| /* |
| * 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 "GrAAHairLinePathRenderer.h" |
| |
| #include "GrContext.h" |
| #include "GrDrawState.h" |
| #include "GrDrawTargetCaps.h" |
| #include "GrEffect.h" |
| #include "GrGpu.h" |
| #include "GrIndexBuffer.h" |
| #include "GrPathUtils.h" |
| #include "GrTBackendEffectFactory.h" |
| #include "SkGeometry.h" |
| #include "SkStroke.h" |
| #include "SkTemplates.h" |
| |
| #include "effects/GrBezierEffect.h" |
| |
| namespace { |
| // quadratics are rendered as 5-sided polys in order to bound the |
| // AA stroke around the center-curve. See comments in push_quad_index_buffer and |
| // bloat_quad. Quadratics and conics share an index buffer |
| static const int kVertsPerQuad = 5; |
| static const int kIdxsPerQuad = 9; |
| |
| // lines are rendered as: |
| // *______________* |
| // |\ -_______ /| |
| // | \ \ / | |
| // | *--------* | |
| // | / ______/ \ | |
| // */_-__________\* |
| // For: 6 vertices and 18 indices (for 6 triangles) |
| static const int kVertsPerLineSeg = 6; |
| static const int kIdxsPerLineSeg = 18; |
| |
| static const int kNumQuadsInIdxBuffer = 256; |
| static const size_t kQuadIdxSBufize = kIdxsPerQuad * |
| sizeof(uint16_t) * |
| kNumQuadsInIdxBuffer; |
| |
| static const int kNumLineSegsInIdxBuffer = 256; |
| static const size_t kLineSegIdxSBufize = kIdxsPerLineSeg * |
| sizeof(uint16_t) * |
| kNumLineSegsInIdxBuffer; |
| |
| static bool push_quad_index_data(GrIndexBuffer* qIdxBuffer) { |
| uint16_t* data = (uint16_t*) qIdxBuffer->lock(); |
| bool tempData = NULL == data; |
| if (tempData) { |
| data = SkNEW_ARRAY(uint16_t, kNumQuadsInIdxBuffer * kIdxsPerQuad); |
| } |
| for (int i = 0; i < kNumQuadsInIdxBuffer; ++i) { |
| |
| // Each quadratic is rendered as a five sided polygon. This poly bounds |
| // the quadratic's bounding triangle but has been expanded so that the |
| // 1-pixel wide area around the curve is inside the poly. |
| // If a,b,c are the original control points then the poly a0,b0,c0,c1,a1 |
| // that is rendered would look like this: |
| // b0 |
| // b |
| // |
| // a0 c0 |
| // a c |
| // a1 c1 |
| // Each is drawn as three triangles specified by these 9 indices: |
| int baseIdx = i * kIdxsPerQuad; |
| uint16_t baseVert = (uint16_t)(i * kVertsPerQuad); |
| data[0 + baseIdx] = baseVert + 0; // a0 |
| data[1 + baseIdx] = baseVert + 1; // a1 |
| data[2 + baseIdx] = baseVert + 2; // b0 |
| data[3 + baseIdx] = baseVert + 2; // b0 |
| data[4 + baseIdx] = baseVert + 4; // c1 |
| data[5 + baseIdx] = baseVert + 3; // c0 |
| data[6 + baseIdx] = baseVert + 1; // a1 |
| data[7 + baseIdx] = baseVert + 4; // c1 |
| data[8 + baseIdx] = baseVert + 2; // b0 |
| } |
| if (tempData) { |
| bool ret = qIdxBuffer->updateData(data, kQuadIdxSBufize); |
| delete[] data; |
| return ret; |
| } else { |
| qIdxBuffer->unlock(); |
| return true; |
| } |
| } |
| |
| static bool push_line_index_data(GrIndexBuffer* lIdxBuffer) { |
| uint16_t* data = (uint16_t*) lIdxBuffer->lock(); |
| bool tempData = NULL == data; |
| if (tempData) { |
| data = SkNEW_ARRAY(uint16_t, kNumLineSegsInIdxBuffer * kIdxsPerLineSeg); |
| } |
| for (int i = 0; i < kNumLineSegsInIdxBuffer; ++i) { |
| // Each line segment is rendered as two quads and two triangles. |
| // p0 and p1 have alpha = 1 while all other points have alpha = 0. |
| // The four external points are offset 1 pixel perpendicular to the |
| // line and half a pixel parallel to the line. |
| // |
| // p4 p5 |
| // p0 p1 |
| // p2 p3 |
| // |
| // Each is drawn as six triangles specified by these 18 indices: |
| int baseIdx = i * kIdxsPerLineSeg; |
| uint16_t baseVert = (uint16_t)(i * kVertsPerLineSeg); |
| data[0 + baseIdx] = baseVert + 0; |
| data[1 + baseIdx] = baseVert + 1; |
| data[2 + baseIdx] = baseVert + 3; |
| |
| data[3 + baseIdx] = baseVert + 0; |
| data[4 + baseIdx] = baseVert + 3; |
| data[5 + baseIdx] = baseVert + 2; |
| |
| data[6 + baseIdx] = baseVert + 0; |
| data[7 + baseIdx] = baseVert + 4; |
