move src/gpu/batches -> src/gpu/ops

Change-Id: I6410eae41f051ce38bef6f38d670924c3483c325
Reviewed-on: https://skia-review.googlesource.com/6163
Commit-Queue: Brian Salomon <bsalomon@google.com>
Reviewed-by: Brian Osman <brianosman@google.com>

1 files changed, 985 insertions, 0 deletions

diff --git a/src/gpu/ops/GrAAHairLinePathRenderer.cpp b/src/gpu/ops/GrAAHairLinePathRenderer.cpp
new file mode 100644
index 0000000000..7707afa6e2
--- /dev/null
+++ b/src/gpu/ops/GrAAHairLinePathRenderer.cpp
@@ -0,0 +1,985 @@
+/*
+ * 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 "GrBatchTest.h"
+#include "GrBuffer.h"
+#include "GrCaps.h"
+#include "GrContext.h"
+#include "GrDefaultGeoProcFactory.h"
+#include "GrOpFlushState.h"
+#include "GrPathUtils.h"
+#include "GrPipelineBuilder.h"
+#include "GrProcessor.h"
+#include "GrResourceProvider.h"
+#include "SkGeometry.h"
+#include "SkStroke.h"
+#include "SkTemplates.h"
+
+#include "ops/GrMeshDrawOp.h"
+
+#include "effects/GrBezierEffect.h"
+
+#define PREALLOC_PTARRAY(N) SkSTArray<(N),SkPoint, true>
+
+// 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
+
+// lines are rendered as:
+//      *______________*
+//      |\ -_______   /|
+//      | \        \ / |
+//      |  *--------*  |
+//      | /  ______/ \ |
+//      */_-__________\*
+// For: 6 vertices and 18 indices (for 6 triangles)
+
+// 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 ((a0,a1,b0), (b0,c1,c0), (a1,c1,b0))
+// specified by these 9 indices:
+static const uint16_t kQuadIdxBufPattern[] = {
+    0, 1, 2,
+    2, 4, 3,
+    1, 4, 2
+};
+
+static const int kIdxsPerQuad = SK_ARRAY_COUNT(kQuadIdxBufPattern);
+static const int kQuadNumVertices = 5;
+static const int kQuadsNumInIdxBuffer = 256;
+GR_DECLARE_STATIC_UNIQUE_KEY(gQuadsIndexBufferKey);
+
+static const GrBuffer* ref_quads_index_buffer(GrResourceProvider* resourceProvider) {
+    GR_DEFINE_STATIC_UNIQUE_KEY(gQuadsIndexBufferKey);
+    return resourceProvider->findOrCreateInstancedIndexBuffer(
+        kQuadIdxBufPattern, kIdxsPerQuad, kQuadsNumInIdxBuffer, kQuadNumVertices,
+        gQuadsIndexBufferKey);
+}
+
+
+// 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:
+
+static const uint16_t kLineSegIdxBufPattern[] = {
+    0, 1, 3,
+    0, 3, 2,
+    0, 4, 5,
+    0, 5, 1,
+    0, 2, 4,
+    1, 5, 3
+};
+
+static const int kIdxsPerLineSeg = SK_ARRAY_COUNT(kLineSegIdxBufPattern);
+static const int kLineSegNumVertices = 6;
+static const int kLineSegsNumInIdxBuffer = 256;
+
+GR_DECLARE_STATIC_UNIQUE_KEY(gLinesIndexBufferKey);
+
+static const GrBuffer* ref_lines_index_buffer(GrResourceProvider* resourceProvider) {
+    GR_DEFINE_STATIC_UNIQUE_KEY(gLinesIndexBufferKey);
+    return resourceProvider->findOrCreateInstancedIndexBuffer(
+        kLineSegIdxBufPattern, kIdxsPerLineSeg,  kLineSegsNumInIdxBuffer, kLineSegNumVertices,
+        gLinesIndexBufferKey);
+}
+
+// Takes 178th time of logf on Z600 / VC2010
+static 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.
