Loads the x and y screen space coordinate directions into a LookAt structure.

Syntax

#include "gbi.h"     /* gbi.h */
typedef union {
        Light l[2];
} LookAt;

LookAt gdSPDefLookAt(signed char rightx, signed char righty, signed char rightz,
        signed char upx, signed char upy, signed char upz)

Arguments

rightx, righty, rightz

x, y, z components in viewing space of x direction in screen space

upx, upy, upz

x, y, z components in viewing space of y direction in screen space

Description

gdSPDefLookAt loads the x and y screen space coordinate directions into a LookAt structure. The x and y direction unit vectors, where components are expressed in the viewing space, must be converted to a signed 8-bit fixed-point representation. Each component c must undergo the conversion.

((int) MIN(((c) * (128.0)), 127.0) & 0xff)

The LookAt structure serves as input for the gSPLookAt macro, used in the set up process for specular highlights or reflection mapping.

See Also

gSPLookAt

Revision History

1999/04/30 Changed Format