2024-10-11 17:11:32 +07:00

97 lines
2.9 KiB
GLSL

precision mediump float;
uniform sampler2D data;
uniform vec2 iResolution;
const int FILTER_UNSHARP_MASKING = 1;
// const int FILTER_CAS = 2;
// constrast = 0.8
const float CAS_CONTRAST_PEAK = 0.8 * -3.0 + 8.0;
// Luminosity factor
const vec3 LUMINOSITY_FACTOR = vec3(0.2126, 0.7152, 0.0722);
uniform int filterId;
uniform float sharpenFactor;
uniform float brightness;
uniform float contrast;
uniform float saturation;
vec3 clarityBoost(sampler2D tex, vec2 coord, vec3 e) {
vec2 texelSize = 1.0 / iResolution.xy;
// Load a collection of samples in a 3x3 neighorhood, where e is the current pixel.
// a b c
// d e f
// g h i
vec3 a = texture2D(tex, coord + texelSize * vec2(-1, 1)).rgb;
vec3 b = texture2D(tex, coord + texelSize * vec2(0, 1)).rgb;
vec3 c = texture2D(tex, coord + texelSize * vec2(1, 1)).rgb;
vec3 d = texture2D(tex, coord + texelSize * vec2(-1, 0)).rgb;
vec3 f = texture2D(tex, coord + texelSize * vec2(1, 0)).rgb;
vec3 g = texture2D(tex, coord + texelSize * vec2(-1, -1)).rgb;
vec3 h = texture2D(tex, coord + texelSize * vec2(0, -1)).rgb;
vec3 i = texture2D(tex, coord + texelSize * vec2(1, -1)).rgb;
// USM
if (filterId == FILTER_UNSHARP_MASKING) {
vec3 gaussianBlur = (a + c + g + i) * 1.0 + (b + d + f + h) * 2.0 + e * 4.0;
gaussianBlur /= 16.0;
// Return edge detection
return e + (e - gaussianBlur) * sharpenFactor / 3.0;
}
// CAS
// Soft min and max.
// a b c b
// d e f * 0.5 + d e f * 0.5
// g h i h
// These are 2.0x bigger (factored out the extra multiply).
vec3 minRgb = min(min(min(d, e), min(f, b)), h);
minRgb += min(min(a, c), min(g, i));
vec3 maxRgb = max(max(max(d, e), max(f, b)), h);
maxRgb += max(max(a, c), max(g, i));
// Smooth minimum distance to signal limit divided by smooth max.
vec3 reciprocalMaxRgb = 1.0 / maxRgb;
vec3 amplifyRgb = clamp(min(minRgb, 2.0 - maxRgb) * reciprocalMaxRgb, 0.0, 1.0);
// Shaping amount of sharpening.
amplifyRgb = inversesqrt(amplifyRgb);
vec3 weightRgb = -(1.0 / (amplifyRgb * CAS_CONTRAST_PEAK));
vec3 reciprocalWeightRgb = 1.0 / (4.0 * weightRgb + 1.0);
// 0 w 0
// Filter shape: w 1 w
// 0 w 0
vec3 window = b + d + f + h;
vec3 outColor = clamp((window * weightRgb + e) * reciprocalWeightRgb, 0.0, 1.0);
return mix(e, outColor, sharpenFactor / 2.0);
}
void main() {
vec2 uv = gl_FragCoord.xy / iResolution.xy;
// Get current pixel
vec3 color = texture2D(data, uv).rgb;
// Clarity boost
color = sharpenFactor > 0.0 ? clarityBoost(data, uv, color) : color;
// Saturation
color = saturation != 1.0 ? mix(vec3(dot(color, LUMINOSITY_FACTOR)), color, saturation) : color;
// Contrast
color = contrast * (color - 0.5) + 0.5;
// Brightness
color = brightness * color;
gl_FragColor = vec4(color, 1.0);
}