function constructGrid(sizesArr){
for(let x = 0; x<gridDivsX-sizesArr[0]+1; x++){
for(let y = 0; y<gridDivsY-sizesArr[1]+1; y++){
let xdim = (rndim(1,sizesArr[0]))
let ydim = (rndim(1,sizesArr[1]))
let fits = (x + xdim > gridDivsX || y + ydim > gridDivsY)? false : true
if(fits){
for(let xc = x; xc < x + xdim; xc++){
for(let yc = y; yc < y + ydim; yc++){
if(bools[xc][yc] == false){
fits = false
}}}}
if(fits){
for(let xc = x; xc < x + xdim; xc++){
for(let yc = y; yc < y + ydim; yc++){
bools[xc][yc] = false
}
}
rectInfo.push({posX:x, posY:y, dimX:xdim, dimY:ydim})
}
}
}
}