Move SkShadowTessellator to GrShadowTessellator

BUG=skia:6119

Change-Id: I9756b5aeaced1f21a65063470ccb013c7b856f28
Reviewed-on: https://skia-review.googlesource.com/7505
Reviewed-by: Brian Salomon <bsalomon@google.com>
Commit-Queue: Jim Van Verth <jvanverth@google.com>

3 files changed, 2 insertions, 391 deletions

diff --git a/src/effects/shadows/SkAmbientShadowMaskFilter.cpp b/src/effects/shadows/SkAmbientShadowMaskFilter.cpp
index e378c184b9..d92a7b548c 100755
--- a/src/effects/shadows/SkAmbientShadowMaskFilter.cpp
+++ b/src/effects/shadows/SkAmbientShadowMaskFilter.cpp
@@ -18,11 +18,11 @@
 #include "GrStyle.h"
 #include "GrTexture.h"
 #include "GrTextureProxy.h"
+#include "effects/GrShadowTessellator.h"
 #include "glsl/GrGLSLFragmentProcessor.h"
 #include "glsl/GrGLSLFragmentShaderBuilder.h"
 #include "glsl/GrGLSLProgramDataManager.h"
 #include "glsl/GrGLSLUniformHandler.h"
-#include "SkShadowTessellator.h"
 #include "SkStrokeRec.h"
 #endif
 
@@ -238,7 +238,7 @@ bool SkAmbientShadowMaskFilterImpl::directFilterMaskGPU(GrTextureProvider* texPr
     GrColor  umbraColor = GrColorPackRGBA(0, 0, fAmbientAlpha*255.9999f, umbraAlpha*255.9999f);
     GrColor  penumbraColor = GrColorPackRGBA(0, 0, fAmbientAlpha*255.9999f, 0);
 
-    SkAmbientShadowTessellator tess(SkMatrix::I(), path, radius, umbraColor, penumbraColor,
+    GrAmbientShadowTessellator tess(SkMatrix::I(), path, radius, umbraColor, penumbraColor,
                                 SkToBool(fFlags & SkShadowFlags::kTransparentOccluder_ShadowFlag));
 
