPoint ptsRot[2] = NULL) { |
| SkVector vec = pts[1] - pts[0]; |
| SkScalar mag = vec.length(); |
| SkScalar inv = mag ? SkScalarInvert(mag) : 0; |
| |
| vec.scale(inv); |
| rotMatrix->setSinCos(-vec.fY, vec.fX, pts[0].fX, pts[0].fY); |
| if (ptsRot) { |
| rotMatrix->mapPoints(ptsRot, pts, 2); |
| // correction for numerical issues if map doesn't make ptsRot exactly horizontal |
| ptsRot[1].fY = pts[0].fY; |
| } |
| } |
| |
| // Assumes phase < sum of all intervals |
| static SkScalar calc_start_adjustment(const SkPathEffect::DashInfo& info) { |
| SkASSERT(info.fPhase < info.fIntervals[0] + info.fIntervals[1]); |
| if (info.fPhase >= info.fIntervals[0] && info.fPhase != 0) { |
| SkScalar srcIntervalLen = info.fIntervals[0] + info.fIntervals[1]; |
| return srcIntervalLen - info.fPhase; |
| } |
| return 0; |
| } |
| |
| static SkScalar calc_end_adjustment(const SkPathEffect::DashInfo& info, const SkPoint pts[2], SkScalar* endingInt) { |
| if (pts[1].fX <= pts[0].fX) { |
| return 0; |
| } |
| SkScalar srcIntervalLen = info.fIntervals[0] + info.fIntervals[1]; |
| SkScalar totalLen = pts[1].fX - pts[0].fX; |
| SkScalar temp = SkScalarDiv(totalLen, srcIntervalLen); |
| SkScalar numFullIntervals = SkScalarFloorToScalar(temp); |
| *endingInt = totalLen - numFullIntervals * srcIntervalLen + info.fPhase; |
| temp = SkScalarDiv(*endingInt, srcIntervalLen); |
| *endingInt = *endingInt - SkScalarFloorToScalar(temp) * srcIntervalLen; |
| if (0 == *endingInt) { |
| *endingInt = srcIntervalLen; |
| } |
| if (*endingInt > info.fIntervals[0]) { |
| if (0 == info.fIntervals[0]) { |
| *endingInt -= 0.01f; // make sure we capture the last zero size pnt (used if has caps) |
| } |
| return *endingInt - info.fIntervals[0]; |
| } |
| return 0; |
| } |
| |
| |
| bool GrDashingEffect::DrawDashLine(const SkPoint pts[2], const SkPaint& paint, GrContext* context) { |
| if (context->getRenderTarget()->isMultisampled()) { |
| return false; |
| } |
| |
| const SkMatrix& viewMatrix = context->getMatrix(); |
| if (!viewMatrix.preservesRightAngles()) { |
| return false; |
| } |
| |
| const SkPathEffect* pe = paint.getPathEffect(); |
| SkPathEffect::DashInfo info; |
| SkPathEffect::DashType dashType = pe->asADash(&info); |
| // Must be a dash effect with 2 intervals (1 on and 1 off) |
| if (SkPathEffect::kDash_DashType != dashType || 2 != info.fCount) { |
| return false; |
| } |
| |
| SkPaint::Cap cap = paint.getStrokeCap(); |
| // Current we do don't handle Round or Square cap dashes |
| if (SkPaint::kRound_Cap == cap) { |
| return false; |
| } |
| |
| SkScalar srcStrokeWidth = paint.getStrokeWidth(); |
| |
| // Get all info about the dash effect |
| SkAutoTArray<SkScalar> intervals(info.fCount); |
| info.fIntervals = intervals.get(); |
| pe->asADash(&info); |
| |
| // the phase should be normalized to be [0, sum of all intervals) |
| SkASSERT(info.fPhase >= 0 && info.fPhase < info.fIntervals[0] + info.fIntervals[1]); |
| |
| SkMatrix coordTrans; |
| |
| // Rotate the src pts so they are aligned horizontally with pts[0].fX < pts[1].fX |
| SkMatrix srcRotInv; |
| SkPoint ptsRot[2]; |
| if (pts[0].fY != pts[1].fY || pts[0].fX > pts[1].fX) { |
| align_to_x_axis(pts, &coordTrans, ptsRot); |
| if(!coordTrans.invert(&srcRotInv)) { |
| return false; |
| } |
| } else { |
| coordTrans.reset(); |
