9fans archive / 2008 / 01 / 477 /    prev next

From: Pietro Gagliardi <pietro10@mac.com>
Subject: Re: [9fans] How to read/write pixels from Memimage
Date: Sat, 26 Jan 2008 09:09:23 -0500

However, I want to be able to read 32-bit color values. How does  
Memimage store colors and will the code I use work? I can change it  
to 24-bit if necessary, but that would make it slower to read files.  
If I do what these programs say, how will my u32int be arranged?

On Jan 26, 2008, at 9:05 AM, Russ Cox wrote:

>> Hello. I'm porting Bell Labs' Pico image language over to Plan 9 to
>> use the Plan 9 native image format (image(6)), and I chose to use
>> Memimage. I'd like to know how to get the 32-bit RGB pixel
>> information out of a Memimage and into a properly allocated array of
>> u32ints, and to do the reverse. Is that possible? Thanks.
>
> A good way to answer questions like these is to
>
> 	cd /sys/src/cmd
> 	grep -n Memimage *.c */*.c */*/*.c
>
> Looking through the output, all of these:
>
> 	/sys/src/cmd/crop.c
> 	/sys/src/cmd/resample.c
> 	/sys/src/cmd/jpg/writepng.c
>
> are examples of programs that use memimages
> in a byte-at-a-time fashion.
>
> Russ
>