Bilibili_Anime4K.js

// ==UserScript==
// @name                Bilibili_Anime4K
// @name:zh-CN          Bilibili Anime4K滤镜
// @description         Bring Anime4K to Bilibili and ACFun's HTML5 player to clearify 2D anime.
// @description:zh-CN   通过Anime4K滤镜让Bilibili和ACFun上的2D番剧更加清晰
// @namespace           http://net2cn.tk/
// @homepageURL         https://github.com/net2cn/Bilibili_Anime4K/
// @supportURL          https://github.com/net2cn/Bilibili_Anime4K/issues
// @version             0.4.12
// @author              net2cn
// @copyright           bloc97, DextroseRe, NeuroWhAI, and all contributors of Anime4K
// @match               *://www.bilibili.com/video/av*
// @match               *://www.bilibili.com/bangumi/play/ep*
// @match               *://www.bilibili.com/bangumi/play/ss*
// @match               *://www.bilibili.com/video/BV*
// @match               *://www.acfun.cn/bangumi/aa*
// @grant               none
// @license             MIT License
// @run-at              document-idle
// ==/UserScript==

// WebGL implementation by NeuroWhAI.
// https://github.com/bloc97/Anime4K/blob/master/web/main.js

function createShader(gl, type, source) {
    var shader = gl.createShader(type);
    gl.shaderSource(shader, source);

    gl.compileShader(shader);
    if (!gl.getShaderParameter(shader, gl.COMPILE_STATUS)) {
        throw new Error(gl.getShaderInfoLog(shader));
    }

    return shader;
}

function createProgram(gl, vertexSource, fragmentSource) {
    var program = gl.createProgram();

    //console.log(fragmentSource)

    var vertexShader = createShader(gl, gl.VERTEX_SHADER, vertexSource);
    var fragmentShader = createShader(gl, gl.FRAGMENT_SHADER, fragmentSource);

    gl.attachShader(program, vertexShader);
    gl.attachShader(program, fragmentShader);

    gl.linkProgram(program);
    if (!gl.getProgramParameter(program, gl.LINK_STATUS)) {
        throw new Error(gl.getProgramInfoLog(program));
    }

    var wrapper = { program: program };

    var numAttributes = gl.getProgramParameter(program, gl.ACTIVE_ATTRIBUTES);
    for (var i = 0; i < numAttributes; i++) {
        var attribute = gl.getActiveAttrib(program, i);
        wrapper[attribute.name] = gl.getAttribLocation(program, attribute.name);
    }
    var numUniforms = gl.getProgramParameter(program, gl.ACTIVE_UNIFORMS);
    for (var i$1 = 0; i$1 < numUniforms; i$1++) {
        var uniform = gl.getActiveUniform(program, i$1);
        wrapper[uniform.name] = gl.getUniformLocation(program, uniform.name);
    }

    return wrapper;
}

function createTexture(gl, filter, data, width, height) {
    var texture = gl.createTexture();
    gl.bindTexture(gl.TEXTURE_2D, texture);
    gl.texParameteri(gl.TEXTURE_2D, gl.TEXTURE_WRAP_S, gl.CLAMP_TO_EDGE);
    gl.texParameteri(gl.TEXTURE_2D, gl.TEXTURE_WRAP_T, gl.CLAMP_TO_EDGE);
    gl.texParameteri(gl.TEXTURE_2D, gl.TEXTURE_MIN_FILTER, filter);
    gl.texParameteri(gl.TEXTURE_2D, gl.TEXTURE_MAG_FILTER, filter);
    if (data instanceof Uint8Array) {
        gl.texImage2D(gl.TEXTURE_2D, 0, gl.RGBA, width, height, 0, gl.RGBA, gl.UNSIGNED_BYTE, data);
    } else {
        gl.texImage2D(gl.TEXTURE_2D, 0, gl.RGBA, gl.RGBA, gl.UNSIGNED_BYTE, data);
    }
    gl.bindTexture(gl.TEXTURE_2D, null);
    return texture;
}

function bindTexture(gl, texture, unit) {
    gl.activeTexture(gl.TEXTURE0 + unit);
    gl.bindTexture(gl.TEXTURE_2D, texture);
}

function updateTexture(gl, texture, src) {
    gl.bindTexture(gl.TEXTURE_2D, texture);
    gl.texImage2D(gl.TEXTURE_2D, 0, gl.RGBA, gl.RGBA, gl.UNSIGNED_BYTE, src);
}

function createBuffer(gl, data) {
    var buffer = gl.createBuffer();
    gl.bindBuffer(gl.ARRAY_BUFFER, buffer);
    gl.bufferData(gl.ARRAY_BUFFER, data, gl.STATIC_DRAW);
    return buffer;
}

function bindAttribute(gl, buffer, attribute, numComponents) {
    gl.bindBuffer(gl.ARRAY_BUFFER, buffer);
    gl.enableVertexAttribArray(attribute);
    gl.vertexAttribPointer(attribute, numComponents, gl.FLOAT, false, 0, 0);
}

function bindFramebuffer(gl, framebuffer, texture) {
    gl.bindFramebuffer(gl.FRAMEBUFFER, framebuffer);
    if (texture) {
        gl.framebufferTexture2D(gl.FRAMEBUFFER, gl.COLOR_ATTACHMENT0, gl.TEXTURE_2D, texture, 0);
    }
}


const quadVert = `
precision mediump float;

attribute vec2 a_pos;
varying vec2 v_tex_pos;

void main() {
    v_tex_pos = a_pos;
    gl_Position = vec4(1.0 - 2.0 * a_pos, 0, 1);
}
`;

const scaleFrag = `
precision mediump float;

uniform sampler2D u_texture;
uniform vec2 u_size;
varying vec2 v_tex_pos;

vec4 interp(const vec2 uv) {
    vec2 px = 1.0 / u_size;
    vec2 vc = (floor(uv * u_size)) * px;
    vec2 f = fract(uv * u_size);
    vec4 tl = texture2D(u_texture, vc);
    vec4 tr = texture2D(u_texture, vc + vec2(px.x, 0));
    vec4 bl = texture2D(u_texture, vc + vec2(0, px.y));
    vec4 br = texture2D(u_texture, vc + px);
    return mix(mix(tl, tr, f.x), mix(bl, br, f.x), f.y);
}

void main() {
    gl_FragColor = interp(1.0 - v_tex_pos);
    //gl_FragColor = texture2D(u_texture, 1.0 - v_tex_pos);
}
`;

const thinLinesFrag = `
precision mediump float;

uniform sampler2D scaled_texture;
uniform float u_scale;
uniform vec2 u_pt;
varying vec2 v_tex_pos;