     sk_sp<ShadowEdgeFP> edgeFP(new ShadowEdgeFP);
diff --git a/src/effects/shadows/SkShadowTessellator.cpp b/src/effects/shadows/SkShadowTessellator.cpp
deleted file mode 100755
index 0a320ceba9..0000000000
--- a/src/effects/shadows/SkShadowTessellator.cpp
+++ /dev/null
@@ -1,314 +0,0 @@
-/*
- * Copyright 2017 Google Inc.
- *
- * Use of this source code is governed by a BSD-style license that can be
- * found in the LICENSE file.
- */
-
-#include "SkShadowTessellator.h"
-#include "SkGeometry.h"
-
-#if SK_SUPPORT_GPU
-#include "GrPathUtils.h"
-
-static bool compute_normal(const SkPoint& p0, const SkPoint& p1, SkScalar radius, SkScalar dir,
-                           SkVector* newNormal) {
-    SkVector normal;
-    // compute perpendicular
-    normal.fX = p0.fY - p1.fY;
-    normal.fY = p1.fX - p0.fX;
-    if (!normal.normalize()) {
-        return false;
-    }
-    normal *= radius*dir;
-    *newNormal = normal;
-    return true;
-}
-
-static void compute_radial_steps(const SkVector& v1, const SkVector& v2, SkScalar r,
-                                 SkScalar* rotSin, SkScalar* rotCos, int* n) {
-    const SkScalar kRecipPixelsPerArcSegment = 0.25f;
-
-    SkScalar rCos = v1.dot(v2);
-    SkScalar rSin = v1.cross(v2);
-    SkScalar theta = SkScalarATan2(rSin, rCos);
-
-    SkScalar steps = r*theta*kRecipPixelsPerArcSegment;
-
-    SkScalar dTheta = theta / steps;
-    *rotSin = SkScalarSinCos(dTheta, rotCos);
-    *n = SkScalarFloorToInt(steps);
-}
-
-SkAmbientShadowTessellator::SkAmbientShadowTessellator(const SkMatrix& viewMatrix,
-                                                       const SkPath& path,
-                                                       SkScalar radius,
-                                                       GrColor umbraColor,
-                                                       GrColor penumbraColor,
-                                                       bool transparent)
-    : fRadius(radius)
-    , fUmbraColor(umbraColor)
-    , fPenumbraColor(penumbraColor)
-    , fTransparent(transparent)
-    , fPrevInnerIndex(-1) {
-
-    // Outer ring: 3*numPts
-    // Middle ring: numPts
-    fPositions.setReserve(4 * path.countPoints());
-    fColors.setReserve(4 * path.countPoints());
-    // Outer ring: 12*numPts
-    // Middle ring: 0
-    fIndices.setReserve(12 * path.countPoints());
-
-    fInitPoints.setReserve(3);
-
-    // walk around the path, tessellate and generate outer ring
-    // if original path is transparent, will accumulate sum of points for centroid
-    SkPath::Iter iter(path, true);
-    SkPoint pts[4];
-    SkPath::Verb verb;
-    if (fTransparent) {
-        *fPositions.push() = SkPoint::Make(0, 0);
-        *fColors.push() = umbraColor;
-        fCentroidCount = 0;
-    }
-    while ((verb = iter.next(pts)) != SkPath::kDone_Verb) {
-        switch (verb) {
-            case SkPath::kLine_Verb:
-                this->handleLine(viewMatrix, pts[1]);
-                break;
-            case SkPath::kQuad_Verb:
-                this->handleQuad(viewMatrix, pts);
-                break;
-            case SkPath::kCubic_Verb:
-                this->handleCubic(viewMatrix, pts);
-                break;
-            case SkPath::kConic_Verb:
-                this->handleConic(viewMatrix, pts, iter.conicWeight());
-                break;
-            case SkPath::kMove_Verb:
-            case SkPath::kClose_Verb:
-            case SkPath::kDone_Verb:
-                break;
-        }
-    }
-
-    SkVector normal;
-    if (compute_normal(fPositions[fPrevInnerIndex], fPositions[fFirstVertex], fRadius, fDirection,
-                       &normal)) {
-        this->addArc(normal);
-
-        // close out previous arc
-        *fPositions.push() = fPositions[fPrevInnerIndex] + normal;
-        *fColors.push() = fPenumbraColor;
-        *fIndices.push() = fPrevInnerIndex;
-        *fIndices.push() = fPositions.count() - 2;
-        *fIndices.push() = fPositions.count() - 1;
-
-        // add final edge
-        *fPositions.push() = fPositions[fFirstVertex] + normal;
-        *fColors.push() = fPenumbraColor;
-
-        *fIndices.push() = fPrevInnerIndex;
-        *fIndices.push() = fPositions.count() - 2;
-        *fIndices.push() = fFirstVertex;
-
-        *fIndices.push() = fPositions.count() - 2;
-        *fIndices.push() = fPositions.count() - 1;
-        *fIndices.push() = fFirstVertex;
-    }
-
-    // finalize centroid
-    if (fTransparent) {
-        fPositions[0] *= SkScalarFastInvert(fCentroidCount);
-
-        *fIndices.push() = 0;
