gecko-dev/gfx/2d/PathCG.cpp

364 lines
9.7 KiB
C++

/* -*- Mode: C++; tab-width: 20; indent-tabs-mode: nil; c-basic-offset: 2 -*-
* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
* file, You can obtain one at http://mozilla.org/MPL/2.0/. */
#include "PathCG.h"
#include <math.h>
#include "DrawTargetCG.h"
#include "Logging.h"
#include "PathHelpers.h"
namespace mozilla {
namespace gfx {
PathBuilderCG::~PathBuilderCG()
{
CGPathRelease(mCGPath);
}
void
PathBuilderCG::MoveTo(const Point &aPoint)
{
if (!aPoint.IsFinite()) {
return;
}
CGPathMoveToPoint(mCGPath, nullptr, aPoint.x, aPoint.y);
}
void
PathBuilderCG::LineTo(const Point &aPoint)
{
if (!aPoint.IsFinite()) {
return;
}
if (CGPathIsEmpty(mCGPath))
MoveTo(aPoint);
else
CGPathAddLineToPoint(mCGPath, nullptr, aPoint.x, aPoint.y);
}
void
PathBuilderCG::BezierTo(const Point &aCP1,
const Point &aCP2,
const Point &aCP3)
{
if (!aCP1.IsFinite() || !aCP2.IsFinite() || !aCP3.IsFinite()) {
return;
}
if (CGPathIsEmpty(mCGPath))
MoveTo(aCP1);
CGPathAddCurveToPoint(mCGPath, nullptr,
aCP1.x, aCP1.y,
aCP2.x, aCP2.y,
aCP3.x, aCP3.y);
}
void
PathBuilderCG::QuadraticBezierTo(const Point &aCP1,
const Point &aCP2)
{
if (!aCP1.IsFinite() || !aCP2.IsFinite()) {
return;
}
if (CGPathIsEmpty(mCGPath))
MoveTo(aCP1);
CGPathAddQuadCurveToPoint(mCGPath, nullptr,
aCP1.x, aCP1.y,
aCP2.x, aCP2.y);
}
void
PathBuilderCG::Close()
{
if (!CGPathIsEmpty(mCGPath))
CGPathCloseSubpath(mCGPath);
}
void
PathBuilderCG::Arc(const Point &aOrigin, Float aRadius, Float aStartAngle,
Float aEndAngle, bool aAntiClockwise)
{
if (!aOrigin.IsFinite() || !IsFinite(aRadius) ||
!IsFinite(aStartAngle) || !IsFinite(aEndAngle)) {
return;
}
// Disabled for now due to a CG bug when using CGPathAddArc with stroke
// dashing and rotation transforms that are multiples of 90 degrees. See:
// https://bugzilla.mozilla.org/show_bug.cgi?id=949661#c8
#if 0
// Core Graphic's initial coordinate system is y-axis up, whereas Moz2D's is
// y-axis down. Core Graphics therefore considers "clockwise" to mean "sweep
// in the direction of decreasing angle" whereas Moz2D considers it to mean
// "sweep in the direction of increasing angle". In other words if this
// Moz2D method is instructed to sweep anti-clockwise we need to tell
// CGPathAddArc to sweep clockwise, and vice versa. Hence why we pass the
// value of aAntiClockwise directly to CGPathAddArc's "clockwise" bool
// parameter.
CGPathAddArc(mCGPath, nullptr,
aOrigin.x, aOrigin.y,
aRadius,
aStartAngle,
aEndAngle,
aAntiClockwise);
#endif
ArcToBezier(this, aOrigin, Size(aRadius, aRadius), aStartAngle, aEndAngle,
aAntiClockwise);
}
Point
PathBuilderCG::CurrentPoint() const
{
Point ret;
if (!CGPathIsEmpty(mCGPath)) {
CGPoint pt = CGPathGetCurrentPoint(mCGPath);
ret.MoveTo(pt.x, pt.y);
}
return ret;
}
void
PathBuilderCG::EnsureActive(const Point &aPoint)
{
}
already_AddRefed<Path>
PathBuilderCG::Finish()
{
return MakeAndAddRef<PathCG>(mCGPath, mFillRule);
}
already_AddRefed<PathBuilder>
PathCG::CopyToBuilder(FillRule aFillRule) const
{
CGMutablePathRef path = CGPathCreateMutableCopy(mPath);
return MakeAndAddRef<PathBuilderCG>(path, aFillRule);
}
already_AddRefed<PathBuilder>
PathCG::TransformedCopyToBuilder(const Matrix &aTransform, FillRule aFillRule) const
{
// 10.7 adds CGPathCreateMutableCopyByTransformingPath it might be faster than doing
// this by hand
struct TransformApplier {
CGMutablePathRef path;
CGAffineTransform transform;
static void
TranformCGPathApplierFunc(void *vinfo, const CGPathElement *element)
{
TransformApplier *info = reinterpret_cast<TransformApplier*>(vinfo);
switch (element->type) {
case kCGPathElementMoveToPoint:
{
CGPoint pt = element->points[0];
CGPathMoveToPoint(info->path, &info->transform, pt.x, pt.y);
break;
}
case kCGPathElementAddLineToPoint:
{
CGPoint pt = element->points[0];
CGPathAddLineToPoint(info->path, &info->transform, pt.x, pt.y);
break;
}
case kCGPathElementAddQuadCurveToPoint:
{
CGPoint cpt = element->points[0];
CGPoint pt = element->points[1];
CGPathAddQuadCurveToPoint(info->path, &info->transform, cpt.x, cpt.y, pt.x, pt.y);
break;
}
case kCGPathElementAddCurveToPoint:
{
CGPoint cpt1 = element->points[0];
CGPoint cpt2 = element->points[1];
CGPoint pt = element->points[2];
