| |
| /* |
| * Copyright 2011 Google Inc. |
| * |
| * Use of this source code is governed by a BSD-style license that can be |
| * found in the LICENSE file. |
| */ |
| |
| #include "GrDefaultPathRenderer.h" |
| |
| #include "GrContext.h" |
| #include "GrDrawState.h" |
| #include "GrPathUtils.h" |
| #include "SkString.h" |
| #include "SkStrokeRec.h" |
| #include "SkTrace.h" |
| |
| |
| GrDefaultPathRenderer::GrDefaultPathRenderer(bool separateStencilSupport, |
| bool stencilWrapOpsSupport) |
| : fSeparateStencil(separateStencilSupport) |
| , fStencilWrapOps(stencilWrapOpsSupport) { |
| } |
| |
| |
| //////////////////////////////////////////////////////////////////////////////// |
| // Stencil rules for paths |
| |
| ////// Even/Odd |
| |
| GR_STATIC_CONST_SAME_STENCIL(gEOStencilPass, |
| kInvert_StencilOp, |
| kKeep_StencilOp, |
| kAlwaysIfInClip_StencilFunc, |
| 0xffff, |
| 0xffff, |
| 0xffff); |
| |
| // ok not to check clip b/c stencil pass only wrote inside clip |
| GR_STATIC_CONST_SAME_STENCIL(gEOColorPass, |
| kZero_StencilOp, |
| kZero_StencilOp, |
| kNotEqual_StencilFunc, |
| 0xffff, |
| 0x0000, |
| 0xffff); |
| |
| // have to check clip b/c outside clip will always be zero. |
| GR_STATIC_CONST_SAME_STENCIL(gInvEOColorPass, |
| kZero_StencilOp, |
| kZero_StencilOp, |
| kEqualIfInClip_StencilFunc, |
| 0xffff, |
| 0x0000, |
| 0xffff); |
| |
| ////// Winding |
| |
| // when we have separate stencil we increment front faces / decrement back faces |
| // when we don't have wrap incr and decr we use the stencil test to simulate |
| // them. |
| |
| GR_STATIC_CONST_STENCIL(gWindStencilSeparateWithWrap, |
| kIncWrap_StencilOp, kDecWrap_StencilOp, |
| kKeep_StencilOp, kKeep_StencilOp, |
| kAlwaysIfInClip_StencilFunc, kAlwaysIfInClip_StencilFunc, |
| 0xffff, 0xffff, |
| 0xffff, 0xffff, |
| 0xffff, 0xffff); |
| |
| // if inc'ing the max value, invert to make 0 |
| // if dec'ing zero invert to make all ones. |
| // we can't avoid touching the stencil on both passing and |
| // failing, so we can't resctrict ourselves to the clip. |
| GR_STATIC_CONST_STENCIL(gWindStencilSeparateNoWrap, |
| kInvert_StencilOp, kInvert_StencilOp, |
| kIncClamp_StencilOp, kDecClamp_StencilOp, |
| kEqual_StencilFunc, kEqual_StencilFunc, |
| 0xffff, 0xffff, |
| 0xffff, 0x0000, |
| 0xffff, 0xffff); |
| |
| // When there are no separate faces we do two passes to setup the winding rule |
| // stencil. First we draw the front faces and inc, then we draw the back faces |
| // and dec. These are same as the above two split into the incrementing and |
| // decrementing passes. |
| GR_STATIC_CONST_SAME_STENCIL(gWindSingleStencilWithWrapInc, |
| kIncWrap_StencilOp, |
| kKeep_StencilOp, |
| kAlwaysIfInClip_StencilFunc, |
| 0xffff, |
| 0xffff, |
| 0xffff); |
| |
| GR_STATIC_CONST_SAME_STENCIL(gWindSingleStencilWithWrapDec, |
| kDecWrap_StencilOp, |
