// VERTEX.GLSL
// ray origin
// ray direction
varying vec3 rO_origin, rD_origin;
void main()
{
gl_Position = ftransform();
// see C# code for explanation on what these hold - sjh jan 18, 2006
rO_origin = gl_MultiTexCoord0;
rD_origin = gl_Color;
}
// FRAGMENT.GLSL
// ray origin
// ray direction
varying vec3 rO_origin, rD_origin;
void main()
{
vec4 frag_colour;
// for quantizing the fragment colour
float palette_size = 32.0;
// perform dot product operation on the fragment ray vector,
// in order to visualize its direction
frag_colour.a = 1.0;
frag_colour.b = floor((palette_size + 1.0) * dot(normalize(rD_origin), vec3(0.0, 0.0, -1.0))) / (palette_size + 1.0);
frag_colour.g = frag_colour.b;
frag_colour.r = 1.0;
gl_FragColor = frag_colour;
}
