/*
* 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 "GrBuffer.h"
#include "GrCaps.h"
#include "GrClip.h"
#include "GrContext.h"
#include "GrDefaultGeoProcFactory.h"
#include "GrDrawOpTest.h"
#include "GrOpFlushState.h"
#include "GrPathUtils.h"
#include "GrProcessor.h"
#include "GrResourceProvider.h"
#include "GrSimpleMeshDrawOpHelper.h"
#include "SkGeometry.h"
#include "SkMatrixPriv.h"
#include "SkPoint3.h"
#include "SkPointPriv.h"
#include "SkRectPriv.h"
#include "SkStroke.h"
#include "SkTemplates.h"
#include "effects/GrBezierEffect.h"
#include "ops/GrMeshDrawOp.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 sk_sp<const GrBuffer> get_quads_index_buffer(GrResourceProvider* resourceProvider) {
GR_DEFINE_STATIC_UNIQUE_KEY(gQuadsIndexBufferKey);
return resourceProvider->findOrCreatePatternedIndexBuffer(
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 sk_sp<const GrBuffer> get_lines_index_buffer(GrResourceProvider* resourceProvider) {
GR_DEFINE_STATIC_UNIQUE_KEY(gLinesIndexBufferKey);
return resourceProvider->findOrCreatePatternedIndexBuffer(
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 =
gDegenerateToLineTol * gDegenerateToLineTol;
if (SkPointPriv::DistanceToSqd(p[0], p[1]) < gDegenerateToLineTolSqd ||
SkPointPriv::DistanceToSqd(p[1], p[2]) < gDegenerateToLineTolSqd) {
return 1;
}
*dsqd = SkPointPriv::DistanceToLineBetweenSqd(p[1], p[0], p[2]);
if (*dsqd < gDegenerateToLineTolSqd) {
return 1;
}
if (SkPointPriv::DistanceToLineBetweenSqd(p[2], 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 <= 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,
SkScalar capLength,
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();
// Whenever a degenerate, zero-length contour is encountered, this code will insert a
// 'capLength' x-aligned line segment. Since this is rendering hairlines it is hoped this will
// suffice for AA square & circle capping.
int verbsInContour = 0; // Does not count moves
bool seenZeroLengthVerb = false;
SkPoint zeroVerbPt;
for (;;) {
SkPoint pathPts[4];
SkPoint devPts[4];
SkPath::Verb verb = iter.next(pathPts, false);
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];
if (verbsInContour == 0 && i == 0 &&
pts[0] == pts[1] && pts[2] == pts[3]) {
seenZeroLengthVerb = true;
zeroVerbPt = pts[0];
}
} 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;
}
}
}
verbsInContour++;
break;
}
case SkPath::kMove_Verb:
// New contour (and last one was unclosed). If it was just a zero length drawing
// operation, and we're supposed to draw caps, then add a tiny line.
if (seenZeroLengthVerb && verbsInContour == 1 && capLength > 0) {
SkPoint* pts = lines->push_back_n(2);
pts[0] = SkPoint::Make(zeroVerbPt.fX - capLength, zeroVerbPt.fY);
pts[1] = SkPoint::Make(zeroVerbPt.fX + capLength, zeroVerbPt.fY);
}
verbsInContour = 0;
seenZeroLengthVerb = false;
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];
if (verbsInContour == 0 && pts[0] == pts[1]) {
seenZeroLengthVerb = true;
zeroVerbPt = pts[0];
}
}
verbsInContour++;
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];
if (verbsInContour == 0 && i == 0 &&
pts[0] == pts[1] && pts[2] == pts[3]) {
seenZeroLengthVerb = true;
zeroVerbPt = pts[0];
}
} 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;
}
}
}
verbsInContour++;
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];
if (verbsInContour == 0 && i == 0 &&
pts[0] == pts[1] && pts[2] == pts[3]) {
seenZeroLengthVerb = true;
zeroVerbPt = pts[0];
}
} 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;
}
}
}
}
verbsInContour++;
break;
case SkPath::kClose_Verb:
// Contour is closed, so we don't need to grow the starting line, unless it's
// *just* a zero length subpath. (SVG Spec 11.4, 'stroke').
