/// scr_gridCollisionLine(startX, startY, endX, endY, tileType);
// REQUIRED MACROS  TILESIZE => size of tiles and TILESIZE1 => one pixel less!
/// @param startx
/// @param starty
/// @param endx
/// @param endy
/// @param tiletype

var sx = argument0;
var sy = argument1;
var tx = argument2;
var ty = argument3;
var tileType = argument4;

// === scr_tileCheck Start + Endpoints === //
if (scr_tileCheck(sx, sy, tileType) || scr_tileCheck(tx, ty, tileType)) return true;

// === Iterate X-Axis === //: scr_tileCheck only precise axis intersections
var deltax=abs(tx div TILESIZE - sx div TILESIZE);
if deltax>0{// if start + end not in the same cell
var xslope = ((ty-sy)/(tx-sx)),// Determine Linear Equation Slope, solving y(x);
dirx = sign(tx-sx),// get direction along xaxis
cx = (sx&~TILESIZE1)+TILESIZE1*(dirx>0),// From Start X get nearest intersection with grid - LEFT or RIGHT (does not escape the start cell);
cy = sy+xslope*(cx-sx);// Mathematically determine the appropriate Y coordinate
if scr_tileCheck(cx, cy, tileType) return true;

repeat(deltax-1){// repeat as often as there are as of yet unchecked cells between Start X and End X;
cx+=TILESIZE*dirx;// If no collision move along X on by given grid_dimensions of 32px;
        cy+=xslope*TILESIZE*dirx;
if scr_tileCheck(cx, cy, tileType) return true;
    }
}

// === Iterate X-Axis === //: scr_tileCheck only precise axis intersections
var deltay=abs((ty div TILESIZE) - (sy div TILESIZE));
if deltay>0{
    var yslope=((tx-sx)/(ty-sy)),
diry = sign(ty-sy),
cy=(sy&~TILESIZE1)+TILESIZE1*(diry>0),
cx=sx+yslope*(cy-sy);
if scr_tileCheck(cx, cy, tileType) return true;

    repeat(deltay-1){
        cy+=TILESIZE*diry;
        cx+=yslope*TILESIZE*diry;
if scr_tileCheck(cx, cy, tileType) return true;
    }
}

return false; // if all checks passed!