| srcRotInv.reset(); |
| memcpy(ptsRot, pts, 2 * sizeof(SkPoint)); |
| } |
| |
| GrPaint grPaint; |
| SkPaint2GrPaintShader(context, paint, true, &grPaint); |
| |
| bool useAA = paint.isAntiAlias(); |
| |
| // Scale corrections of intervals and stroke from view matrix |
| SkScalar parallelScale; |
| SkScalar perpScale; |
| calc_dash_scaling(¶llelScale, &perpScale, viewMatrix, ptsRot); |
| |
| bool hasCap = SkPaint::kSquare_Cap == cap && 0 != srcStrokeWidth; |
| |
| // We always want to at least stroke out half a pixel on each side in device space |
| // so 0.5f / perpScale gives us this min in src space |
| SkScalar halfStroke = SkMaxScalar(srcStrokeWidth * 0.5f, 0.5f / perpScale); |
| |
| SkScalar xStroke; |
| if (!hasCap) { |
| xStroke = 0.f; |
| } else { |
| xStroke = halfStroke; |
| } |
| |
| // If we are using AA, check to see if we are drawing a partial dash at the start. If so |
| // draw it separately here and adjust our start point accordingly |
| if (useAA) { |
| if (info.fPhase > 0 && info.fPhase < info.fIntervals[0]) { |
| SkPoint startPts[2]; |
| startPts[0] = ptsRot[0]; |
| startPts[1].fY = startPts[0].fY; |
| startPts[1].fX = SkMinScalar(startPts[0].fX + info.fIntervals[0] - info.fPhase, |
| ptsRot[1].fX); |
| SkRect startRect; |
| startRect.set(startPts, 2); |
| startRect.outset(xStroke, halfStroke); |
| context->drawRect(grPaint, startRect, NULL, &srcRotInv); |
| |
| ptsRot[0].fX += info.fIntervals[0] + info.fIntervals[1] - info.fPhase; |
| info.fPhase = 0; |
| } |
| } |
| |
| // adjustments for start and end of bounding rect so we only draw dash intervals |
| // contained in the original line segment. |
| SkScalar startAdj = calc_start_adjustment(info); |
| SkScalar endingInterval = 0; |
| SkScalar endAdj = calc_end_adjustment(info, ptsRot, &endingInterval); |
| if (ptsRot[0].fX + startAdj >= ptsRot[1].fX - endAdj) { |
| // Nothing left to draw so just return |
| return true; |
| } |
| |
| // If we are using AA, check to see if we are drawing a partial dash at then end. If so |
| // draw it separately here and adjust our end point accordingly |
| if (useAA) { |
| // If we adjusted the end then we will not be drawing a partial dash at the end. |
| // If we didn't adjust the end point then we just need to make sure the ending |
| // dash isn't a full dash |
| if (0 == endAdj && endingInterval != info.fIntervals[0]) { |
| |
| SkPoint endPts[2]; |
| endPts[1] = ptsRot[1]; |
| endPts[0].fY = endPts[1].fY; |
| endPts[0].fX = endPts[1].fX - endingInterval; |
| |
| SkRect endRect; |
| endRect.set(endPts, 2); |
| endRect.outset(xStroke, halfStroke); |
| context->drawRect(grPaint, endRect, NULL, &srcRotInv); |
| |
| ptsRot[1].fX -= endingInterval + info.fIntervals[1]; |
| if (ptsRot[0].fX >= ptsRot[1].fX) { |
| // Nothing left to draw so just return |
| return true; |
| } |
| } |
| } |
| coordTrans.postConcat(viewMatrix); |
| |
| SkPoint devicePts[2]; |
| viewMatrix.mapPoints(devicePts, ptsRot, 2); |
| |
| info.fIntervals[0] *= parallelScale; |
| info.fIntervals[1] *= parallelScale; |
| info.fPhase *= parallelScale; |
| SkScalar strokeWidth = srcStrokeWidth * perpScale; |
| |
| if ((strokeWidth < 1.f && !useAA) || 0.f == strokeWidth) { |
| strokeWidth = 1.f; |
| } |
| |
| // Set up coordTransform for device space transforms |
