14 - default.frag

#version 330 core

out vec4 MauFrag;
in vec3 vtht, bThg, mauSac;
in vec2 txCrd;

uniform sampler2D pTan, pChieu;
uniform vec4 mauDen;
uniform vec3 vtDen, vtCam;

vec4 sangCoHuong()
{
	vec3 huongDen = vtDen - vtht;
	float kCach = length(huongDen);
	float a = 2.0, b = 0.3;
	float cuongDo = 1.0f / (a * kCach * kCach + b * kCach + 1.0f);

	float mTrg = 0.2f;
	vec3 bthg = normalize(bThg);
	vec3 huongSang = normalize(huongDen);
	float phanTan = max(dot(bthg, huongSang), 0.0f);

	float phanChieu = 0.5f;
	vec3 huongNhin = normalize(vtCam - vtht);
	vec3 huongChieu = reflect(-huongSang, bthg);
	
	float luongSang = pow(max(dot(huongNhin, huongChieu), 0.0f), 16);
	float anhSang = luongSang * phanChieu;
	return (texture(pTan, txCrd) * (phanTan * cuongDo + mTrg) + texture(pChieu, txCrd).r * anhSang * cuongDo) * mauDen;
}

vec4 sangTrucTiep()
{
	float mTrg = 0.2f;
	vec3 bthg = normalize(bThg);
	vec3 huongSang = normalize(vec3(1.0f, 1.0f, 0.0f));
	float phanTan = max(dot(bthg, huongSang), 0.0f);

	float phanChieu = 0.5f;
	vec3 huongNhin = normalize(vtCam - vtht);
	vec3 huongChieu = reflect(-huongSang, bthg);
	
	float luongSang = pow(max(dot(huongNhin, huongChieu), 0.0f), 16);
	float anhSang = luongSang * phanChieu;
	return (texture(pTan, txCrd) * (phanTan + mTrg) + texture(pChieu, txCrd).r * anhSang) * mauDen;
}

vec4 sang1diem()
{
	float benNgoai = 0.7f, benTrg = 0.85f, mTrg = 0.2f;
	vec3 bthg = normalize(bThg), huongDen = vtDen - vtht;
	vec3 huongSang = normalize(huongDen);
	float phanTan = max(dot(bthg, huongSang), 0.0f);

	float phanChieu = 0.5f;
	vec3 huongNhin = normalize(vtCam - vtht);
	vec3 huongChieu = reflect(-huongSang, bthg);
	
	float luongSang = pow(max(dot(huongNhin, huongChieu), 0.0f), 16);
	float anhSang = luongSang * phanChieu;
	float goc = dot(vec3(0.0f, -1.0f, 0.0f), -huongSang);
	float cuongDo = clamp((goc - benNgoai) / (benTrg - benNgoai), 0.0f, 1.0f);
	
	return (texture(pTan, txCrd) * (phanTan * cuongDo + mTrg) + texture(pChieu, txCrd).r * anhSang * cuongDo) * mauDen;
}

float gan = 0.1f, xa = 100.0f;
float tuyenTinhSau(float sau)
{
	return (2.0 * gan / xa) / (gan + xa - (sau * 2.0 - 1.0) * (xa - gan));
}

float logicSau(float sau)
{
	float z = tuyenTinhSau(sau), doc = 0.5f, bu = 5.0f;
	return (1 / (1 + exp(-doc * (z - bu))));
}

void main()
{
	float doSau = logicSau(gl_FragCoord.z);
	MauFrag = sangTrucTiep() * (1.0f - doSau) + vec4(doSau * vec3(0.85f, 0.85f, 0.90f), 1.0f);
}