| data[8 + baseIdx] = baseVert + 5; |
| |
| data[9 + baseIdx] = baseVert + 0; |
| data[10+ baseIdx] = baseVert + 5; |
| data[11+ baseIdx] = baseVert + 1; |
| |
| data[12 + baseIdx] = baseVert + 0; |
| data[13 + baseIdx] = baseVert + 2; |
| data[14 + baseIdx] = baseVert + 4; |
| |
| data[15 + baseIdx] = baseVert + 1; |
| data[16 + baseIdx] = baseVert + 5; |
| data[17 + baseIdx] = baseVert + 3; |
| } |
| if (tempData) { |
| bool ret = lIdxBuffer->updateData(data, kLineSegIdxSBufize); |
| delete[] data; |
| return ret; |
| } else { |
| lIdxBuffer->unlock(); |
| return true; |
| } |
| } |
| } |
| |
| GrPathRenderer* GrAAHairLinePathRenderer::Create(GrContext* context) { |
| GrGpu* gpu = context->getGpu(); |
| GrIndexBuffer* qIdxBuf = gpu->createIndexBuffer(kQuadIdxSBufize, false); |
| SkAutoTUnref<GrIndexBuffer> qIdxBuffer(qIdxBuf); |
| if (NULL == qIdxBuf || !push_quad_index_data(qIdxBuf)) { |
| return NULL; |
| } |
| GrIndexBuffer* lIdxBuf = gpu->createIndexBuffer(kLineSegIdxSBufize, false); |
| SkAutoTUnref<GrIndexBuffer> lIdxBuffer(lIdxBuf); |
| if (NULL == lIdxBuf || !push_line_index_data(lIdxBuf)) { |
| return NULL; |
| } |
| return SkNEW_ARGS(GrAAHairLinePathRenderer, |
| (context, lIdxBuf, qIdxBuf)); |
| } |
| |
| GrAAHairLinePathRenderer::GrAAHairLinePathRenderer( |
| const GrContext* context, |
| const GrIndexBuffer* linesIndexBuffer, |
| const GrIndexBuffer* quadsIndexBuffer) { |
| fLinesIndexBuffer = linesIndexBuffer; |
| linesIndexBuffer->ref(); |
| fQuadsIndexBuffer = quadsIndexBuffer; |
| quadsIndexBuffer->ref(); |
| } |
| |
| GrAAHairLinePathRenderer::~GrAAHairLinePathRenderer() { |
| fLinesIndexBuffer->unref(); |
| fQuadsIndexBuffer->unref(); |
| } |
| |
| namespace { |
| |
| #define PREALLOC_PTARRAY(N) SkSTArray<(N),SkPoint, true> |
| |
| // Takes 178th time of logf on Z600 / VC2010 |
| int get_float_exp(float x) { |
| GR_STATIC_ASSERT(sizeof(int) == sizeof(float)); |
| #ifdef SK_DEBUG |
| static bool tested; |
| if (!tested) { |
| tested = true; |
| SkASSERT(get_float_exp(0.25f) == -2); |
| SkASSERT(get_float_exp(0.3f) == -2); |
| SkASSERT(get_float_exp(0.5f) == -1); |
| SkASSERT(get_float_exp(1.f) == 0); |
| SkASSERT(get_float_exp(2.f) == 1); |
| SkASSERT(get_float_exp(2.5f) == 1); |
| SkASSERT(get_float_exp(8.f) == 3); |
| SkASSERT(get_float_exp(100.f) == 6); |
| SkASSERT(get_float_exp(1000.f) == 9); |
| SkASSERT(get_float_exp(1024.f) == 10); |
| SkASSERT(get_float_exp(3000000.f) == 21); |
| } |
| #endif |
| const int* iptr = (const int*)&x; |
| return (((*iptr) & 0x7f800000) >> 23) - 127; |
| } |
| |
| // Uses the max curvature function for quads to estimate |
| // where to chop the conic. If the max curvature is not |
| // found along the curve segment it will return 1 and |
| // dst[0] is the original conic. If it returns 2 the dst[0] |
| // and dst[1] are the two new conics. |
| int split_conic(const SkPoint src[3], SkConic dst[2], const SkScalar weight) { |
| SkScalar t = SkFindQuadMaxCurvature(src); |
| if (t == 0) { |
| if (dst) { |
| dst[0].set(src, weight); |
| } |
| return 1; |
| } else { |
| if (dst) { |
| SkConic conic; |
| conic.set(src, weight); |
| conic.chopAt(t, dst); |
| } |
| return 2; |
| } |
| } |
| |
| // Calls split_conic on the entire conic and then once more on each subsection. |
| // Most cases will result in either 1 conic (chop point is not within t range) |
| // or 3 points (split once and then one subsection is split again). |
| int chop_conic(const SkPoint src[3], SkConic dst[4], const SkScalar weight) { |
| SkConic dstTemp[2]; |
| int conicCnt = split_conic(src, dstTemp, weight); |
| if (2 == conicCnt) { |
| int conicCnt2 = split_conic(dstTemp[0].fPts, dst, dstTemp[0].fW); |
| conicCnt = conicCnt2 + split_conic(dstTemp[1].fPts, &dst[conicCnt2], dstTemp[1].fW); |
| } else { |
| dst[0] = dstTemp[0]; |
| } |
| return conicCnt; |
| } |
| |
| // returns 0 if quad/conic is degen or close to it |
| // in this case approx the path with lines |
| // otherwise returns 1 |
| int is_degen_quad_or_conic(const SkPoint p[3]) { |
