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?
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
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