void
DrawBlur(gfxContext* aDestinationCtx,
SourceSurface* aBlur,
const IntPoint& aTopLeft,
const Rect* aDirtyRect)
{
DrawTarget *dest = aDestinationCtx->GetDrawTarget();
nsRefPtr<gfxPattern> thebesPat = aDestinationCtx->GetPattern();
Pattern* pat = thebesPat->GetPattern(dest, nullptr);
Matrix oldTransform = dest->GetTransform();
Matrix newTransform = oldTransform;
newTransform.Translate(aTopLeft.x, aTopLeft.y);
// Avoid a semi-expensive clip operation if we can, otherwise
// clip to the dirty rect
if (aDirtyRect) {
dest->PushClipRect(*aDirtyRect);
}
dest->SetTransform(newTransform);
dest->MaskSurface(*pat, aBlur, Point(0, 0));
dest->SetTransform(oldTransform);
if (aDirtyRect) {
dest->PopClip();
}
}
void
gfxAlphaBoxBlur::Paint(gfxContext* aDestinationCtx)
{
if (!mContext)
return;
mBlur->Blur(mData);
mozilla::gfx::Rect* dirtyRect = mBlur->GetDirtyRect();
DrawTarget *dest = aDestinationCtx->GetDrawTarget();
if (!dest) {
NS_ERROR("Blurring not supported for Thebes contexts!");
return;
}
mozilla::RefPtr<SourceSurface> mask
= dest->CreateSourceSurfaceFromData(mData,
mBlur->GetSize(),
mBlur->GetStride(),
FORMAT_A8);
if (!mask) {
NS_ERROR("Failed to create mask!");
return;
}
nsRefPtr<gfxPattern> thebesPat = aDestinationCtx->GetPattern();
Pattern* pat = thebesPat->GetPattern(dest, nullptr);
Matrix oldTransform = dest->GetTransform();
Matrix newTransform = oldTransform;
newTransform.Translate(mBlur->GetRect().x, mBlur->GetRect().y);
// Avoid a semi-expensive clip operation if we can, otherwise
// clip to the dirty rect
if (dirtyRect) {
dest->PushClipRect(*dirtyRect);
}
dest->SetTransform(newTransform);
dest->MaskSurface(*pat, mask, Point(0, 0));
dest->SetTransform(oldTransform);
if (dirtyRect) {
dest->PopClip();
}
}
void
gfxAlphaBoxBlur::Paint(gfxContext* aDestinationCtx)
{
if (!mAccelerated && !mData) {
return;
}
DrawTarget *dest = aDestinationCtx->GetDrawTarget();
if (!dest) {
NS_WARNING("Blurring not supported for Thebes contexts!");
return;
}
RefPtr<gfxPattern> thebesPat = aDestinationCtx->GetPattern();
Pattern* pat = thebesPat->GetPattern(dest, nullptr);
if (!pat) {
NS_WARNING("Failed to get pattern for blur!");
return;
}
IntPoint topLeft;
RefPtr<SourceSurface> mask = DoBlur(nullptr, &topLeft);
if (!mask) {
NS_ERROR("Failed to create mask!");
return;
}
// Avoid a semi-expensive clip operation if we can, otherwise
// clip to the dirty rect
Rect* dirtyRect = mBlur.GetDirtyRect();
if (dirtyRect) {
dest->PushClipRect(*dirtyRect);
}
Matrix oldTransform = dest->GetTransform();
Matrix newTransform = oldTransform;
newTransform.PreTranslate(topLeft);
dest->SetTransform(newTransform);
dest->MaskSurface(*pat, mask, Point(0, 0));
dest->SetTransform(oldTransform);
if (dirtyRect) {
dest->PopClip();
}
}
/* static */ void
gfxAlphaBoxBlur::BlurRectangle(gfxContext* aDestinationCtx,
const gfxRect& aRect,
const RectCornerRadii* aCornerRadii,
const gfxPoint& aBlurStdDev,
const Color& aShadowColor,
const gfxRect& aDirtyRect,
const gfxRect& aSkipRect)
{
IntSize blurRadius = CalculateBlurRadius(aBlurStdDev);
bool mirrorCorners = !aCornerRadii || aCornerRadii->AreRadiiSame();
IntRect rect = RoundedToInt(ToRect(aRect));
IntMargin blurMargin;
IntMargin slice;
IntSize minSize;
RefPtr<SourceSurface> boxShadow = GetBlur(aDestinationCtx,
rect.Size(), blurRadius,
aCornerRadii, aShadowColor, mirrorCorners,
blurMargin, slice, minSize);
if (!boxShadow) {
return;
}
DrawTarget* destDrawTarget = aDestinationCtx->GetDrawTarget();
destDrawTarget->PushClipRect(ToRect(aDirtyRect));
// Copy the right parts from boxShadow into destDrawTarget. The middle parts
// will be stretched, border-image style.
Rect srcOuter(Point(blurMargin.left, blurMargin.top), Size(minSize));
Rect srcInner(srcOuter);
srcOuter.Inflate(Margin(blurMargin));
srcInner.Deflate(Margin(slice));
Rect dstOuter(rect);
Rect dstInner(rect);
dstOuter.Inflate(Margin(blurMargin));
dstInner.Deflate(Margin(slice));
Rect skipRect = ToRect(aSkipRect);
if (minSize == rect.Size()) {
// The target rect is smaller than the minimal size so just draw the surface
if (mirrorCorners) {
DrawMirroredBoxShadow(destDrawTarget, boxShadow, dstOuter);
} else {
destDrawTarget->DrawSurface(boxShadow, dstOuter, srcOuter);
}
} else {
if (mirrorCorners) {
DrawMirroredMinBoxShadow(destDrawTarget, boxShadow, dstOuter, dstInner,
srcOuter, srcInner, skipRect, true);
} else {
DrawMinBoxShadow(destDrawTarget, boxShadow, dstOuter, dstInner,
srcOuter, srcInner, skipRect, true);
}
}
// A note about anti-aliasing and seems between adjacent parts:
// We don't explicitly disable anti-aliasing in the DrawSurface calls above,
// so if there's a transform on destDrawTarget that is not pixel-aligned,
// there will be seams between adjacent parts of the box-shadow. It's hard to
// avoid those without the use of an intermediate surface.
// You might think that we could avoid those by just turning of AA, but there
// is a problem with that: Box-shadow rendering needs to clip out the
// element's border box, and we'd like that clip to have anti-aliasing -
// especially if the element has rounded corners! So we can't do that unless
// we have a way to say "Please anti-alias the clip, but don't antialias the
// destination rect of the DrawSurface call".
// On OS X there is an additional problem with turning off AA: CoreGraphics
// will not just fill the pixels that have their pixel center inside the
// filled shape. Instead, it will fill all the pixels which are partially
// covered by the shape. So for pixels on the edge between two adjacent parts,
// all those pixels will be painted to by both parts, which looks very bad.
destDrawTarget->PopClip();
}