+static 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);
+            if (!conic.chopAt(t, dst)) {
+                dst[0].set(src, weight);
+                return 1;
+            }
+        }
+        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).
+static 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
+static int is_degen_quad_or_conic(const SkPoint p[3], SkScalar* dsqd) {
+    static const SkScalar gDegenerateToLineTol = GrPathUtils::kDefaultTolerance;
+    static const SkScalar gDegenerateToLineTolSqd =
+        SkScalarMul(gDegenerateToLineTol, gDegenerateToLineTol);
+
+    if (p[0].distanceToSqd(p[1]) < gDegenerateToLineTolSqd ||
+        p[1].distanceToSqd(p[2]) < gDegenerateToLineTolSqd) {
+        return 1;
+    }
+
+    *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;
+}
+
+static int is_degen_quad_or_conic(const SkPoint p[3]) {
+    SkScalar dsqd;
+    return is_degen_quad_or_conic(p, &dsqd);
+}
+
+// we subdivide the quads to avoid huge overfill
+// if it returns -1 then should be drawn as lines
+static int num_quad_subdivs(const SkPoint p[3]) {
+    SkScalar dsqd;
+    if (is_degen_quad_or_conic(p, &dsqd)) {
+        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)
+
+        // +1 since we're ignoring the mantissa contribution.
+        int log = get_float_exp(dsqd/(gSubdivTol*gSubdivTol)) + 1;
+        log = SkTMin(SkTMax(0, log), kMaxSub);
+        return log;
+    }
+}
+
+/**
+ * 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.
+ */
+static int gather_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 (;;) {
+        SkPoint pathPts[4];
+        SkPoint 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 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, &q);
+                    } else {
+                        GrPathUtils::convertCubicToQuads(devPts, SK_Scalar1, &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 {
+    SkPoint fPos;
+    float fCoverage;
+};
+
+struct BezierVertex {
+    SkPoint fPos;
+    union {
+        struct {
+            SkScalar fK;
+            SkScalar fL;
+            SkScalar fM;
+        } fConic;
+        SkVector   fQuadCoord;
+        struct {
+            SkScalar fBogus[4];
+        };
+    };
+};
+
+GR_STATIC_ASSERT(sizeof(BezierVertex) == 3 * sizeof(SkPoint));
+
+static 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);
+}
+
+static void set_uv_quad(const SkPoint qpts[3], BezierVertex verts[kQuadNumVertices]) {
+    // this should be in the src space, not dev coords, when we have perspective
+    GrPathUtils::QuadUVMatrix DevToUV(qpts);
+    DevToUV.apply<kQuadNumVertices, sizeof(BezierVertex), sizeof(SkPoint)>(verts);
+}
+
+static void bloat_quad(const SkPoint qpts[3], const SkMatrix* toDevice,
+                       const SkMatrix* toSrc, BezierVertex verts[kQuadNumVertices]) {
+    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);
+
+    if (toSrc) {
+        toSrc->mapPointsWithStride(&verts[0].fPos, sizeof(BezierVertex), kQuadNumVertices);
+    }
+}
+
+// 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
+static void set_conic_coeffs(const SkPoint p[3], BezierVertex verts[kQuadNumVertices],
