vertexshader

#version 430

in vec3 position;
in vec2 textureCoords;
in vec3 normal;

out vec3 colour;
out vec3 surfaceNormal;
out vec4 clipSpace;
out float visibility;
out vec3 toLightVector[4];
out vec2 textureCoords_fs;

uniform mat4 PMatrix;
uniform mat4 VMatrix;

uniform vec3 lightPosition[4];
uniform vec4 plane;
uniform bool fog;

const float density = 0.004;
const float gradient = 5.0;

void main(void) {

    vec4 worldPosition = vec4(position.x, position.y, position.z, 1.0);
    vec4 positionRelativeToCamera = VMatrix * worldPosition;
    gl_ClipDistance[0] = dot(worldPosition, plane);
    clipSpace = PMatrix * positionRelativeToCamera;
    gl_Position = clipSpace;

    textureCoords_fs = textureCoords * 8;
    surfaceNormal = normal;

    for(int i = 0; i < 4; i++) {
        toLightVector[i] = lightPosition[i] - worldPosition.xyz;
    }

    if(fog) {
        float distance = length(vec3(positionRelativeToCamera.x, positionRelativeToCamera.y * 0.2, positionRelativeToCamera.z));
        visibility = exp(-pow((distance*density), gradient));
        visibility = clamp(visibility, 0.0, 1.0);
    }


}