| #extension GL_OES_EGL_image_external : require |
| |
| precision mediump float; |
| uniform samplerExternalOES texUnit; |
| uniform float opacity; |
| uniform float saturation; |
| uniform float gamma; |
| varying vec2 UV; |
| |
| vec3 rgb2hsl(vec3 rgb) |
| { |
| float e = 1.0e-7; |
| |
| vec4 p = rgb.g < rgb.b ? vec4(rgb.bg, -1.0, 2.0 / 3.0) : vec4(rgb.gb, 0.0, -1.0 / 3.0); |
| vec4 q = rgb.r < p.x ? vec4(p.xyw, rgb.r) : vec4(rgb.r, p.yzx); |
| |
| float v = q.x; |
| float c = v - min(q.w, q.y); |
| float h = abs((q.w - q.y) / (6.0 * c + e) + q.z); |
| float l = v - c * 0.5; |
| float s = c / (1.0 - abs(2.0 * l - 1.0) + e); |
| return clamp(vec3(h, s, l), 0.0, 1.0); |
| } |
| |
| vec3 hsl2rgb(vec3 hsl) |
| { |
| vec3 h = vec3(hsl.x * 6.0); |
| vec3 p = abs(h - vec3(3.0, 2.0, 4.0)); |
| vec3 q = 2.0 - p; |
| |
| vec3 rgb = clamp(vec3(p.x - 1.0, q.yz), 0.0, 1.0); |
| float c = (1.0 - abs(2.0 * hsl.z - 1.0)) * hsl.y; |
| return (rgb - vec3(0.5)) * c + hsl.z; |
| } |
| |
| void main() |
| { |
| vec4 color = texture2D(texUnit, UV); |
| vec3 hsl = rgb2hsl(color.xyz); |
| vec3 rgb = pow(hsl2rgb(vec3(hsl.x, hsl.y * saturation, hsl.z * opacity)), vec3(gamma)); |
| gl_FragColor = vec4(rgb, 1.0); |
| } |