| kKeep_StencilOp, |
| kAlwaysIfInClip_StencilFunc, |
| 0xffff, |
| 0xffff, |
| 0xffff); |
| |
| GR_STATIC_CONST_SAME_STENCIL(gWindSingleStencilNoWrapInc, |
| kInvert_StencilOp, |
| kIncClamp_StencilOp, |
| kEqual_StencilFunc, |
| 0xffff, |
| 0xffff, |
| 0xffff); |
| |
| GR_STATIC_CONST_SAME_STENCIL(gWindSingleStencilNoWrapDec, |
| kInvert_StencilOp, |
| kDecClamp_StencilOp, |
| kEqual_StencilFunc, |
| 0xffff, |
| 0x0000, |
| 0xffff); |
| |
| // Color passes are the same whether we use the two-sided stencil or two passes |
| |
| GR_STATIC_CONST_SAME_STENCIL(gWindColorPass, |
| kZero_StencilOp, |
| kZero_StencilOp, |
| kNonZeroIfInClip_StencilFunc, |
| 0xffff, |
| 0x0000, |
| 0xffff); |
| |
| GR_STATIC_CONST_SAME_STENCIL(gInvWindColorPass, |
| kZero_StencilOp, |
| kZero_StencilOp, |
| kEqualIfInClip_StencilFunc, |
| 0xffff, |
| 0x0000, |
| 0xffff); |
| |
| ////// Normal render to stencil |
| |
| // Sometimes the default path renderer can draw a path directly to the stencil |
| // buffer without having to first resolve the interior / exterior. |
| GR_STATIC_CONST_SAME_STENCIL(gDirectToStencil, |
| kZero_StencilOp, |
| kIncClamp_StencilOp, |
| kAlwaysIfInClip_StencilFunc, |
| 0xffff, |
| 0x0000, |
| 0xffff); |
| |
| //////////////////////////////////////////////////////////////////////////////// |
| // Helpers for drawPath |
| |
| #define STENCIL_OFF 0 // Always disable stencil (even when needed) |
| |
| static inline bool single_pass_path(const SkPath& path, const SkStrokeRec& stroke) { |
| #if STENCIL_OFF |
| return true; |
| #else |
| if (!stroke.isHairlineStyle() && !path.isInverseFillType()) { |
| return path.isConvex(); |
| } |
| return false; |
| #endif |
| } |
| |
| GrPathRenderer::StencilSupport GrDefaultPathRenderer::onGetStencilSupport( |
| const SkPath& path, |
| const SkStrokeRec& stroke, |
| const GrDrawTarget*) const { |
| if (single_pass_path(path, stroke)) { |
| return GrPathRenderer::kNoRestriction_StencilSupport; |
| } else { |
| return GrPathRenderer::kStencilOnly_StencilSupport; |
| } |
| } |
| |
| static inline void append_countour_edge_indices(bool hairLine, |
| uint16_t fanCenterIdx, |
| uint16_t edgeV0Idx, |
| uint16_t** indices) { |
| // when drawing lines we're appending line segments along |
| // the contour. When applying the other fill rules we're |
| // drawing triangle fans around fanCenterIdx. |
| if (!hairLine) { |
| *((*indices)++) = fanCenterIdx; |
| } |
| *((*indices)++) = edgeV0Idx; |
| *((*indices)++) = edgeV0Idx + 1; |
| } |
| |
| bool GrDefaultPathRenderer::createGeom(const SkPath& path, |
| const SkStrokeRec& stroke, |
| SkScalar srcSpaceTol, |
| GrDrawTarget* target, |
| GrPrimitiveType* primType, |
| int* vertexCnt, |
| int* indexCnt, |
| GrDrawTarget::AutoReleaseGeometry* arg) { |
| { |
| SK_TRACE_EVENT0("GrDefaultPathRenderer::createGeom"); |
| |
| SkScalar srcSpaceTolSqd = SkScalarMul(srcSpaceTol, srcSpaceTol); |
