#vertex

uniform mat4 view;

void main() {
    vec4 pos = gl_ModelViewMatrix * gl_Vertex;
    gl_FrontColor = gl_Color;
    gl_BackColor = gl_Color;
    gl_TexCoord[0] = pos;
    gl_Position = gl_ProjectionMatrix * view * pos;
}

#fragment

uniform sampler2D t;

void main() {
    vec3 c = gl_Color.xyz;
    float z = 1.0 - 25.0 * (1.0 / gl_FragCoord.z - 1.0);
    z = 0.9 * (1.0 - z * z);
    c *= z;
    z = 0.5 * (texture2D(t, gl_TexCoord[0].xy).r - 0.5);
    c += z;
    gl_FragColor = vec4(c.xyz, gl_Color.a);
}