light.h

Ray tracing on PS3, using the acceleration of PPU, No SPE acceleration is used. The code must be com

/* Copyright (c) 2007 Massachusetts Institute of Technology
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy of
 * this software and associated documentation files (the "Software"), to deal in
 * the Software without restriction, including without limitation the rights to
 * use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of
 * the Software, and to permit persons to whom the Software is furnished to do so,
 * subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in all
 * copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS
 * FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR
 * COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER
 * IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
 * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
 */
/**
 * light.h - blue-steel Light class
 * @author Russel Ryan
 *
 * Contains the definition of the light structure for storing information about light sources, as well
 * as numerical constants for specifying the type of light that a specific light object represents. 
 * As this single class holds information for all types of lights (directional, point, and spot), some
 * information has different meanings depending on the type declared, and some data is not even used for
 * some types.
 * The parameters that are defined for each of the lights is as follows:
 *   directional lights : direction, color
 *   point lights : position, color, 3 attenuation factors (attn_x, attn_y, and attn_z)
 *   spotlight :  position, direction, color, alpha/phi, powerfactor/fallof
 *     arg1 = chphi, arg2 = chalpha, arg3=power
 * 
 * In order to use a light of a specific type, all defined information must be filled in before passing the light
 * into the ray tracing engine.
 */

#ifndef _LIGHT_H_
#define _LIGHT_H_

#include "rgbpacket.h"

#define LIGHT_DIRECTIONAL 0
#define LIGHT_POINT 1
#define LIGHT_SPOT 2
#define LIGHT_TYPES 3


struct light {
  unsigned char type;
  
  union {
    vector float CPDA_x;
    struct {
      float color_x;
      float position_x;
      float direction_x;
      float attn_x;
    };
  };
  union {
    vector float CPDA_y;
    struct {
      float color_y;
      float position_y;
      float direction_y;
      float attn_y;
    };
  };
  union {
    vector float CPDA_z;
    struct {
      float color_z;
      float position_z;
      float direction_z;
      float attn_z;
    };
  };
  union {
    vector float args_v;
    struct {
      float arg1;
      float arg2;
      float arg3;
      float arg4;
    };
  };

} __attribute__((aligned(16)));

#define LIGHT_ILLUMINATION(name) \
  void name(light &source, RGBPacket &rgbp, vector float &dirToLight_x, vector float &dirToLight_y, vector float &dirToLight_z, \
	    vector float &distanceToLight, const vector float &p_x, const vector float &p_y, const vector float &p_z)

#define LIGHT_ILLUMINATION_FP(name) LIGHT_ILLUMINATION((*name))

LIGHT_ILLUMINATION(light_getIllumination);
LIGHT_ILLUMINATION(light_getPointIllumination);
LIGHT_ILLUMINATION(light_getDirectionalIllumination);
LIGHT_ILLUMINATION(light_getSpotIllumination);

typedef LIGHT_ILLUMINATION_FP(light_illumination);

#endif