/*
* Copyright 2012 Google Inc.
*
* Use of this source code is governed by a BSD-style license that can be
* found in the LICENSE file.
*/
#include "GrGLPath.h"
#include "GrGLPathRendering.h"
#include "GrGLGpu.h"
namespace {
inline GrGLubyte verb_to_gl_path_cmd(SkPath::Verb verb) {
static const GrGLubyte gTable[] = {
GR_GL_MOVE_TO,
GR_GL_LINE_TO,
GR_GL_QUADRATIC_CURVE_TO,
GR_GL_CONIC_CURVE_TO,
GR_GL_CUBIC_CURVE_TO,
GR_GL_CLOSE_PATH,
};
GR_STATIC_ASSERT(0 == SkPath::kMove_Verb);
GR_STATIC_ASSERT(1 == SkPath::kLine_Verb);
GR_STATIC_ASSERT(2 == SkPath::kQuad_Verb);
GR_STATIC_ASSERT(3 == SkPath::kConic_Verb);
GR_STATIC_ASSERT(4 == SkPath::kCubic_Verb);
GR_STATIC_ASSERT(5 == SkPath::kClose_Verb);
SkASSERT(verb >= 0 && (size_t)verb < SK_ARRAY_COUNT(gTable));
return gTable[verb];
}
#ifdef SK_DEBUG
inline int num_coords(SkPath::Verb verb) {
static const int gTable[] = {
2, // move
2, // line
4, // quad
5, // conic
6, // cubic
0, // close
};
GR_STATIC_ASSERT(0 == SkPath::kMove_Verb);
GR_STATIC_ASSERT(1 == SkPath::kLine_Verb);
GR_STATIC_ASSERT(2 == SkPath::kQuad_Verb);
GR_STATIC_ASSERT(3 == SkPath::kConic_Verb);
GR_STATIC_ASSERT(4 == SkPath::kCubic_Verb);
GR_STATIC_ASSERT(5 == SkPath::kClose_Verb);
SkASSERT(verb >= 0 && (size_t)verb < SK_ARRAY_COUNT(gTable));
return gTable[verb];
}
#endif
inline GrGLenum join_to_gl_join(SkPaint::Join join) {
static GrGLenum gSkJoinsToGrGLJoins[] = {
GR_GL_MITER_REVERT,
GR_GL_ROUND,
GR_GL_BEVEL
};
return gSkJoinsToGrGLJoins[join];
GR_STATIC_ASSERT(0 == SkPaint::kMiter_Join);
GR_STATIC_ASSERT(1 == SkPaint::kRound_Join);
GR_STATIC_ASSERT(2 == SkPaint::kBevel_Join);
GR_STATIC_ASSERT(SK_ARRAY_COUNT(gSkJoinsToGrGLJoins) == SkPaint::kJoinCount);
}
inline GrGLenum cap_to_gl_cap(SkPaint::Cap cap) {
static GrGLenum gSkCapsToGrGLCaps[] = {
GR_GL_FLAT,
GR_GL_ROUND,
GR_GL_SQUARE
};
return gSkCapsToGrGLCaps[cap];
GR_STATIC_ASSERT(0 == SkPaint::kButt_Cap);
GR_STATIC_ASSERT(1 == SkPaint::kRound_Cap);
GR_STATIC_ASSERT(2 == SkPaint::kSquare_Cap);
GR_STATIC_ASSERT(SK_ARRAY_COUNT(gSkCapsToGrGLCaps) == SkPaint::kCapCount);
}
inline void points_to_coords(const SkPoint points[], size_t first_point, size_t amount,
GrGLfloat coords[]) {
for (size_t i = 0; i < amount; ++i) {
coords[i * 2] = SkScalarToFloat(points[first_point + i].fX);
coords[i * 2 + 1] = SkScalarToFloat(points[first_point + i].fY);
}
}
template<bool checkForDegenerates>
inline bool init_path_object_for_general_path(GrGLGpu* gpu, GrGLuint pathID,
const SkPath& skPath) {
SkDEBUGCODE(int numCoords = 0);
int verbCnt = skPath.countVerbs();
int pointCnt = skPath.countPoints();
int minCoordCnt = pointCnt * 2;
SkSTArray<16, GrGLubyte, true> pathCommands(verbCnt);
SkSTArray<16, GrGLfloat, true> pathCoords(minCoordCnt);
bool lastVerbWasMove = true; // A path with just "close;" means "moveto(0,0); close;"