if (capLength > 0) {
if (seenZeroLengthVerb && verbsInContour == 1) {
SkPoint* pts = lines->push_back_n(2);
pts[0] = SkPoint::Make(zeroVerbPt.fX - capLength, zeroVerbPt.fY);
pts[1] = SkPoint::Make(zeroVerbPt.fX + capLength, zeroVerbPt.fY);
} else if (verbsInContour == 0) {
// Contour was (moveTo, close). Add a line.
m.mapPoints(devPts, pathPts, 1);
devPts[1] = devPts[0];
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] = SkPoint::Make(devPts[0].fX - capLength, devPts[0].fY);
pts[1] = SkPoint::Make(devPts[1].fX + capLength, devPts[1].fY);
}
}
}
break;
case SkPath::kDone_Verb:
if (seenZeroLengthVerb && verbsInContour == 1 && capLength > 0) {
// Path ended with a dangling (moveTo, line|quad|etc). If the final verb is
// degenerate, we need to draw a line.
SkPoint* pts = lines->push_back_n(2);
pts[0] = SkPoint::Make(zeroVerbPt.fX - capLength, zeroVerbPt.fY);
pts[1] = SkPoint::Make(zeroVerbPt.fX + capLength, zeroVerbPt.fY);
}
return totalQuadCount;
}
}
}
struct LineVertex {
SkPoint fPos;
float fCoverage;
};
struct BezierVertex {
SkPoint fPos;
union {
struct {
SkScalar fKLM[3];
} 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 = normA.fX * normB.fY - normA.fY * normB.fX;
wInv = SkScalarInvert(wInv);
result->fX = normA.fY * lineBW - lineAW * normB.fY;
result->fX *= wInv;
result->fY = lineAW * normB.fX - normA.fX * lineBW;
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;
SkPointPriv::SetOrthog(&abN, ab, SkPointPriv::kLeft_Side);
if (abN.dot(ac) > 0) {
abN.negate();
}
cb.normalize();
SkVector cbN;
SkPointPriv::SetOrthog(&cbN, cb, SkPointPriv::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) {
SkMatrixPriv::MapPointsWithStride(*toSrc, &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) {
SkMatrix klm;
GrPathUtils::getConicKLM(p, weight, &klm);
for (int i = 0; i < kQuadNumVertices; ++i) {
const SkPoint3 pt3 = {verts[i].fPos.x(), verts[i].fPos.y(), 1.f};
klm.mapHomogeneousPoints((SkPoint3* ) verts[i].fConic.fKLM, &pt3, 1);
}
}
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;
SkScalar lengthSqd = SkPointPriv::LengthSqd(vec);
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);
if (lengthSqd >= 1.0f) {
// Relative to points a and b:
// The inner vertices are inset half a pixel along the line a,b
(*vert)[0].fPos = a + vec;
(*vert)[0].fCoverage = floatCoverage;
(*vert)[1].fPos = b - vec;
(*vert)[1].fCoverage = floatCoverage;
} else {
// The inner vertices are inset a distance of length(a,b) from the outer edge of
// geometry. For the "a" inset this is the same as insetting from b by half a pixel.
// The coverage is then modulated by the length. This gives us the correct
// coverage for rects shorter than a pixel as they get translated subpixel amounts
// inside of a pixel.
SkScalar length = SkScalarSqrt(lengthSqd);
(*vert)[0].fPos = b - vec;
(*vert)[0].fCoverage = floatCoverage * length;
(*vert)[1].fPos = a + vec;
(*vert)[1].fCoverage = floatCoverage * length;
}
// Relative to points a and b:
// The outer vertices are outset half a pixel along the line a,b and then a whole pixel
// orthogonally.
