blob: d6ad9d32c9c73ef6d6f9ef288e65bd9408de4dc5 [file] [log] [blame]
/*
* 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 "GrBatchFlushState.h"
#include "GrBatchTest.h"
#include "GrCaps.h"
#include "GrContext.h"
#include "GrDefaultGeoProcFactory.h"
#include "GrIndexBuffer.h"
#include "GrPathUtils.h"
#include "GrPipelineBuilder.h"
#include "GrProcessor.h"
#include "GrResourceProvider.h"
#include "GrVertexBuffer.h"
#include "SkGeometry.h"
#include "SkStroke.h"
#include "SkTemplates.h"
#include "batches/GrVertexBatch.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 GrIndexBuffer* 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 GrIndexBuffer* 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);
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).
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 don't need a direction if we aren't constraining the subdivision
const SkPathPriv::FirstDirection kDummyDir = SkPathPriv::kCCW_FirstDirection;
// 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 {
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 (!args.fAntiAlias) {
return false;
}
if (!IsStrokeHairlineOrEquivalent(*args.fStroke, *args.fViewMatrix, nullptr)) {
return false;
}
if (SkPath::kLine_SegmentMask == args.fPath->getSegmentMasks() ||
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 AAHairlineBatch : public GrVertexBatch {
public:
DEFINE_BATCH_CLASS_ID
struct Geometry {
GrColor fColor;
uint8_t fCoverage;
SkMatrix fViewMatrix;
SkPath fPath;
SkIRect fDevClipBounds;
};
static GrDrawBatch* Create(const Geometry& geometry) { return new AAHairlineBatch(geometry); }
const char* name() const override { return "AAHairlineBatch"; }
void computePipelineOptimizations(GrInitInvariantOutput* color,
GrInitInvariantOutput* coverage,
GrBatchToXPOverrides* overrides) const override {
// When this is called on a batch, there is only one geometry bundle
color->setKnownFourComponents(fGeoData[0].fColor);
coverage->setUnknownSingleComponent();
overrides->fUsePLSDstRead = true;
}
private:
void initBatchTracker(const GrXPOverridesForBatch& overrides) override {
// Handle any color overrides
if (!overrides.readsColor()) {
fGeoData[0].fColor = GrColor_ILLEGAL;
}
overrides.getOverrideColorIfSet(&fGeoData[0].fColor);
// setup batch properties
fBatch.fColorIgnored = !overrides.readsColor();
fBatch.fColor = fGeoData[0].fColor;
fBatch.fUsesLocalCoords = overrides.readsLocalCoords();
fBatch.fCoverageIgnored = !overrides.readsCoverage();
fBatch.fCoverage = fGeoData[0].fCoverage;
}
SkSTArray<1, Geometry, true>* geoData() { return &fGeoData; }
void onPrepareDraws(Target*) const override;
typedef SkTArray<SkPoint, true> PtArray;
typedef SkTArray<int, true> IntArray;
typedef SkTArray<float, true> FloatArray;
AAHairlineBatch(const Geometry& geometry) : INHERITED(ClassID()) {
fGeoData.push_back(geometry);
// compute bounds
fBounds = geometry.fPath.getBounds();
geometry.fViewMatrix.mapRect(&fBounds);
// This is b.c. hairlines are notionally infinitely thin so without expansion
// two overlapping lines could be reordered even though they hit the same pixels.
