Re: [B2-devel] MacOS X port screenshot

[Lauri P. <lpe...@ni...>]

On Tue, 5 Dec 2000 11:04:47 +1100 (EST), you wrote:

>	OK. There is a version at:
>
>http://www.zing.com/picture/pb170d94c2499614696882e49f59d1c52/ff20c279.jpg
>
>
>Sorry that it:
>
>1) Is scaled down in size.
>   Looks like Zing does that on upload
>
>2) Has a cyan cast.
>   The Basilisk and MacOS X bitmap buffer layouts are in
>   different formats, and I haven't worked out a fast way
>   to copy the former to the latter with translation.

I think I had the same problem once:

http://www.kearney.net/~mhoffman/basiliskII/online.JPG

The color distortion looks quite similar. As far as I remember, I was
blitting in 15 bits mode when I should have done it in 16 bit mode,
or vice versa. Consequently I wrote some conversion routines.
In the current Windows port they are in x86 assembly, but some of
the  C code is still present in comments. The bitmasks seem to be 
derived from the memory.cpp frame_host_XXX_lput() functions.

The file is video_windows.cpp in zip archive

http://gamma.nic.fi/~lpesonen/BasiliskII/BasiliskII_win32_src_18062000.zip

The functions are memcpy15() and memcpy16(), unrolled by 4.

On a x86, code like this is not that slow since it pairs well:

 *p4++ = ((b1 & 0x007F007F) << 9) | ((b1 & 0x1F001F00) >> 8) | ((b1 &
0xE000E000) >> 7);

Lauri