Gl.Scissor (gb.opengl)

Static Sub Scissor ( X As Integer, Y As Integer, Width As Integer, Height As Integer )

Define the scissor box.

Parameters

x, y

Specify the lower left corner of the scissor box. Initially (0, 0).
width, height

Specify the width and height of the scissor box. When a GL context is first attached to a window, width and height are set to the dimensions of that window.

Description

Gl.Scissor defines a rectangle, called the scissor box, in window coordinates. The first two arguments, x and y, specify the lower left corner of the box. width and height specify the width and height of the box.

To enable and disable the scissor test, call Gl.Enable and Gl.Disable with argument Gl.SCISSOR_TEST. The test is initially disabled. While the test is enabled, only pixels that lie within the scissor box can be modified by drawing commands. Window coordinates have integer values at the shared corners of frame buffer pixels. glScissor(0,0,1,1) allows modification of only the lower left pixel in the window, and glScissor(0,0,0,0) doesn't allow modification of any pixels in the window.

When the scissor test is disabled, it is as though the scissor box includes the entire window.

Errors

Gl.INVALID_VALUE is generated if either width or height is negative.

Associated Gets

Gl.Get with argument Gl.SCISSOR_BOX

Gl.IsEnabled with argument Gl.SCISSOR_TEST

See also

Gl.Enable,

See original documentation on OpenGL website