/**

* floodFillOnImageData ImageData를 위한 floodFill. 32비트로 동작. 8비트보다 33%보다 빠르다!

* @param  {ImageData} imageData

* @param  {int} xf start x

* @param  {int} yf start y

* @param  {Array} colorset  [INT r, INT g, INT b, FLOAT alpha]

* @return {Boolean}           true:success , false:fail

*/

 function floodFillOnImageData(imageData,xf,yf,colorset){

var w = imageData.width;

var h = imageData.height;

if(xf < 0 || xf > w || yf < 0 ||yf > h){

console.error("wrong x,y");

return false;

}

if(isNaN(colorset[0])||isNaN(colorset[1])||isNaN(colorset[2])||isNaN(colorset[3]) || colorset[3] > 1){

console.error("wrong colorset");

return false;

}

let data32 = new Uint32Array(imageData.data.buffer);

let point ={x:xf,y:yf}

let x0 = w;

let y0 = h;

let colorData = [ colorset[0], colorset[1], colorset[2], colorset[3]*255 ];

let uint8bytes = Uint8Array.from(colorData);

let data32RGBA_rp = new Uint32Array(uint8bytes.buffer)[0];

let data32RGBA_sh = data32[(point.y*w+point.x)];

//-- 이미 같은 색으로 칠해져있다면 무시

if(data32RGBA_rp==data32RGBA_sh){

console.log("skip: start color is data32RGBA_rp==data32RGBA_sh");

return false;

}

let p1 = -1;

let stack = [];

let currPt = null;

let t32 = null;

let data32RGBA_cr = null;

stack.push(point);

while(stack.length > 0) {

currPt = stack.pop();

p1 = (currPt.y*w+currPt.x);

if(data32[p1] !== data32RGBA_sh){

continue;

}

data32[p1] = data32RGBA_rp

if(currPt.x < w-1) stack.push({x:currPt.x + 1, y:currPt.y}); // Fill the east neighbour

if(currPt.y < h-1) stack.push({x:currPt.x, y:currPt.y + 1}); // Fill the south neighbour

if(currPt.x > 0) stack.push({x:currPt.x - 1, y:currPt.y}); // Fill the west neighbour

if(currPt.y > 0) stack.push({x:currPt.x, y:currPt.y - 1}); // Fill the north neighbour

}

// imageData.data.set(data32.buffer);

return true;

}