#define strength (min(u_scale / 6.0, 1.0))

vec4 HOOKED_tex(vec2 pos) {
    return texture2D(scaled_texture, pos);
}

float getLum(vec4 rgb) {
	return (rgb.r + rgb.r + rgb.g + rgb.g + rgb.g + rgb.b) / 6.0;
}

vec4 getLargest(vec4 cc, vec4 lightestColor, vec4 a, vec4 b, vec4 c) {
	vec4 newColor = cc * (1.0 - strength) + ((a + b + c) / 3.0) * strength;
	if (newColor.a > lightestColor.a) {
		return newColor;
	}
	return lightestColor;
}

vec4 getRGBL(vec2 pos) {
    return vec4(HOOKED_tex(pos).rgb, getLum(HOOKED_tex(pos)));
}

float min3v(vec4 a, vec4 b, vec4 c) {
	return min(min(a.a, b.a), c.a);
}
float max3v(vec4 a, vec4 b, vec4 c) {
	return max(max(a.a, b.a), c.a);
}

void main() {
    vec2 HOOKED_pos = v_tex_pos;

	vec2 d = u_pt;

    vec4 cc = getRGBL(HOOKED_pos);
	vec4 t = getRGBL(HOOKED_pos + vec2(0.0, -d.y));
	vec4 tl = getRGBL(HOOKED_pos + vec2(-d.x, -d.y));
	vec4 tr = getRGBL(HOOKED_pos + vec2(d.x, -d.y));

	vec4 l = getRGBL(HOOKED_pos + vec2(-d.x, 0.0));
	vec4 r = getRGBL(HOOKED_pos + vec2(d.x, 0.0));

	vec4 b = getRGBL(HOOKED_pos + vec2(0.0, d.y));
	vec4 bl = getRGBL(HOOKED_pos + vec2(-d.x, d.y));
	vec4 br = getRGBL(HOOKED_pos + vec2(d.x, d.y));

	vec4 lightestColor = cc;

	//Kernel 0 and 4
	float maxDark = max3v(br, b, bl);
	float minLight = min3v(tl, t, tr);

	if (minLight > cc.a && minLight > maxDark) {
		lightestColor = getLargest(cc, lightestColor, tl, t, tr);
	} else {
		maxDark = max3v(tl, t, tr);
		minLight = min3v(br, b, bl);
		if (minLight > cc.a && minLight > maxDark) {
			lightestColor = getLargest(cc, lightestColor, br, b, bl);
		}
	}

	//Kernel 1 and 5
	maxDark = max3v(cc, l, b);
	minLight = min3v(r, t, tr);

	if (minLight > maxDark) {
		lightestColor = getLargest(cc, lightestColor, r, t, tr);
	} else {
		maxDark = max3v(cc, r, t);
		minLight = min3v(bl, l, b);
		if (minLight > maxDark) {
			lightestColor = getLargest(cc, lightestColor, bl, l, b);
		}
	}

	//Kernel 2 and 6
	maxDark = max3v(l, tl, bl);
	minLight = min3v(r, br, tr);

	if (minLight > cc.a && minLight > maxDark) {
		lightestColor = getLargest(cc, lightestColor, r, br, tr);
	} else {
		maxDark = max3v(r, br, tr);
		minLight = min3v(l, tl, bl);
		if (minLight > cc.a && minLight > maxDark) {
			lightestColor = getLargest(cc, lightestColor, l, tl, bl);
		}
	}

	//Kernel 3 and 7
	maxDark = max3v(cc, l, t);
	minLight = min3v(r, br, b);

	if (minLight > maxDark) {
		lightestColor = getLargest(cc, lightestColor, r, br, b);
	} else {
		maxDark = max3v(cc, r, b);
		minLight = min3v(t, l, tl);
		if (minLight > maxDark) {
			lightestColor = getLargest(cc, lightestColor, t, l, tl);
		}
    }

    gl_FragColor = lightestColor;
}
`;

const lumaFrag = `
precision mediump float;

uniform sampler2D scaled_texture;
uniform sampler2D post_kernel_texture;
uniform vec2 u_pt;
varying vec2 v_tex_pos;

vec4 HOOKED_tex(vec2 pos) {
    return texture2D(scaled_texture, pos);
}

float getLum(vec4 rgb) {
	return (rgb.r + rgb.r + rgb.g + rgb.g + rgb.g + rgb.b) / 6.0;
}

void main() { //Save lum on OUTPUT
    vec2 HOOKED_pos = v_tex_pos;

	vec4 rgb = HOOKED_tex(HOOKED_pos);
	float lum = getLum(rgb);
    gl_FragColor = vec4(lum);
}
`;

const lumaGausXFrag = `
precision mediump float;

uniform sampler2D scaled_texture;
uniform sampler2D post_kernel_texture;
uniform vec2 u_pt;
varying vec2 v_tex_pos;

vec4 HOOKED_tex(vec2 pos) {
    return texture2D(scaled_texture, pos);
}

vec4 LUMA_tex(vec2 pos){
    return texture2D(post_kernel_texture, pos);
}

float lumGaussian5(vec2 pos, vec2 d) {
	float g = LUMA_tex(pos - (d * 2.0)).x * 0.187691;
	g = g + LUMA_tex(pos - d).x * 0.206038;
	g = g + LUMA_tex(pos).x * 0.212543;
	g = g + LUMA_tex(pos + d).x * 0.206038;
	g = g + LUMA_tex(pos + (d * 2.0)).x * 0.187691;

	return clamp(g, 0.0, 1.0); //Clamp for sanity check
}


void main() {
    vec2 HOOKED_pos = v_tex_pos;
    vec2 HOOKED_pt = u_pt;

