glRectsv

glRect: man2/glRect.xml

glRect supports efficient specification of rectangles as two corner points. Each rectangle command takes four arguments, organized either as two consecutive pairs of x y coordinates or as two pointers to arrays, each containing an x y pair. The resulting rectangle is defined in the z = 0 plane. glRect ( x1, y1, x2, y2 ) is exactly equivalent to the following sequence:

glBegin( $(D_INLINECODE GL_POLYGON));
glVertex2( $(D_INLINECODE x1),  $(D_INLINECODE y1));
glVertex2( $(D_INLINECODE x2),  $(D_INLINECODE y1));
glVertex2( $(D_INLINECODE x2),  $(D_INLINECODE y2));
glVertex2( $(D_INLINECODE x1),  $(D_INLINECODE y2));
glEnd();

Note that if the second vertex is above and to the right of the first vertex, the rectangle is constructed with a counterclockwise winding.