GXSetTevOp

C Specification

#include <revolution/gx.h>

void GXSetTevOp( GXTevStageID id, GXTevMode mode );

Arguments

`id`	TEV stage ID. Accepted values are: `GX_TEVSTAGE0`, `GX_TEVSTAGE1`, `GX_TEVSTAGE2`, through `GX_TEVSTAGE15`.
`mode`	Predefined color combining modes. The applicable values are `GX_MODULATE`, `GX_DECAL`, `GX_REPLACE`, `GX_BLEND` and `GX_PASSCLR`. (For further details, see the table below.)

Return Values

None.

Description

This is a convenient function designed to make initial programming of the Texture Environment unit (TEV) easier. This macro calls GXSetTevColorIn, GXSetTevColorOp, GXSetTevAlphaIn, and GXSetTevAlphaOp with predefined arguments to implement familiar texture combining functions.

To enable a consecutive set of TEV stages, you must call the GXSetNumTevStages function.

In the table below, Cv is the output color for the stage, Cr is the output color of previous stage, and Ct is the texture color. Av is the output alpha for a stage, Ar is the output alpha of previous stage, and At is the texture alpha. As a special case, rasterized color (GX_CC_RASC) is used as Cr and rasterized alpha (GX_CA_RASA) is used as Ar at the first TEV stage because there is no previous stage.

mode	Color Op	Alpha Op
`GX_MODULATE`	Cv=CrCt	Av=ArAt
`GX_DECAL`	Cv=(1-At)Cr + AtCt	Av=Ar
`GX_REPLACE`	Cv=Ct	Av=At
`GX_BLEND`	Cv=(1-Ct)Cr + Ct	Av=AtAr
`GX_PASSCLR`	Cv=Cr	Av=Ar

Revision History

2006/03/01 Initial version.