| static const SkScalar gDegenerateToLineTol = SK_Scalar1; |
| static const SkScalar gDegenerateToLineTolSqd = |
| SkScalarMul(gDegenerateToLineTol, gDegenerateToLineTol); |
| |
| if (p[0].distanceToSqd(p[1]) < gDegenerateToLineTolSqd || |
| p[1].distanceToSqd(p[2]) < gDegenerateToLineTolSqd) { |
| return 1; |
| } |
| |
| SkScalar dsqd = p[1].distanceToLineBetweenSqd(p[0], p[2]); |
| if (dsqd < gDegenerateToLineTolSqd) { |
| return 1; |
| } |
| |
| if (p[2].distanceToLineBetweenSqd(p[1], p[0]) < gDegenerateToLineTolSqd) { |
| return 1; |
| } |
| return 0; |
| } |
| |
| // we subdivide the quads to avoid huge overfill |
| // if it returns -1 then should be drawn as lines |
| int num_quad_subdivs(const SkPoint p[3]) { |
| static const SkScalar gDegenerateToLineTol = SK_Scalar1; |
| static const SkScalar gDegenerateToLineTolSqd = |
| SkScalarMul(gDegenerateToLineTol, gDegenerateToLineTol); |
| |
| if (p[0].distanceToSqd(p[1]) < gDegenerateToLineTolSqd || |
| p[1].distanceToSqd(p[2]) < gDegenerateToLineTolSqd) { |
| return -1; |
| } |
| |
| SkScalar dsqd = p[1].distanceToLineBetweenSqd(p[0], p[2]); |
| if (dsqd < gDegenerateToLineTolSqd) { |
| return -1; |
| } |
| |
| if (p[2].distanceToLineBetweenSqd(p[1], p[0]) < gDegenerateToLineTolSqd) { |
| return -1; |
| } |
| |
| // tolerance of triangle height in pixels |
| // tuned on windows Quadro FX 380 / Z600 |
| // trade off of fill vs cpu time on verts |
| // maybe different when do this using gpu (geo or tess shaders) |
| static const SkScalar gSubdivTol = 175 * SK_Scalar1; |
| |
| if (dsqd <= SkScalarMul(gSubdivTol, gSubdivTol)) { |
| return 0; |
| } else { |
| static const int kMaxSub = 4; |
| // subdividing the quad reduces d by 4. so we want x = log4(d/tol) |
| // = log4(d*d/tol*tol)/2 |
| // = log2(d*d/tol*tol) |
| |
| #ifdef SK_SCALAR_IS_FLOAT |
| // +1 since we're ignoring the mantissa contribution. |
| int log = get_float_exp(dsqd/(gSubdivTol*gSubdivTol)) + 1; |
| log = GrMin(GrMax(0, log), kMaxSub); |
| return log; |
| #else |
| SkScalar log = SkScalarLog( |
| SkScalarDiv(dsqd, |
| SkScalarMul(gSubdivTol, gSubdivTol))); |
| static const SkScalar conv = SkScalarInvert(SkScalarLog(2)); |
| log = SkScalarMul(log, conv); |
| return GrMin(GrMax(0, SkScalarCeilToInt(log)),kMaxSub); |
| #endif |
| } |
| } |
| |
| /** |
| * Generates the lines and quads to be rendered. Lines are always recorded in |
| * device space. We will do a device space bloat to account for the 1pixel |
| * thickness. |
| * Quads are recorded in device space unless m contains |
| * perspective, then in they are in src space. We do this because we will |
| * subdivide large quads to reduce over-fill. This subdivision has to be |
| * performed before applying the perspective matrix. |
| */ |
| int generate_lines_and_quads(const SkPath& path, |
| const SkMatrix& m, |
| const SkIRect& devClipBounds, |
| GrAAHairLinePathRenderer::PtArray* lines, |
| GrAAHairLinePathRenderer::PtArray* quads, |
| GrAAHairLinePathRenderer::PtArray* conics, |
| GrAAHairLinePathRenderer::IntArray* quadSubdivCnts, |
| GrAAHairLinePathRenderer::FloatArray* conicWeights) { |
| SkPath::Iter iter(path, false); |
| |
| int totalQuadCount = 0; |
| SkRect bounds; |
| SkIRect ibounds; |
| |
| bool persp = m.hasPerspective(); |
| |
| for (;;) { |
| GrPoint pathPts[4]; |
| GrPoint devPts[4]; |
| SkPath::Verb verb = iter.next(pathPts); |
| switch (verb) { |
| case SkPath::kConic_Verb: { |
| SkConic dst[4]; |
| // We chop the conics to create tighter clipping to hide error |
| // that appears near max curvature of very thin conics. Thin |
| // hyperbolas with high weight still show error. |
| int conicCnt = chop_conic(pathPts, dst, iter.conicWeight()); |
| for (int i = 0; i < conicCnt; ++i) { |
| SkPoint* chopPnts = dst[i].fPts; |
| m.mapPoints(devPts, chopPnts, 3); |
| bounds.setBounds(devPts, 3); |
| bounds.outset(SK_Scalar1, SK_Scalar1); |
| bounds.roundOut(&ibounds); |
| if (SkIRect::Intersects(devClipBounds, ibounds)) { |
