Skip to content
New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Jump to bottom

Color blending functions with transparency. #1704

Merged
merged 4 commits into from
Dec 8, 2013
Merged

Color blending functions with transparency. #1704

Show file tree
Hide file tree
Changes from all commits
Commits
Show all changes
4 commits
Select commit Hold shift + click to select a range
61ff14b
color-blending-with-transparency: initial implementation
seven-phases-max Nov 29, 2013
28e5295
color-blending-with-transparency: fixed negative result alpha handlin…
seven-phases-max Dec 1, 2013
f835b17
color-blending-with-transparency: removed debug log statement mistake…
seven-phases-max Dec 3, 2013
1f57576
color-blending-with-transparency: changed func dispatch method from c…
seven-phases-max Dec 7, 2013
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
132 changes: 72 additions & 60 deletions lib/less/functions.js
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -367,66 +367,6 @@ tree.functions = {
_isa: function (n, Type) {
return (n instanceof Type) ? tree.True : tree.False;
},

/* Blending modes */

multiply: function(color1, color2) {
var r = color1.rgb[0] * color2.rgb[0] / 255;
var g = color1.rgb[1] * color2.rgb[1] / 255;
var b = color1.rgb[2] * color2.rgb[2] / 255;
return this.rgb(r, g, b);
},
screen: function(color1, color2) {
var r = 255 - (255 - color1.rgb[0]) * (255 - color2.rgb[0]) / 255;
var g = 255 - (255 - color1.rgb[1]) * (255 - color2.rgb[1]) / 255;
var b = 255 - (255 - color1.rgb[2]) * (255 - color2.rgb[2]) / 255;
return this.rgb(r, g, b);
},
overlay: function(color1, color2) {
var r = color1.rgb[0] < 128 ? 2 * color1.rgb[0] * color2.rgb[0] / 255 : 255 - 2 * (255 - color1.rgb[0]) * (255 - color2.rgb[0]) / 255;
var g = color1.rgb[1] < 128 ? 2 * color1.rgb[1] * color2.rgb[1] / 255 : 255 - 2 * (255 - color1.rgb[1]) * (255 - color2.rgb[1]) / 255;
var b = color1.rgb[2] < 128 ? 2 * color1.rgb[2] * color2.rgb[2] / 255 : 255 - 2 * (255 - color1.rgb[2]) * (255 - color2.rgb[2]) / 255;
return this.rgb(r, g, b);
},
softlight: function(color1, color2) {
var t = color2.rgb[0] * color1.rgb[0] / 255;
var r = t + color1.rgb[0] * (255 - (255 - color1.rgb[0]) * (255 - color2.rgb[0]) / 255 - t) / 255;
t = color2.rgb[1] * color1.rgb[1] / 255;
var g = t + color1.rgb[1] * (255 - (255 - color1.rgb[1]) * (255 - color2.rgb[1]) / 255 - t) / 255;
t = color2.rgb[2] * color1.rgb[2] / 255;
var b = t + color1.rgb[2] * (255 - (255 - color1.rgb[2]) * (255 - color2.rgb[2]) / 255 - t) / 255;
return this.rgb(r, g, b);
},
hardlight: function(color1, color2) {
var r = color2.rgb[0] < 128 ? 2 * color2.rgb[0] * color1.rgb[0] / 255 : 255 - 2 * (255 - color2.rgb[0]) * (255 - color1.rgb[0]) / 255;
var g = color2.rgb[1] < 128 ? 2 * color2.rgb[1] * color1.rgb[1] / 255 : 255 - 2 * (255 - color2.rgb[1]) * (255 - color1.rgb[1]) / 255;
var b = color2.rgb[2] < 128 ? 2 * color2.rgb[2] * color1.rgb[2] / 255 : 255 - 2 * (255 - color2.rgb[2]) * (255 - color1.rgb[2]) / 255;
return this.rgb(r, g, b);
},
difference: function(color1, color2) {
var r = Math.abs(color1.rgb[0] - color2.rgb[0]);
var g = Math.abs(color1.rgb[1] - color2.rgb[1]);
var b = Math.abs(color1.rgb[2] - color2.rgb[2]);
return this.rgb(r, g, b);
},
exclusion: function(color1, color2) {
var r = color1.rgb[0] + color2.rgb[0] * (255 - color1.rgb[0] - color1.rgb[0]) / 255;
var g = color1.rgb[1] + color2.rgb[1] * (255 - color1.rgb[1] - color1.rgb[1]) / 255;
var b = color1.rgb[2] + color2.rgb[2] * (255 - color1.rgb[2] - color1.rgb[2]) / 255;
return this.rgb(r, g, b);
},
average: function(color1, color2) {
var r = (color1.rgb[0] + color2.rgb[0]) / 2;
var g = (color1.rgb[1] + color2.rgb[1]) / 2;
var b = (color1.rgb[2] + color2.rgb[2]) / 2;
return this.rgb(r, g, b);
},
negation: function(color1, color2) {
var r = 255 - Math.abs(255 - color2.rgb[0] - color1.rgb[0]);
var g = 255 - Math.abs(255 - color2.rgb[1] - color1.rgb[1]);
var b = 255 - Math.abs(255 - color2.rgb[2] - color1.rgb[2]);
return this.rgb(r, g, b);
},
tint: function(color, amount) {
return this.mix(this.rgb(255,255,255), color, amount);
},
Expand Down Expand Up @@ -637,6 +577,78 @@ for(var i = 0; i < mathFunctions.length; i++) {
tree.functions[mathFunctions[i].name] = createMathFunction(mathFunctions[i].name, mathFunctions[i].unit);
}

