shaders.cpp

/*
 * Copyright 1993-2015 NVIDIA Corporation.  All rights reserved.
 *
 * Please refer to the NVIDIA end user license agreement (EULA) associated
 * with this source code for terms and conditions that govern your use of
 * this software. Any use, reproduction, disclosure, or distribution of
 * this software and related documentation outside the terms of the EULA
 * is strictly prohibited.
 *
 */

#define STRINGIFY(A) #A

// BChange
// vertex shader
// const char *vertexShader = STRINGIFY(
//                                uniform float pointRadius;  // point size in world space
//                                uniform float pointScale;   // scale to calculate size in pixels
//                                uniform float densityScale;
//                                uniform float densityOffset;
//                                void main()
// {
//     // calculate window-space point size
//     vec3 posEye = vec3(gl_ModelViewMatrix * vec4(gl_Vertex.xyz, 1.0));
//     float dist = length(posEye);
//     gl_PointSize = pointRadius * (pointScale / dist);

//     gl_TexCoord[0] = gl_MultiTexCoord0;
//     gl_Position = gl_ModelViewProjectionMatrix * vec4(gl_Vertex.xyz, 1.0);

//     gl_FrontColor = gl_Color;
// }
//                            );

// vertex shader
const char *vertexShader = STRINGIFY(
  attribute vec2 pos;
  attribute vec4 color;
  attribute float rad;
  uniform float pointScale;   // scale to calculate size in pixels
  uniform float densityScale;
  uniform float densityOffset;
  void main()
  {
      // calculate window-space point size
	  float x = -pos.x;
	  float y = 0;
	  float z = pos.y;
	  if (z > 1000.0f) {
		  y = rad;
		  z = z - 2000.0f;
	  }
      vec3 posEye = vec3(gl_ModelViewMatrix * vec4(0, y, z, 1.0));
      float dist = length(posEye);
      gl_PointSize = rad * (pointScale / dist);

      gl_TexCoord[0] = gl_MultiTexCoord0;
      gl_Position = gl_ModelViewProjectionMatrix * vec4(x, y, z, 1.0);

      gl_FrontColor = color;
  }
);

// EChange
// pixel shader for rendering points as shaded spheres
const char *spherePixelShader = STRINGIFY(
  uniform vec3 lightDir;
  void main()
  {
    // const vec3 lightDir = vec3(0.577, 0.577, 0.577);

    // calculate normal from texture coordinates
    vec3 N;
    N.xy = gl_TexCoord[0].xy*vec2(2.0, -2.0) + vec2(-1.0, 1.0);
    float mag = dot(N.xy, N.xy);

    if (mag > 1.0) discard;   // kill pixels outside circle

    N.z = sqrt(1.0-mag);

    // calculate lighting
    float diffuse = max(0.0, dot(lightDir, N));

    gl_FragColor = gl_Color * diffuse;
    gl_FragColor = gl_Color;
}
                                );