diff options
Diffstat (limited to 'node_modules/chroma-js/src/conversions/rgb2hsi.coffee')
| -rw-r--r-- | node_modules/chroma-js/src/conversions/rgb2hsi.coffee | 25 |
1 files changed, 25 insertions, 0 deletions
diff --git a/node_modules/chroma-js/src/conversions/rgb2hsi.coffee b/node_modules/chroma-js/src/conversions/rgb2hsi.coffee new file mode 100644 index 0000000000..f074d0d9b7 --- /dev/null +++ b/node_modules/chroma-js/src/conversions/rgb2hsi.coffee @@ -0,0 +1,25 @@ + +rgb2hsi = () -> + ### + borrowed from here: + http://hummer.stanford.edu/museinfo/doc/examples/humdrum/keyscape2/rgb2hsi.cpp + ### + [r,g,b] = unpack arguments + TWOPI = Math.PI*2 + r /= 255 + g /= 255 + b /= 255 + min = Math.min(r,g,b) + i = (r+g+b) / 3 + s = 1 - min/i + if s == 0 + h = 0 + else + h = ((r-g)+(r-b)) / 2 + h /= Math.sqrt((r-g)*(r-g) + (r-b)*(g-b)) + h = Math.acos(h) + if b > g + h = TWOPI - h + h /= TWOPI + [h*360,s,i] + |