| if (is_degen_quad_or_conic(devPts)) { |
| SkPoint* pts = lines->push_back_n(4); |
| pts[0] = devPts[0]; |
| pts[1] = devPts[1]; |
| pts[2] = devPts[1]; |
| pts[3] = devPts[2]; |
| } else { |
| // when in perspective keep conics in src space |
| SkPoint* cPts = persp ? chopPnts : devPts; |
| SkPoint* pts = conics->push_back_n(3); |
| pts[0] = cPts[0]; |
| pts[1] = cPts[1]; |
| pts[2] = cPts[2]; |
| conicWeights->push_back() = dst[i].fW; |
| } |
| } |
| } |
| break; |
| } |
| case SkPath::kMove_Verb: |
| break; |
| case SkPath::kLine_Verb: |
| m.mapPoints(devPts, pathPts, 2); |
| bounds.setBounds(devPts, 2); |
| bounds.outset(SK_Scalar1, SK_Scalar1); |
| bounds.roundOut(&ibounds); |
| if (SkIRect::Intersects(devClipBounds, ibounds)) { |
| SkPoint* pts = lines->push_back_n(2); |
| pts[0] = devPts[0]; |
| pts[1] = devPts[1]; |
| } |
| break; |
| case SkPath::kQuad_Verb: { |
| SkPoint choppedPts[5]; |
| // Chopping the quad helps when the quad is either degenerate or nearly degenerate. |
| // When it is degenerate it allows the approximation with lines to work since the |
| // chop point (if there is one) will be at the parabola's vertex. In the nearly |
| // degenerate the QuadUVMatrix computed for the points is almost singular which |
| // can cause rendering artifacts. |
| int n = SkChopQuadAtMaxCurvature(pathPts, choppedPts); |
| for (int i = 0; i < n; ++i) { |
| SkPoint* quadPts = choppedPts + i * 2; |
| m.mapPoints(devPts, quadPts, 3); |
| bounds.setBounds(devPts, 3); |
| bounds.outset(SK_Scalar1, SK_Scalar1); |
| bounds.roundOut(&ibounds); |
| |
| if (SkIRect::Intersects(devClipBounds, ibounds)) { |
| int subdiv = num_quad_subdivs(devPts); |
| SkASSERT(subdiv >= -1); |
| if (-1 == subdiv) { |
| SkPoint* pts = lines->push_back_n(4); |
| pts[0] = devPts[0]; |
| pts[1] = devPts[1]; |
| pts[2] = devPts[1]; |
| pts[3] = devPts[2]; |
| } else { |
| // when in perspective keep quads in src space |
| SkPoint* qPts = persp ? quadPts : devPts; |
| SkPoint* pts = quads->push_back_n(3); |
| pts[0] = qPts[0]; |
| pts[1] = qPts[1]; |
| pts[2] = qPts[2]; |
| quadSubdivCnts->push_back() = subdiv; |
| totalQuadCount += 1 << subdiv; |
| } |
| } |
| } |
| break; |
| } |
| case SkPath::kCubic_Verb: |
| m.mapPoints(devPts, pathPts, 4); |
| bounds.setBounds(devPts, 4); |
| bounds.outset(SK_Scalar1, SK_Scalar1); |
| bounds.roundOut(&ibounds); |
| if (SkIRect::Intersects(devClipBounds, ibounds)) { |
| PREALLOC_PTARRAY(32) q; |
| // we don't need a direction if we aren't constraining the subdivision |
| static const SkPath::Direction kDummyDir = SkPath::kCCW_Direction; |
| // We convert cubics to quadratics (for now). |
| // In perspective have to do conversion in src space. |
| if (persp) { |
| SkScalar tolScale = |
| GrPathUtils::scaleToleranceToSrc(SK_Scalar1, m, |
| path.getBounds()); |
| GrPathUtils::convertCubicToQuads(pathPts, tolScale, false, kDummyDir, &q); |
| } else { |
| GrPathUtils::convertCubicToQuads(devPts, SK_Scalar1, false, kDummyDir, &q); |
| } |
| for (int i = 0; i < q.count(); i += 3) { |
| SkPoint* qInDevSpace; |
| // bounds has to be calculated in device space, but q is |
| // in src space when there is perspective. |
| if (persp) { |
| m.mapPoints(devPts, &q[i], 3); |
| bounds.setBounds(devPts, 3); |
| qInDevSpace = devPts; |
| } else { |
| bounds.setBounds(&q[i], 3); |
| qInDevSpace = &q[i]; |
| } |
| bounds.outset(SK_Scalar1, SK_Scalar1); |
| bounds.roundOut(&ibounds); |
| if (SkIRect::Intersects(devClipBounds, ibounds)) { |
| int subdiv = num_quad_subdivs(qInDevSpace); |
| SkASSERT(subdiv >= -1); |
| if (-1 == subdiv) { |
| SkPoint* pts = lines->push_back_n(4); |
| // lines should always be in device coords |
| pts[0] = qInDevSpace[0]; |
| pts[1] = qInDevSpace[1]; |
| pts[2] = qInDevSpace[1]; |
| pts[3] = qInDevSpace[2]; |
| } else { |
| SkPoint* pts = quads->push_back_n(3); |
| // q is already in src space when there is no |
| // perspective and dev coords otherwise. |
| pts[0] = q[0 + i]; |
| pts[1] = q[1 + i]; |
| pts[2] = q[2 + i]; |