| // We rotate the dashed line such that it is horizontal with the start point at smaller x |
| // then we translate the start point to the origin |
| if (devicePts[0].fY != devicePts[1].fY || devicePts[0].fX > devicePts[1].fX) { |
| SkMatrix rot; |
| align_to_x_axis(devicePts, &rot); |
| coordTrans.postConcat(rot); |
| } |
| coordTrans.postTranslate(-devicePts[0].fX, -devicePts[0].fY); |
| coordTrans.postTranslate(info.fIntervals[1] * 0.5f + info.fPhase, 0); |
| |
| if (SkPaint::kSquare_Cap == cap && 0 != srcStrokeWidth) { |
| // add cap to on interveal and remove from off interval |
| info.fIntervals[0] += strokeWidth; |
| info.fIntervals[1] -= strokeWidth; |
| } |
| |
| if (info.fIntervals[1] > 0.f) { |
| GrEffectEdgeType edgeType= useAA ? kFillAA_GrEffectEdgeType : |
| kFillBW_GrEffectEdgeType; |
| grPaint.addCoverageEffect( |
| GrDashingEffect::Create(edgeType, info, coordTrans, strokeWidth))->unref(); |
| grPaint.setAntiAlias(false); |
| } |
| |
| SkRect rect; |
| bool bloat = useAA && info.fIntervals[1] > 0.f; |
| SkScalar bloatX = bloat ? 0.5f / parallelScale : 0.f; |
| SkScalar bloatY = bloat ? 0.5f / perpScale : 0.f; |
| ptsRot[0].fX += startAdj; |
| ptsRot[1].fX -= endAdj; |
| if (!hasCap) { |
| xStroke = 0.f; |
| } else { |
| xStroke = halfStroke; |
| } |
| rect.set(ptsRot, 2); |
| rect.outset(bloatX + xStroke, bloatY + halfStroke); |
| context->drawRect(grPaint, rect, NULL, &srcRotInv); |
| |
| return true; |
| } |
| |
| ////////////////////////////////////////////////////////////////////////////// |
| |
| class GLDashingLineEffect; |
| |
| class DashingLineEffect : public GrEffect { |
| public: |
| typedef SkPathEffect::DashInfo DashInfo; |
| |
| /** |
| * The effect calculates the coverage for the case of a horizontal line in device space. |
| * The matrix that is passed in should be able to convert a line in source space to a |
| * horizontal line in device space. Additionally, the coord transform matrix should translate |
| * the the start of line to origin, and the shift it along the positive x-axis by the phase |
| * and half the off interval. |
| */ |
| static GrEffectRef* Create(GrEffectEdgeType edgeType, const DashInfo& info, |
| const SkMatrix& matrix, SkScalar strokeWidth); |
| |
| virtual ~DashingLineEffect(); |
| |
| static const char* Name() { return "DashingEffect"; } |
| |
| GrEffectEdgeType getEdgeType() const { return fEdgeType; } |
| |
| const SkRect& getRect() const { return fRect; } |
| |
| SkScalar getIntervalLength() const { return fIntervalLength; } |
| |
| typedef GLDashingLineEffect GLEffect; |
| |
| virtual void getConstantColorComponents(GrColor* color, uint32_t* validFlags) const SK_OVERRIDE; |
| |
| virtual const GrBackendEffectFactory& getFactory() const SK_OVERRIDE; |
| |
| private: |
| DashingLineEffect(GrEffectEdgeType edgeType, const DashInfo& info, const SkMatrix& matrix, |
| SkScalar strokeWidth); |
| |
| virtual bool onIsEqual(const GrEffect& other) const SK_OVERRIDE; |
| |
| GrEffectEdgeType fEdgeType; |
| GrCoordTransform fCoordTransform; |
| SkRect fRect; |
| SkScalar fIntervalLength; |
| |
| GR_DECLARE_EFFECT_TEST; |
| |
| typedef GrEffect INHERITED; |
| }; |
| |
| ////////////////////////////////////////////////////////////////////////////// |
| |
| class GLDashingLineEffect : public GrGLEffect { |