fBounds.outset(0.5f, 0.5f);
}
bool onCombineIfPossible(GrBatch* t, const GrCaps& caps) override {
AAHairlineBatch* that = t->cast<AAHairlineBatch>();
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;
}
fGeoData.push_back_n(that->geoData()->count(), that->geoData()->begin());
this->joinBounds(that->bounds());
return true;
}
GrColor color() const { return fBatch.fColor; }
uint8_t coverage() const { return fBatch.fCoverage; }
bool usesLocalCoords() const { return fBatch.fUsesLocalCoords; }
const SkMatrix& viewMatrix() const { return fGeoData[0].fViewMatrix; }
bool coverageIgnored() const { return fBatch.fCoverageIgnored; }
struct BatchTracker {
GrColor fColor;
uint8_t fCoverage;
SkRect fDevBounds;
bool fUsesLocalCoords;
bool fColorIgnored;
bool fCoverageIgnored;
};
BatchTracker fBatch;
SkSTArray<1, Geometry, true> fGeoData;
typedef GrVertexBatch INHERITED;
};
void AAHairlineBatch::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;
}
SkAutoTUnref<const 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.reset(GrDefaultGeoProcFactory::Create(color, coverage, localCoords,
*geometryProcessorViewM));
}
SkAutoTUnref<const GrGeometryProcessor> quadGP(
GrQuadEffect::Create(this->color(),
*geometryProcessorViewM,
kHairlineAA_GrProcessorEdgeType,
target->caps(),
*geometryProcessorLocalM,
this->usesLocalCoords(),
this->coverage()));
SkAutoTUnref<const GrGeometryProcessor> conicGP(
GrConicEffect::Create(this->color(),
*geometryProcessorViewM,
kHairlineAA_GrProcessorEdgeType,
target->caps(),
*geometryProcessorLocalM,
this->usesLocalCoords(),
this->coverage()));
// 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 = fGeoData.count();
for (int i = 0; i < instanceCount; i++) {
const Geometry& args = fGeoData[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) {
SkAutoTUnref<const GrIndexBuffer> linesIndexBuffer(
ref_lines_index_buffer(target->resourceProvider()));
target->initDraw(lineGP, this->pipeline());
const GrVertexBuffer* 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);
}
{
GrVertices vertices;
vertices.initInstanced(kTriangles_GrPrimitiveType, vertexBuffer, linesIndexBuffer,
firstVertex, kLineSegNumVertices, kIdxsPerLineSeg, lineCount,
kLineSegsNumInIdxBuffer);
target->draw(vertices);
}
}
if (quadCount || conicCount) {
const GrVertexBuffer* vertexBuffer;
int firstVertex;
SkAutoTUnref<const GrIndexBuffer> 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) {
target->initDraw(quadGP, this->pipeline());
{
GrVertices tempVerts;
tempVerts.initInstanced(kTriangles_GrPrimitiveType, vertexBuffer, quadsIndexBuffer,
firstVertex, kQuadNumVertices, kIdxsPerQuad, quadCount,
kQuadsNumInIdxBuffer);
target->draw(tempVerts);
firstVertex += quadCount * kQuadNumVertices;
}
}
if (conicCount > 0) {
target->initDraw(conicGP, this->pipeline());
{
GrVertices tempVerts;
tempVerts.initInstanced(kTriangles_GrPrimitiveType, vertexBuffer, quadsIndexBuffer,
firstVertex, kQuadNumVertices, kIdxsPerQuad, conicCount,
kQuadsNumInIdxBuffer);
target->draw(tempVerts);
}
}
}
}
static GrDrawBatch* create_hairline_batch(GrColor color,
const SkMatrix& viewMatrix,
const SkPath& path,
const GrStrokeInfo& stroke,
const SkIRect& devClipBounds) {
SkScalar hairlineCoverage;
uint8_t newCoverage = 0xff;
if (GrPathRenderer::IsStrokeHairlineOrEquivalent(stroke, viewMatrix, &hairlineCoverage)) {
newCoverage = SkScalarRoundToInt(hairlineCoverage * 0xff);
}
AAHairlineBatch::Geometry geometry;
geometry.fColor = color;
geometry.fCoverage = newCoverage;
geometry.fViewMatrix = viewMatrix;
geometry.fPath = path;
geometry.fDevClipBounds = devClipBounds;
return AAHairlineBatch::Create(geometry);
}
bool GrAAHairLinePathRenderer::onDrawPath(const DrawPathArgs& args) {
SkIRect devClipBounds;
GrRenderTarget* rt = args.fPipelineBuilder->getRenderTarget();
args.fPipelineBuilder->clip().getConservativeBounds(rt->width(), rt->height(), &devClipBounds);
SkAutoTUnref<GrDrawBatch> batch(create_hairline_batch(args.fColor, *args.fViewMatrix, *args.fPath,
*args.fStroke, devClipBounds));
args.fTarget->drawBatch(*args.fPipelineBuilder, batch);
return true;
}
///////////////////////////////////////////////////////////////////////////////////////////////////
#ifdef GR_TEST_UTILS
DRAW_BATCH_TEST_DEFINE(AAHairlineBatch) {
GrColor color = GrRandomColor(random);
SkMatrix viewMatrix = GrTest::TestMatrix(random);
GrStrokeInfo stroke(SkStrokeRec::kHairline_InitStyle);
SkPath path = GrTest::TestPath(random);
SkIRect devClipBounds;
devClipBounds.setEmpty();
return create_hairline_batch(color, viewMatrix, path, stroke, devClipBounds);
}
#endif