uniform sampler2D Texture;
varying vec2 texCoord;
varying vec3 vWorldPos;

uniform vec3 eyePos;    // Позиция камеры
uniform vec3 targetPos; // Цель камеры

void main() 
{
/*
	float maxDistance = 2000;
	float alpha = 0.0;
    vec4 color = texture2D(Texture, texCoord);
    
    vec3 dir = targetPos - eyePos;
    float dirLengthSq = dot(dir, dir);
    
    if (dirLengthSq > 0.0) 
    {
        vec3 objToEye = vWorldPos - eyePos;
        float t = dot(objToEye, dir) / dirLengthSq;
        
        if (t >= 0.0 && t <= 1.0) 
        {
            vec3 projection = eyePos + t * dir;
            vec3 delta = vWorldPos - projection;
            float distSq = dot(delta, delta);
            
            if (distSq < maxDistance * maxDistance) 
            {
                //color.a *= alpha; // Применяем прозрачность
				color.rgb = vec3(1,0,0);
            }
        }
    }
    */
	vec4 color;
	
	vec3 dirToCamera = normalize(eyePos - targetPos);
    vec3 dirToVertex = normalize(vWorldPos - targetPos);
	
	float dotProduct = dot(dirToCamera, dirToVertex);
	
	float distanceX = abs(vWorldPos.x);
	float distanceZ = abs(vWorldPos.z);
	
	float distanceToCamera = length(vWorldPos - targetPos);
	
	if ((distanceX > 750 || distanceZ > 750) && (dotProduct > 0.93))
	{
		//color.rgba = vec4(1,0,0,1);
		discard;
    }
	else
	{
		color.rgb = texture2D(Texture, texCoord).rgb;
		//color.rgb = vec3(clamp(vWorldPos.z/500, 0, 1), 0, 0);
		color.a = 1;
	}
	gl_FragColor = color;
}