GXSetTexCoordBias

Syntax

#include <revolution/gx.h>

void GXSetTexCoordBias(GXTexCoordID texcoord,
                       GXBool s_enable,
                       GXBool t_enable);

Arguments

texcoord	The texture coordinate ID to be changed. Accepted values are: `GX_TEXCOORD0`, `GX_TEXCOORD1`, `GX_TEXCOORD2` through `GX_TEXCOORD7`.
s_enable	`GX_TRUE` = enable range bias; `GX_FALSE` = disable range bias.
t_enable	`GX_TRUE` = enable range bias; `GX_FALSE` = disable range bias.

Return Values

None.

Description

Range bias is used for texture coordinates to which the wrap mode GX_REPEAT is applied in order to increase the precision of texture coordinates spread over a large area. Primitive texture coordinate values are biased in the zero direction (using equal integers) before entering the graphics pipeline. Bits necessary for calculations upon exiting the pipeline are maintained in this way. Since coordinates repeat, integer-based bias has no effect on the actual external appearance of a texture.

The texture coordinate range bias is usually set automatically by the GX API (inside the GXBegin function). However, the associated bias is not changed by the GX library if texture coordinates are being manually scaled (using the GXSetTexCoordScaleManually function). It is therefore possible to use the GXSetTexCoordBias function to change the bias while texture coordinates are being manually controlled.

Revision History

2006/03/01 Initial version.