Re: New bitmap code - testers required

[Willem Rein Oudshoorn]

Pete French <pete@twisted.org.uk> writes:
>
> The code allows bitmaps to scale properly and also handles a much larger
> range of image layouts than before, including planar data, CMYK format
> images, one-is-black grescale images, bit padded data and variable bit
> length sample sizes. This should not noticeably slow dwn the rendering of
> the original images either as these are handled by a special case.
> Magnification is done using the nearest pixel, minification using a colour
> average over all the pixels in the image covered by the on screen pixel.
> 
> Let me know what you think...

I have taken a very short look at it.  The nice thing is
that image scaling works now in GWorkspace.  However I have
two concerns.

(1) Performance,  this is a minor concern.  The code
    can be optimized and improved.

(2) I am not sure the approach is right.  From a glance
    at the source code it seems that you ALWAY scale
    the image in _bitmap_combine_alpha
    And I do not think that this is correct.   The scaling
    should be determined by the different transformation
    matrices.  And you have also to remembter that a clipping
    path can be set for the XGGState and I think that
    the normal behaviour should be to clip to the 
    XGGState `window size'.

Also, I have never looked at colorspaces, but I feel a little
uncomfortable of how colorspaces are handled.  I will have
to read the documentation of understanding what is going on,
but changing the current colorspace in the NSDrawBitMap
code might upset other DPS code who just sees the colorspace
changed while it did not expect this.  

I am a little pressed for time right now, so I probably do 
not have the time to look into it right now.

But all in all, it is very nice to have scaled images.

Wim Oudshoorn.