	float g = lumGaussian5(HOOKED_pos, vec2(HOOKED_pt.x, 0));
    gl_FragColor = vec4(LUMA_tex(HOOKED_pos).x, g, LUMA_tex(HOOKED_pos).zw);
}
`;

const lumaGausYFrag = `
precision mediump float;

uniform sampler2D scaled_texture;
uniform sampler2D post_kernel_texture;
uniform vec2 u_pt;
varying vec2 v_tex_pos;

vec4 HOOKED_tex(vec2 pos) {
    return texture2D(scaled_texture, pos);
}

vec4 LUMAG_tex(vec2 pos){
    return texture2D(post_kernel_texture, pos);
}

float lumGaussian5(vec2 pos, vec2 d) {
	float g = LUMAG_tex(pos - (d * 2.0)).x * 0.187691;
	g = g + LUMAG_tex(pos - d).x * 0.206038;
	g = g + LUMAG_tex(pos).x * 0.212543;
	g = g + LUMAG_tex(pos + d).x * 0.206038;
	g = g + LUMAG_tex(pos + (d * 2.0)).x * 0.187691;

	return clamp(g, 0.0, 1.0); //Clamp for sanity check
}

void main() {
    vec2 HOOKED_pos = v_tex_pos;
    vec2 HOOKED_pt = u_pt;

	float g = lumGaussian5(HOOKED_pos, vec2(0, HOOKED_pt.y));
    gl_FragColor = vec4(LUMAG_tex(HOOKED_pos).x, g, LUMAG_tex(HOOKED_pos).zw);
}
`;

const lineDetectFrag = `
precision mediump float;

uniform sampler2D scaled_texture;
uniform sampler2D post_kernel_texture;
uniform vec2 u_pt;
varying vec2 v_tex_pos;

#define BlendColorDodgef(base, blend) 	(((blend) == 1.0) ? (blend) : min((base) / (1.0 - (blend)), 1.0))
#define BlendColorDividef(top, bottom) 	(((bottom) == 1.0) ? (bottom) : min((top) / (bottom), 1.0))

// Component wise blending
#define Blend(base, blend, funcf) 		vec3(funcf(base.r, blend.r), funcf(base.g, blend.g), funcf(base.b, blend.b))
#define BlendColorDodge(base, blend) 	Blend(base, blend, BlendColorDodgef)

vec4 HOOKED_tex(vec2 pos) {
    return texture2D(scaled_texture, pos);
}

vec4 POSTKERNEL_tex(vec2 pos){
    return texture2D(post_kernel_texture, pos);
}

void main() {
    vec2 HOOKED_pos = v_tex_pos;

	float lum = clamp(POSTKERNEL_tex(HOOKED_pos).x, 0.001, 0.999);
	float lumg = clamp(POSTKERNEL_tex(HOOKED_pos).y, 0.001, 0.999);

	float pseudolines = BlendColorDividef(lum, lumg);
	pseudolines = 1.0 - clamp(pseudolines - 0.05, 0.0, 1.0);

    gl_FragColor = vec4(pseudolines, 0, 0, 0);
}
`;

const lineGausXFrag = `
precision mediump float;

uniform sampler2D scaled_texture;
uniform sampler2D post_kernel_texture;
uniform vec2 u_pt;
varying vec2 v_tex_pos;

vec4 HOOKED_tex(vec2 pos) {
    return texture2D(scaled_texture, pos);
}

vec4 LUMAG_tex(vec2 pos){
    return texture2D(post_kernel_texture, pos);
}

float lumGaussian5(vec2 pos, vec2 d) {
	float g = LUMAG_tex(pos - (d * 2.0)).x * 0.187691;
	g = g + LUMAG_tex(pos - d).x * 0.206038;
	g = g + LUMAG_tex(pos).x * 0.212543;
	g = g + LUMAG_tex(pos + d).x * 0.206038;
	g = g + LUMAG_tex(pos + (d * 2.0)).x * 0.187691;

	return clamp(g, 0.0, 1.0); //Clamp for sanity check
}


void main() {
    vec2 HOOKED_pos = v_tex_pos;
    vec2 HOOKED_pt = u_pt;

	float g = lumGaussian5(HOOKED_pos, vec2(HOOKED_pt.x, 0.0));
    gl_FragColor = vec4(g, 0, 0, 0);
}
`;

const lineGausYFrag = `
precision mediump float;

uniform sampler2D scaled_texture;
uniform sampler2D post_kernel_texture;
uniform vec2 u_pt;
varying vec2 v_tex_pos;

vec4 HOOKED_tex(vec2 pos) {
    return texture2D(scaled_texture, pos);
}

vec4 LUMAG_tex(vec2 pos){
    return texture2D(post_kernel_texture, pos);
}

float lumGaussian5(vec2 pos, vec2 d) {
	float g = LUMAG_tex(pos - (d * 2.0)).x * 0.187691;
	g = g + LUMAG_tex(pos - d).x * 0.206038;
	g = g + LUMAG_tex(pos).x * 0.212543;
	g = g + LUMAG_tex(pos + d).x * 0.206038;
	g = g + LUMAG_tex(pos + (d * 2.0)).x * 0.187691;

	return clamp(g, 0.0, 1.0); //Clamp for sanity check
}

void main() {
    vec2 HOOKED_pos = v_tex_pos;
    vec2 HOOKED_pt = u_pt;

	float g = lumGaussian5(HOOKED_pos, vec2(0.0, HOOKED_pt.y));
    gl_FragColor = vec4(g, 0, 0, 0);
}
`;

const gradFrag = `
precision mediump float;

uniform sampler2D u_texture;
uniform sampler2D u_textureTemp;
uniform vec2 u_pt;
varying vec2 v_tex_pos;

vec4 HOOKED_tex(vec2 pos) {
    return texture2D(u_texture, 1.0 - pos);
}

vec4 POSTKERNEL_tex(vec2 pos) {
    return texture2D(u_textureTemp, 1.0 - pos);
}

vec4 getRGBL(vec2 pos) {
    return vec4(HOOKED_tex(pos).rgb, POSTKERNEL_tex(pos).x);
}

void main() {
    vec2 HOOKED_pos = v_tex_pos;

	vec2 d = u_pt;