// Color Blending
// ref: http://www.w3.org/TR/compositing-1

function colorBlend(mode, color1, color2) {
var ab = color1.alpha, cb, // backdrop
as = color2.alpha, cs, // source
ar, cr, r = []; // result

ar = as + ab * (1 - as);
for (var i = 0; i < 3; i++) {
cb = color1.rgb[i] / 255;
cs = color2.rgb[i] / 255;
cr = mode(cb, cs);
if (ar) {
cr = (as * cs + ab * (cb
- as * (cb + cs - cr))) / ar;
}
r[i] = cr * 255;
}

return new(tree.Color)(r, ar);
}

var colorBlendMode = {
multiply: function(cb, cs) {
return cb * cs;
},
screen: function(cb, cs) {
return cb + cs - cb * cs;
},
overlay: function(cb, cs) {
cb *= 2;
return (cb <= 1)
? colorBlendMode.multiply(cb, cs)
: colorBlendMode.screen(cb - 1, cs);
},
softlight: function(cb, cs) {
var d = 1, e = cb;
if (cs > 0.5) {
e = 1;
d = (cb > 0.25) ? Math.sqrt(cb)
: ((16 * cb - 12) * cb + 4) * cb;
}
return cb - (1 - 2 * cs) * e * (d - cb);
},
hardlight: function(cb, cs) {
return colorBlendMode.overlay(cs, cb);
},
difference: function(cb, cs) {
return Math.abs(cb - cs);
},
exclusion: function(cb, cs) {
return cb + cs - 2 * cb * cs;
},

// non-w3c functions:
average: function(cb, cs) {
return (cb + cs) / 2;
},
negation: function(cb, cs) {
return 1 - Math.abs(cb + cs - 1);
}
};

function colorBlendInit() {
for (var f in colorBlendMode) {
tree.functions[f] = colorBlend.bind(null, colorBlendMode[f]);
}
} colorBlendInit();

// ~ End of Color Blending

function hsla(color) {
return tree.functions.hsla(color.h, color.s, color.l, color.a);
}
Expand Down
2 changes: 1 addition & 1 deletion test/css/functions.css
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -126,7 +126,7 @@
multiply: #ed0000;
screen: #f600f6;
overlay: #ed0000;
softlight: #ff0000;
softlight: #fa0000;
hardlight: #0000ed;
difference: #f600f6;
exclusion: #f600f6;
Expand Down