#version 410 core

uniform sampler2D textureSampler;
uniform sampler2D normalSampler;

uniform vec3 lightPos;
uniform vec3 cameraPos;

in vec3 interpNormal;
in vec2 interpTexCoord;
in vec3 fragPos;

in vec3 viewDirTS;
in vec3 lightDirTS;


float near = 0.25f;
float far = 100.0f;

float linearizeDepth(float depth)
{
    return (2.0 * near * far) / (far + near - (depth * 2.0 - 1.0) * (far - near));
}


float logisticDepth(float depth, float steepness, float offset);

float logisticDepth(float depth, float steepness, float offset)

{
    float zVal = linearizeDepth(depth);
    return (1 / (1 + exp(-steepness * (zVal - offset))));
}

void main()
{

	float depth = logisticDepth(gl_FragCoord.z, 0.5f, 5.0f);
	vec2 modifiedTexCoord = vec2(interpTexCoord.x, 1.0 - interpTexCoord.y); // Poprawka dla tekstur Ziemi, ktore bez tego wyswietlaja sie 'do gory nogami'

	vec3 color = texture2D(textureSampler, modifiedTexCoord).rgb;

	vec3 lightDir = normalize(lightDirTS);
	vec3 V = normalize(viewDirTS);
	vec3 normal = normalize(vec3(texture2D(normalSampler, modifiedTexCoord)) * 2 - 1);
	vec3 R = reflect(-normalize(lightDir),normal);
	
	float specular = pow(max(0,dot(R,V)),100);
	float diffuse = max(0,dot(normal,normalize(lightDir)));
	gl_FragColor = vec4(mix(color,color*diffuse+vec3(1)*specular,0.9), 1.0) * (1.0f - depth) + vec4(depth * vec3(5.0f/255.0f, 35.0f/255.0f, 95.0f/255.0f), 1.0f);
}