View Full Version : reading image file into an array

01-05-2003, 02:06 AM
Most of us can read in a texture image file and map it onto a polygon/shape.
But I want to know how can I read nay image file into an array. So Im able to have access to any (x,y) position and its rgb values.


01-05-2003, 09:03 AM
Either you write the code yourself. For that you need to know the file format. You can find doc on www.wotsit.org. (http://www.wotsit.org) Or you use an API to do that. I recommend DevIL. This API has been discussed recently on this board.

[This message has been edited by Morglum (edited 01-06-2003).]

01-05-2003, 12:51 PM
I'm not sure I understand the question.If you can use the image as an opengl texture then you upload it using an glTexture*D call.The last arg to this call is a pointer(an array) to the pixels.Accessing specific RGB values of pixels denpends on the format of the image but it should be easy to do.

01-05-2003, 04:57 PM
once you have the data into the array, the formula for plotting coordinates is:

array[x + (y*w)]

x is the x coordinate you want to modify
y is the y coordinate
w is the width of the texture in pixels

this approach works best when you use a struct for holding rgb triples or quads, or else you have to use an offset for the data...or just store the data in unsigned ints