| int contourCnt; |
| int maxPts = GrPathUtils::worstCasePointCount(path, &contourCnt, |
| srcSpaceTol); |
| |
| if (maxPts <= 0) { |
| return false; |
| } |
| if (maxPts > ((int)SK_MaxU16 + 1)) { |
| GrPrintf("Path not rendered, too many verts (%d)\n", maxPts); |
| return false; |
| } |
| |
| GrVertexLayout layout = 0; |
| bool indexed = contourCnt > 1; |
| |
| const bool isHairline = stroke.isHairlineStyle(); |
| |
| int maxIdxs = 0; |
| if (isHairline) { |
| if (indexed) { |
| maxIdxs = 2 * maxPts; |
| *primType = kLines_GrPrimitiveType; |
| } else { |
| *primType = kLineStrip_GrPrimitiveType; |
| } |
| } else { |
| if (indexed) { |
| maxIdxs = 3 * maxPts; |
| *primType = kTriangles_GrPrimitiveType; |
| } else { |
| *primType = kTriangleFan_GrPrimitiveType; |
| } |
| } |
| |
| |
| if (!arg->set(target, layout, maxPts, maxIdxs)) { |
| return false; |
| } |
| |
| uint16_t* idxBase = reinterpret_cast<uint16_t*>(arg->indices()); |
| uint16_t* idx = idxBase; |
| uint16_t subpathIdxStart = 0; |
| |
| GrPoint* base = reinterpret_cast<GrPoint*>(arg->vertices()); |
| GrAssert(NULL != base); |
| GrPoint* vert = base; |
| |
| GrPoint pts[4]; |
| |
| bool first = true; |
| int subpath = 0; |
| |
| SkPath::Iter iter(path, false); |
| |
| for (;;) { |
| GrPathCmd cmd = (GrPathCmd)iter.next(pts); |
| switch (cmd) { |
| case kMove_PathCmd: |
| if (!first) { |
| uint16_t currIdx = (uint16_t) (vert - base); |
| subpathIdxStart = currIdx; |
| ++subpath; |
| } |
| *vert = pts[0]; |
| vert++; |
| break; |
| case kLine_PathCmd: |
| if (indexed) { |
| uint16_t prevIdx = (uint16_t)(vert - base) - 1; |
| append_countour_edge_indices(isHairline, subpathIdxStart, |
| prevIdx, &idx); |
| } |
| *(vert++) = pts[1]; |
| break; |
| case kQuadratic_PathCmd: { |
| // first pt of quad is the pt we ended on in previous step |
| uint16_t firstQPtIdx = (uint16_t)(vert - base) - 1; |
| uint16_t numPts = (uint16_t) |
| GrPathUtils::generateQuadraticPoints( |
| pts[0], pts[1], pts[2], |
| srcSpaceTolSqd, &vert, |
| GrPathUtils::quadraticPointCount(pts, srcSpaceTol)); |
| if (indexed) { |
| for (uint16_t i = 0; i < numPts; ++i) { |
| append_countour_edge_indices(isHairline, subpathIdxStart, |
| firstQPtIdx + i, &idx); |
| } |
| } |
| break; |
| } |
| case kCubic_PathCmd: { |
| // first pt of cubic is the pt we ended on in previous step |
| uint16_t firstCPtIdx = (uint16_t)(vert - base) - 1; |
| uint16_t numPts = (uint16_t) GrPathUtils::generateCubicPoints( |
| pts[0], pts[1], pts[2], pts[3], |
| srcSpaceTolSqd, &vert, |
| GrPathUtils::cubicPointCount(pts, srcSpaceTol)); |
| if (indexed) { |
| for (uint16_t i = 0; i < numPts; ++i) { |
| append_countour_edge_indices(isHairline, subpathIdxStart, |
| firstCPtIdx + i, &idx); |
| } |
| } |
| break; |
| } |
| case kClose_PathCmd: |
| break; |
| case kEnd_PathCmd: |
