diff options
Diffstat (limited to 'node_modules/chroma-js/src/conversions/hsi2rgb.coffee')
| -rw-r--r-- | node_modules/chroma-js/src/conversions/hsi2rgb.coffee | 30 |
1 files changed, 30 insertions, 0 deletions
diff --git a/node_modules/chroma-js/src/conversions/hsi2rgb.coffee b/node_modules/chroma-js/src/conversions/hsi2rgb.coffee new file mode 100644 index 0000000000..3c8afe97a2 --- /dev/null +++ b/node_modules/chroma-js/src/conversions/hsi2rgb.coffee @@ -0,0 +1,30 @@ + +hsi2rgb = (h,s,i) -> + ### + borrowed from here: + http://hummer.stanford.edu/museinfo/doc/examples/humdrum/keyscape2/hsi2rgb.cpp + ### + [h,s,i] = unpack arguments + + # normalize hue + #h += 360 if h < 0 + #h -= 360 if h > 360 + h /= 360 + if h < 1/3 + b = (1-s)/3 + r = (1+s*cos(TWOPI*h)/cos(PITHIRD-TWOPI*h))/3 + g = 1 - (b+r) + else if h < 2/3 + h -= 1/3 + r = (1-s)/3 + g = (1+s*cos(TWOPI*h)/cos(PITHIRD-TWOPI*h))/3 + b = 1 - (r+g) + else + h -= 2/3 + g = (1-s)/3 + b = (1+s*cos(TWOPI*h)/cos(PITHIRD-TWOPI*h))/3 + r = 1 - (g+b) + r = limit i*r*3 + g = limit i*g*3 + b = limit i*b*3 + [r*255,g*255,b*255] |