-        *fIndices.push() = fPrevInnerIndex;
-        *fIndices.push() = fFirstVertex;
-    }
-
-    // final fan
-    if (fPositions.count() >= 3) {
-        fPrevInnerIndex = fFirstVertex;
-        fPrevNormal = normal;
-        this->addArc(fFirstNormal);
-
-        *fIndices.push() = fFirstVertex;
-        *fIndices.push() = fPositions.count() - 1;
-        *fIndices.push() = fFirstVertex + 1;
-    }
-}
-
-// tesselation tolerance values, in device space pixels
-static const SkScalar kQuadTolerance = 0.2f;
-static const SkScalar kCubicTolerance = 0.2f;
-static const SkScalar kConicTolerance = 0.5f;
-
-void SkAmbientShadowTessellator::handleLine(const SkPoint& p)  {
-    if (fInitPoints.count() < 2) {
-        *fInitPoints.push() = p;
-        return;
-    }
-
-    if (fInitPoints.count() == 2) {
-        // determine if cw or ccw
-        SkVector v0 = fInitPoints[1] - fInitPoints[0];
-        SkVector v1 = p - fInitPoints[0];
-        SkScalar perpDot = v0.fX*v1.fY - v0.fY*v1.fX;
-        if (SkScalarNearlyZero(perpDot)) {
-            // nearly parallel, just treat as straight line and continue
-            fInitPoints[1] = p;
-            return;
-        }
-
-        // if perpDot > 0, winding is ccw
-        fDirection = (perpDot > 0) ? -1 : 1;
-
-        // add first quad
-        if (!compute_normal(fInitPoints[0], fInitPoints[1], fRadius, fDirection,
-                            &fFirstNormal)) {
-            // first two points are incident, make the third point the second and continue
-            fInitPoints[1] = p;
-            return;
-        }
-
-        fFirstVertex = fPositions.count();
-        fPrevNormal = fFirstNormal;
-        fPrevInnerIndex = fFirstVertex;
-
-        *fPositions.push() = fInitPoints[0];
-        *fColors.push() = fUmbraColor;
-        *fPositions.push() = fInitPoints[0] + fFirstNormal;
-        *fColors.push() = fPenumbraColor;
-        if (fTransparent) {
-            fPositions[0] += fInitPoints[0];
-            fCentroidCount = 1;
-        }
-        this->addEdge(fInitPoints[1], fFirstNormal);
-
-        // to ensure we skip this block next time
-        *fInitPoints.push() = p;
-    }
-
-    SkVector normal;
-    if (compute_normal(fPositions[fPrevInnerIndex], p, fRadius, fDirection, &normal)) {
-        this->addArc(normal);
-        this->addEdge(p, normal);
-    }
-}
-
-void SkAmbientShadowTessellator::handleLine(const SkMatrix& m, SkPoint p)  {
-    m.mapPoints(&p, 1);
-    this->handleLine(p);
-}
-
-void SkAmbientShadowTessellator::handleQuad(const SkPoint pts[3]) {
-    int maxCount = GrPathUtils::quadraticPointCount(pts, kQuadTolerance);
-    fPointBuffer.setReserve(maxCount);
-    SkPoint* target = fPointBuffer.begin();
-    int count = GrPathUtils::generateQuadraticPoints(pts[0], pts[1], pts[2],
-                                                     kQuadTolerance, &target, maxCount);
-    fPointBuffer.setCount(count);
-    for (int i = 0; i < count; i++) {
-        this->handleLine(fPointBuffer[i]);
-    }
-}
-
-void SkAmbientShadowTessellator::handleQuad(const SkMatrix& m, SkPoint pts[3]) {
-    m.mapPoints(pts, 3);
-    this->handleQuad(pts);
-}
-
-void SkAmbientShadowTessellator::handleCubic(const SkMatrix& m, SkPoint pts[4]) {
-    m.mapPoints(pts, 4);
-    int maxCount = GrPathUtils::cubicPointCount(pts, kCubicTolerance);
-    fPointBuffer.setReserve(maxCount);
-    SkPoint* target = fPointBuffer.begin();
-    int count = GrPathUtils::generateCubicPoints(pts[0], pts[1], pts[2], pts[3],
-                                                 kCubicTolerance, &target, maxCount);
-    fPointBuffer.setCount(count);
-    for (int i = 0; i < count; i++) {
-        this->handleLine(fPointBuffer[i]);
-    }
-}
-
-void SkAmbientShadowTessellator::handleConic(const SkMatrix& m, SkPoint pts[3], SkScalar w) {
-    m.mapPoints(pts, 3);
-    SkAutoConicToQuads quadder;
-    const SkPoint* quads = quadder.computeQuads(pts, w, kConicTolerance);
-    SkPoint lastPoint = *(quads++);
-    int count = quadder.countQuads();
-    for (int i = 0; i < count; ++i) {
-        SkPoint quadPts[3];
-        quadPts[0] = lastPoint;
-        quadPts[1] = quads[0];
-        quadPts[2] = i == count - 1 ? pts[2] : quads[1];
-        this->handleQuad(quadPts);
-        lastPoint = quadPts[2];
-        quads += 2;
-    }
-}
-
-void SkAmbientShadowTessellator::addArc(const SkVector& nextNormal) {
-    // fill in fan from previous quad
-    SkScalar rotSin, rotCos;
-    int numSteps;
-    compute_radial_steps(fPrevNormal, nextNormal, fRadius, &rotSin, &rotCos, &numSteps);
-    SkVector prevNormal = fPrevNormal;
