void
PathBuilderNVpr::Close()
{
MakeWritable();
mDescription.AppendCommand(GL_CLOSE_PATH_NV);
mCurrentPoint = mStartPoint;
}
bool EnsureWritablePagesNoThrow(void* p, size_t len)
{
BYTE* pStart = (BYTE*)p;
if (len == 0)
return true;
if (!AreAnyCOWPageBitsSet(pStart, len))
return true;
return MakeWritable(pStart, len, PAGE_READWRITE);
}
void
PathBuilderNVpr::Arc(const Point& aOrigin, Float aRadius, Float aStartAngle,
Float aEndAngle, bool aAntiClockwise)
{
MakeWritable();
const Point startPoint(aOrigin.x + cos(aStartAngle) * aRadius,
aOrigin.y + sin(aStartAngle) * aRadius);
// The spec says to begin with a line to the start point.
LineTo(startPoint);
mIsPolygon = false;
if (fabs(aEndAngle - aStartAngle) > 2 * M_PI - 1e-5) {
// The spec says to just draw the whole circle in this case.
mDescription.AppendCommand(GL_CIRCULAR_CCW_ARC_TO_NV);
mDescription.AppendPoint(aOrigin);
mDescription.AppendFloat(aRadius);
mDescription.AppendFloat(aStartAngle * 180 / M_PI);
mDescription.AppendFloat(360 + aStartAngle * 180 / M_PI);
return;
}
const Point endPoint(aOrigin.x + cos(aEndAngle) * aRadius,
aOrigin.y + sin(aEndAngle) * aRadius);
if (aAntiClockwise && aEndAngle < aStartAngle) {
aEndAngle += 2 * M_PI;
} else if (!aAntiClockwise && aEndAngle > aStartAngle) {
aEndAngle -= 2 * M_PI;
}
// 'Anticlockwise' in HTML5 seems to be relative to a downward-pointing Y-axis,
// whereas CW/CCW are relative to an upward-facing Y-axis in NV_path_rendering.
if (fabs(aEndAngle - aStartAngle) < M_PI) {
mDescription.AppendCommand(aAntiClockwise ? GL_LARGE_CW_ARC_TO_NV
: GL_LARGE_CCW_ARC_TO_NV);
} else {
mDescription.AppendCommand(aAntiClockwise ? GL_SMALL_CW_ARC_TO_NV
: GL_SMALL_CCW_ARC_TO_NV);
}
mDescription.AppendFloat(aRadius); // x-radius
mDescription.AppendFloat(aRadius); // y-radius
mDescription.AppendFloat(0);
mDescription.AppendPoint(endPoint);
mCurrentPoint = endPoint;
}
void
PathBuilderNVpr::MoveTo(const Point& aPoint)
{
MakeWritable();
if (!mDescription.IsEmpty()) {
mIsPolygon = false;
}
mDescription.AppendCommand(GL_MOVE_TO_NV);
mDescription.AppendPoint(aPoint);
mStartPoint = aPoint;
mCurrentPoint = aPoint;
}
void
PathBuilderNVpr::QuadraticBezierTo(const Point& aCP1,
const Point& aCP2)
{
MakeWritable();
if (mDescription.IsEmpty()) {
MoveTo(aCP1);
}
mDescription.AppendCommand(GL_QUADRATIC_CURVE_TO_NV);
mDescription.AppendPoint(aCP1);
mDescription.AppendPoint(aCP2);
mCurrentPoint = aCP2;
mIsPolygon = false;
}
void
PathBuilderNVpr::LineTo(const Point& aPoint)
{
MakeWritable();
if (mDescription.IsEmpty()) {
MoveTo(aPoint);
return;
}
if (mDescription.mCommands.back() != GL_MOVE_TO_NV
&& mDescription.mCommands.back() != GL_LINE_TO_NV) {
mIsPolygon = false;
}
mDescription.AppendCommand(GL_LINE_TO_NV);
mDescription.AppendPoint(aPoint);
mCurrentPoint = aPoint;
}