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SG_LIGHT(3) Library Functions Manual SG_LIGHT(3) NAME SG_Light -- Agar-SG light source node SYNOPSIS #include <agar/core.h> #include <agar/sg.h> DESCRIPTION The SG_Light node defines a light source in a SG(3) scene-graph. Each light source is associated with a priority number, which determines which lights are used in the rendering. The number of lights supported for rendering is dependent on the renderer implementation. INHERITANCE HIERARCHY AG_Object(3) -> SG_Node(3) -> SG_Light. INITIALIZATION SG_Light * SG_LightNew(SG_Node *parent, const char *name) void SG_LightAmbient(SG_Light *lt, M_Color c) void SG_LightDiffuse(SG_Light *lt, M_Color c) void SG_LightSpecular(SG_Light *lt, M_Color c) void SG_LightSpot(SG_Light *lt, M_Real cutoff, M_Real exponent, M_Vector3 dir) The SG_LightNew() function allocates, initializes, and attaches a SG_Light object. The functions SG_LightAmbient(), SG_LightDiffuse() and SG_LightSpecular() configure the colors associated with the ambient, diffuse and specular components of the light source. SG_LightSpot() sets the spot parameters of the light source. cutoff specifies the cutoff angle in degrees, exponent specifies the light in- tensity (the higher the exponent, the more focused the light source; a value of 0 provides uniform distribution), and dir is the direction vector. If the cutoff angle is < 180 degrees, the light source is di- rectional, otherwise it is treated as a point source and the direction vector is ignored. INTERNAL WIDGET API void SG_LightSetup(SG_Light *lt, SG_View *sv) The SG_LightSetup() function sets up the renderer states associated with a light, prior to rendering. This function is usually invoked from the draw() operation of an SG_View(3) (or derived) widget, prior to rendering a scene. STRUCTURE DATA For the SG_Light object: int pri Priority of light source when number of sources is limited (0 = highest priority). M_Color ambient Ambient color component of source. M_Color diffuse Diffuse color component of source. M_Color specular Specular color component of source. M_Real spot_cutoff Spotlight cutoff angle (or 180 for point source). M_Real spot_exponent Spotlight intensity distribution. M_Vector3 spot_dir Spotlight direction. M_Real Kc Constant light attenuation factor. M_Real Kl Linear light attenuation factor. M_Real Kq Quadratic light attenuation factor. SEE ALSO M_Real(3), M_Vector(3), SG(3), SG_Intro(3), SG_Node(3), SG_View(3) HISTORY The SG_Light node class first appeared in Agar 1.6.0. Agar 1.7 December 21, 2022 SG_LIGHT(3)
NAME | SYNOPSIS | DESCRIPTION | INHERITANCE HIERARCHY | INITIALIZATION | INTERNAL WIDGET API | STRUCTURE DATA | SEE ALSO | HISTORY
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