STATIC SUB Frustum ( Left AS Float, Right AS Float, Bottom AS Float, Top AS Float, Near AS Float, Far AS Float )
Multiply the current matrix by a perspective matrix.
- left, right
Specify the coordinates for the left and right vertical clipping planes.
- bottom, top
Specify the coordinates for the bottom and top horizontal clipping planes.
- nearVal, farVal
Specify the distances to the near and far depth clipping planes.
Both distances must be positive.
describes a perspective matrix that produces a perspective projection.
The current matrix (see Gl.MatrixMode
) is multiplied by this matrix
and the result replaces the current matrix, as if
Gl.MultMatrix were called with the following matrix
as its argument:
Typically, the matrix mode is Gl.PROJECTION, and
specify the points on the near clipping plane that are mapped
to the lower left and upper right corners of the window,
assuming that the eye is located at (0, 0, 0).
specifies the location of the far clipping plane.
must be positive.
to save and restore
the current matrix stack.
Depth buffer precision is affected by the values specified for
The greater the ratio of farVal
the less effective the depth buffer will be at distinguishing between
surfaces that are near each other.
bits of depth buffer precision are lost.
approaches infinity as nearVal
must never be set to 0.
Gl.INVALID_VALUE is generated if nearVal
positive, or if left
, or bottom
Gl.INVALID_OPERATION is generated if Gl.Frustum
is executed between the execution of Gl.Begin
and the corresponding execution of Gl.End
with argument Gl.MATRIX_MODE
Gl.Get with argument Gl.MODELVIEW_MATRIX
Gl.Get with argument Gl.PROJECTION_MATRIX
Gl.Get with argument Gl.TEXTURE_MATRIX
Gl.Get with argument Gl.COLOR_MATRIX
See original documentation on OpenGL website