Definition: |
include pGUI.e
include opengl.e glViewport(integer x, y, w, h) |
Description: |
The glViewport function sets the viewport.
x,y: The lower-left corner of the viewport rectangle, in pixels. The default is (0,0). width,height: The width and height of the viewport. When an OpenGL context is first attached to a window, width and height are set to the dimensions of that window. If either width or height was negative, glGetError() will return GL_INVALID_VALUE. If this routine is called between glBegin and glEnd, glGetError() will return GL_INVALID_OPERATION. |
Remarks |
The glViewport function specifies the affine transformation of x and y from normalized device coordinates to window coordinates. Let (xnd, ynd) be normalized device coordinates. The window coordinates (xw, yw) are then computed as follows: ![]() Viewport width and height are silently clamped to a range that depends on the implementation. This range is queried by calling glGet with argument GL_MAX_VIEWPORT_DIMS. The following functions retrieve information related to glViewport: glGet with argument GL_VIEWPORT glGet with argument GL_MAX_VIEWPORT_DIMS |
See Also: |
glBegin,
int_to_bits
DEV See also --glBegin glDepthRange |