CGPathAddCurveToPoint(info->path, &info->transform, cpt1.x, cpt1.y, cpt2.x, cpt2.y, pt.x, pt.y);
break;
}
case kCGPathElementCloseSubpath:
{
CGPathCloseSubpath(info->path);
break;
}
}
}
};
TransformApplier ta;
ta.path = CGPathCreateMutable();
ta.transform = GfxMatrixToCGAffineTransform(aTransform);
CGPathApply(mPath, &ta, TransformApplier::TranformCGPathApplierFunc);
return MakeAndAddRef<PathBuilderCG>(ta.path, aFillRule);
}
static void
StreamPathToSinkApplierFunc(void *vinfo, const CGPathElement *element)
{
PathSink *sink = reinterpret_cast<PathSink*>(vinfo);
switch (element->type) {
case kCGPathElementMoveToPoint:
{
CGPoint pt = element->points[0];
sink->MoveTo(CGPointToPoint(pt));
break;
}
case kCGPathElementAddLineToPoint:
{
CGPoint pt = element->points[0];
sink->LineTo(CGPointToPoint(pt));
break;
}
case kCGPathElementAddQuadCurveToPoint:
{
CGPoint cpt = element->points[0];
CGPoint pt = element->points[1];
sink->QuadraticBezierTo(CGPointToPoint(cpt),
CGPointToPoint(pt));
break;
}
case kCGPathElementAddCurveToPoint:
{
CGPoint cpt1 = element->points[0];
CGPoint cpt2 = element->points[1];
CGPoint pt = element->points[2];
sink->BezierTo(CGPointToPoint(cpt1),
CGPointToPoint(cpt2),
CGPointToPoint(pt));
break;
}
case kCGPathElementCloseSubpath:
{
sink->Close();
break;
}
}
}
void
PathCG::StreamToSink(PathSink *aSink) const
{
CGPathApply(mPath, aSink, StreamPathToSinkApplierFunc);
}
bool
PathCG::ContainsPoint(const Point &aPoint, const Matrix &aTransform) const
{
Matrix inverse = aTransform;
inverse.Invert();
Point transformedPoint = inverse.TransformPoint(aPoint);
// We could probably drop the input transform and just transform the point at the caller?
CGPoint point = {transformedPoint.x, transformedPoint.y};
// The transform parameter of CGPathContainsPoint doesn't seem to work properly on OS X 10.5
// so we transform aPoint ourselves.
return CGPathContainsPoint(mPath, nullptr, point, mFillRule == FillRule::FILL_EVEN_ODD);
}
static size_t
PutBytesNull(void *info, const void *buffer, size_t count)
{
return count;
}
/* The idea of a scratch context comes from WebKit */
static CGContextRef
CreateScratchContext()
{
CGDataConsumerCallbacks callbacks = {PutBytesNull, nullptr};
CGDataConsumerRef consumer = CGDataConsumerCreate(nullptr, &callbacks);
CGContextRef cg = CGPDFContextCreate(consumer, nullptr, nullptr);
CGDataConsumerRelease(consumer);
return cg;
}
static CGContextRef
ScratchContext()
{
static CGContextRef cg = CreateScratchContext();
return cg;
}
bool
PathCG::StrokeContainsPoint(const StrokeOptions &aStrokeOptions,
const Point &aPoint,
const Matrix &aTransform) const
{
Matrix inverse = aTransform;
inverse.Invert();
Point transformedPoint = inverse.TransformPoint(aPoint);
// We could probably drop the input transform and just transform the point at the caller?
CGPoint point = {transformedPoint.x, transformedPoint.y};
CGContextRef cg = ScratchContext();
CGContextSaveGState(cg);
CGContextBeginPath(cg);
CGContextAddPath(cg, mPath);
SetStrokeOptions(cg, aStrokeOptions);
CGContextReplacePathWithStrokedPath(cg);
CGContextRestoreGState(cg);
CGPathRef sPath = CGContextCopyPath(cg);
bool inStroke = CGPathContainsPoint(sPath, nullptr, point, false);
CGPathRelease(sPath);
return inStroke;
}
//XXX: what should these functions return for an empty path?
// currently they return CGRectNull {inf,inf, 0, 0}
Rect
PathCG::GetBounds(const Matrix &aTransform) const
{
//XXX: are these bounds tight enough
Rect bounds = CGRectToRect(CGPathGetBoundingBox(mPath));
//XXX: currently this returns the bounds of the transformed bounds
// this is strictly looser than the bounds of the transformed path
return aTransform.TransformBounds(bounds);
}
Rect
PathCG::GetStrokedBounds(const StrokeOptions &aStrokeOptions,
const Matrix &aTransform) const
{
// 10.7 has CGPathCreateCopyByStrokingPath which we could use
// instead of this scratch context business
CGContextRef cg = ScratchContext();
CGContextSaveGState(cg);
CGContextBeginPath(cg);
CGContextAddPath(cg, mPath);
SetStrokeOptions(cg, aStrokeOptions);
CGContextReplacePathWithStrokedPath(cg);
Rect bounds = CGRectToRect(CGContextGetPathBoundingBox(cg));
CGContextRestoreGState(cg);
if (!bounds.IsFinite()) {
return Rect();
}
return aTransform.TransformBounds(bounds);
}
} // namespace gfx
} // namespace mozilla