372176 - Complete GIF decoder transition to cairo gfx

Status: RESOLVED FIXED

(Core :: Graphics: ImageLib, defect)

Description

[tor]

Attachment: update to the cairo gfx world

imgContainerGIF was still trying to use the separate alpha data when combining frames, and nsGIFDecoder2.cpp had some old code tracking alpha lines.

Comment 1

[Alfred Kayser]

The part in nsGIFDecoder2.cpp is ok.

However for imgContainerGIF.cpp, I think the whole BuildCompositeMask function is no longer needed for Cairo.

BuildCompositeMask was needed for some platforms where the 'frame::DrawTo' resp. 'image::DrawToImage' didn't handle the alpha transparancy. 
However the Thebes implementation uses Cairo to correctly draw the image on top of the current frame:
547     dst->Translate(gfxPoint(aDX, aDY));
548     dst->Rectangle(gfxRect(0, 0, aDWidth, aDHeight), PR_TRUE);
549     dst->Scale(double(aDWidth)/mWidth, double(aDHeight)/mHeight);
550 
551     dst->SetSource(ThebesSurface());
552     dst->Paint();

See also bug 317748 – Merge BlackenFrame and SetMaskVisibility into ClearFrame

Comment 2

[tor]

Attachment: nsGIFDecoder changes only

Only the nsGIFDecoder changes - leave imgContainerGIF for bug 317748.

Comment 3

[Alfred Kayser]

Comment on attachment 256915 [details] [diff] [review]
nsGIFDecoder changes only

Btw, smart trick on the tpixel.

Comment 4

[tor]

Checked in.