(*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) {
SkMatrixPriv::MapPointsWithStride(*toSrc, &(*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;
}
///////////////////////////////////////////////////////////////////////////////
GrPathRenderer::CanDrawPath
GrAAHairLinePathRenderer::onCanDrawPath(const CanDrawPathArgs& args) const {
if (GrAAType::kCoverage != args.fAAType) {
return CanDrawPath::kNo;
}
if (!IsStrokeHairlineOrEquivalent(args.fShape->style(), *args.fViewMatrix, nullptr)) {
return CanDrawPath::kNo;
}
// We don't currently handle dashing in this class though perhaps we should.
if (args.fShape->style().pathEffect()) {
return CanDrawPath::kNo;
}
if (SkPath::kLine_SegmentMask == args.fShape->segmentMask() ||
args.fCaps->shaderCaps()->shaderDerivativeSupport()) {
return CanDrawPath::kYes;
}
return CanDrawPath::kNo;
}
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 {
SkRectPriv::GrowToInclude(&actualBounds, pos);
}
}
if (!first) {
return tolDevBounds.contains(actualBounds);
}
return true;
}
namespace {
class AAHairlineOp final : public GrMeshDrawOp {
private:
using Helper = GrSimpleMeshDrawOpHelperWithStencil;
public:
DEFINE_OP_CLASS_ID
static std::unique_ptr<GrDrawOp> Make(GrPaint&& paint,
const SkMatrix& viewMatrix,
const SkPath& path,
const GrStyle& style,
const SkIRect& devClipBounds,
const GrUserStencilSettings* stencilSettings) {
SkScalar hairlineCoverage;
uint8_t newCoverage = 0xff;
if (GrPathRenderer::IsStrokeHairlineOrEquivalent(style, viewMatrix, &hairlineCoverage)) {
newCoverage = SkScalarRoundToInt(hairlineCoverage * 0xff);
}
const SkStrokeRec& stroke = style.strokeRec();
SkScalar capLength = SkPaint::kButt_Cap != stroke.getCap() ? hairlineCoverage * 0.5f : 0.0f;
return Helper::FactoryHelper<AAHairlineOp>(std::move(paint), newCoverage, viewMatrix, path,
devClipBounds, capLength, stencilSettings);
}
AAHairlineOp(const Helper::MakeArgs& helperArgs,
GrColor color,
uint8_t coverage,
const SkMatrix& viewMatrix,
const SkPath& path,
SkIRect devClipBounds,
SkScalar capLength,
const GrUserStencilSettings* stencilSettings)
: INHERITED(ClassID())
, fHelper(helperArgs, GrAAType::kCoverage, stencilSettings)
, fColor(color)
, fCoverage(coverage) {
fPaths.emplace_back(PathData{viewMatrix, path, devClipBounds, capLength});
this->setTransformedBounds(path.getBounds(), viewMatrix, HasAABloat::kYes,
IsZeroArea::kYes);
}
const char* name() const override { return "AAHairlineOp"; }
void visitProxies(const VisitProxyFunc& func) const override {
fHelper.visitProxies(func);
}
SkString dumpInfo() const override {
SkString string;
string.appendf("Color: 0x%08x Coverage: 0x%02x, Count: %d\n", fColor, fCoverage,
fPaths.count());
string += INHERITED::dumpInfo();
string += fHelper.dumpInfo();
return string;
}
FixedFunctionFlags fixedFunctionFlags() const override { return fHelper.fixedFunctionFlags(); }
RequiresDstTexture finalize(const GrCaps& caps, const GrAppliedClip* clip,
GrPixelConfigIsClamped dstIsClamped) override {
return fHelper.xpRequiresDstTexture(caps, clip, dstIsClamped,
GrProcessorAnalysisCoverage::kSingleChannel, &fColor);
}
private:
void onPrepareDraws(Target*) 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 (!fHelper.isCompatible(that->fHelper, caps, this->bounds(), that->bounds())) {
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 combine 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;
}
if (fHelper.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; }
const SkMatrix& viewMatrix() const { return fPaths[0].fViewMatrix; }
struct PathData {
SkMatrix fViewMatrix;