| public: |
| GLDashingLineEffect(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 fRectUniform; |
| GrGLUniformManager::UniformHandle fIntervalUniform; |
| SkRect fPrevRect; |
| SkScalar fPrevIntervalLength; |
| typedef GrGLEffect INHERITED; |
| }; |
| |
| GLDashingLineEffect::GLDashingLineEffect(const GrBackendEffectFactory& factory, |
| const GrDrawEffect& drawEffect) |
| : INHERITED (factory) { |
| fPrevRect.fLeft = SK_ScalarNaN; |
| fPrevIntervalLength = SK_ScalarMax; |
| |
| } |
| |
| void GLDashingLineEffect::emitCode(GrGLShaderBuilder* builder, |
| const GrDrawEffect& drawEffect, |
| EffectKey key, |
| const char* outputColor, |
| const char* inputColor, |
| const TransformedCoordsArray& coords, |
| const TextureSamplerArray& samplers) { |
| const DashingLineEffect& de = drawEffect.castEffect<DashingLineEffect>(); |
| const char *rectName; |
| // The rect uniform's xyzw refer to (left + 0.5, top + 0.5, right - 0.5, bottom - 0.5), |
| // respectively. |
| fRectUniform = builder->addUniform(GrGLShaderBuilder::kFragment_Visibility, |
| kVec4f_GrSLType, |
| "rect", |
| &rectName); |
| const char *intervalName; |
| // The interval uniform's refers to the total length of the interval (on + off) |
| fIntervalUniform = builder->addUniform(GrGLShaderBuilder::kFragment_Visibility, |
| kFloat_GrSLType, |
| "interval", |
| &intervalName); |
| // transforms all points so that we can compare them to our test rect |
| builder->fsCodeAppendf("\t\tfloat xShifted = %s.x - floor(%s.x / %s) * %s;\n", |
| coords[0].c_str(), coords[0].c_str(), intervalName, intervalName); |
| builder->fsCodeAppendf("\t\tvec2 fragPosShifted = vec2(xShifted, %s.y);\n", coords[0].c_str()); |
| if (GrEffectEdgeTypeIsAA(de.getEdgeType())) { |
| // The amount of coverage removed in x and y by the edges is computed as a pair of negative |
| // numbers, xSub and ySub. |
| builder->fsCodeAppend("\t\tfloat xSub, ySub;\n"); |
| builder->fsCodeAppendf("\t\txSub = min(fragPosShifted.x - %s.x, 0.0);\n", rectName); |
| builder->fsCodeAppendf("\t\txSub += min(%s.z - fragPosShifted.x, 0.0);\n", rectName); |
| builder->fsCodeAppendf("\t\tySub = min(fragPosShifted.y - %s.y, 0.0);\n", rectName); |
| builder->fsCodeAppendf("\t\tySub += min(%s.w - fragPosShifted.y, 0.0);\n", rectName); |
| // Now compute coverage in x and y and multiply them to get the fraction of the pixel |
| // covered. |
| builder->fsCodeAppendf("\t\tfloat alpha = (1.0 + max(xSub, -1.0)) * (1.0 + max(ySub, -1.0));\n"); |
| } else { |
| // Assuming the bounding geometry is tight so no need to check y values |
| builder->fsCodeAppendf("\t\tfloat alpha = 1.0;\n"); |
| builder->fsCodeAppendf("\t\talpha *= (fragPosShifted.x - %s.x) > -0.5 ? 1.0 : 0.0;\n", rectName); |
| builder->fsCodeAppendf("\t\talpha *= (%s.z - fragPosShifted.x) >= -0.5 ? 1.0 : 0.0;\n", rectName); |
| } |
| builder->fsCodeAppendf("\t\t%s = %s;\n", outputColor, |
| (GrGLSLExpr4(inputColor) * GrGLSLExpr1("alpha")).c_str()); |
| } |
| |
| void GLDashingLineEffect::setData(const GrGLUniformManager& uman, const GrDrawEffect& drawEffect) { |
| const DashingLineEffect& de = drawEffect.castEffect<DashingLineEffect>(); |
| const SkRect& rect = de.getRect(); |
| SkScalar intervalLength = de.getIntervalLength(); |
| if (rect != fPrevRect || intervalLength != fPrevIntervalLength) { |
