How do I fill the screen with a rectangle in OpenGL ortho mode?

I ha开发者_如何学编程ve a single 640x480 texture that needs to fill the screen. So far, I can make it work with a square texture, but not a rectangular one.

glViewport(0, 0, display->w, display->h);

glMatrixMode(GL_PROJECTION);
glLoadIdentity();

double aspectRatio = (double)display->w / (double)display->h;

if (display->w <= display->h)
    glOrtho(-1, 1, -1 / aspectRatio, 1 / aspectRatio, -1, 1);
else
    glOrtho(-1 * aspectRatio, 1 * aspectRatio, -1, 1, -1, 1);

glMatrixMode(GL_MODELVIEW);
glLoadIdentity();

What modifications do I need to make so that it will fit any texture to the screen, regardless of its aspect ratio?

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This may have some relevance.

Tiling texture bmp file as texture onto a rectangle in OpenGL?

You may wish to consider ARB extension texture rectangle as an alternative approach to (assuming glTexImage2D?) http://glprogramming.com/red/chapter09.html