SkPath fPath;
SkIRect fDevClipBounds;
SkScalar fCapLength;
};
SkSTArray<1, PathData, true> fPaths;
Helper fHelper;
GrColor fColor;
uint8_t fCoverage;
typedef GrMeshDrawOp INHERITED;
};
} // anonymous namespace
void AAHairlineOp::onPrepareDraws(Target* target) {
// 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,
args.fCapLength, &lines, &quads, &conics, &qSubdivs,
&cWeights);
}
int lineCount = lines.count() / 2;
int conicCount = conics.count() / 3;
const GrPipeline* pipeline = fHelper.makePipeline(target);
// do lines first
if (lineCount) {
sk_sp<GrGeometryProcessor> lineGP;
{
using namespace GrDefaultGeoProcFactory;
Color color(this->color());
LocalCoords localCoords(fHelper.usesLocalCoords() ? LocalCoords::kUsePosition_Type
: LocalCoords::kUnused_Type);
localCoords.fMatrix = geometryProcessorLocalM;
lineGP = GrDefaultGeoProcFactory::Make(color, Coverage::kAttribute_Type, localCoords,
*geometryProcessorViewM);
}
sk_sp<const GrBuffer> linesIndexBuffer = get_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(GrPrimitiveType::kTriangles);
mesh.setIndexedPatterned(linesIndexBuffer.get(), kIdxsPerLineSeg, kLineSegNumVertices,
lineCount, kLineSegsNumInIdxBuffer);
mesh.setVertexData(vertexBuffer, firstVertex);
target->draw(lineGP.get(), pipeline, mesh);
}
if (quadCount || conicCount) {
sk_sp<GrGeometryProcessor> quadGP(GrQuadEffect::Make(this->color(),
*geometryProcessorViewM,
GrClipEdgeType::kHairlineAA,
target->caps(),
*geometryProcessorLocalM,
fHelper.usesLocalCoords(),
this->coverage()));
sk_sp<GrGeometryProcessor> conicGP(GrConicEffect::Make(this->color(),
*geometryProcessorViewM,
GrClipEdgeType::kHairlineAA,
target->caps(),
*geometryProcessorLocalM,
fHelper.usesLocalCoords(),
this->coverage()));
const GrBuffer* vertexBuffer;
int firstVertex;
sk_sp<const GrBuffer> quadsIndexBuffer = get_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(GrPrimitiveType::kTriangles);
mesh.setIndexedPatterned(quadsIndexBuffer.get(), kIdxsPerQuad, kQuadNumVertices,
quadCount, kQuadsNumInIdxBuffer);
mesh.setVertexData(vertexBuffer, firstVertex);
target->draw(quadGP.get(), pipeline, mesh);
firstVertex += quadCount * kQuadNumVertices;
}
if (conicCount > 0) {
GrMesh mesh(GrPrimitiveType::kTriangles);
mesh.setIndexedPatterned(quadsIndexBuffer.get(), kIdxsPerQuad, kQuadNumVertices,
conicCount, kQuadsNumInIdxBuffer);
mesh.setVertexData(vertexBuffer, firstVertex);
target->draw(conicGP.get(), pipeline, mesh);
}
}
}
bool GrAAHairLinePathRenderer::onDrawPath(const DrawPathArgs& args) {
GR_AUDIT_TRAIL_AUTO_FRAME(args.fRenderTargetContext->auditTrail(),
"GrAAHairlinePathRenderer::onDrawPath");
SkASSERT(GrFSAAType::kUnifiedMSAA != args.fRenderTargetContext->fsaaType());
SkIRect devClipBounds;
args.fClip->getConservativeBounds(args.fRenderTargetContext->width(),
args.fRenderTargetContext->height(),
&devClipBounds);
SkPath path;
args.fShape->asPath(&path);
std::unique_ptr<GrDrawOp> op =
AAHairlineOp::Make(std::move(args.fPaint), *args.fViewMatrix, path,
args.fShape->style(), devClipBounds, args.fUserStencilSettings);
args.fRenderTargetContext->addDrawOp(*args.fClip, std::move(op));
return true;
}
///////////////////////////////////////////////////////////////////////////////////////////////////
#if GR_TEST_UTILS
GR_DRAW_OP_TEST_DEFINE(AAHairlineOp) {
SkMatrix viewMatrix = GrTest::TestMatrix(random);
SkPath path = GrTest::TestPath(random);
SkIRect devClipBounds;
devClipBounds.setEmpty();
return AAHairlineOp::Make(std::move(paint), viewMatrix, path, GrStyle::SimpleHairline(),
devClipBounds, GrGetRandomStencil(random, context));
}
#endif