gfx3DMatrix
Layer::SnapTransform(const gfx3DMatrix& aTransform,
const gfxRect& aSnapRect,
gfxMatrix* aResidualTransform)
{
if (aResidualTransform) {
*aResidualTransform = gfxMatrix();
}
gfxMatrix matrix2D;
gfx3DMatrix result;
if (mManager->IsSnappingEffectiveTransforms() &&
aTransform.Is2D(&matrix2D) &&
matrix2D.HasNonIntegerTranslation() &&
!matrix2D.IsSingular() &&
!matrix2D.HasNonAxisAlignedTransform()) {
gfxMatrix snappedMatrix;
gfxPoint topLeft = matrix2D.Transform(aSnapRect.TopLeft());
topLeft.Round();
// first compute scale factors that scale aSnapRect to the snapped rect
if (aSnapRect.IsEmpty()) {
snappedMatrix.xx = matrix2D.xx;
snappedMatrix.yy = matrix2D.yy;
} else {
gfxPoint bottomRight = matrix2D.Transform(aSnapRect.BottomRight());
bottomRight.Round();
snappedMatrix.xx = (bottomRight.x - topLeft.x)/aSnapRect.Width();
snappedMatrix.yy = (bottomRight.y - topLeft.y)/aSnapRect.Height();
}
// compute translation factors that will move aSnapRect to the snapped rect
// given those scale factors
snappedMatrix.x0 = topLeft.x - aSnapRect.X()*snappedMatrix.xx;
snappedMatrix.y0 = topLeft.y - aSnapRect.Y()*snappedMatrix.yy;
result = gfx3DMatrix::From2D(snappedMatrix);
if (aResidualTransform && !snappedMatrix.IsSingular()) {
// set aResidualTransform so that aResidual * snappedMatrix == matrix2D.
// (i.e., appying snappedMatrix after aResidualTransform gives the
// ideal transform.
gfxMatrix snappedMatrixInverse = snappedMatrix;
snappedMatrixInverse.Invert();
*aResidualTransform = matrix2D * snappedMatrixInverse;
}
} else {
result = aTransform;
}
return result;
}
bool
gfxContext::UserToDevicePixelSnapped(gfxRect& rect, bool ignoreScale) const
{
if (GetFlags() & FLAG_DISABLE_SNAPPING)
return PR_FALSE;
// if we're not at 1.0 scale, don't snap, unless we're
// ignoring the scale. If we're not -just- a scale,
// never snap.
const gfxFloat epsilon = 0.0000001;
#define WITHIN_E(a,b) (fabs((a)-(b)) < epsilon)
cairo_matrix_t mat;
cairo_get_matrix(mCairo, &mat);
if (!ignoreScale &&
(!WITHIN_E(mat.xx,1.0) || !WITHIN_E(mat.yy,1.0) ||
!WITHIN_E(mat.xy,0.0) || !WITHIN_E(mat.yx,0.0)))
return PR_FALSE;
#undef WITHIN_E
gfxPoint p1 = UserToDevice(rect.TopLeft());
gfxPoint p2 = UserToDevice(rect.TopRight());
gfxPoint p3 = UserToDevice(rect.BottomRight());
// Check that the rectangle is axis-aligned. For an axis-aligned rectangle,
// two opposite corners define the entire rectangle. So check if
// the axis-aligned rectangle with opposite corners p1 and p3
// define an axis-aligned rectangle whose other corners are p2 and p4.
// We actually only need to check one of p2 and p4, since an affine
// transform maps parallelograms to parallelograms.
if (p2 == gfxPoint(p1.x, p3.y) || p2 == gfxPoint(p3.x, p1.y)) {
p1.Round();
p3.Round();
rect.MoveTo(gfxPoint(NS_MIN(p1.x, p3.x), NS_MIN(p1.y, p3.y)));
rect.SizeTo(gfxSize(NS_MAX(p1.x, p3.x) - rect.X(),
NS_MAX(p1.y, p3.y) - rect.Y()));
return PR_TRUE;
}
return PR_FALSE;
}
gfx3DMatrix
Layer::SnapTransform(const gfx3DMatrix& aTransform,
const gfxRect& aSnapRect,
gfxMatrix* aResidualTransform)
{
if (aResidualTransform) {
*aResidualTransform = gfxMatrix();
}
gfxMatrix matrix2D;
gfx3DMatrix result;
if (!(mContentFlags & CONTENT_DISABLE_TRANSFORM_SNAPPING) &&
mManager->IsSnappingEffectiveTransforms() &&
aTransform.Is2D(&matrix2D) &&
gfxSize(1.0, 1.0) <= aSnapRect.Size() &&
matrix2D.PreservesAxisAlignedRectangles()) {
gfxPoint transformedTopLeft = matrix2D.Transform(aSnapRect.TopLeft());
transformedTopLeft.Round();
gfxPoint transformedTopRight = matrix2D.Transform(aSnapRect.TopRight());
transformedTopRight.Round();
gfxPoint transformedBottomRight = matrix2D.Transform(aSnapRect.BottomRight());
transformedBottomRight.Round();
gfxMatrix snappedMatrix = gfxUtils::TransformRectToRect(aSnapRect,
transformedTopLeft, transformedTopRight, transformedBottomRight);
result = gfx3DMatrix::From2D(snappedMatrix);
if (aResidualTransform && !snappedMatrix.IsSingular()) {
// set aResidualTransform so that aResidual * snappedMatrix == matrix2D.