| quadSubdivCnts->push_back() = subdiv; |
| totalQuadCount += 1 << subdiv; |
| } |
| } |
| } |
| } |
| break; |
| case SkPath::kClose_Verb: |
| break; |
| case SkPath::kDone_Verb: |
| return totalQuadCount; |
| } |
| } |
| } |
| |
| struct LineVertex { |
| GrPoint fPos; |
| GrColor fCoverage; |
| }; |
| |
| struct BezierVertex { |
| GrPoint fPos; |
| union { |
| struct { |
| SkScalar fK; |
| SkScalar fL; |
| SkScalar fM; |
| } fConic; |
| GrVec fQuadCoord; |
| struct { |
| SkScalar fBogus[4]; |
| }; |
| }; |
| }; |
| |
| GR_STATIC_ASSERT(sizeof(BezierVertex) == 3 * sizeof(GrPoint)); |
| |
| void intersect_lines(const SkPoint& ptA, const SkVector& normA, |
| const SkPoint& ptB, const SkVector& normB, |
| SkPoint* result) { |
| |
| SkScalar lineAW = -normA.dot(ptA); |
| SkScalar lineBW = -normB.dot(ptB); |
| |
| SkScalar wInv = SkScalarMul(normA.fX, normB.fY) - |
| SkScalarMul(normA.fY, normB.fX); |
| wInv = SkScalarInvert(wInv); |
| |
| result->fX = SkScalarMul(normA.fY, lineBW) - SkScalarMul(lineAW, normB.fY); |
| result->fX = SkScalarMul(result->fX, wInv); |
| |
| result->fY = SkScalarMul(lineAW, normB.fX) - SkScalarMul(normA.fX, lineBW); |
| result->fY = SkScalarMul(result->fY, wInv); |
| } |
| |
| void set_uv_quad(const SkPoint qpts[3], BezierVertex verts[kVertsPerQuad]) { |
| // this should be in the src space, not dev coords, when we have perspective |
| GrPathUtils::QuadUVMatrix DevToUV(qpts); |
| DevToUV.apply<kVertsPerQuad, sizeof(BezierVertex), sizeof(GrPoint)>(verts); |
| } |
| |
| void bloat_quad(const SkPoint qpts[3], const SkMatrix* toDevice, |
| const SkMatrix* toSrc, BezierVertex verts[kVertsPerQuad], |
| SkRect* devBounds) { |
| SkASSERT(!toDevice == !toSrc); |
| // original quad is specified by tri a,b,c |
| SkPoint a = qpts[0]; |
| SkPoint b = qpts[1]; |
| SkPoint c = qpts[2]; |
| |
| if (toDevice) { |
| toDevice->mapPoints(&a, 1); |
| toDevice->mapPoints(&b, 1); |
| toDevice->mapPoints(&c, 1); |
| } |
| // make a new poly where we replace a and c by a 1-pixel wide edges orthog |
| // to edges ab and bc: |
| // |
| // before | after |
| // | b0 |
| // b | |
| // | |
| // | a0 c0 |
| // a c | a1 c1 |
| // |
| // edges a0->b0 and b0->c0 are parallel to original edges a->b and b->c, |
| // respectively. |
| BezierVertex& a0 = verts[0]; |
| BezierVertex& a1 = verts[1]; |
| BezierVertex& b0 = verts[2]; |
| BezierVertex& c0 = verts[3]; |
| BezierVertex& c1 = verts[4]; |
| |
| SkVector ab = b; |
| ab -= a; |
| SkVector ac = c; |
| ac -= a; |
| SkVector cb = b; |
| cb -= c; |
| |
| // We should have already handled degenerates |
| SkASSERT(ab.length() > 0 && cb.length() > 0); |
| |
| ab.normalize(); |
| SkVector abN; |
| abN.setOrthog(ab, SkVector::kLeft_Side); |
| if (abN.dot(ac) > 0) { |
| abN.negate(); |
| } |
| |
| cb.normalize(); |
| SkVector cbN; |
| cbN.setOrthog(cb, SkVector::kLeft_Side); |
| if (cbN.dot(ac) < 0) { |
| cbN.negate(); |
| } |
| |
| a0.fPos = a; |
| a0.fPos += abN; |
| a1.fPos = a; |
| a1.fPos -= abN; |
| |
| c0.fPos = c; |
| c0.fPos += cbN; |
| c1.fPos = c; |
| c1.fPos -= cbN; |
| |
| intersect_lines(a0.fPos, abN, c0.fPos, cbN, &b0.fPos); |
| devBounds->growToInclude(&verts[0].fPos, sizeof(BezierVertex), kVertsPerQuad); |
| |
| if (toSrc) { |
| toSrc->mapPointsWithStride(&verts[0].fPos, sizeof(BezierVertex), kVertsPerQuad); |
| } |
| } |
| |
| // Equations based off of Loop-Blinn Quadratic GPU Rendering |
| // Input Parametric: |
| // P(t) = (P0*(1-t)^2 + 2*w*P1*t*(1-t) + P2*t^2) / (1-t)^2 + 2*w*t*(1-t) + t^2) |
| // Output Implicit: |
| // f(x, y, w) = f(P) = K^2 - LM |
| // K = dot(k, P), L = dot(l, P), M = dot(m, P) |
| // k, l, m are calculated in function GrPathUtils::getConicKLM |
| void set_conic_coeffs(const SkPoint p[3], BezierVertex verts[kVertsPerQuad], |
| const SkScalar weight) { |
| SkScalar klm[9]; |
| |
| GrPathUtils::getConicKLM(p, weight, klm); |
| |
| for (int i = 0; i < kVertsPerQuad; ++i) { |
| const SkPoint pnt = verts[i].fPos; |
| verts[i].fConic.fK = pnt.fX * klm[0] + pnt.fY * klm[1] + klm[2]; |