SkPoint points[4];
SkPath::RawIter iter(skPath);
SkPath::Verb verb;
while ((verb = iter.next(points)) != SkPath::kDone_Verb) {
pathCommands.push_back(verb_to_gl_path_cmd(verb));
GrGLfloat coords[6];
int coordsForVerb;
switch (verb) {
case SkPath::kMove_Verb:
if (checkForDegenerates) {
lastVerbWasMove = true;
}
points_to_coords(points, 0, 1, coords);
coordsForVerb = 2;
break;
case SkPath::kLine_Verb:
if (checkForDegenerates) {
if (SkPath::IsLineDegenerate(points[0], points[1], true)) {
return false;
}
lastVerbWasMove = false;
}
points_to_coords(points, 1, 1, coords);
coordsForVerb = 2;
break;
case SkPath::kConic_Verb:
if (checkForDegenerates) {
if (SkPath::IsQuadDegenerate(points[0], points[1], points[2], true)) {
return false;
}
lastVerbWasMove = false;
}
points_to_coords(points, 1, 2, coords);
coords[4] = SkScalarToFloat(iter.conicWeight());
coordsForVerb = 5;
break;
case SkPath::kQuad_Verb:
if (checkForDegenerates) {
if (SkPath::IsQuadDegenerate(points[0], points[1], points[2], true)) {
return false;
}
lastVerbWasMove = false;
}
points_to_coords(points, 1, 2, coords);
coordsForVerb = 4;
break;
case SkPath::kCubic_Verb:
if (checkForDegenerates) {
if (SkPath::IsCubicDegenerate(points[0], points[1], points[2], points[3],
true)) {
return false;
}
lastVerbWasMove = false;
}
points_to_coords(points, 1, 3, coords);
coordsForVerb = 6;
break;
case SkPath::kClose_Verb:
if (checkForDegenerates) {
if (lastVerbWasMove) {
// Interpret "move(x,y);close;" as "move(x,y);lineto(x,y);close;".
// which produces a degenerate segment.
return false;
}
}
continue;
default:
SkASSERT(false); // Not reached.
continue;
}
SkDEBUGCODE(numCoords += num_coords(verb));
pathCoords.push_back_n(coordsForVerb, coords);
}
SkASSERT(verbCnt == pathCommands.count());
SkASSERT(numCoords == pathCoords.count());
GR_GL_CALL(gpu->glInterface(), PathCommands(pathID, pathCommands.count(), &pathCommands[0],
pathCoords.count(), GR_GL_FLOAT, &pathCoords[0]));
return true;
}
/*
* For now paths only natively support winding and even odd fill types
*/
static GrPathRendering::FillType convert_skpath_filltype(SkPath::FillType fill) {
switch (fill) {
default:
SkFAIL("Incomplete Switch\n");
case SkPath::kWinding_FillType:
case SkPath::kInverseWinding_FillType:
return GrPathRendering::kWinding_FillType;
case SkPath::kEvenOdd_FillType:
case SkPath::kInverseEvenOdd_FillType:
return GrPathRendering::kEvenOdd_FillType;
}
}
} // namespace
bool GrGLPath::InitPathObjectPathDataCheckingDegenerates(GrGLGpu* gpu, GrGLuint pathID,
const SkPath& skPath) {
return init_path_object_for_general_path<true>(gpu, pathID, skPath);
}
void GrGLPath::InitPathObjectPathData(GrGLGpu* gpu,
GrGLuint pathID,
const SkPath& skPath) {
SkASSERT(!skPath.isEmpty());
#ifdef SK_SCALAR_IS_FLOAT
// This branch does type punning, converting SkPoint* to GrGLfloat*.
