source: trunk/gui/vizservers/nanovis/shaders/one_volume.cg @ 401

/*
 * ======================================================================
 *  AUTHOR:  Wei Qiao <qiaow@purdue.edu>
 *           Purdue Rendering and Perceptualization Lab (PURPL)
 *
 *  Copyright (c) 2004-2006  Purdue Research Foundation
 *
 *  See the file "license.terms" for information on usage and
 *  redistribution of this file, and for a DISCLAIMER OF ALL WARRANTIES.
 * ======================================================================
 */

#include "common.cg"

/*
 * render one volume 
 */


#define PHONG_SHADING

PixelOut main(v2f IN, /* uniform sampler1D tf,*/
                uniform sampler3D volume,
                uniform sampler1D tf,
                uniform float4x4 modelViewInv,
                uniform float4x4 modelView,
                uniform float4 renderParameters)
{
        
  PixelOut OUT;
  float4 tex_coord = mul(modelViewInv, IN.TexCoord);
        
//if(renderParameters.y==1){ //1 component

    float4 sample = tex3D(volume, tex_coord.xyz);

#ifdef PHONG_SHADING
      //lighting parameters 
      float3 normal;
      if(length(sample.yzw)>0.0)
        normal = normalize(sample.yzw);

      float3 light_vector = normalize(IN.Light);
      float3 eye_vector = normalize(IN.EyeVector);
      float3 half_vector = normalize(eye_vector+light_vector);

#endif

      //sample the transfer function texture
      float4 color = tex1D(tf, sample.x);
      color.w = 30*color.w/renderParameters.x;

      //float4 color = float4(sample.x, 0, 0, 1);
        

#ifdef PHONG_SHADING
      //lighting computation
      float normal_dot_light = max(dot(normal, light_vector), 0);
      float normal_dot_half = max(dot(normal, half_vector), 0);

      float ambient = 0.1;
      float diffuse = normal_dot_light * renderParameters.z;
      float specular = pow(normal_dot_half, renderParameters.w)*(1-ambient-diffuse);

      float lighting = ambient + diffuse + specular;
      color.xyz = color.xyz * lighting;

      //debug
      //color.xyz = normal.xyz;       //display normals
#endif

      OUT.Color = color;
//  }

/*
  else if(renderParameters.y==0){
    //3 component
    float3 sample = tex3D(volume, tex_coord.xyz).xyz;
    OUT.Color = float4(3*sample, 2*length(sample)/renderParameters.x);
  }
*/

  //debug
  //OUT.Color = float4(tex_coord, 1);

  return OUT;
}