	//[tl  t tr]
	//[ l cc  r]
	//[bl  b br]
    vec4 cc = getRGBL(HOOKED_pos);
	vec4 t = getRGBL(HOOKED_pos + vec2(0.0, -d.y));
	vec4 tl = getRGBL(HOOKED_pos + vec2(-d.x, -d.y));
	vec4 tr = getRGBL(HOOKED_pos + vec2(d.x, -d.y));

	vec4 l = getRGBL(HOOKED_pos + vec2(-d.x, 0.0));
	vec4 r = getRGBL(HOOKED_pos + vec2(d.x, 0.0));

	vec4 b = getRGBL(HOOKED_pos + vec2(0.0, d.y));
	vec4 bl = getRGBL(HOOKED_pos + vec2(-d.x, d.y));
	vec4 br = getRGBL(HOOKED_pos + vec2(d.x, d.y));

	//Horizontal Gradient
	//[-1  0  1]
	//[-2  0  2]
	//[-1  0  1]
	float xgrad = (-tl.a + tr.a - l.a - l.a + r.a + r.a - bl.a + br.a);

	//Vertical Gradient
	//[-1 -2 -1]
	//[ 0  0  0]
	//[ 1  2  1]
    float ygrad = (-tl.a - t.a - t.a - tr.a + bl.a + b.a + b.a + br.a);

    gl_FragColor = vec4(1.0 - clamp(sqrt(xgrad * xgrad + ygrad * ygrad), 0.0, 1.0));
}
`;

const refineFrag = `
precision mediump float;

uniform sampler2D u_texture;
uniform sampler2D u_textureTemp;
uniform vec2 u_pt;
uniform float u_scale;
varying vec2 v_tex_pos;

vec4 HOOKED_tex(vec2 pos) {
    return texture2D(u_texture, vec2(pos.x, 1.0 - pos.y));
}

vec4 POSTKERNEL_tex(vec2 pos) {
    return texture2D(u_textureTemp, vec2(pos.x, 1.0 - pos.y));
}

#define LINE_DETECT_MUL 8.0
#define LINE_DETECT_THRESHOLD 0.2

#define strength (min(u_scale, 1.0))
#define lineprob (POSTKERNEL_tex(v_tex_pos).y)

vec4 getAverage(vec4 cc, vec4 a, vec4 b, vec4 c) {
	float prob = clamp(lineprob * LINE_DETECT_MUL, 0.0, 1.0);
	if (prob < LINE_DETECT_THRESHOLD) {
		prob = 0.0;
	}
	float realstrength = clamp(strength * prob, 0.0, 1.0);
	return cc * (1.0 - realstrength) + ((a + b + c) / 3.0) * realstrength;
}

vec4 getRGBL(vec2 pos) {
    return vec4(HOOKED_tex(pos).rgb, POSTKERNEL_tex(pos).z);
}

float min3v(vec4 a, vec4 b, vec4 c) {
	return min(min(a.a, b.a), c.a);
}
float max3v(vec4 a, vec4 b, vec4 c) {
	return max(max(a.a, b.a), c.a);
}

void main()  {
    vec2 HOOKED_pos = v_tex_pos;

	vec2 d = u_pt;

    vec4 cc = getRGBL(HOOKED_pos);
	vec4 t = getRGBL(HOOKED_pos + vec2(0.0, -d.y));
	vec4 tl = getRGBL(HOOKED_pos + vec2(-d.x, -d.y));
	vec4 tr = getRGBL(HOOKED_pos + vec2(d.x, -d.y));

	vec4 l = getRGBL(HOOKED_pos + vec2(-d.x, 0.0));
	vec4 r = getRGBL(HOOKED_pos + vec2(d.x, 0.0));

	vec4 b = getRGBL(HOOKED_pos + vec2(0.0, d.y));
	vec4 bl = getRGBL(HOOKED_pos + vec2(-d.x, d.y));
	vec4 br = getRGBL(HOOKED_pos + vec2(d.x, d.y));

	//Kernel 0 and 4
	float maxDark = max3v(br, b, bl);
	float minLight = min3v(tl, t, tr);

	if (minLight > cc.a && minLight > maxDark) {
        gl_FragColor = getAverage(cc, tl, t, tr);
        return;
	} else {
		maxDark = max3v(tl, t, tr);
		minLight = min3v(br, b, bl);
		if (minLight > cc.a && minLight > maxDark) {
            gl_FragColor = getAverage(cc, br, b, bl);
            return;
		}
	}

	//Kernel 1 and 5
	maxDark = max3v(cc, l, b);
	minLight = min3v(r, t, tr);

	if (minLight > maxDark) {
        gl_FragColor = getAverage(cc, r, t, tr);
        return;
	} else {
		maxDark = max3v(cc, r, t);
		minLight = min3v(bl, l, b);
		if (minLight > maxDark) {
            gl_FragColor = getAverage(cc, bl, l, b);
            return;
		}
	}

	//Kernel 2 and 6
	maxDark = max3v(l, tl, bl);
	minLight = min3v(r, br, tr);

	if (minLight > cc.a && minLight > maxDark) {
        gl_FragColor = getAverage(cc, r, br, tr);
        return;
	} else {
		maxDark = max3v(r, br, tr);
		minLight = min3v(l, tl, bl);
		if (minLight > cc.a && minLight > maxDark) {
            gl_FragColor = getAverage(cc, l, tl, bl);
            return;
		}
	}

	//Kernel 3 and 7
	maxDark = max3v(cc, l, t);
	minLight = min3v(r, br, b);

	if (minLight > maxDark) {
        gl_FragColor = getAverage(cc, r, br, b);
        return;
	} else {
		maxDark = max3v(cc, r, b);
		minLight = min3v(t, l, tl);
		if (minLight > maxDark) {
            gl_FragColor = getAverage(cc, t, l, tl);
            return;
		}
	}


	gl_FragColor = cc;
}
`;

const fxaaFrag = `
precision mediump float;

uniform sampler2D u_texture;
uniform sampler2D u_textureTemp;
uniform vec2 u_pt;
uniform float u_scale;
varying vec2 v_tex_pos;

vec4 HOOKED_tex(vec2 pos) {
    return texture2D(u_texture, vec2(pos.x, 1.0 - pos.y));
}

vec4 POSTKERNEL_tex(vec2 pos) {
    return texture2D(u_textureTemp, vec2(pos.x, 1.0 - pos.y));
}

