#version 400
uniform sampler2D tex; //this is the texture
uniform sampler2D border; //this is the texture
uniform sampler2D rock; //this is the texture
smooth in vec3 vNormal;
smooth in vec3 vWorldPos;
in vec3 fragVert;
in float z_pos;
uniform vec3 cameraPosition;

uniform mat4 modelMatrix;
in vec2 tilePos;
in vec2 fragTexCoord; //this is the texture coord
out vec4 finalColor; //this is the output color of the pixel




struct SimpleDirectionalLight
{
   vec3 vColor;
   vec3 vDirection;
   float fAmbientIntensity;
};



uniform SimpleDirectionalLight sunLight;

vec4 GetDirectionalLightColor(SimpleDirectionalLight dirLight, vec3 vNormal)
{
        float fDiffuseIntensity =  dot(vNormal, -dirLight.vDirection);
        float fMult = pow(dirLight.fAmbientIntensity+fDiffuseIntensity,1.0);//clamp(dirLight.fAmbientIntensity+fDiffuseIntensity, -1.0, 1.0);
  // if(dirLight.iSkybox == 1)fMult = dirLight.fAmbientIntensity;
        return vec4(dirLight.vColor*fMult, 1.0);
}

vec4 GetSpecularColor(vec3 vWorldPos, vec3 vEyePos,  SimpleDirectionalLight dLight, vec3 vNormal)
{
   vec4 vResult = vec4(0.0, 0.0, 0.0, 0.0);

   vec3 vReflectedVector = normalize(reflect(dLight.vDirection, vNormal));
   vec3 vVertexToEyeVector = normalize(vEyePos-vWorldPos);
   float fSpecularFactor = dot(vVertexToEyeVector, vReflectedVector);

   if (fSpecularFactor > 0)
   {
      fSpecularFactor = pow(fSpecularFactor, 1.0);
      vResult = vec4(dLight.vColor, 1.0) * 1.0 * fSpecularFactor;
   }

   return vResult;
}

void main() {

    vec3 surfaceToLight = normalize(sunLight.vDirection);
    vec3 surfacePos = vec3(modelMatrix * vec4(fragVert, 1));
    vec3 surfaceToCamera = normalize(cameraPosition - surfacePos);
    vec4 bcolor = texture(border, vec2(tilePos.x,tilePos.y*1.154734411));
    float fDiffuseIntensity = max(0.0, dot(normalize(vNormal), -sunLight.vDirection));

    float addval = bcolor.a;
    vec4 vSpecularColor = GetSpecularColor(vWorldPos, cameraPosition, sunLight, normalize(vNormal))+ GetDirectionalLightColor(sunLight,normalize(vNormal));
    vec4 ground = texture(tex, fragTexCoord);
    vec4 rockt = texture(rock, fragTexCoord);

    float gndfac = 1.0;
    if (z_pos>0.3)
         gndfac = 0.0;
    else if (z_pos>0.1)
        gndfac=1.0 - 1.0 / 0.2 * (z_pos-0.1) ;
    finalColor = (ground *gndfac+rockt *(1.0-gndfac) +bcolor*addval) * vSpecularColor; //texture(tex, fragTexCoord) * pow(max(0.0, dot(surfaceToCamera, reflect(-surfaceToLight, normal))), 0.5);

    // (texture(tex, fragTexCoord)+bcolor*addval)*vec4(sunLight.vColor*(sunLight.fAmbientIntensity+fDiffuseIntensity), 1.0);

}