| // uint16_t currIdx = (uint16_t) (vert - base); |
| goto FINISHED; |
| } |
| first = false; |
| } |
| FINISHED: |
| GrAssert((vert - base) <= maxPts); |
| GrAssert((idx - idxBase) <= maxIdxs); |
| |
| *vertexCnt = vert - base; |
| *indexCnt = idx - idxBase; |
| |
| } |
| return true; |
| } |
| |
| bool GrDefaultPathRenderer::internalDrawPath(const SkPath& path, |
| const SkStrokeRec& stroke, |
| GrDrawTarget* target, |
| bool stencilOnly) { |
| |
| SkMatrix viewM = target->getDrawState().getViewMatrix(); |
| SkScalar tol = SK_Scalar1; |
| tol = GrPathUtils::scaleToleranceToSrc(tol, viewM, path.getBounds()); |
| |
| int vertexCnt; |
| int indexCnt; |
| GrPrimitiveType primType; |
| GrDrawTarget::AutoReleaseGeometry arg; |
| if (!this->createGeom(path, |
| stroke, |
| tol, |
| target, |
| &primType, |
| &vertexCnt, |
| &indexCnt, |
| &arg)) { |
| return false; |
| } |
| |
| GrAssert(NULL != target); |
| GrDrawTarget::AutoStateRestore asr(target, GrDrawTarget::kPreserve_ASRInit); |
| GrDrawState* drawState = target->drawState(); |
| bool colorWritesWereDisabled = drawState->isColorWriteDisabled(); |
| // face culling doesn't make sense here |
| GrAssert(GrDrawState::kBoth_DrawFace == drawState->getDrawFace()); |
| |
| int passCount = 0; |
| const GrStencilSettings* passes[3]; |
| GrDrawState::DrawFace drawFace[3]; |
| bool reverse = false; |
| bool lastPassIsBounds; |
| |
| if (stroke.isHairlineStyle()) { |
| passCount = 1; |
| if (stencilOnly) { |
| passes[0] = &gDirectToStencil; |
| } else { |
| passes[0] = NULL; |
| } |
| lastPassIsBounds = false; |
| drawFace[0] = GrDrawState::kBoth_DrawFace; |
| } else { |
| if (single_pass_path(path, stroke)) { |
| passCount = 1; |
| if (stencilOnly) { |
| passes[0] = &gDirectToStencil; |
| } else { |
| passes[0] = NULL; |
| } |
| drawFace[0] = GrDrawState::kBoth_DrawFace; |
| lastPassIsBounds = false; |
| } else { |
| switch (path.getFillType()) { |
| case SkPath::kInverseEvenOdd_FillType: |
| reverse = true; |
| // fallthrough |
| case SkPath::kEvenOdd_FillType: |
| passes[0] = &gEOStencilPass; |
| if (stencilOnly) { |
| passCount = 1; |
| lastPassIsBounds = false; |
| } else { |
| passCount = 2; |
| lastPassIsBounds = true; |
| if (reverse) { |
| passes[1] = &gInvEOColorPass; |
| } else { |
| passes[1] = &gEOColorPass; |
| } |
| } |
| drawFace[0] = drawFace[1] = GrDrawState::kBoth_DrawFace; |
| break; |
| |
| case SkPath::kInverseWinding_FillType: |
| reverse = true; |
| // fallthrough |
| case SkPath::kWinding_FillType: |
| if (fSeparateStencil) { |
| if (fStencilWrapOps) { |
| passes[0] = &gWindStencilSeparateWithWrap; |
| } else { |
| passes[0] = &gWindStencilSeparateNoWrap; |
| } |
| passCount = 2; |
| drawFace[0] = GrDrawState::kBoth_DrawFace; |
| } else { |
| if (fStencilWrapOps) { |
| passes[0] = &gWindSingleStencilWithWrapInc; |
| passes[1] = &gWindSingleStencilWithWrapDec; |
| } else { |
