displacement-map
Version:
Mid-point displacement map
1 lines • 681 B
JavaScript
;var buf8,roughness;function clamp(num){return Math.min(Math.max(num,0),255)}function variance(){return-128+Math.random()*255}function generateMidpoint(start,end){var length=end-start;var avg=(buf8[end]+buf8[start])/2;var displacement=.5*variance()*roughness*(length/buf8.length-1);buf8[start+length/2]=clamp(avg*1+displacement)}function generate(step){if(!step){step=1}var size=(buf8.length-1)*step;for(var i=0;i<buf8.length-1;i+=size){generateMidpoint(i,i+size)}if(size>2){generate(step*.5);return}done()}self.addEventListener("message",function(event){buf8=event.data.buf8;roughness=event.data.roughness||1;generate()});function done(){self.postMessage({buf8:buf8})}