# OpenGL Animations in OpenGL and SDL

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Hello! I have a PNG image. It is 256x32 sized. I have put it up so that each 32px horizontally there starts a new tile. Each tile is 32px in height. My question is: How would I go about making it so that I can texture a bit of the texture instead of the whole thing? Thanks alot in advance!

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Change the texture coordinates. You have 0 to 1 for each side. Upper left is 0,0, upper right is 1,0, lower right is 1,1, lower left is 0,1. 1 is your width and height, depending on where it is. So if your image is 128x64, 1,1 would be 128x64. If you want to display half of the texture, you would put texture coordinates 0.5, 0.5. So basically to set width and height, you can do this: glTexCoord = width or height to display /(divided by) width or height of the image. So if you want to display 32,32 to 48,64 in a 128x64 image, to get your tex coords you'd do this:
32/128 = 0.25
32/64 = 0.5
48/128 = 0.375
64/64 = 1
So your new glTexCoords would be (0.25, 0.5), (0.25, 1), (0.375, 1), and (0.375, 0.25) starting in the top left corner going counterclockwise.

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Thanks, I just wondered if the coordinates in the glTexCoord command supported decimals or just 0 and 1. [smile]

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