vs_3d.vertexshader

#version 330 core

layout(location = 0) in float x; 
layout(location = 1) in float y; 
layout(location = 2) in float h; 
out vec3 oColor;

uniform mat4 u_transform;
uniform mat4 u_model;
uniform float u_R;

const float PI = 3.1415926535897932384626433832795;
const float PI_2 = PI*0.5;

void main(){
    if      (h < 0   )  oColor = vec3(0.,       1.,       0.);//->green
    else if (h < 500 )  oColor = vec3(0.,       h/500,    0.);//->green
    else if (h < 1000)  oColor = vec3(h/500-1,  1.,       0.);//->yellow
    else if (h < 2000)  oColor = vec3(1.,       2.-h/1000,0.);//->red
    else                oColor = vec3(1.,       h/2000-1 ,h/2000-1);  //->white

    vec4 pos = u_model * vec4(x, y, 0, 1.0);
    float a = -PI + (pos.x + 1)*PI;
    float b = -PI_2 + (pos.y + 1)*PI_2;
    vec3 v = normalize(vec3(cos(a)*cos(b), sin(b), sin(a)*cos(b)));
    v = v * (u_R+h/100000);
    gl_Position = u_transform *vec4(v.x, v.y, v.z, 1.0);
}