GXReadBoundingBox

C Specification

#include <revolution/gx.h>

void GXReadBoundingBox( 
u16*       left,
u16*       top,
u16*       right,
u16*       bottom );

Arguments

`left`	The leftmost pixel in the bounding box
`top`	The uppermost line in the bounding box
`right`	The rightmost pixel in the bounding box
`bottom`	The lowest line in the bounding box

Return Values

None.

Description

The graphics hardware keeps track of a bounding box of pixel coordinates that are drawn in the Embedded Frame Buffer (EFB). These bounding box values can be used to determine the area of the EFB to copy (using GXSetTexCopySrc).

This function reads the bounding box values. GXClearBoundingBox can be used to reset the values of the bounding box.

Since hardware can only test the bounding box in quads (2x2 pixel blocks), the result of this function may contain error of plus or minus 1 pixel. Also because of this, left and top are always even-numbered and right and bottom are always odd-numbered.

Revision History