GXPokeAlphaRead

Syntax

#include <revolution/gx.h>

void GXPokeAlphaRead( GXAlphaReadMode mode );

Arguments

mode

Determines value of alpha read from a frame buffer with no alpha channel. Accepted values are:

Name	Alpha value you can read
GX_READ_00	`0x00.`
GX_READ_FF	`0xFF.`
GX_READ_NONE	Alpha value from the EFB.

GX_READ_NONE can be used if you want to get an alpha value from the EFB. If the EFB doesn't have an alpha plane, the alpha value is undefined.

Return Values

None.

Description

This function determines the alpha value to read from the EFB. mode is applied only for the GXPeek* functions. The GXPeek* functions allow the CPU to read the EFB directly.

This functionality will work no matter what pixel type is used (see the GXSetPixelFmt function). When using an EFB with an alpha plane, the use of GX_READ_NONE is recommended to read the correct alpha values from the EFB. When using an EFP without alpha values, use either GX_READ_00 or GX_READ_FF to get the constant value.

Revision History

2006/03/01 Initial version.