| uman.set4f(fRectUniform, rect.fLeft + 0.5f, rect.fTop + 0.5f, |
| rect.fRight - 0.5f, rect.fBottom - 0.5f); |
| uman.set1f(fIntervalUniform, intervalLength); |
| fPrevRect = rect; |
| fPrevIntervalLength = intervalLength; |
| } |
| } |
| |
| GrGLEffect::EffectKey GLDashingLineEffect::GenKey(const GrDrawEffect& drawEffect, |
| const GrGLCaps&) { |
| const DashingLineEffect& de = drawEffect.castEffect<DashingLineEffect>(); |
| return de.getEdgeType(); |
| } |
| |
| ////////////////////////////////////////////////////////////////////////////// |
| |
| GrEffectRef* DashingLineEffect::Create(GrEffectEdgeType edgeType, const DashInfo& info, |
| const SkMatrix& matrix, SkScalar strokeWidth) { |
| if (info.fCount != 2) { |
| return NULL; |
| } |
| |
| return CreateEffectRef(AutoEffectUnref(SkNEW_ARGS(DashingLineEffect, |
| (edgeType, info, matrix, strokeWidth)))); |
| } |
| |
| DashingLineEffect::~DashingLineEffect() {} |
| |
| void DashingLineEffect::getConstantColorComponents(GrColor* color, uint32_t* validFlags) const { |
| *validFlags = 0; |
| } |
| |
| const GrBackendEffectFactory& DashingLineEffect::getFactory() const { |
| return GrTBackendEffectFactory<DashingLineEffect>::getInstance(); |
| } |
| |
| DashingLineEffect::DashingLineEffect(GrEffectEdgeType edgeType, const DashInfo& info, |
| const SkMatrix& matrix, SkScalar strokeWidth) |
| : fEdgeType(edgeType) |
| , fCoordTransform(kLocal_GrCoordSet, matrix) { |
| SkScalar onLen = info.fIntervals[0]; |
| SkScalar offLen = info.fIntervals[1]; |
| SkScalar halfOffLen = SkScalarHalf(offLen); |
| SkScalar halfStroke = SkScalarHalf(strokeWidth); |
| fIntervalLength = onLen + offLen; |
| fRect.set(halfOffLen, -halfStroke, halfOffLen + onLen, halfStroke); |
| |
| addCoordTransform(&fCoordTransform); |
| } |
| |
| bool DashingLineEffect::onIsEqual(const GrEffect& other) const { |
| const DashingLineEffect& de = CastEffect<DashingLineEffect>(other); |
| return (fEdgeType == de.fEdgeType && |
| fCoordTransform == de.fCoordTransform && |
| fRect == de.fRect && |
| fIntervalLength == de.fIntervalLength); |
| } |
| |
| GR_DEFINE_EFFECT_TEST(DashingLineEffect); |
| |
| GrEffectRef* DashingLineEffect::TestCreate(SkRandom* random, |
| GrContext*, |
| const GrDrawTargetCaps& caps, |
| GrTexture*[]) { |
| GrEffectRef* effect; |
| SkMatrix m; |
| m.reset(); |
| GrEffectEdgeType edgeType = static_cast<GrEffectEdgeType>(random->nextULessThan( |
| kGrEffectEdgeTypeCnt)); |
| SkScalar strokeWidth = random->nextRangeScalar(0, 100.f); |
| DashInfo info; |
| info.fCount = 2; |
| SkAutoTArray<SkScalar> intervals(info.fCount); |
| info.fIntervals = intervals.get(); |
| info.fIntervals[0] = random->nextRangeScalar(0, 10.f); |
| info.fIntervals[1] = random->nextRangeScalar(0, 10.f); |
| info.fPhase = random->nextRangeScalar(0, info.fIntervals[0] + info.fIntervals[1]); |
| |
| effect = DashingLineEffect::Create(edgeType, info, m, strokeWidth); |
| return effect; |
| } |
| |
| ////////////////////////////////////////////////////////////////////////////// |
| |
| GrEffectRef* GrDashingEffect::Create(GrEffectEdgeType edgeType, const SkPathEffect::DashInfo& info, |
| const SkMatrix& matrix, SkScalar strokeWidth) { |
| return DashingLineEffect::Create(edgeType, info, matrix, strokeWidth); |
| } |