Re: [PD] GEM mapping units to pixels

On 5/13/07, altern altern2@gmail.com wrote:

ah!... now i see ... so [rectangle 1 1] is equivalent to

 glBegin(GL_QUADS)
 glVertex3f(-1.0, 1.0, 0.0)
 glVertex3f(1.0, 1.0, 0.0)
 glVertex3f(1.0, -1.0, 0.0)
 glVertex3f(-1.0, -1.0, 0.0)
 glEnd()

so the final width and height is actually 2 units ... this is a bit confusing in the documentation help patch, i mean i know some opengl but still when i read width height words i thought about the width and height of a rectangle in normal geometry and not opengl postion of the vertex location from the current position.

You are correct that the size of the rectangle is the dimensions from the center of the object. Arguments can be made for treating size this way or making the size the actual final dimensions in GL units, but both are valid as long as the use is consistent.