#version 330 core

// Configuración
#define SCANLINES
#define MULTISAMPLE

#define SCANLINE_WEIGHT 6.0
#define SCANLINE_GAP_BRIGHTNESS 0.12
#define BLOOM_FACTOR 3.5

// Inputs desde vertex shader
in vec2 vTexCoord;
in float vFilterWidth;

// Output
out vec4 FragColor;

// Uniforms existentes
uniform sampler2D Texture;
uniform vec2 TextureSize;
uniform float uVignette;      // 0 = sin viñeta, 1 = máxima
uniform float uScanlines;     // 0 = desactivadas, 1 = plenas
uniform float uChroma;        // 0 = sin aberración, 1 = máxima
uniform float uOutputHeight;  // altura del viewport en pixels de pantalla

// Nuevos uniforms
uniform float uMask;          // 0 = sin máscara de fósforo, 1 = máxima
uniform float uGamma;         // 0 = sin corrección gamma, 1 = gamma 2.4/2.2 plena
uniform float uCurvature;     // 0 = plana, 1 = curvatura barrel máxima
uniform float uBleeding;      // 0 = sin sangrado NTSC, 1 = máximo

// Conversores YCbCr para efecto NTSC
vec3 rgb_to_ycc(vec3 rgb) {
	return vec3(
		 0.299*rgb.r + 0.587*rgb.g + 0.114*rgb.b,
		-0.169*rgb.r - 0.331*rgb.g + 0.500*rgb.b + 0.5,
		 0.500*rgb.r - 0.419*rgb.g - 0.081*rgb.b + 0.5
	);
}
vec3 ycc_to_rgb(vec3 ycc) {
	float y  = ycc.x;
	float cb = ycc.y - 0.5;
	float cr = ycc.z - 0.5;
	return clamp(vec3(
		y + 1.402*cr,
		y - 0.344*cb - 0.714*cr,
		y + 1.772*cb
	), 0.0, 1.0);
}

float CalcScanLineWeight(float dist)
{
	return max(1.0 - dist * dist * SCANLINE_WEIGHT, SCANLINE_GAP_BRIGHTNESS);
}

void main()
{
	vec2 texcoord = vTexCoord;

	// Curvatura barrel CRT (distorsión en UV antes de muestrear)
	if (uCurvature > 0.0) {
		vec2 c = texcoord - 0.5;
		float rsq = dot(c, c);
		vec2 dist = vec2(0.05, 0.1) * uCurvature;
		vec2 barrelScale = 1.0 - 0.23 * dist;
		c += c * (dist * rsq);
		c *= barrelScale;
		if (abs(c.x) >= 0.5 || abs(c.y) >= 0.5) {
			FragColor = vec4(0.0);
			return;
		}
		texcoord = c + 0.5;
	}

	vec2 texcoordInPixels = texcoord * TextureSize;

	float tempY = floor(texcoordInPixels.y) + 0.5;
	float yCoord = tempY / TextureSize.y;

	// Scanline en espacio de pantalla (subpíxel)
	float scaleY = uOutputHeight / TextureSize.y;
	float screenY = texcoord.y * uOutputHeight;
	float posInRow = mod(screenY, scaleY);
	float scanLineDY = posInRow / scaleY - 0.5;
	float localFilterWidth = 1.0 / scaleY;
	float scanLineWeight = CalcScanLineWeight(scanLineDY);
	scanLineWeight += CalcScanLineWeight(scanLineDY - localFilterWidth);
	scanLineWeight += CalcScanLineWeight(scanLineDY + localFilterWidth);
	scanLineWeight *= 0.3333333;

	// Phosphor blur en espacio textura
	float dy = texcoordInPixels.y - tempY;
	float signY = sign(dy);
	dy = dy * dy;
	dy = dy * dy;
	dy *= 8.0;
	dy /= TextureSize.y;
	dy *= signY;
	vec2 tc = vec2(texcoord.x, yCoord + dy);

	// Muestra base en centro
	vec3 base = texture(Texture, tc).rgb;

	// Sangrado NTSC — difuminado horizontal de crominancia
	vec3 colour;
	if (uBleeding > 0.0) {
		float tw = TextureSize.x;
		vec3 ycc    = rgb_to_ycc(base);
		vec3 ycc_l2 = rgb_to_ycc(texture(Texture, tc - vec2(2.0/tw, 0.0)).rgb);
		vec3 ycc_l1 = rgb_to_ycc(texture(Texture, tc - vec2(1.0/tw, 0.0)).rgb);
		vec3 ycc_r1 = rgb_to_ycc(texture(Texture, tc + vec2(1.0/tw, 0.0)).rgb);
		vec3 ycc_r2 = rgb_to_ycc(texture(Texture, tc + vec2(2.0/tw, 0.0)).rgb);
		ycc.yz = (ycc_l2.yz + ycc_l1.yz*2.0 + ycc.yz*2.0 + ycc_r1.yz*2.0 + ycc_r2.yz) / 8.0;
		colour = mix(base, ycc_to_rgb(ycc), uBleeding);
	} else {
		colour = base;
	}

	// Aberración cromática
	float ca = uChroma * 0.005;
	colour.r = texture(Texture, tc + vec2(ca, 0.0)).r;
	colour.b = texture(Texture, tc - vec2(ca, 0.0)).b;

	// Corrección gamma (linealizar antes de scanlines, codificar después)
	if (uGamma > 0.0) {
		vec3 lin = pow(colour, vec3(2.4));
		colour = mix(colour, lin, uGamma);
	}

	// Scanlines
	scanLineWeight *= BLOOM_FACTOR;
	colour *= mix(1.0, scanLineWeight, uScanlines);

	if (uGamma > 0.0) {
		vec3 enc = pow(colour, vec3(1.0 / 2.2));
		colour = mix(colour, enc, uGamma);
	}

	// Viñeta
	if (uVignette > 0.0) {
		vec2 uv = texcoord - vec2(0.5);
		float vig = 1.0 - dot(uv, uv) * uVignette * 4.0;
		colour *= clamp(vig, 0.0, 1.0);
	}

	// Máscara de fósforo RGB
	if (uMask > 0.0) {
		float whichMask = fract(gl_FragCoord.x * 0.3333333);
		vec3 mask = vec3(0.80);
		if (whichMask < 0.3333333)
			mask.x = 1.0;
		else if (whichMask < 0.6666666)
			mask.y = 1.0;
		else
			mask.z = 1.0;
		colour = mix(colour, colour * mask, uMask);
	}

	FragColor = vec4(colour, 1.0);
}