1 #ifndef MSP_GL_LIGHT_H_
2 #define MSP_GL_LIGHT_H_
5 #include <msp/datafile/objectloader.h>
16 Stores properties of a single light source. Lights can be directional, point
17 lights or spotlights. No explicit type parameter is provided; rather the
18 other parameters determine what kind of light it is. If the fourth component
19 of position is zero, it's a directional light. Otherwise, if the spot cutoff
20 is not 180 degrees, it's a spotlight. Otherwise it's an omnidirectional point
23 Lights are usually grouped with a Lighting object, which can be used in a
26 Lights do not cast shadows by themselves. See ShadowMap for that.
28 class Light: public Placeable
31 class Loader: public DataFile::ObjectLoader<Light>
37 void attenuation(float, float, float);
38 void color(float, float, float);
39 void position(float, float, float, float);
40 void spot_direction(float, float, float);
41 void spot_exponent(float);
42 void spot_cutoff(float);
52 Geometry::Angle<float> spot_cutoff;
62 /** Sets the color of the Light. Provided
63 to shaders as light_sources[i].color. */
64 void set_color(const Color &);
66 /** Sets a multiplier on how much light actually reaches the target. Used
67 when modeling an atmosphere. */
68 void set_transmittance(const Color &);
70 const Color &get_color() const { return color; }
71 const Color &get_transmittance() const { return transmittance; }
73 DEPRECATED void set_diffuse(const Color &c) { set_color(c); }
74 DEPRECATED void set_specular(const Color &) { }
75 DEPRECATED const Color &get_diffuse() const { return color; }
76 DEPRECATED const Color &get_specular() const { return color; }
78 /** Sets the postion and orientation of the Light from a matrix. Negative Z
79 axis is used as the spot direction, other axes are ignored. */
80 virtual void set_matrix(const Matrix &);
82 /** Sets the position of the Light. For a directional light, set the xyz
83 components to a vector pointing towards the light and the w component to 0. */
84 void set_position(const Vector4 &);
86 const Vector4 &get_position() const { return position; }
88 /** Sets the direction of a spotlight. Has no effect if spotlight cutoff is
90 void set_spot_direction(const Vector3 &);
92 /** Sets the angular falloff exponent of the spotlight. Must be >= 0. */
93 void set_spot_exponent(float);
95 /** Sets the cutoff angle of a spotlight. Beyond this angle from its axis
96 the spotlight provides no illumination. Must be between 0 and 90 degrees,
97 or exactly 180 degrees to indicate a non-spotlight. */
98 void set_spot_cutoff(const Geometry::Angle<float> &);
100 /** Disables spotlight, reverting to an omnidirectional point light.
101 Equivalent to setting the spot cutoff to 180 degrees. */
102 void disable_spot_cutoff();
104 const Vector3 &get_spot_direction() const { return spot_dir; }
105 float get_spot_exponent() const { return spot_exp; }
106 const Geometry::Angle<float> &get_spot_cutoff() const { return spot_cutoff; }
107 void set_attenuation(float, float, float);
108 const float *get_attenuation() const { return attenuation; }
110 /** Updates a ProgramData object with the uniforms for the Light. A view
111 matrix and light source index must be passed in. */
112 void update_shader_data(ProgramData &, const Matrix &, unsigned) const;