//TINCS Vertex Shader

varying vec3 normal;
varying vec3 halfV;
varying vec4 lightVertexVec;

uniform vec4 position;

uniform mat4 modelViewMatrix;

//I get my eyeDIR (eye direction vector, for specular) and lightPOS (light position vector) from the APP
uniform vec3 eyeDIR;
uniform vec4 lightPIS;


void main()
{
    
        //I need the world position of the vertex, so i can get a direction vector between it and the light
        vec4 calculatedVertex = gl_Vertex - position;
    
        //I need the light-vertex vector, to grab direction and distance off
        lightVertexVec = ((lightPIS) - (calculatedVertex));

        //Make sure everything that needs to be applied to the normal is
        normal = gl_Normal;
    
        //We only need one set of vertex co-ordinates
        gl_TexCoord[0] = gl_MultiTexCoord0;
    
        //Optmized setting of position
        gl_Position = gl_ProjectionMatrix * gl_ModelViewMatrix * (gl_Vertex + position);

} 

//TINCS Fragment Shader

//sampler2D for diffuse map and specular map
uniform sampler2D tex, spec;
varying vec3 normal;
varying float Power, lightDistance;
varying vec3 halfV;
uniform vec3 eyeDIR;
varying vec4 lightVertexVec;


void main()
{

        //I store the final specular value in a single float
        float specPower;
        vec4 specular;
        float specFinal;
    
        //Att = multiplyer for light distance stuff
        float att;
    
        //Quick ambient, I'm going to set ambient to uniform when i link it in with TINCS, so map makers can set it
        vec4 ambient = vec4(0.03,0.03,0.03,0.03);
        vec4 color = ambient;

        //Now, I normalize the light-vertex vector to get the direction of the light to the vertex
        vec4 lightDirection = normalize(lightVertexVec);
        //Then I just get the length for distance
        vec4 lightDistance = length(lightVertexVec);

        //Calculate the halfVector, (for specular stuff) I think this code might be dodgey! Take a good look darkblu :P
        halfV = normalize((lightDirection + (vec4(eyeDIR.x,eyeDIR.y,eyeDIR.z,0) * gl_ProjectionMatrix * gl_ModelViewMatrix)) / 2);

        //Cacluate the power of the light, by getting the dot product of the normal and light direction
        Power = max(dot(normalize(normal), normalize(lightDirection)),0.0);

        //Get the diffuse value off the texture and if there is no diffuse, we set it to white
        vec4 diffuse = texture2D(tex,gl_TexCoord[0].st);

        if(diffuse == 0)
        {
            diffuse = vec4(2,1,1,1);
        }
    
        //Get the specular value off the specular texture
        specular = texture2D(spec,gl_TexCoord[0].st);
    
        float specMulti = specular;

        //attenuation equals one over the linear and quadratic power of the light, lower you go, the more powerful the light is
        att = 1 / (0.00001 * lightDistance + 0.1 *  lightDistance * lightDistance);
        //add the diffuse values onto the final color
        color +=  att * (diffuse * Power);
    
        if(specMulti < 1.0 && specMulti > 0.0)
        {
            //I've taken out the spec stuff for now, so we can solve this
            //specPower = max(dot(normal, halfV),0.0);
            //specFinal = 1 * pow(specPower,specMulti);
            //color += att * specFinal;
        }
        

        //Get the final color!
        gl_FragColor = color;
}