if ((skPath.getSegmentMasks() & SkPath::kConic_SegmentMask) == 0) {
int verbCnt = skPath.countVerbs();
int pointCnt = skPath.countPoints();
int coordCnt = pointCnt * 2;
SkSTArray<16, GrGLubyte, true> pathCommands(verbCnt);
SkSTArray<16, GrGLfloat, true> pathCoords(coordCnt);
static_assert(sizeof(SkPoint) == sizeof(GrGLfloat) * 2, "sk_point_not_two_floats");
pathCommands.resize_back(verbCnt);
pathCoords.resize_back(coordCnt);
skPath.getPoints(reinterpret_cast<SkPoint*>(&pathCoords[0]), pointCnt);
skPath.getVerbs(&pathCommands[0], verbCnt);
SkDEBUGCODE(int verbCoordCnt = 0);
for (int i = 0; i < verbCnt; ++i) {
SkPath::Verb v = static_cast<SkPath::Verb>(pathCommands[i]);
pathCommands[i] = verb_to_gl_path_cmd(v);
SkDEBUGCODE(verbCoordCnt += num_coords(v));
}
SkASSERT(verbCnt == pathCommands.count());
SkASSERT(verbCoordCnt == pathCoords.count());
GR_GL_CALL(gpu->glInterface(), PathCommands(pathID, pathCommands.count(), &pathCommands[0],
pathCoords.count(), GR_GL_FLOAT,
&pathCoords[0]));
return;
}
#endif
SkAssertResult(init_path_object_for_general_path<false>(gpu, pathID, skPath));
}
void GrGLPath::InitPathObjectStroke(GrGLGpu* gpu, GrGLuint pathID, const GrStrokeInfo& stroke) {
SkASSERT(stroke.needToApply());
SkASSERT(!stroke.isDashed());
SkASSERT(!stroke.isHairlineStyle());
GR_GL_CALL(gpu->glInterface(),
PathParameterf(pathID, GR_GL_PATH_STROKE_WIDTH, SkScalarToFloat(stroke.getWidth())));
GR_GL_CALL(gpu->glInterface(),
PathParameterf(pathID, GR_GL_PATH_MITER_LIMIT, SkScalarToFloat(stroke.getMiter())));
GrGLenum join = join_to_gl_join(stroke.getJoin());
GR_GL_CALL(gpu->glInterface(), PathParameteri(pathID, GR_GL_PATH_JOIN_STYLE, join));
GrGLenum cap = cap_to_gl_cap(stroke.getCap());
GR_GL_CALL(gpu->glInterface(), PathParameteri(pathID, GR_GL_PATH_END_CAPS, cap));
GR_GL_CALL(gpu->glInterface(), PathParameterf(pathID, GR_GL_PATH_STROKE_BOUND, 0.02f));
}
void GrGLPath::InitPathObjectEmptyPath(GrGLGpu* gpu, GrGLuint pathID) {
GR_GL_CALL(gpu->glInterface(), PathCommands(pathID, 0, nullptr, 0, GR_GL_FLOAT, nullptr));
}
GrGLPath::GrGLPath(GrGLGpu* gpu, const SkPath& origSkPath, const GrStrokeInfo& origStroke)
: INHERITED(gpu, origSkPath, origStroke),
fPathID(gpu->glPathRendering()->genPaths(1)) {
if (origSkPath.isEmpty()) {
InitPathObjectEmptyPath(gpu, fPathID);
fShouldStroke = false;
fShouldFill = false;
} else {
const SkPath* skPath = &origSkPath;
SkTLazy<SkPath> tmpPath;
const GrStrokeInfo* stroke = &origStroke;
GrStrokeInfo tmpStroke(SkStrokeRec::kFill_InitStyle);
if (stroke->isDashed()) {
// Skia stroking and NVPR stroking differ with respect to dashing
// pattern.
// Convert a dashing to either a stroke or a fill.
if (stroke->applyDashToPath(tmpPath.init(), &tmpStroke, *skPath)) {
skPath = tmpPath.get();
stroke = &tmpStroke;
}
}
bool didInit = false;
if (stroke->needToApply() && stroke->getCap() != SkPaint::kButt_Cap) {
// Skia stroking and NVPR stroking differ with respect to stroking
// end caps of empty subpaths.
// Convert stroke to fill if path contains empty subpaths.
didInit = InitPathObjectPathDataCheckingDegenerates(gpu, fPathID, *skPath);
if (!didInit) {
if (!tmpPath.isValid()) {
tmpPath.init();
}
SkAssertResult(stroke->applyToPath(tmpPath.get(), *skPath));
skPath = tmpPath.get();
tmpStroke.setFillStyle();
stroke = &tmpStroke;
}
}
if (!didInit) {
InitPathObjectPathData(gpu, fPathID, *skPath);
}
fShouldStroke = stroke->needToApply();
fShouldFill = stroke->isFillStyle() ||
stroke->getStyle() == SkStrokeRec::kStrokeAndFill_Style;
fFillType = convert_skpath_filltype(skPath->getFillType());
fBounds = skPath->getBounds();
if (fShouldStroke) {
InitPathObjectStroke(gpu, fPathID, *stroke);
// FIXME: try to account for stroking, without rasterizing the stroke.
fBounds.outset(stroke->getWidth(), stroke->getWidth());
}
}
this->registerWithCache();
}
void GrGLPath::onRelease() {
if (0 != fPathID && this->shouldFreeResources()) {
static_cast<GrGLGpu*>(this->getGpu())->glPathRendering()->deletePaths(fPathID, 1);
fPathID = 0;
}
INHERITED::onRelease();
}
void GrGLPath::onAbandon() {
fPathID = 0;
INHERITED::onAbandon();
}