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Texture Coordinates -- Grey Square

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For my project I am trying to draw an image onto the screen from a sheet of multiple images. I am trying to draw the first 16x16 tile of a 256x256 bitmap, but whenever I set the texture coordinates to anything but the ones necessary to draw the whole image*, it draws a grey square instead.

This is my code:


glBindTexture( GL_TEXTURE_2D, texid[sprite]);
glBegin( GL_QUADS );
glTexCoord2i(0.0,0.9375);
glVertex3f( 0, 0, 0 );
glTexCoord2i(0.0625,0.9375);
glVertex3f( 16, 0, 0 );
glTexCoord2i(0.0625,1.0);
glVertex3f( 16, 16, 0 );
glTexCoord2i(0.0,1.0);
glVertex3f( 0, 16, 0 );
glEnd();
SDL_GL_SwapBuffers();

Wheras:

glBindTexture( GL_TEXTURE_2D, texid[sprite]);
glBegin( GL_QUADS );
glTexCoord2i(0.0,0.0);
glVertex3f( 0, 0, 0 );
glTexCoord2i(1.0,0.0);
glVertex3f( 256, 0, 0 );
glTexCoord2i(1.0,1.0);
glVertex3f( 256, 256, 0 );
glTexCoord2i(0.0,1.0);
glVertex3f( 0, 256, 0 );
glEnd();
SDL_GL_SwapBuffers();

Works flawlessly.

*The exception is when I set the coordinates to something like:

glTexCoord2i(0.0,0.5);
glVertex3f( 0, 0, 0 );
glTexCoord2i(1.0,0.5);
glVertex3f( 256, 0, 0 );
glTexCoord2i(1.0,0.5);
glVertex3f( 256, 256, 0 );
glTexCoord2i(0.0,1.0); /***When I set this one to .5 it draws the first row of pixels stretched down across the whole image.
When I set it to 5 though, the image gets repeated 5 times vertically within the 256 pixels. If I set it lower than one it simple doesn't work.***/
glVertex3f( 0, 256, 0 );

Then nothing happens. I don't understand what's going on.


EDIT: After further experimentation, only the last coordinate and the 1st one, 2nd line actually do anything. If they are changed, the pixels from the top and left side are repeated across the entire image, respectively.

Here's a screenshot of what happens when the both are less than 1.0.
http://i383.photobucket.com/albums/oo277/meep112233/Screenshot-UntitledWindow.png

[Edited by - _DivideByZero_ on December 24, 2010 7:32:54 PM]

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