| verts[i].fConic.fL = pnt.fX * klm[3] + pnt.fY * klm[4] + klm[5]; |
| verts[i].fConic.fM = pnt.fX * klm[6] + pnt.fY * klm[7] + klm[8]; |
| } |
| } |
| |
| void add_conics(const SkPoint p[3], |
| const SkScalar weight, |
| const SkMatrix* toDevice, |
| const SkMatrix* toSrc, |
| BezierVertex** vert, |
| SkRect* devBounds) { |
| bloat_quad(p, toDevice, toSrc, *vert, devBounds); |
| set_conic_coeffs(p, *vert, weight); |
| *vert += kVertsPerQuad; |
| } |
| |
| void add_quads(const SkPoint p[3], |
| int subdiv, |
| const SkMatrix* toDevice, |
| const SkMatrix* toSrc, |
| BezierVertex** vert, |
| SkRect* devBounds) { |
| SkASSERT(subdiv >= 0); |
| if (subdiv) { |
| SkPoint newP[5]; |
| SkChopQuadAtHalf(p, newP); |
| add_quads(newP + 0, subdiv-1, toDevice, toSrc, vert, devBounds); |
| add_quads(newP + 2, subdiv-1, toDevice, toSrc, vert, devBounds); |
| } else { |
| bloat_quad(p, toDevice, toSrc, *vert, devBounds); |
| set_uv_quad(p, *vert); |
| *vert += kVertsPerQuad; |
| } |
| } |
| |
| void add_line(const SkPoint p[2], |
| const SkMatrix* toSrc, |
| GrColor coverage, |
| LineVertex** vert) { |
| const SkPoint& a = p[0]; |
| const SkPoint& b = p[1]; |
| |
| SkVector ortho, vec = b; |
| vec -= a; |
| |
| if (vec.setLength(SK_ScalarHalf)) { |
| // Create a vector orthogonal to 'vec' and of unit length |
| ortho.fX = 2.0f * vec.fY; |
| ortho.fY = -2.0f * vec.fX; |
| |
| (*vert)[0].fPos = a; |
| (*vert)[0].fCoverage = coverage; |
| (*vert)[1].fPos = b; |
| (*vert)[1].fCoverage = coverage; |
| (*vert)[2].fPos = a - vec + ortho; |
| (*vert)[2].fCoverage = 0; |
| (*vert)[3].fPos = b + vec + ortho; |
| (*vert)[3].fCoverage = 0; |
| (*vert)[4].fPos = a - vec - ortho; |
| (*vert)[4].fCoverage = 0; |
| (*vert)[5].fPos = b + vec - ortho; |
| (*vert)[5].fCoverage = 0; |
| |
| if (NULL != toSrc) { |
| toSrc->mapPointsWithStride(&(*vert)->fPos, |
| sizeof(LineVertex), |
| kVertsPerLineSeg); |
| } |
| } else { |
| // just make it degenerate and likely offscreen |
| for (int i = 0; i < kVertsPerLineSeg; ++i) { |
| (*vert)[i].fPos.set(SK_ScalarMax, SK_ScalarMax); |
| } |
| } |
| |
| *vert += kVertsPerLineSeg; |
| } |
| |
| } |
| |
| /////////////////////////////////////////////////////////////////////////////// |
| |
| namespace { |
| |
| // position + edge |
| extern const GrVertexAttrib gHairlineBezierAttribs[] = { |
| {kVec2f_GrVertexAttribType, 0, kPosition_GrVertexAttribBinding}, |
| {kVec4f_GrVertexAttribType, sizeof(GrPoint), kEffect_GrVertexAttribBinding} |
| }; |
| |
| // position + coverage |
| extern const GrVertexAttrib gHairlineLineAttribs[] = { |
| {kVec2f_GrVertexAttribType, 0, kPosition_GrVertexAttribBinding}, |
| {kVec4ub_GrVertexAttribType, sizeof(GrPoint), kCoverage_GrVertexAttribBinding}, |
| }; |
| |
| }; |
| |
| bool GrAAHairLinePathRenderer::createLineGeom(const SkPath& path, |
| GrDrawTarget* target, |
| const PtArray& lines, |
| int lineCnt, |
| GrDrawTarget::AutoReleaseGeometry* arg, |
| SkRect* devBounds) { |
| GrDrawState* drawState = target->drawState(); |
| |
| const SkMatrix& viewM = drawState->getViewMatrix(); |
| |
| int vertCnt = kVertsPerLineSeg * lineCnt; |
| |
| drawState->setVertexAttribs<gHairlineLineAttribs>(SK_ARRAY_COUNT(gHairlineLineAttribs)); |
| SkASSERT(sizeof(LineVertex) == drawState->getVertexSize()); |
| |
| if (!arg->set(target, vertCnt, 0)) { |
| return false; |
| } |
| |
| LineVertex* verts = reinterpret_cast<LineVertex*>(arg->vertices()); |
| |
| const SkMatrix* toSrc = NULL; |
| SkMatrix ivm; |
| |
| if (viewM.hasPerspective()) { |
| if (viewM.invert(&ivm)) { |
| toSrc = &ivm; |
| } |
| } |
| devBounds->set(lines.begin(), lines.count()); |
| for (int i = 0; i < lineCnt; ++i) { |
| add_line(&lines[2*i], toSrc, drawState->getCoverage(), &verts); |
| } |
| // All the verts computed by add_line are within sqrt(1^2 + 0.5^2) of the end points. |
| static const SkScalar kSqrtOfOneAndAQuarter = SkFloatToScalar(1.118f); |
| // Add a little extra to account for vector normalization precision. |