#define FXAA_MIN (1.0 / 128.0)
#define FXAA_MUL (1.0 / 8.0)
#define FXAA_SPAN 8.0

#define LINE_DETECT_MUL 4.0
#define LINE_DETECT_THRESHOLD 0.2

#define strength (min(u_scale, 1.0))
#define lineprob (POSTKERNEL_tex(v_tex_pos).y)

vec4 getAverage(vec4 cc, vec4 xc) {
	float prob = clamp(lineprob * LINE_DETECT_MUL, 0.0, 1.0);
	if (prob < LINE_DETECT_THRESHOLD) {
		prob = 0.0;
	}
	float realstrength = clamp(strength * prob, 0.0, 1.0);
	return cc * (1.0 - realstrength) + xc * realstrength;
}

float getLum(vec4 rgb) {
	return (rgb.r + rgb.r + rgb.g + rgb.g + rgb.g + rgb.b) / 6.0;
}

void main()  {
    vec2 HOOKED_pos = v_tex_pos;

	vec2 d = u_pt;

    vec4 cc = HOOKED_tex(HOOKED_pos);
    vec4 xc = cc;

	float t = POSTKERNEL_tex(HOOKED_pos + vec2(0, -d.y)).x;
	float l = POSTKERNEL_tex(HOOKED_pos + vec2(-d.x, 0)).x;
	float r = POSTKERNEL_tex(HOOKED_pos + vec2(d.x, 0)).x;
	float b = POSTKERNEL_tex(HOOKED_pos + vec2(0, d.y)).x;

    float tl = POSTKERNEL_tex(HOOKED_pos + vec2(-d.x, -d.y)).x;
    float tr = POSTKERNEL_tex(HOOKED_pos + vec2(d.x, -d.y)).x;
    float bl = POSTKERNEL_tex(HOOKED_pos + vec2(-d.x, d.y)).x;
    float br = POSTKERNEL_tex(HOOKED_pos + vec2(d.x, d.y)).x;
    float cl  = POSTKERNEL_tex(HOOKED_pos).x;

    float minl = min(cl, min(min(tl, tr), min(bl, br)));
    float maxl = max(cl, max(max(tl, tr), max(bl, br)));

    vec2 dir = vec2(- tl - tr + bl + br, tl - tr + bl - br);

    float dirReduce = max((tl + tr + bl + br) *
                          (0.25 * FXAA_MUL), FXAA_MIN);

    float rcpDirMin = 1.0 / (min(abs(dir.x), abs(dir.y)) + dirReduce);
    dir = min(vec2(FXAA_SPAN, FXAA_SPAN),
              max(vec2(-FXAA_SPAN, -FXAA_SPAN),
              dir * rcpDirMin)) * d;

    vec4 rgbA = 0.5 * (
        HOOKED_tex(HOOKED_pos + dir * -(1.0/6.0)) +
        HOOKED_tex(HOOKED_pos + dir * (1.0/6.0)));
    vec4 rgbB = rgbA * 0.5 + 0.25 * (
        HOOKED_tex(HOOKED_pos + dir * -0.5) +
        HOOKED_tex(HOOKED_pos + dir * 0.5));

    //vec4 luma = vec4(0.299, 0.587, 0.114, 0.0);
    //float lumb = dot(rgbB, luma);
    float lumb = getLum(rgbB);

    if ((lumb < minl) || (lumb > maxl)) {
        xc = rgbA;
    } else {
        xc = rgbB;
	}
    gl_FragColor = getAverage(cc, xc);
}
`;

const drawFrag = `
precision mediump float;

uniform sampler2D u_texture;
varying vec2 v_tex_pos;

void main() {
    vec4 color = texture2D(u_texture, vec2(v_tex_pos.x, 1.0 - v_tex_pos.y));
    gl_FragColor = color;
}
`;


function Scaler(gl) {
    this.gl = gl;

    this.inputTex = null;
    this.inputMov = null;
    this.inputWidth = 0;
    this.inputHeight = 0;

    this.quadBuffer = createBuffer(gl, new Float32Array([0, 0, 1, 0, 0, 1, 0, 1, 1, 0, 1, 1]));
    this.framebuffer = gl.createFramebuffer();

    console.log('Compiling shaders...')
    this.scaleProgram = createProgram(gl, quadVert, scaleFrag);
    this.thinLinesProgram = createProgram(gl, quadVert, thinLinesFrag);
    this.lumaProgram = createProgram(gl, quadVert, lumaFrag);
    this.lumaGausXProgram = createProgram(gl, quadVert, lumaGausXFrag);
    this.lumaGausYProgram = createProgram(gl, quadVert, lumaGausYFrag);
    this.lineDetectProgram = createProgram(gl, quadVert, lineDetectFrag);
    this.lineGausXProgram = createProgram(gl, quadVert, lineGausXFrag);
    this.lineGausYProgram = createProgram(gl, quadVert, lineGausYFrag);
    this.gradProgram = createProgram(gl, quadVert, gradFrag);
    this.refineProgram = createProgram(gl, quadVert, refineFrag);
    this.fxaaProgram = createProgram(gl, quadVert, fxaaFrag);
    this.drawProgram = createProgram(gl, quadVert, drawFrag);

    this.postKernelTexture = null;
    this.postKernelTexture2 = null;

    this.scale = 1.0;
    this.screenRatio = window.screen.width/window.screen.height;
    this.playerRatio = 16/9 // Assuming default player ratio is 16:9 (this is true for Bilibili and ACFun).
    this.isLoggedPaused = false;
    this.isFullscreen = true;   // Setting this to true to resize the board on start.
    console.log("Default screen aspect ratio is set to " + this.screenRatio)
}

