HP b2600 Reference Manual page 315

Typically, the matrix mode is GL_PROJECTION, and (left, bottom, zNear) and (right,
top, zNear) specify the points on the near clipping plane that are mapped to the lower left
and upper right corners of the window, respectively, assuming that the eye is located at
(0, 0, 0). zFar specifies the location of the far clipping plane. Both zNear and zFar can be
either positive or negative.
Use glPushMatrix and glPopMatrix to save and restore the current matrix stack.
Errors
•
Associated Gets
glGet with argument GL_MATRIX_MODE
glGet with argument GL_MODELVIEW_MATRIX
glGet with argument GL_PROJECTION_MATRIX
glGet with argument GL_TEXTURE_MATRIX
See Also
glFrustum,
glMatrixMode,
glMultMatrix,
glPushMatrix,
glViewport
Chapter 13
GL_INVALID_OPERATION is generated if glOrtho is executed between the
execution of glBegin and the corresponding execution of glEnd.
O
glOrtho
315