18170 - [BACKGROUND]rendering problems with tables with non opaque background images

Status: VERIFIED FIXED

(Core :: Layout: Tables, defect, P3)

Description

[Ben]

pages such as www.rasterman.com and as.themes.org which have table background
images which have clear parts do not display properly. The backgroudn part wich
should be clear or black is displaied as psudo-random garble.

This occurs in Linux and Windows98 with the latest nightly build (as well as
older nightly builds) with both apprunner and viewer.

Comment 1

[Jerry Baker]

There is more to it than this. Simply creating a table with a transparent GIF or
PNG as a cell background does not cause this. There is some sort of interaction
going on here. It is not one thing, but the interaction of two or more elements
causing this.

Comment 2

[Jerry Baker]

The problem is in the GIF's. The lines in t5.gif are the same color as the
background, but they are a different palette index number. So, even though the
background and the lines are black, the user specifies say index number 5 for
the color of the lines and index number 12 for the transparency. Both are 0,0,0
(R,G,B), but just different palette indices.

I tried creating a new image that is similar to this, but Mozilla did not choke
on it. There is something definitely going on with the images. This is beyond my
area of expertise.

My question is whether Netscape 4.X and IE5 are correct in displaying this, or
is Mozilla correct for saying "black is black"? I don't know enough about the
GIF specification to know if this is even really a bug or not. I guess Pam would
know.

Comment 3

[karnaze (gone)]

Kevin, here is another painting problem similar to a bug I just reassigned to
you.

Comment 4

[Gervase Markham [:gerv]]

*** Bug 20350 has been marked as a duplicate of this bug. ***

Comment 5

[Kevin McCluskey (gone)]

The problem is in nsCSSRendering::PaintBackground.
If I comment force it to do the following slow blitting code by commenting
out the TileImage logic above it works fine.

   // slow blitting, one tile at a time....
      for(y=y0;y<y1;y+=tileHeight){
        for(x=x0;x<x1;x+=tileWidth){
          aRenderingContext.DrawImage(image,x,y,tileWidth,tileHeight);
        }
      }

Reassigning to dcone to fix the tile logic.

Comment 6

[Kevin McCluskey (gone)]

*** Bug 18162 has been marked as a duplicate of this bug. ***

Comment 7

[dcone (gone)]

The quickblitting does not do transparency.  

Comment 8

[Mats Palmgren (inactive)]

*** Bug 25895 has been marked as a duplicate of this bug. ***

Comment 9

[Mats Palmgren (inactive)]

*** Bug 25905 has been marked as a duplicate of this bug. ***

Comment 10

[dcone (gone)]

Fixed. The transparent GIF could not use the fast blitting algorithm because of 
the mask..

Comment 11

[Christine Hoffman]

Using 7/13 build, pages look okay. Verifying bug fixed.