Scaler.prototype.inputImage = function (img) {
    const gl = this.gl;

    this.inputWidth = img.width;
    this.inputHeight = img.height;

    this.inputTex = createTexture(gl, gl.LINEAR, img);
    this.inputMov = null;
}

Scaler.prototype.inputVideo = function (mov) {
    const gl = this.gl;

    const width = mov.videoWidth;
    const height = mov.videoHeight;

    this.inputWidth = width;
    this.inputHeight = height;

    let emptyPixels = new Uint8Array(width * height * 4);
    this.inputTex = createTexture(gl, gl.LINEAR, emptyPixels, width, height);
    this.inputMov = mov;
}

Scaler.prototype.resize = function (scale) {
    const gl = this.gl;

    const width = Math.round(this.inputWidth * scale);
    const height = Math.round(this.inputHeight * scale);

    gl.canvas.width = width;
    gl.canvas.height = height;

    let emptyPixels = new Uint8Array(width * height * 4);
    this.scaleTexture = createTexture(gl, gl.LINEAR, emptyPixels, width, height);
    this.scaleTexture2 = createTexture(gl, gl.LINEAR, emptyPixels, width, height);
    this.postKernelTexture = createTexture(gl, gl.LINEAR, emptyPixels, width, height);
    this.postKernelTexture2 = createTexture(gl, gl.LINEAR, emptyPixels, width, height);
}

Scaler.prototype.resizeBoard = function(originRatio, newRatio){
    if (Math.abs(originRatio-newRatio) > 0.001){    // To prevent precision-caused problem.
        console.log("Video ratio mismatched!")
        console.log("Video Ratio: " + originRatio)
        console.log("Screen ratio: " + newRatio)
        if(originRatio>newRatio){   // Not-so-wide screen, change height.
            let newHeight = newRatio/originRatio*100
            console.log("Setting new height precentage: " + newHeight + "%")
            globalBoard.style.height = newHeight + "%"
            globalBoard.style.marginTop = (100-newHeight)/3 + "%"
        } else {    // Wide screen, change width.
            let newWidth = originRatio/newRatio*100
            console.log("Setting new width precentage: " + newWidth + "%")
            globalBoard.style.width = newWidth + "%"
            globalBoard.style.marginLeft = (100-newWidth)/2 + "%"
        }
    }
}

Scaler.prototype.render = async function () {
    if (!this.inputMov || !this.inputTex) {
        return;
    }

    const gl = this.gl;
    const scalePgm = this.scaleProgram;
    const thinLinesPgm = this.thinLinesProgram;
    const lumaPgm = this.lumaProgram;
    const lumaGausXPgm = this.lumaGausXProgram;
    const lumaGausYPgm = this.lumaGausYProgram;
    const lineDetectPgm = this.lineDetectProgram;
    const lineGausXPgm = this.lineGausXProgram;
    const lineGausYPgm = this.lineGausYProgram;
    const gradPgm = this.gradProgram;
    const refinePgm = this.refineProgram;
    const fxaaPgm = this.fxaaProgram;
    const drawPgm = this.drawProgram;

    // Nasty trick to fix video quailty changing bug.
    if (gl.getError() == gl.INVALID_VALUE) {
        console.log('glError detected! Fetching new viedo tag... (This may happen due to resolution change)')
        let newMov = await getVideoTag()
        this.inputVideo(newMov)
    }

    let videoRatio = this.inputMov.videoWidth/this.inputMov.videoHeight
    if (document.fullscreenElement!=null) {  // To prevent float precision caused problem.
        if(!this.isFullscreen){
            console.log("Fullscreen detected.")
            this.resizeBoard(videoRatio, this.screenRatio)
            this.isFullscreen = true
        }
    } else {
        if(this.isFullscreen){
            console.log("Fullscreen deactivated.")
            // Reset all style.
            globalBoard.style.width = "100%"
            globalBoard.style.height = "100%"
            globalBoard.style.marginLeft = null
            globalBoard.style.marginTop = null
            // Then re-calculate board ratio.
            this.resizeBoard(videoRatio, this.playerRatio)
            this.isFullscreen = false
        }
    }

    // Check if video is paused.
    if (this.inputMov.paused){
        // If paused we stop rendering new frames.
        if(!this.isLoggedPaused){
            console.log("Video paused.")
            this.isLoggedPaused = true
        }
        return
    } else {
        // Else we continue rendering new frames.
        if(this.isLoggedPaused){
            console.log("Video continued.")
            this.isLoggedPaused = false
        }
    }

    if (this.inputMov) {
        updateTexture(gl, this.inputTex, this.inputMov);
    }

    // Automatic change scale according to original video resolution.
    // Upscaled to 1440p.
    let newScale = 1440 / this.inputMov.videoHeight;
    if (this.scale != newScale){
        this.scale = newScale;
        console.log('Setting scale to ' + this.scale);
    }

    gl.disable(gl.DEPTH_TEST);
    gl.disable(gl.STENCIL_TEST);

    gl.viewport(0, 0, gl.canvas.width, gl.canvas.height);


    // First upscaling with Bicubic interpolation.
    // Upscaling
    bindFramebuffer(gl, this.framebuffer, this.scaleTexture);

    gl.useProgram(scalePgm.program);

    bindAttribute(gl, this.quadBuffer, scalePgm.a_pos, 2);
    bindTexture(gl, this.inputTex, 0);
    gl.uniform1i(scalePgm.u_texture, 0);
    gl.uniform2f(scalePgm.u_size, this.inputWidth, this.inputHeight);

    gl.drawArrays(gl.TRIANGLES, 0, 6);


    // Scaled: scaleTexture

    // Thin Lines
    bindFramebuffer(gl, this.framebuffer, this.scaleTexture2);

    gl.useProgram(thinLinesPgm.program);

    bindAttribute(gl, this.quadBuffer, thinLinesPgm.a_pos, 2);
    bindTexture(gl, this.scaleTexture, 0);
    gl.uniform1i(thinLinesPgm.scaled_texture, 0);
    gl.uniform1f(thinLinesPgm.u_scale, this.scale);
    gl.uniform2f(thinLinesPgm.u_pt, 1.0 / gl.canvas.width, 1.0 / gl.canvas.height);

    gl.drawArrays(gl.TRIANGLES, 0, 6);