// (i.e., appying snappedMatrix after aResidualTransform gives the
// ideal transform.
gfxMatrix snappedMatrixInverse = snappedMatrix;
snappedMatrixInverse.Invert();
*aResidualTransform = matrix2D * snappedMatrixInverse;
}
} else {
result = aTransform;
}
return result;
}
bool
gfxContext::UserToDevicePixelSnapped(gfxRect& rect, bool ignoreScale) const
{
if (mDT->GetUserData(&sDisablePixelSnapping))
return false;
// if we're not at 1.0 scale, don't snap, unless we're
// ignoring the scale. If we're not -just- a scale,
// never snap.
const gfxFloat epsilon = 0.0000001;
#define WITHIN_E(a,b) (fabs((a)-(b)) < epsilon)
Matrix mat = mTransform;
if (!ignoreScale &&
(!WITHIN_E(mat._11,1.0) || !WITHIN_E(mat._22,1.0) ||
!WITHIN_E(mat._12,0.0) || !WITHIN_E(mat._21,0.0)))
return false;
#undef WITHIN_E
gfxPoint p1 = UserToDevice(rect.TopLeft());
gfxPoint p2 = UserToDevice(rect.TopRight());
gfxPoint p3 = UserToDevice(rect.BottomRight());
// Check that the rectangle is axis-aligned. For an axis-aligned rectangle,
// two opposite corners define the entire rectangle. So check if
// the axis-aligned rectangle with opposite corners p1 and p3
// define an axis-aligned rectangle whose other corners are p2 and p4.
// We actually only need to check one of p2 and p4, since an affine
// transform maps parallelograms to parallelograms.
if (p2 == gfxPoint(p1.x, p3.y) || p2 == gfxPoint(p3.x, p1.y)) {
p1.Round();
p3.Round();
rect.MoveTo(gfxPoint(std::min(p1.x, p3.x), std::min(p1.y, p3.y)));
rect.SizeTo(gfxSize(std::max(p1.x, p3.x) - rect.X(),
std::max(p1.y, p3.y) - rect.Y()));
return true;
}
return false;
}
Matrix4x4
Layer::SnapTransform(const Matrix4x4& aTransform,
const gfxRect& aSnapRect,
Matrix* aResidualTransform)
{
if (aResidualTransform) {
*aResidualTransform = Matrix();
}
Matrix matrix2D;
Matrix4x4 result;
if (mManager->IsSnappingEffectiveTransforms() &&
aTransform.Is2D(&matrix2D) &&
gfx::Size(1.0, 1.0) <= ToSize(aSnapRect.Size()) &&
matrix2D.PreservesAxisAlignedRectangles()) {
IntPoint transformedTopLeft = RoundedToInt(matrix2D * ToPoint(aSnapRect.TopLeft()));
IntPoint transformedTopRight = RoundedToInt(matrix2D * ToPoint(aSnapRect.TopRight()));
IntPoint transformedBottomRight = RoundedToInt(matrix2D * ToPoint(aSnapRect.BottomRight()));
Matrix snappedMatrix = gfxUtils::TransformRectToRect(aSnapRect,
transformedTopLeft, transformedTopRight, transformedBottomRight);
result = Matrix4x4::From2D(snappedMatrix);
if (aResidualTransform && !snappedMatrix.IsSingular()) {
// set aResidualTransform so that aResidual * snappedMatrix == matrix2D.
// (i.e., appying snappedMatrix after aResidualTransform gives the
// ideal transform.
Matrix snappedMatrixInverse = snappedMatrix;
snappedMatrixInverse.Invert();
*aResidualTransform = matrix2D * snappedMatrixInverse;
}
} else {
result = aTransform;
}
return result;
}