-    for (int i = 0; i < numSteps; ++i) {
-        SkVector nextNormal;
-        nextNormal.fX = prevNormal.fX*rotCos - prevNormal.fY*rotSin;
-        nextNormal.fY = prevNormal.fY*rotCos + prevNormal.fX*rotSin;
-        *fPositions.push() = fPositions[fPrevInnerIndex] + nextNormal;
-        *fColors.push() = fPenumbraColor;
-        *fIndices.push() = fPrevInnerIndex;
-        *fIndices.push() = fPositions.count() - 2;
-        *fIndices.push() = fPositions.count() - 1;
-
-        prevNormal = nextNormal;
-    }
-}
-
-
-void SkAmbientShadowTessellator::finishArcAndAddEdge(const SkPoint& nextPoint,
-                                                     const SkVector& nextNormal) {
-    // close out previous arc
-    *fPositions.push() = fPositions[fPrevInnerIndex] + nextNormal;
-    *fColors.push() = fPenumbraColor;
-    *fIndices.push() = fPrevInnerIndex;
-    *fIndices.push() = fPositions.count() - 2;
-    *fIndices.push() = fPositions.count() - 1;
-
-    this->addEdge(nextPoint, nextNormal);
-}
-
-void SkAmbientShadowTessellator::addEdge(const SkPoint& nextPoint, const SkVector& nextNormal) {
-    // add next quad
-    *fPositions.push() = nextPoint;
-    *fColors.push() = fUmbraColor;
-    *fPositions.push() = nextPoint + nextNormal;
-    *fColors.push() = fPenumbraColor;
-
-    *fIndices.push() = fPrevInnerIndex;
-    *fIndices.push() = fPositions.count() - 3;
-    *fIndices.push() = fPositions.count() - 2;
-
-    *fIndices.push() = fPositions.count() - 3;
-    *fIndices.push() = fPositions.count() - 1;
-    *fIndices.push() = fPositions.count() - 2;
-
-    // if transparent, add point to first one in array and add to center fan
-    if (fTransparent) {
-        fPositions[0] += nextPoint;
-        ++fCentroidCount;
-
-        *fIndices.push() = 0;
-        *fIndices.push() = fPrevInnerIndex;
-        *fIndices.push() = fPositions.count() - 2;
-    }
-
-    fPrevInnerIndex = fPositions.count() - 2;
-    fPrevNormal = nextNormal;
-}
-
-#endif
diff --git a/src/effects/shadows/SkShadowTessellator.h b/src/effects/shadows/SkShadowTessellator.h
deleted file mode 100755
index 91274340df..0000000000
--- a/src/effects/shadows/SkShadowTessellator.h
+++ /dev/null
@@ -1,75 +0,0 @@
-/*
- * Copyright 2017 Google Inc.
- *
- * Use of this source code is governed by a BSD-style license that can be
- * found in the LICENSE file.
- */
-
-#ifndef SkShadowTessellator_DEFINED
-#define SkShadowTessellator_DEFINED
-
-#include "SkTDArray.h"
-#include "SkPoint.h"
-
-#if SK_SUPPORT_GPU
-#include "GrColor.h"
-
-class SkMatrix;
-class SkPath;
-
-/**
- * This class generates an ambient shadow for a path by walking the path, outsetting by the
- * radius, and setting inner and outer colors to umbraColor and penumbraColor, respectively.
- * If transparent is true, then the center of the ambient shadow will be filled in.
- */
-class SkAmbientShadowTessellator {
-public:
-    SkAmbientShadowTessellator(const SkMatrix& viewMatrix, const SkPath& path, SkScalar radius,
-                               GrColor umbraColor, GrColor penumbraColor, bool transparent);
-
-    int      vertexCount() { return fPositions.count(); }
-    SkPoint* positions() { return fPositions.begin(); }
-    GrColor* colors() { return fColors.begin(); }
-    int      indexCount() { return fIndices.count(); }
-    uint16_t* indices() { return fIndices.begin(); }
-
-private:
-    void handleLine(const SkPoint& p);
-    void handleLine(const SkMatrix& m, SkPoint p);
-
-    void handleQuad(const SkPoint pts[3]);
-    void handleQuad(const SkMatrix& m, SkPoint pts[3]);
-
-    void handleCubic(const SkMatrix& m, SkPoint pts[4]);
-
-    void handleConic(const SkMatrix& m, SkPoint pts[3], SkScalar w);
-
-    void addArc(const SkVector& nextNormal);
-    void finishArcAndAddEdge(const SkVector& nextPoint, const SkVector& nextNormal);
-    void addEdge(const SkVector& nextPoint, const SkVector& nextNormal);
-
-    SkScalar            fRadius;
-    GrColor             fUmbraColor;
-    GrColor             fPenumbraColor;
-    bool                fTransparent;
-
-    SkTDArray<SkPoint>  fPositions;
-    SkTDArray<GrColor>  fColors;
-    SkTDArray<uint16_t> fIndices;
-
-    int                 fPrevInnerIndex;
-    SkVector            fPrevNormal;
-    int                 fFirstVertex;
-    SkVector            fFirstNormal;
-    SkScalar            fDirection;
-    int                 fCentroidCount;
-
-    // first three points
-    SkTDArray<SkPoint>  fInitPoints;
-    // temporary buffer
-    SkTDArray<SkPoint>  fPointBuffer;
-};
-
-#endif
-
-#endif