# G3_FrustumW

## Syntax

      #include <nitro/gx/g3_util.h>

      void G3_FrustumW(
          fx32 t,
          fx32 b,
          fx32 l,
          fx32 r,
          fx32 n,
          fx32 f,
          fx32 scaleW,
          MtxFx44 * mtx
      );

## Arguments

t | Y coordinate at the top of the near clipping plane
b | Y coordinate at the bottom of the near clipping plane
l | X coordinate at the left of the near clipping plane
r | X coordinate at the right of the near clipping plane
n | Distance from viewpoint to the near clipping plane
f | Distance from viewpoint to the far clipping plane
scaleW | Precision adjustment parameter for the view volume
mtx | Pointer to a 4x4 matrix.

## Return Values

None.

## Description

This function sets the Matrix mode to the Projection mode. This function also sets the Frustum matrix as the current matrix. If `mtx` is not `NULL`, then the perspective projection matrix is also set in *`mtx`.
The diagram shows the matrix that is set.

× scaleW

The divider is used internally. Refer to Divider Usage Notes when using this function inside an interrupt.

## See Also

`G3_Frustum, G3_PerspectiveW, G3_OrthoW`

## Revision History

2004/04/27 Initial version.

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