+                             const SkScalar weight) {
+    SkScalar klm[9];
+
+    GrPathUtils::getConicKLM(p, weight, klm);
+
+    for (int i = 0; i < kQuadNumVertices; ++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];
+    }
+}
+
+static void add_conics(const SkPoint p[3],
+                       const SkScalar weight,
+                       const SkMatrix* toDevice,
+                       const SkMatrix* toSrc,
+                       BezierVertex** vert) {
+    bloat_quad(p, toDevice, toSrc, *vert);
+    set_conic_coeffs(p, *vert, weight);
+    *vert += kQuadNumVertices;
+}
+
+static void add_quads(const SkPoint p[3],
+                      int subdiv,
+                      const SkMatrix* toDevice,
+                      const SkMatrix* toSrc,
+                      BezierVertex** vert) {
+    SkASSERT(subdiv >= 0);
+    if (subdiv) {
+        SkPoint newP[5];
+        SkChopQuadAtHalf(p, newP);
+        add_quads(newP + 0, subdiv-1, toDevice, toSrc, vert);
+        add_quads(newP + 2, subdiv-1, toDevice, toSrc, vert);
+    } else {
+        bloat_quad(p, toDevice, toSrc, *vert);
+        set_uv_quad(p, *vert);
+        *vert += kQuadNumVertices;
+    }
+}
+
+static void add_line(const SkPoint p[2],
+                     const SkMatrix* toSrc,
+                     uint8_t 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;
+
+        float floatCoverage = GrNormalizeByteToFloat(coverage);
+
+        (*vert)[0].fPos = a;
+        (*vert)[0].fCoverage = floatCoverage;
+        (*vert)[1].fPos = b;
+        (*vert)[1].fCoverage = floatCoverage;
+        (*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 (toSrc) {
+            toSrc->mapPointsWithStride(&(*vert)->fPos,
+                                       sizeof(LineVertex),
+                                       kLineSegNumVertices);
+        }
+    } else {
+        // just make it degenerate and likely offscreen
+        for (int i = 0; i < kLineSegNumVertices; ++i) {
+            (*vert)[i].fPos.set(SK_ScalarMax, SK_ScalarMax);
+        }
+    }
+
+    *vert += kLineSegNumVertices;
+}
+
+///////////////////////////////////////////////////////////////////////////////
+
+bool GrAAHairLinePathRenderer::onCanDrawPath(const CanDrawPathArgs& args) const {
+    if (GrAAType::kCoverage != args.fAAType) {
+        return false;
+    }
+
+    if (!IsStrokeHairlineOrEquivalent(args.fShape->style(), *args.fViewMatrix, nullptr)) {
+        return false;
+    }
+
+    // We don't currently handle dashing in this class though perhaps we should.
+    if (args.fShape->style().pathEffect()) {
+        return false;
+    }
+
+    if (SkPath::kLine_SegmentMask == args.fShape->segmentMask() ||
+        args.fShaderCaps->shaderDerivativeSupport()) {
+        return true;
+    }
+
+    return false;
+}
+
+template <class VertexType>
+bool check_bounds(const SkMatrix& viewMatrix, 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 (viewMatrix.hasPerspective()) {
+        tolDevBounds.outset(SK_Scalar1 / 1000, SK_Scalar1 / 1000);
+    } else {
+        // Non-persp matrices cause this path renderer to draw in device space.
