static PRUint64
PackPreserveAspectRatio(const SVGPreserveAspectRatio& par)
{
// All preserveAspectRatio values are enum values (do not interpolate), so we
// can safely collate them and treat them as a single enum as for SMIL.
PRUint64 packed = 0;
packed |= PRUint64(par.GetDefer() ? 1 : 0) << 16;
packed |= PRUint64(par.GetAlign()) << 8;
packed |= PRUint64(par.GetMeetOrSlice());
return packed;
}
gfxMatrix
nsSVGUtils::GetViewBoxTransform(nsSVGElement* aElement,
float aViewportWidth, float aViewportHeight,
float aViewboxX, float aViewboxY,
float aViewboxWidth, float aViewboxHeight,
const SVGPreserveAspectRatio &aPreserveAspectRatio)
{
NS_ASSERTION(aViewportWidth >= 0, "viewport width must be nonnegative!");
NS_ASSERTION(aViewportHeight >= 0, "viewport height must be nonnegative!");
NS_ASSERTION(aViewboxWidth > 0, "viewBox width must be greater than zero!");
NS_ASSERTION(aViewboxHeight > 0, "viewBox height must be greater than zero!");
PRUint16 align = aPreserveAspectRatio.GetAlign();
PRUint16 meetOrSlice = aPreserveAspectRatio.GetMeetOrSlice();
// default to the defaults
if (align == nsIDOMSVGPreserveAspectRatio::SVG_PRESERVEASPECTRATIO_UNKNOWN)
align = nsIDOMSVGPreserveAspectRatio::SVG_PRESERVEASPECTRATIO_XMIDYMID;
if (meetOrSlice == nsIDOMSVGPreserveAspectRatio::SVG_MEETORSLICE_UNKNOWN)
meetOrSlice = nsIDOMSVGPreserveAspectRatio::SVG_MEETORSLICE_MEET;
float a, d, e, f;
a = aViewportWidth / aViewboxWidth;
d = aViewportHeight / aViewboxHeight;
e = 0.0f;
f = 0.0f;
if (align != nsIDOMSVGPreserveAspectRatio::SVG_PRESERVEASPECTRATIO_NONE &&
a != d) {
if ((meetOrSlice == nsIDOMSVGPreserveAspectRatio::SVG_MEETORSLICE_MEET &&
a < d) ||
(meetOrSlice == nsIDOMSVGPreserveAspectRatio::SVG_MEETORSLICE_SLICE &&
d < a)) {
d = a;
switch (align) {
case nsIDOMSVGPreserveAspectRatio::SVG_PRESERVEASPECTRATIO_XMINYMIN:
case nsIDOMSVGPreserveAspectRatio::SVG_PRESERVEASPECTRATIO_XMIDYMIN:
case nsIDOMSVGPreserveAspectRatio::SVG_PRESERVEASPECTRATIO_XMAXYMIN:
break;
case nsIDOMSVGPreserveAspectRatio::SVG_PRESERVEASPECTRATIO_XMINYMID:
case nsIDOMSVGPreserveAspectRatio::SVG_PRESERVEASPECTRATIO_XMIDYMID:
case nsIDOMSVGPreserveAspectRatio::SVG_PRESERVEASPECTRATIO_XMAXYMID:
f = (aViewportHeight - a * aViewboxHeight) / 2.0f;
break;
case nsIDOMSVGPreserveAspectRatio::SVG_PRESERVEASPECTRATIO_XMINYMAX:
case nsIDOMSVGPreserveAspectRatio::SVG_PRESERVEASPECTRATIO_XMIDYMAX:
case nsIDOMSVGPreserveAspectRatio::SVG_PRESERVEASPECTRATIO_XMAXYMAX:
f = aViewportHeight - a * aViewboxHeight;
break;
default:
NS_NOTREACHED("Unknown value for align");
}
}
else if (
(meetOrSlice == nsIDOMSVGPreserveAspectRatio::SVG_MEETORSLICE_MEET &&
d < a) ||
(meetOrSlice == nsIDOMSVGPreserveAspectRatio::SVG_MEETORSLICE_SLICE &&
a < d)) {
a = d;
switch (align) {
case nsIDOMSVGPreserveAspectRatio::SVG_PRESERVEASPECTRATIO_XMINYMIN:
case nsIDOMSVGPreserveAspectRatio::SVG_PRESERVEASPECTRATIO_XMINYMID:
case nsIDOMSVGPreserveAspectRatio::SVG_PRESERVEASPECTRATIO_XMINYMAX:
break;
case nsIDOMSVGPreserveAspectRatio::SVG_PRESERVEASPECTRATIO_XMIDYMIN:
case nsIDOMSVGPreserveAspectRatio::SVG_PRESERVEASPECTRATIO_XMIDYMID:
case nsIDOMSVGPreserveAspectRatio::SVG_PRESERVEASPECTRATIO_XMIDYMAX:
e = (aViewportWidth - a * aViewboxWidth) / 2.0f;
break;
case nsIDOMSVGPreserveAspectRatio::SVG_PRESERVEASPECTRATIO_XMAXYMIN:
case nsIDOMSVGPreserveAspectRatio::SVG_PRESERVEASPECTRATIO_XMAXYMID:
case nsIDOMSVGPreserveAspectRatio::SVG_PRESERVEASPECTRATIO_XMAXYMAX:
e = aViewportWidth - a * aViewboxWidth;
break;
default:
NS_NOTREACHED("Unknown value for align");
}
}
else NS_NOTREACHED("Unknown value for meetOrSlice");
}
if (aViewboxX) e += -a * aViewboxX;
if (aViewboxY) f += -d * aViewboxY;
return gfxMatrix(a, 0.0f, 0.0f, d, e, f);
}