shader_type canvas_item; // Color space code from // HSV: https://godotshaders.com/shader/hsv-adjustment/ // LAB/XYZ: https://gist.github.com/msbarry/cd98f928542f5152111a // Note: don't use the XYZ space, but sources use it to convert to LAB uniform sampler2D screen_texture : hint_screen_texture; uniform float param : hint_range(0.0, 255.0, 1.0); uniform float param2 : hint_range(0.0, 255.0, 1.0); vec3 rgb2hsv(vec3 c) { vec4 K = vec4(0.0, -1.0 / 3.0, 2.0 / 3.0, -1.0); vec4 p = mix(vec4(c.bg, K.wz), vec4(c.gb, K.xy), step(c.b, c.g)); vec4 q = mix(vec4(p.xyw, c.r), vec4(c.r, p.yzx), step(p.x, c.r)); float d = q.x - min(q.w, q.y); float e = 1.0e-10; return vec3(abs(q.z + (q.w - q.y) / (6.0 * d + e)), d / (q.x + e), q.x); } vec3 hsv2rgb(vec3 c) { vec4 K = vec4(1.0, 2.0 / 3.0, 1.0 / 3.0, 3.0); vec3 p = abs(fract(c.xxx + K.xyz) * 6.0 - K.www); return c.z * mix(K.xxx, clamp(p - K.xxx, 0.0, 1.0), c.y); } vec3 rgb2xyz(vec3 c) { float R = ((c.r > 0.04045) ? pow((( c.r + 0.055 ) / 1.055), 2.4) : (c.r / 12.92)) * 100.0; float G = ((c.g > 0.04045) ? pow((( c.g + 0.055 ) / 1.055), 2.4) : (c.g / 12.92)) * 100.0; float B = ((c.b > 0.04045) ? pow((( c.b + 0.055 ) / 1.055), 2.4) : (c.b / 12.92)) * 100.0; float X = R * 0.4124 + G * 0.3576 + B * 0.1805; float Y = R * 0.2126 + G * 0.7152 + B * 0.0722; float Z = R * 0.0193 + G * 0.1192 + B * 0.9505; return vec3(X, Y, Z); } vec3 xyz2rgb(vec3 c) { float X = c.x / 100.0; float Y = c.y / 100.0; float Z = c.z / 100.0; float R = X * 3.2406 + Y * -1.5372 + Z * -0.4986; float G = X * -0.9689 + Y * 1.8758 + Z * 0.0415; float B = X * 0.0557 + Y * -0.2040 + Z * 1.0570; R = ((R > 0.0031308) ? (1.055 * ( pow( R, 1./2.4 ) ) - 0.055) : (12.92 * R)); G = ((G > 0.0031308) ? (1.055 * ( pow( G, 1./2.4 ) ) - 0.055) : (12.92 * G)); B = ((B > 0.0031308) ? (1.055 * ( pow( B, 1./2.4 ) ) - 0.055) : (12.92 * B)); return vec3(R, G, B); } vec3 xyz2lab(vec3 c) { float X = c.x / 95.047; float Y = c.y / 100.0; float Z = c.z / 108.883; X = ((X > 0.008856) ? (pow( X, 1./3.)) : (( 7.787 * X ) + ( 16./116.))); Y = ((Y > 0.008856) ? (pow( Y, 1./3.)) : (( 7.787 * Y ) + ( 16./116.))); Z = ((Z > 0.008856) ? (pow( Z, 1./3.)) : (( 7.787 * Z ) + ( 16./116.))); float L = ( 116. * Y ) - 16.; float a = 500. * ( X - Y ); float b = 200. * ( Y - Z ); return vec3(L, a, b); } vec3 lab2xyz(vec3 c) { float L = c.x; float a = c.y; float b = c.z; float Y = ( L + 16. ) / 116.; float X = a / 500. + Y; float Z = Y - b / 200.; Y = ((pow(Y,3.) > 0.008856) ? (pow(Y,3.)) : ((Y - 16. / 116.) / 7.787)); X = ((pow(X,3.) > 0.008856) ? (pow(X,3.)) : ((X - 16. / 116.) / 7.787)); Z = ((pow(Z,3.) > 0.008856) ? (pow(Z,3.)) : ((Z - 16. / 116.) / 7.787)); float ref_X = 95.047; float ref_Y = 100.0; float ref_Z = 108.883; return vec3(ref_X * X, ref_Y * Y, ref_Z * Z); } vec3 band_colors(vec3 rgb) { return round(rgb * param) / param; } vec3 band_colors_preserve_hue_lum(vec3 rgb, float ncolors) { vec3 hsv = rgb2hsv(rgb); hsv.r = round(hsv.r * ncolors) / ncolors; vec3 lab = xyz2lab(rgb2xyz(rgb)); lab.r = round(lab.r * (ncolors / 100.0)) / (ncolors / 100.0); // Into HSV vec2 sv = rgb2hsv(xyz2rgb(lab2xyz(lab))).gb; hsv.gb = sv; return hsv2rgb(hsv); } uniform float scale = 2.0; uniform int grid = 5; vec3 band_dither(vec3 rgb, vec2 uv) { uv *= (1.0 / scale); int x = int(mod(uv.x, float(grid))) + 1; int y = int(mod(uv.y, float(grid))) + 1; vec3 hsv = rgb2hsv(rgb); int g = int(round(mix(float(grid), float(2), fract(hsv.r * param)))); if (x % g == 0 && y % g == 0) { hsv.r = ceil(hsv.r * param) / param; } else { hsv.r = floor(hsv.r * param) / param; } vec3 lab = xyz2lab(rgb2xyz(rgb)); if (x % g == 0 && y % g == 0) { lab.r = ceil(lab.r * (param / 100.0)) / (param / 100.0); } else { lab.r = floor(lab.r * (param / 100.0)) / (param / 100.0); } // Into HSV vec2 sv = rgb2hsv(xyz2rgb(lab2xyz(lab))).gb; hsv.gb = sv; return hsv2rgb(hsv); } uniform float anim_period : hint_range(0.1, 5, 0.01); void fragment() { vec3 rgb = texture(screen_texture, SCREEN_UV).rgb; vec3 band1 = band_colors_preserve_hue_lum(rgb, param); vec3 band2 = band_colors_preserve_hue_lum(rgb, param2); float weight = mod(TIME, anim_period) / anim_period; float double_weight = mod(TIME, anim_period*2.0) / (anim_period*2.0); weight = double_weight > 0.5 ? (1.-weight) : weight; vec3 mixed = mix(band1, band2, weight); COLOR.rgb = mixed; //COLOR.rgb = banded_nostalgia; }