+        SkASSERT(viewMatrix.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;
+        }
+        viewMatrix.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;
+}
+
+class AAHairlineOp final : public GrMeshDrawOp {
+public:
+    DEFINE_OP_CLASS_ID
+
+    static sk_sp<GrDrawOp> Make(GrColor color,
+                                const SkMatrix& viewMatrix,
+                                const SkPath& path,
+                                const GrStyle& style,
+                                const SkIRect& devClipBounds) {
+        SkScalar hairlineCoverage;
+        uint8_t newCoverage = 0xff;
+        if (GrPathRenderer::IsStrokeHairlineOrEquivalent(style, viewMatrix, &hairlineCoverage)) {
+            newCoverage = SkScalarRoundToInt(hairlineCoverage * 0xff);
+        }
+
+        return sk_sp<GrDrawOp>(
+                new AAHairlineOp(color, newCoverage, viewMatrix, path, devClipBounds));
+    }
+
+    const char* name() const override { return "AAHairlineOp"; }
+
+    SkString dumpInfo() const override {
+        SkString string;
+        string.appendf("Color: 0x%08x Coverage: 0x%02x, Count: %d\n", fColor, fCoverage,
+                       fPaths.count());
+        string.append(INHERITED::dumpInfo());
+        return string;
+    }
+
+    void computePipelineOptimizations(GrInitInvariantOutput* color,
+                                      GrInitInvariantOutput* coverage,
+                                      GrBatchToXPOverrides* overrides) const override {
+        color->setKnownFourComponents(fColor);
+        coverage->setUnknownSingleComponent();
+    }
+
+private:
+    AAHairlineOp(GrColor color,
+                 uint8_t coverage,
+                 const SkMatrix& viewMatrix,
+                 const SkPath& path,
+                 SkIRect devClipBounds)
+            : INHERITED(ClassID()), fColor(color), fCoverage(coverage) {
+        fPaths.emplace_back(PathData{viewMatrix, path, devClipBounds});
+
+        this->setTransformedBounds(path.getBounds(), viewMatrix, HasAABloat::kYes,
+                                   IsZeroArea::kYes);
+    }
+
+    void initBatchTracker(const GrXPOverridesForBatch& overrides) override {
+        // Handle any color overrides
+        if (!overrides.readsColor()) {
+            fColor = GrColor_ILLEGAL;
+        }
+        overrides.getOverrideColorIfSet(&fColor);
+
+        fUsesLocalCoords = overrides.readsLocalCoords();
+    }
+
+    void onPrepareDraws(Target*) const override;
+
+    typedef SkTArray<SkPoint, true> PtArray;
+    typedef SkTArray<int, true> IntArray;
+    typedef SkTArray<float, true> FloatArray;
+
+    bool onCombineIfPossible(GrOp* t, const GrCaps& caps) override {
+        AAHairlineOp* that = t->cast<AAHairlineOp>();
+
+        if (!GrPipeline::CanCombine(*this->pipeline(), this->bounds(), *that->pipeline(),
+                                    that->bounds(), caps)) {
+            return false;
+        }
+
+        if (this->viewMatrix().hasPerspective() != that->viewMatrix().hasPerspective()) {
+            return false;
+        }
+
+        // We go to identity if we don't have perspective
+        if (this->viewMatrix().hasPerspective() &&
+            !this->viewMatrix().cheapEqualTo(that->viewMatrix())) {
+            return false;
+        }
+
+        // TODO we can actually batch hairlines if they are the same color in a kind of bulk method
+        // but we haven't implemented this yet
+        // TODO investigate going to vertex color and coverage?
+        if (this->coverage() != that->coverage()) {
+            return false;
+        }
+
+        if (this->color() != that->color()) {
+            return false;
+        }
+
+        SkASSERT(this->usesLocalCoords() == that->usesLocalCoords());
+        if (this->usesLocalCoords() && !this->viewMatrix().cheapEqualTo(that->viewMatrix())) {
+            return false;
+        }
+
+        fPaths.push_back_n(that->fPaths.count(), that->fPaths.begin());
+        this->joinBounds(*that);
+        return true;
+    }
+
+    GrColor color() const { return fColor; }
+    uint8_t coverage() const { return fCoverage; }
+    bool usesLocalCoords() const { return fUsesLocalCoords; }
+    const SkMatrix& viewMatrix() const { return fPaths[0].fViewMatrix; }
+
+    struct PathData {
+        SkMatrix fViewMatrix;
+        SkPath fPath;
+        SkIRect fDevClipBounds;
+    };
+
+    GrColor fColor;
+    uint8_t fCoverage;
+    bool fUsesLocalCoords;
+
+    SkSTArray<1, PathData, true> fPaths;
+
+    typedef GrMeshDrawOp INHERITED;
+};
+
+void AAHairlineOp::onPrepareDraws(Target* target) const {
+    // Setup the viewmatrix and localmatrix for the GrGeometryProcessor.