    // Scaled: scaleTexture2

    // Compute Luminance
    bindFramebuffer(gl, this.framebuffer, this.postKernelTexture);

    gl.useProgram(lumaPgm.program);

    bindAttribute(gl, this.quadBuffer, lumaPgm.a_pos, 2);
    bindTexture(gl, this.scaleTexture2, 0);
    gl.uniform1i(lumaPgm.scaled_texture, 0);
    gl.uniform2f(lumaPgm.u_pt, 1.0 / gl.canvas.width, 1.0 / gl.canvas.height);

    gl.drawArrays(gl.TRIANGLES, 0, 6);

    // Scaled: scaleTexture2 (unchanged)
    // PostKernel: postKernelTexture (luminance)

    // Compute Luminance Gaussian X
    bindFramebuffer(gl, this.framebuffer, this.postKernelTexture2);

    gl.useProgram(lumaGausXPgm.program);

    bindAttribute(gl, this.quadBuffer, lumaGausXPgm.a_pos, 2);
    bindTexture(gl, this.scaleTexture2, 0);
    bindTexture(gl, this.postKernelTexture, 1);
    gl.uniform1i(lumaGausXPgm.scaled_texture, 0);
    gl.uniform1i(lumaGausXPgm.post_kernel_texture, 1);
    gl.uniform2f(lumaGausXPgm.u_pt, 1.0 / gl.canvas.width, 1.0 / gl.canvas.height);

    gl.drawArrays(gl.TRIANGLES, 0, 6);

    // PostKernel: postKernelTexture2

    // Compute Luminance Gaussian Y
    bindFramebuffer(gl, this.framebuffer, this.postKernelTexture);

    gl.useProgram(lumaGausYPgm.program);

    bindAttribute(gl, this.quadBuffer, lumaGausYPgm.a_pos, 2);
    bindTexture(gl, this.scaleTexture2, 0);
    bindTexture(gl, this.postKernelTexture2, 1);
    gl.uniform1i(lumaGausYPgm.scaled_texture, 0);
    gl.uniform1i(lumaGausYPgm.post_kernel_texture, 1);
    gl.uniform2f(lumaGausYPgm.u_pt, 1.0 / gl.canvas.width, 1.0 / gl.canvas.height);

    gl.drawArrays(gl.TRIANGLES, 0, 6);

    // PostKernel: postKernelTexture

    // Line detect
    bindFramebuffer(gl, this.framebuffer, this.postKernelTexture2);

    gl.useProgram(lineDetectPgm.program);

    bindAttribute(gl, this.quadBuffer, lumaGausYPgm.a_pos, 2);
    bindTexture(gl, this.scaleTexture2, 0);
    bindTexture(gl, this.postKernelTexture, 1);
    gl.uniform1i(lineDetectPgm.scaled_texture, 0);
    gl.uniform1i(lineDetectPgm.post_kernel_texture, 1);
    gl.uniform2f(lineDetectPgm.u_pt, 1.0 / gl.canvas.width, 1.0 / gl.canvas.height);

    gl.drawArrays(gl.TRIANGLES, 0, 6);

    // PostKernel: postKernelTexture2

    // Compute Line Gaussian X
    bindFramebuffer(gl, this.framebuffer, this.postKernelTexture);

    gl.useProgram(lineGausXPgm.program);

    bindAttribute(gl, this.quadBuffer, lineGausXPgm.a_pos, 2);
    bindTexture(gl, this.scaleTexture2, 0);
    bindTexture(gl, this.postKernelTexture2, 1);
    gl.uniform1i(lineGausXPgm.scaled_texture, 0);
    gl.uniform1i(lineGausXPgm.post_kernel_texture, 1);
    gl.uniform2f(lineGausXPgm.u_pt, 1.0 / gl.canvas.width, 1.0 / gl.canvas.height);

    gl.drawArrays(gl.TRIANGLES, 0, 6);

    // PostKernel: postKernelTexture

    // Compute Line Gaussian Y
    bindFramebuffer(gl, this.framebuffer, this.postKernelTexture2);

    gl.useProgram(lineGausYPgm.program);

    bindAttribute(gl, this.quadBuffer, lineGausYPgm.a_pos, 2);
    bindTexture(gl, this.scaleTexture2, 0);
    bindTexture(gl, this.postKernelTexture, 1);
    gl.uniform1i(lineGausYPgm.scaled_texture, 0);
    gl.uniform1i(lineGausYPgm.post_kernel_texture, 1);
    gl.uniform2f(lineGausYPgm.u_pt, 1.0 / gl.canvas.width, 1.0 / gl.canvas.height);

    gl.drawArrays(gl.TRIANGLES, 0, 6);

    // PostKernel: postKernelTexture2

    // Compute Gradient
    bindFramebuffer(gl, this.framebuffer, this.postKernelTexture);

    gl.useProgram(gradPgm.program);

    bindAttribute(gl, this.quadBuffer, gradPgm.a_pos, 2);
    bindTexture(gl, this.scaleTexture2, 0);
    bindTexture(gl, this.postKernelTexture2, 1);
    gl.uniform1i(gradPgm.scaleFrag, 0);
    gl.uniform1i(gradPgm.post_kernel_texture, 1);
    gl.uniform2f(gradPgm.u_pt, 1.0 / gl.canvas.width, 1.0 / gl.canvas.height);

    gl.drawArrays(gl.TRIANGLES, 0, 6);

    // PostKernel: postKernelTexture

    // Refine
    bindFramebuffer(gl, this.framebuffer, this.scaleTexture);

    gl.useProgram(refinePgm.program);

    bindAttribute(gl, this.quadBuffer, refinePgm.a_pos, 2);
    bindTexture(gl, this.scaleTexture2, 0);
    bindTexture(gl, this.postKernelTexture, 1);
    gl.uniform1i(refinePgm.u_texture, 0);
    gl.uniform1i(refinePgm.u_textureTemp, 1);
    gl.uniform1f(refinePgm.u_scale, this.scale);
    gl.uniform2f(refinePgm.u_pt, 1.0 / gl.canvas.width, 1.0 / gl.canvas.height);

    gl.drawArrays(gl.TRIANGLES, 0, 6);