| static const SkScalar kOutset = kSqrtOfOneAndAQuarter + SK_Scalar1 / 20; |
| devBounds->outset(kOutset, kOutset); |
| |
| return true; |
| } |
| |
| bool GrAAHairLinePathRenderer::createBezierGeom( |
| const SkPath& path, |
| GrDrawTarget* target, |
| const PtArray& quads, |
| int quadCnt, |
| const PtArray& conics, |
| int conicCnt, |
| const IntArray& qSubdivs, |
| const FloatArray& cWeights, |
| GrDrawTarget::AutoReleaseGeometry* arg, |
| SkRect* devBounds) { |
| GrDrawState* drawState = target->drawState(); |
| |
| const SkMatrix& viewM = drawState->getViewMatrix(); |
| |
| int vertCnt = kVertsPerQuad * quadCnt + kVertsPerQuad * conicCnt; |
| |
| target->drawState()->setVertexAttribs<gHairlineBezierAttribs>(SK_ARRAY_COUNT(gHairlineBezierAttribs)); |
| SkASSERT(sizeof(BezierVertex) == target->getDrawState().getVertexSize()); |
| |
| if (!arg->set(target, vertCnt, 0)) { |
| return false; |
| } |
| |
| BezierVertex* verts = reinterpret_cast<BezierVertex*>(arg->vertices()); |
| |
| const SkMatrix* toDevice = NULL; |
| const SkMatrix* toSrc = NULL; |
| SkMatrix ivm; |
| |
| if (viewM.hasPerspective()) { |
| if (viewM.invert(&ivm)) { |
| toDevice = &viewM; |
| toSrc = &ivm; |
| } |
| } |
| |
| // Seed the dev bounds with some pts known to be inside. Each quad and conic grows the bounding |
| // box to include its vertices. |
| SkPoint seedPts[2]; |
| if (quadCnt) { |
| seedPts[0] = quads[0]; |
| seedPts[1] = quads[2]; |
| } else if (conicCnt) { |
| seedPts[0] = conics[0]; |
| seedPts[1] = conics[2]; |
| } |
| if (NULL != toDevice) { |
| toDevice->mapPoints(seedPts, 2); |
| } |
| devBounds->set(seedPts[0], seedPts[1]); |
| |
| int unsubdivQuadCnt = quads.count() / 3; |
| for (int i = 0; i < unsubdivQuadCnt; ++i) { |
| SkASSERT(qSubdivs[i] >= 0); |
| add_quads(&quads[3*i], qSubdivs[i], toDevice, toSrc, &verts, devBounds); |
| } |
| |
| // Start Conics |
| for (int i = 0; i < conicCnt; ++i) { |
| add_conics(&conics[3*i], cWeights[i], toDevice, toSrc, &verts, devBounds); |
| } |
| return true; |
| } |
| |
| bool GrAAHairLinePathRenderer::canDrawPath(const SkPath& path, |
| const SkStrokeRec& stroke, |
| const GrDrawTarget* target, |
| bool antiAlias) const { |
| if (!stroke.isHairlineStyle() || !antiAlias) { |
| return false; |
| } |
| |
| if (SkPath::kLine_SegmentMask == path.getSegmentMasks() || |
| target->caps()->shaderDerivativeSupport()) { |
| return true; |
| } |
| return false; |
| } |
| |
| template <class VertexType> |
| bool check_bounds(GrDrawState* drawState, const SkRect& devBounds, void* vertices, int vCount) |
| { |
| SkRect tolDevBounds = devBounds; |
| // The bounds ought to be tight, but in perspective the below code runs the verts |
| // through the view matrix to get back to dev coords, which can introduce imprecision. |
| if (drawState->getViewMatrix().hasPerspective()) { |
| tolDevBounds.outset(SK_Scalar1 / 1000, SK_Scalar1 / 1000); |
| } else { |
| // Non-persp matrices cause this path renderer to draw in device space. |
| SkASSERT(drawState->getViewMatrix().isIdentity()); |
| } |
| SkRect actualBounds; |
| |
| VertexType* verts = reinterpret_cast<VertexType*>(vertices); |
| bool first = true; |
| for (int i = 0; i < vCount; ++i) { |
| SkPoint pos = verts[i].fPos; |
| // This is a hack to workaround the fact that we move some degenerate segments offscreen. |
| if (SK_ScalarMax == pos.fX) { |
| continue; |
| } |
| drawState->getViewMatrix().mapPoints(&pos, 1); |
| if (first) { |
| actualBounds.set(pos.fX, pos.fY, pos.fX, pos.fY); |
| first = false; |
| } else { |
| actualBounds.growToInclude(pos.fX, pos.fY); |
| } |
| } |
| if (!first) { |
| return tolDevBounds.contains(actualBounds); |
| } |
| |
| return true; |
| } |
| |
| bool GrAAHairLinePathRenderer::onDrawPath(const SkPath& path, |
| const SkStrokeRec&, |
| GrDrawTarget* target, |
| bool antiAlias) { |
| |
| GrDrawState* drawState = target->drawState(); |
| |
| SkIRect devClipBounds; |
| target->getClip()->getConservativeBounds(drawState->getRenderTarget(), &devClipBounds); |
