glVertex: how to use other version of this call

I can only use glVertex3f in my computer, which specifies the position of vertex by the ratio of x,y,z-axes. Is there a way to specify the position of the vertex by giving the pixel numbers? Then I can use integer numbers.

I know I c开发者_运维知识库an scale the view and then I can use glVertex3i.

Is there other way?

Like the example in redbook of OpenGL, they directly use integer numbers in some calls. I have to use some float number less than 1.

By using an apropriate projection

glMatrixMode(GL_PROJECTION)
glLoadIdentity()
glOrtho(0, window_width, 0, window_height, -1, 1)

glMatrixMode(GL_MODELVIEW)
glLoadIdentity()

# world XY coordinates now map to viewport XY

Keep in mind that immediate mode (glBegin(...); for(...){ glVertex(...); } glEnd();) is slow and deprecated. Use Vertex Arrays and Vertex Buffer Objects instead.

For normal coordinates, trying to get a 1:1 mapping from input numbers to pixel coordinates doesn't make much sense. In particular, all three coordinates interact with your projection matrix to map from a coordinate to a pixel position on screen.

OpenGL does have some bitmap functions (e.g., glBitmap, glDrawPixels) that let you work directly in pixel coordinates. Without knowing what you're trying to accomplish, it's hard to guess whether that'll be useful for you.