Initial commit

engine/3d/src/LightingParameters.hpp

@@ -0,0 +1,158 @@
+/**
+ @file LightingParameters.h
+
+ @maintainer Morgan McGuire, matrix@graphics3d.com
+ @created 2002-10-05
+ @edited  2005-06-01
+
+ Copyright 2000-2005, Morgan McGuire.
+ All rights reserved.
+ */
+
+#ifndef G3D_LIGHTINGPARAMETERS_H
+#define G3D_LIGHTINGPARAMETERS_H
+
+#include "platform.hpp"
+#include "Color3.hpp"
+#include "Vector3.hpp"
+#include "CoordinateFrame.hpp"
+#include "GLight.hpp"
+
+namespace G3D
+{
+
+#define BROWN_UNIVERSITY_LATITUDE 41.7333f
+#define BROWN_UNIVERSITY_LONGITUDE 71.4333f
+
+/* Initital star offset on Jan 1 1970 midnight */
+/* Definition of a sidereal day */
+#define SIDEREAL_DAY ((23 * HOUR) + (56 * MINUTE) + (4.071f * SECOND))
+
+/**
+ Provides a reasonable (but not 100% physically correct) set of lighting
+ parameters based on the time of day.  See also G3D::Lighting, which describes
+ a rich lighting environment.
+ */
+class LightingParameters
+{
+public:
+    /** Multiply this by all emissive values when rendering.
+        Some algorithms (e.g. contrib/ArticulatedModel/ToneMap) scale
+        down light intensity to preserve dynamic range.*/
+    Color3 emissiveScale;
+
+    /** Modulate sky box color */
+    Color3 skyAmbient;
+
+    /**
+     Use this for objects that do not receive directional lighting
+     (e.g. billboards).
+     */
+    Color3 diffuseAmbient;
+
+    /**
+     Directional light color.
+     */
+    Color3 lightColor;
+    Color3 ambient;
+
+    /** Only one light source, the sun or moon, is active at a given time. */
+    Vector3 lightDirection;
+    enum
+    {
+        SUN,
+        MOON
+    } source;
+
+    /** Using physically correct parameters.  When false, the sun and moon
+        travel in a perfectly east-west arc where +x = east and -x = west. */
+    bool physicallyCorrect;
+
+    /** The vector <B>to</B> the sun */
+    Vector3 trueSunPosition;
+    Vector3 sunPosition;
+
+    /** The vector <B>to</B> the moon */
+    Vector3 trueMoonPosition;
+    Vector3 moonPosition;
+    double moonPhase;
+
+    /** The coordinate frame and vector related to the starfield */
+    CoordinateFrame starFrame;
+    CoordinateFrame trueStarFrame;
+    Vector3 starVec;
+
+    /* Geographic position */
+    float geoLatitude;
+    // float		    geoLongitude;
+
+    Color3 skyAmbient2; // used for some cheap sky gradient (secondary, horizon-level color)     -- Max
+
+    LightingParameters();
+
+    /**
+     Sets light parameters for the sun/moon based on the
+     specified time since midnight, as well as geographic
+     latitude for starfield orientation (positive for north
+     of the equator and negative for south) and geographic
+     longitude for sun positioning (postive for east of
+     Greenwich, and negative for west). The latitude and
+     longitude is set by default to that of Providence, RI,
+     USA.
+     */
+    LightingParameters(const GameTime _time, bool _physicallyCorrect = true, float _latitude = BROWN_UNIVERSITY_LATITUDE);
+
+    void setTime(const GameTime _time);
+    void setLatitude(float _latitude);
+
+    /**
+     Returns a directional light composed from the light direction
+     and color.
+     */
+    GLight directionalLight() const;
+};
+
+
+/** A rich environment lighting model that contains both global and local sources.
+    See also LightingParameters, a class that describes a sun and moon lighting
+    model. */
+class Lighting
+{
+private:
+    Lighting()
+        : emissiveScale(Color3::white())
+    {
+    }
+
+public:
+    /** Multiply this by all emissive values when rendering.
+        Some algorithms (e.g. contrib/ArticulatedModel/ToneMap) scale
+        down light intensity to preserve dynamic range.*/
+    Color3 emissiveScale;
+
+    /** Light reflected from the sky (usually slightly blue) */
+    Color3 ambientTop;
+
+    /** Light reflected from the ground.  A simpler code path is taken
+        if identical to ambientTop. */
+    Color3 ambientBottom;
+
+    /** Color to modulate environment map by */
+    Color3 environmentMapColor;
+
+    /** Local illumination sources that do not cast shadows. */
+    Array<GLight> lightArray;
+
+    /** Local illumination sources that cast shadows. */
+    Array<GLight> shadowedLightArray;
+
+    /** Creates a (dark) environment. */
+    static Lighting* create()
+    {
+        return new Lighting();
+    }
+};
+
+} // namespace G3D
+
+#endif