+    SkMatrix invert;
+    if (!this->viewMatrix().invert(&invert)) {
+        return;
+    }
+
+    // we will transform to identity space if the viewmatrix does not have perspective
+    bool hasPerspective = this->viewMatrix().hasPerspective();
+    const SkMatrix* geometryProcessorViewM = &SkMatrix::I();
+    const SkMatrix* geometryProcessorLocalM = &invert;
+    const SkMatrix* toDevice = nullptr;
+    const SkMatrix* toSrc = nullptr;
+    if (hasPerspective) {
+        geometryProcessorViewM = &this->viewMatrix();
+        geometryProcessorLocalM = &SkMatrix::I();
+        toDevice = &this->viewMatrix();
+        toSrc = &invert;
+    }
+
+    // This is hand inlined for maximum performance.
+    PREALLOC_PTARRAY(128) lines;
+    PREALLOC_PTARRAY(128) quads;
+    PREALLOC_PTARRAY(128) conics;
+    IntArray qSubdivs;
+    FloatArray cWeights;
+    int quadCount = 0;
+
+    int instanceCount = fPaths.count();
+    for (int i = 0; i < instanceCount; i++) {
+        const PathData& args = fPaths[i];
+        quadCount += gather_lines_and_quads(args.fPath, args.fViewMatrix, args.fDevClipBounds,
+                                            &lines, &quads, &conics, &qSubdivs, &cWeights);
+    }
+
+    int lineCount = lines.count() / 2;
+    int conicCount = conics.count() / 3;
+
+    // do lines first
+    if (lineCount) {
+        sk_sp<GrGeometryProcessor> lineGP;
+        {
+            using namespace GrDefaultGeoProcFactory;
+
+            Color color(this->color());
+            Coverage coverage(Coverage::kAttribute_Type);
+            LocalCoords localCoords(this->usesLocalCoords() ? LocalCoords::kUsePosition_Type :
+                                    LocalCoords::kUnused_Type);
+            localCoords.fMatrix = geometryProcessorLocalM;
+            lineGP = GrDefaultGeoProcFactory::Make(color, coverage, localCoords,
+                                                   *geometryProcessorViewM);
+        }
+
+        sk_sp<const GrBuffer> linesIndexBuffer(
+            ref_lines_index_buffer(target->resourceProvider()));
+
+        const GrBuffer* vertexBuffer;
+        int firstVertex;
+
+        size_t vertexStride = lineGP->getVertexStride();
+        int vertexCount = kLineSegNumVertices * lineCount;
+        LineVertex* verts = reinterpret_cast<LineVertex*>(
+            target->makeVertexSpace(vertexStride, vertexCount, &vertexBuffer, &firstVertex));
+
+        if (!verts|| !linesIndexBuffer) {
+            SkDebugf("Could not allocate vertices\n");
+            return;
+        }
+
+        SkASSERT(lineGP->getVertexStride() == sizeof(LineVertex));
+
+        for (int i = 0; i < lineCount; ++i) {
+            add_line(&lines[2*i], toSrc, this->coverage(), &verts);
+        }
+
+        GrMesh mesh;
+        mesh.initInstanced(kTriangles_GrPrimitiveType, vertexBuffer, linesIndexBuffer.get(),
+                           firstVertex, kLineSegNumVertices, kIdxsPerLineSeg, lineCount,
+                           kLineSegsNumInIdxBuffer);
+        target->draw(lineGP.get(), mesh);
+    }
+
+    if (quadCount || conicCount) {
+        sk_sp<GrGeometryProcessor> quadGP(
+            GrQuadEffect::Make(this->color(),
+                               *geometryProcessorViewM,
+                               kHairlineAA_GrProcessorEdgeType,
+                               target->caps(),
+                               *geometryProcessorLocalM,
+                               this->usesLocalCoords(),
+                               this->coverage()));
+
+        sk_sp<GrGeometryProcessor> conicGP(
+            GrConicEffect::Make(this->color(),