| |
| int lineCnt; |
| int quadCnt; |
| int conicCnt; |
| PREALLOC_PTARRAY(128) lines; |
| PREALLOC_PTARRAY(128) quads; |
| PREALLOC_PTARRAY(128) conics; |
| IntArray qSubdivs; |
| FloatArray cWeights; |
| quadCnt = generate_lines_and_quads(path, drawState->getViewMatrix(), devClipBounds, |
| &lines, &quads, &conics, &qSubdivs, &cWeights); |
| lineCnt = lines.count() / 2; |
| conicCnt = conics.count() / 3; |
| |
| // do lines first |
| if (lineCnt) { |
| GrDrawTarget::AutoReleaseGeometry arg; |
| SkRect devBounds; |
| |
| if (!this->createLineGeom(path, |
| target, |
| lines, |
| lineCnt, |
| &arg, |
| &devBounds)) { |
| return false; |
| } |
| |
| GrDrawTarget::AutoStateRestore asr; |
| |
| // createLineGeom transforms the geometry to device space when the matrix does not have |
| // perspective. |
| if (target->getDrawState().getViewMatrix().hasPerspective()) { |
| asr.set(target, GrDrawTarget::kPreserve_ASRInit); |
| } else if (!asr.setIdentity(target, GrDrawTarget::kPreserve_ASRInit)) { |
| return false; |
| } |
| GrDrawState* drawState = target->drawState(); |
| |
| // Check devBounds |
| SkASSERT(check_bounds<LineVertex>(drawState, devBounds, arg.vertices(), |
| kVertsPerLineSeg * lineCnt)); |
| |
| { |
| GrDrawState::AutoRestoreEffects are(drawState); |
| target->setIndexSourceToBuffer(fLinesIndexBuffer); |
| int lines = 0; |
| while (lines < lineCnt) { |
| int n = GrMin(lineCnt - lines, kNumLineSegsInIdxBuffer); |
| target->drawIndexed(kTriangles_GrPrimitiveType, |
| kVertsPerLineSeg*lines, // startV |
| 0, // startI |
| kVertsPerLineSeg*n, // vCount |
| kIdxsPerLineSeg*n, // iCount |
| &devBounds); |
| lines += n; |
| } |
| } |
| } |
| |
| // then quadratics/conics |
| if (quadCnt || conicCnt) { |
| GrDrawTarget::AutoReleaseGeometry arg; |
| SkRect devBounds; |
| |
| if (!this->createBezierGeom(path, |
| target, |
| quads, |
| quadCnt, |
| conics, |
| conicCnt, |
| qSubdivs, |
| cWeights, |
| &arg, |
| &devBounds)) { |
| return false; |
| } |
| |
| GrDrawTarget::AutoStateRestore asr; |
| |
| // createGeom transforms the geometry to device space when the matrix does not have |
| // perspective. |
| if (target->getDrawState().getViewMatrix().hasPerspective()) { |
| asr.set(target, GrDrawTarget::kPreserve_ASRInit); |
| } else if (!asr.setIdentity(target, GrDrawTarget::kPreserve_ASRInit)) { |
| return false; |
| } |
| GrDrawState* drawState = target->drawState(); |
| |
| static const int kEdgeAttrIndex = 1; |
| |
| // Check devBounds |
| SkASSERT(check_bounds<BezierVertex>(drawState, devBounds, arg.vertices(), |
| kVertsPerQuad * quadCnt + kVertsPerQuad * conicCnt)); |
| |
| if (quadCnt > 0) { |
| GrEffectRef* hairQuadEffect = GrQuadEffect::Create(kHairAA_GrBezierEdgeType, |
| *target->caps()); |
| SkASSERT(NULL != hairQuadEffect); |
| GrDrawState::AutoRestoreEffects are(drawState); |
| target->setIndexSourceToBuffer(fQuadsIndexBuffer); |
| drawState->addCoverageEffect(hairQuadEffect, kEdgeAttrIndex)->unref(); |
| int quads = 0; |
| while (quads < quadCnt) { |
| int n = GrMin(quadCnt - quads, kNumQuadsInIdxBuffer); |
| target->drawIndexed(kTriangles_GrPrimitiveType, |
| kVertsPerQuad*quads, // startV |
| 0, // startI |
| kVertsPerQuad*n, // vCount |
| kIdxsPerQuad*n, // iCount |
| &devBounds); |
| quads += n; |
| } |
| } |
| |
| if (conicCnt > 0) { |
| GrDrawState::AutoRestoreEffects are(drawState); |
| GrEffectRef* hairConicEffect = GrConicEffect::Create(kHairAA_GrBezierEdgeType, |
| *target->caps()); |
| SkASSERT(NULL != hairConicEffect); |
| drawState->addCoverageEffect(hairConicEffect, 1, 2)->unref(); |
| int conics = 0; |
| while (conics < conicCnt) { |
| int n = GrMin(conicCnt - conics, kNumQuadsInIdxBuffer); |
| target->drawIndexed(kTriangles_GrPrimitiveType, |
| kVertsPerQuad*(quadCnt + conics), // startV |
| 0, // startI |
| kVertsPerQuad*n, // vCount |
| kIdxsPerQuad*n, // iCount |
| &devBounds); |
| conics += n; |
| } |
| } |
| } |
| |
| target->resetIndexSource(); |
| |
| return true; |
| } |