| passes[0] = &gWindSingleStencilNoWrapInc; |
| passes[1] = &gWindSingleStencilNoWrapDec; |
| } |
| // which is cw and which is ccw is arbitrary. |
| drawFace[0] = GrDrawState::kCW_DrawFace; |
| drawFace[1] = GrDrawState::kCCW_DrawFace; |
| passCount = 3; |
| } |
| if (stencilOnly) { |
| lastPassIsBounds = false; |
| --passCount; |
| } else { |
| lastPassIsBounds = true; |
| drawFace[passCount-1] = GrDrawState::kBoth_DrawFace; |
| if (reverse) { |
| passes[passCount-1] = &gInvWindColorPass; |
| } else { |
| passes[passCount-1] = &gWindColorPass; |
| } |
| } |
| break; |
| default: |
| GrAssert(!"Unknown path fFill!"); |
| return false; |
| } |
| } |
| } |
| |
| { |
| for (int p = 0; p < passCount; ++p) { |
| drawState->setDrawFace(drawFace[p]); |
| if (NULL != passes[p]) { |
| *drawState->stencil() = *passes[p]; |
| } |
| |
| if (lastPassIsBounds && (p == passCount-1)) { |
| if (!colorWritesWereDisabled) { |
| drawState->disableState(GrDrawState::kNoColorWrites_StateBit); |
| } |
| GrRect bounds; |
| GrDrawState::AutoDeviceCoordDraw adcd; |
| if (reverse) { |
| GrAssert(NULL != drawState->getRenderTarget()); |
| // draw over the whole world. |
| bounds.setLTRB(0, 0, |
| SkIntToScalar(drawState->getRenderTarget()->width()), |
| SkIntToScalar(drawState->getRenderTarget()->height())); |
| SkMatrix vmi; |
| // mapRect through persp matrix may not be correct |
| if (!drawState->getViewMatrix().hasPerspective() && |
| drawState->getViewInverse(&vmi)) { |
| vmi.mapRect(&bounds); |
| } else { |
| adcd.set(drawState); |
| } |
| } else { |
| bounds = path.getBounds(); |
| } |
| GrDrawTarget::AutoGeometryPush agp(target); |
| target->drawSimpleRect(bounds, NULL); |
| } else { |
| if (passCount > 1) { |
| drawState->enableState(GrDrawState::kNoColorWrites_StateBit); |
| } |
| if (indexCnt) { |
| target->drawIndexed(primType, 0, 0, |
| vertexCnt, indexCnt); |
| } else { |
| target->drawNonIndexed(primType, 0, vertexCnt); |
| } |
| } |
| } |
| } |
| return true; |
| } |
| |
| bool GrDefaultPathRenderer::canDrawPath(const SkPath& path, |
| const SkStrokeRec& stroke, |
| const GrDrawTarget* target, |
| bool antiAlias) const { |
| // this class can draw any path with any fill but doesn't do any anti-aliasing. |
| return (stroke.isFillStyle() || stroke.isHairlineStyle()) && !antiAlias; |
| } |
| |
| bool GrDefaultPathRenderer::onDrawPath(const SkPath& path, |
| const SkStrokeRec& stroke, |
| GrDrawTarget* target, |
| bool antiAlias) { |
| return this->internalDrawPath(path, |
| stroke, |
| target, |
| false); |
| } |
| |
| void GrDefaultPathRenderer::onStencilPath(const SkPath& path, |
| const SkStrokeRec& stroke, |
| GrDrawTarget* target) { |
| GrAssert(SkPath::kInverseEvenOdd_FillType != path.getFillType()); |
| GrAssert(SkPath::kInverseWinding_FillType != path.getFillType()); |
| this->internalDrawPath(path, stroke, target, true); |
| } |