+                                *geometryProcessorViewM,
+                                kHairlineAA_GrProcessorEdgeType,
+                                target->caps(),
+                                *geometryProcessorLocalM,
+                                this->usesLocalCoords(),
+                                this->coverage()));
+
+        const GrBuffer* vertexBuffer;
+        int firstVertex;
+
+        sk_sp<const GrBuffer> quadsIndexBuffer(
+            ref_quads_index_buffer(target->resourceProvider()));
+
+        size_t vertexStride = sizeof(BezierVertex);
+        int vertexCount = kQuadNumVertices * quadCount + kQuadNumVertices * conicCount;
+        void *vertices = target->makeVertexSpace(vertexStride, vertexCount,
+                                                 &vertexBuffer, &firstVertex);
+
+        if (!vertices || !quadsIndexBuffer) {
+            SkDebugf("Could not allocate vertices\n");
+            return;
+        }
+
+        // Setup vertices
+        BezierVertex* bezVerts = reinterpret_cast<BezierVertex*>(vertices);
+
+        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, &bezVerts);
+        }
+
+        // Start Conics
+        for (int i = 0; i < conicCount; ++i) {
+            add_conics(&conics[3*i], cWeights[i], toDevice, toSrc, &bezVerts);
+        }
+
+        if (quadCount > 0) {
+            GrMesh mesh;
+            mesh.initInstanced(kTriangles_GrPrimitiveType, vertexBuffer, quadsIndexBuffer.get(),
+                               firstVertex, kQuadNumVertices, kIdxsPerQuad, quadCount,
+                               kQuadsNumInIdxBuffer);
+            target->draw(quadGP.get(), mesh);
+            firstVertex += quadCount * kQuadNumVertices;
+        }
+
+        if (conicCount > 0) {
+            GrMesh mesh;
+            mesh.initInstanced(kTriangles_GrPrimitiveType, vertexBuffer, quadsIndexBuffer.get(),
+                               firstVertex, kQuadNumVertices, kIdxsPerQuad, conicCount,
+                               kQuadsNumInIdxBuffer);
+            target->draw(conicGP.get(), mesh);
+        }
+    }
+}
+
+bool GrAAHairLinePathRenderer::onDrawPath(const DrawPathArgs& args) {
+    GR_AUDIT_TRAIL_AUTO_FRAME(args.fRenderTargetContext->auditTrail(),
+                              "GrAAHairlinePathRenderer::onDrawPath");
+    SkASSERT(!args.fRenderTargetContext->isUnifiedMultisampled());
+
+    SkIRect devClipBounds;
+    args.fClip->getConservativeBounds(args.fRenderTargetContext->width(),
+                                      args.fRenderTargetContext->height(),
+                                      &devClipBounds);
+    SkPath path;
+    args.fShape->asPath(&path);
+    sk_sp<GrDrawOp> op = AAHairlineOp::Make(args.fPaint->getColor(), *args.fViewMatrix, path,
+                                            args.fShape->style(), devClipBounds);
+    GrPipelineBuilder pipelineBuilder(*args.fPaint, args.fAAType);
+    pipelineBuilder.setUserStencil(args.fUserStencilSettings);
+    args.fRenderTargetContext->addDrawOp(pipelineBuilder, *args.fClip, std::move(op));
+    return true;
+}
+
+///////////////////////////////////////////////////////////////////////////////////////////////////
+
+#ifdef GR_TEST_UTILS
+
+DRAW_BATCH_TEST_DEFINE(AAHairlineOp) {
+    GrColor color = GrRandomColor(random);
+    SkMatrix viewMatrix = GrTest::TestMatrix(random);
+    SkPath path = GrTest::TestPath(random);
+    SkIRect devClipBounds;
+    devClipBounds.setEmpty();
+    return AAHairlineOp::Make(color, viewMatrix, path, GrStyle::SimpleHairline(), devClipBounds)
+            .release();
+}
+
+#endif