    // PostKernel: scaleTexture

    // FXAA
    bindFramebuffer(gl, this.framebuffer, this.scaleTexture2);

    gl.useProgram(fxaaPgm.program);

    bindAttribute(gl, this.quadBuffer, fxaaPgm.a_pos, 2);
    bindTexture(gl, this.scaleTexture, 0);
    bindTexture(gl, this.postKernelTexture, 1);
    gl.uniform1i(fxaaPgm.u_texture, 0);
    gl.uniform1i(fxaaPgm.u_textureTemp, 1);
    gl.uniform1f(fxaaPgm.u_scale, this.scale);
    gl.uniform2f(fxaaPgm.u_pt, 1.0 / gl.canvas.width, 1.0 / gl.canvas.height);

    gl.drawArrays(gl.TRIANGLES, 0, 6);

    // PostKernel: scaleTexture2

    // Draw
    bindFramebuffer(gl, null);

    gl.useProgram(drawPgm.program);

    bindAttribute(gl, this.quadBuffer, drawPgm.a_pos, 2);
    bindTexture(gl, this.scaleTexture2, 0);
    gl.uniform1i(drawPgm.u_texture, 0);

    gl.drawArrays(gl.TRIANGLES, 0, 6);
}

// Parameters.
let globalScaler = null;
let globalMovOrig = null;
let globalBoard = null;
let globalScale = 2.0;
let globalCurrentHref=window.location.href

let globalUpdateId, globalPreviousDelta = 0;
let globalFpsLimit = 30;    // Limit fps to 30 fps. Change here if you want more frames to be rendered. (But usually 30 fps is pretty enough for most anime as they are mostly done on threes.)

function getScreenRefreshRate(callback, runIndefinitely = false){
    let requestId = null;
    let callbackTriggered = false;
    runIndefinitely = runIndefinitely || false;

    if (!window.requestAnimationFrame) {
        window.requestAnimationFrame = window.mozRequestAnimationFrame || window.webkitRequestAnimationFrame;
    }
    
    let DOMHighResTimeStampCollection = [];

    let triggerAnimation = function(DOMHighResTimeStamp){
        DOMHighResTimeStampCollection.unshift(DOMHighResTimeStamp);
        
        if (DOMHighResTimeStampCollection.length > 10) {
            let t0 = DOMHighResTimeStampCollection.pop();
            let fps = Math.floor(1000 * 10 / (DOMHighResTimeStamp - t0));

            if(!callbackTriggered){
                callback.call(undefined, fps, DOMHighResTimeStampCollection);
            }

            if(runIndefinitely){
                callbackTriggered = false;
            }else{
                callbackTriggered = true;
            }
        }
    
        requestId = window.requestAnimationFrame(triggerAnimation);
    };
    
    window.requestAnimationFrame(triggerAnimation);

    // Stop after half second if it shouldn't run indefinitely
    if(!runIndefinitely){
        window.setTimeout(function(){
            window.cancelAnimationFrame(requestId);
            requestId = null;
        }, 500);
    }
}

async function injectCanvas() {
    console.log('Injecting canvas...')

    // Create a canvas (since video tag do not support WebGL).
    globalMovOrig = await getVideoTag()

    let div = globalMovOrig.parentElement
    if(window.location.href.toLowerCase().includes("bilibili.com")){
        console.log("Working on bilibili.com.")
        while(div.className!="bilibili-player-video") {
            await new Promise(r => setTimeout(r, 500));
        }
        div = globalMovOrig.parentElement
    }
    div.style.backgroundColor = "black" // Patch for ACFun.

    if (!globalBoard){
        console.log("globalBoard not exists. Creating new one.")

        globalBoard = document.createElement('canvas');
        // Make it visually fill the positioned parent
        globalBoard.style.width = '100%';
        globalBoard.style.height = '100%';
        // ...then set the internal size to match
        globalBoard.width = globalBoard.offsetWidth;
        globalBoard.height = globalBoard.offsetHeight;
        // Add it back to the div where contains the video tag we use as input.
    }
    console.log("Adding new canvas.")
    div.appendChild(globalBoard)

    // Hide original video tag, we don't need it to be displayed.
    globalMovOrig.style.display = 'none'
}

async function getVideoTag() {
    while(document.getElementsByTagName("video").length <= 0) {
        await new Promise(r => setTimeout(r, 500));
    }
    
    globalMovOrig=document.getElementsByTagName("video")[0]
    
    globalMovOrig.addEventListener('loadedmetadata', function () {
        globalScaler = !globalScaler?new Scaler(globalBoard.getContext('webgl')):globalScaler;
        globalScaler.inputVideo(globalMovOrig);
        globalScaler.resize(globalScale);
        globalScaler.scale = globalScale;
    }, true);
    globalMovOrig.addEventListener('error', function () {
        alert("Can't get video, sorry.");
    }, true);

    return globalMovOrig
}

async function doFilter() {
    // Setting our parameters for filtering.
    // scale: multipliers that we need to zoom in.
    // Here's the fun part. We create a pixel shader for our canvas
    console.log('Enabling filter...')

    // Auto detect refresh rate.
    getScreenRefreshRate(function(screenRefreshRate){
        globalFpsLimit = Math.floor((screenRefreshRate+1) / 2);
        globalFpsLimit = globalFpsLimit<30?30:globalFpsLimit;   // If refresh rate is below 30 fps we round it up to 30.
        console.log("Framerate limit is set to " + globalFpsLimit + " FPS.");
    });

    // Do it! Filter it! Profit!
    async function render(currentDelta) {
        // Notice that limiting the framerate here did increase performance.
        globalUpdateId = requestAnimationFrame(render);
        let delta = currentDelta - globalPreviousDelta;

        if (globalFpsLimit && delta < 1000/globalFpsLimit){
            return;
        }

        if (globalScaler) {
            globalScaler.render();
        }

        if (globalCurrentHref!=window.location.href){
            console.log("Page changed!")
            await injectCanvas()
            globalCurrentHref=window.location.href
        }

        globalPreviousDelta = currentDelta
    }

    globalUpdateId = requestAnimationFrame(render);
}

(async function () {
    console.log('Bilibili_Anime4K starting...')
    await injectCanvas()
    doFilter()
})();