adds luminosity function

This commit is contained in:
Francisco Dans 2015-01-22 17:33:48 +01:00
parent 1696005d77
commit 7be487755a

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@ -58,7 +58,8 @@ torque_filters.prototype = {
var ctx = this._ctx; var ctx = this._ctx;
var colored = ctx.getImageData(0, 0, this._canvas.width, this._canvas.height); var colored = ctx.getImageData(0, 0, this._canvas.width, this._canvas.height);
this._colorize(colored.data, this._grad); //this._colorize(colored.data, this._grad);
this._brilliance(colored.data);
ctx.putImageData(colored, 0, 0); ctx.putImageData(colored, 0, 0);
return this; return this;
@ -74,6 +75,68 @@ torque_filters.prototype = {
pixels[i - 1] = gradient[j + 2]; pixels[i - 1] = gradient[j + 2];
} }
} }
},
_brilliance: function(pixels){
function hslToRgb(h, s, l){
var r, g, b;
if(s == 0){
r = g = b = l; // achromatic
}else{
var hue2rgb = function hue2rgb(p, q, t){
if(t < 0) t += 1;
if(t > 1) t -= 1;
if(t < 1/6) return p + (q - p) * 6 * t;
if(t < 1/2) return q;
if(t < 2/3) return p + (q - p) * (2/3 - t) * 6;
return p;
}
var q = l < 0.5 ? l * (1 + s) : l + s - l * s;
var p = 2 * l - q;
r = hue2rgb(p, q, h + 1/3);
g = hue2rgb(p, q, h);
b = hue2rgb(p, q, h - 1/3);
}
return [Math.round(r * 255), Math.round(g * 255), Math.round(b * 255)];
}
function rgbToHsl(r, g, b) {
r /= 255, g /= 255, b /= 255;
var max = Math.max(r, g, b), min = Math.min(r, g, b);
var h, s, l = (max + min) / 2;
if(max == min){
h = s = 0; // achromatic
} else {
var d = max - min;
s = l > 0.5 ? d / (2 - max - min) : d / (max + min);
switch(max){
case r: h = (g - b) / d ; break;
case g: h = 2 + ( (b - r) / d); break;
case b: h = 4 + ( (r - g) / d); break;
}
h*=60;
if (h < 0) h +=360;
}
return([h, s, l]);
}
var refColor = rgbToHsl(189, 100, 194);
for (var i = 3; i < pixels.length; i += 4) {
var opacity = pixels[i]/255;
if (opacity > 0) {
var colorWithBrilliance = hslToRgb(refColor[0]/360, refColor[1], opacity);
// pixels[i] = 255;
pixels[i - 3] = colorWithBrilliance[0];
pixels[i - 2] = colorWithBrilliance[1];
pixels[i - 1] = colorWithBrilliance[2];
}
}
} }
}; };