3D Graphics Programming with QuickDraw 3D 1.5.4

Spot Light Data Structure

You use a spot light data structure to get or set information about a spot light source. A spot light data structure is defined by the TQ3SpotLightData data type.



 
typedef struct TQ3SpotLightData {

    TQ3LightData                        lightData;

    TQ3Boolean                          castsShadows;

    TQ3AttenuationType                  attenuation;

    TQ3Point3D                          location;

    TQ3Vector3D                         direction;

    float                               hotAngle;

    float                               outerAngle;

    TQ3FallOffType                      fallOff;

} TQ3SpotLightData;

lightData: A light data structure specifying basic information about the spot light.
castsShadows: A Boolean value that indicates whether the spot light casts shadows (kQ3True ) or not (kQ3False ).
attenuation: The type of attenuation of the spot light. See "Light Attenuation Values" for a description of the constants that can be used in this field.
location: The location of the spot light, in world coordinates.
direction: The direction of the spot light. Note that the direction is defined as a world-space vector away from the light source. This vector does not need to be normalized, but vectors returned by QuickDraw 3D in this field might be normalized.
hotAngle: The hot angle of the spot light. The hot angle of a spot light is the half-angle, measured in radians, from the center of the cone of light within which the light remains at constant full intensity. The value in this field is a floating-point number in the range 0.0 to /2, inclusive.
outerAngle: The outer angle of the spot light. The outer angle of a spot light is the half angle, measured in radians, from the center of the cone of light to the edge of the light's influence. The value in this field is a floating-point number in the range 0.0 to /2, inclusive, and should always be greater than or equal to the value in the hotAngle field.
fallOff: The fall-off value for the spot light. See "Light Fall-Off Values" for a description of the constants that can be used in this field.