void main(void)
{
   vec3 ecPosition = vec3(gl_ModelViewMatrix * gl_Vertex);
    
    float red = 1-abs(ecPosition.z) / 200.0;
    
    gl_FrontColor = vec4(red, 0.0, 0.0, 1);
    gl_Position = ftransform();
}
void main(void)
{
   //gl_FragColor = vec4( 0.4, 0.0, 0.9, 1.0 );
   gl_FragColor = gl_Color;
}