@Miscreant suggested alternate triangles code for you:
var t_coords = [86, 269];
Triangle(t_coords[0] + 47, t_coords[1], t_coords[0], t_coords[1] + 48, t_coords[0] + 96, t_coords[1] + 48, White);
Triangle(t_coords[0] + 47, t_coords[1] + 1, t_coords[0] + 2, t_coords[1] + 47, t_coords[0] + 94, t_coords[1] + 47, Black);
Triangle(t_coords[0] + 47, t_coords[1] + 8, t_coords[0] + 12, t_coords[1] + 44, t_coords[0] + 84, t_coords[1] + 44, White);
Triangle(t_coords[0] + 47, t_coords[1] + 9, t_coords[0] + 14, t_coords[1] + 43, t_coords[0] + 82, t_coords[1] + 43, Black);
if (LVL1C === true){TSE.blit(t_coords[0] + 32, t_coords[1] + 11);}
if (LVL2C === true){TSW.blit(t_coords[0] + 48, t_coords[1] + 11);}
if (LVL3C === true){TSE.blit(t_coords[0] + 16, t_coords[1] + 27);}
if (LVL4C === true){TNW.blit(t_coords[0] + 32, t_coords[1] + 27);}
if (LVL5C === true){TSE.blit(t_coords[0] + 32, t_coords[1] + 27);}
if (LVL6C === true){TNW.blit(t_coords[0] + 48, t_coords[1] + 27);}
if (LVL7C === true){TSE.blit(t_coords[0] + 48, t_coords[1] + 27);}
if (LVL8C === true){TSW.blit(t_coords[0] + 64, t_coords[1] + 27);}
changes:
1. I've floored the coordinates
2. I've put the coordinates into an array so you only have one variable to remember and update
3. as I assume the dimensions don't change I've used just one coordinate pair then added some known offsets in the drawing function calls.