§ Программный код
SCREEN 13
DATA 1,1,1,1,1,1,1,1
DATA 1,1,0,0,1,0,0,1
DATA 1,0,0,0,1,0,0,1
DATA 1,0,0,0,0,0,0,1
DATA 1,0,0,0,0,0,0,1
DATA 1,0,0,0,0,0,0,1
DATA 1,0,0,2,0,0,0,1
DATA 1,1,1,1,1,1,1,1
DIM map(8, 8)
FOR i = 1 TO 8
FOR j = 1 TO 8
READ a%
map(i, j) = a%
IF a% = 2 THEN px = j + 0.5: py = i + 0.5
NEXT
NEXT
FOR x = -160 TO 159
z = 0
dx = x / 160
dz = -1
intx = INT(px): fx = px - intx
inty = INT(py): fy = py - inty
FOR i = 1 TO 16
IF dx > 0 THEN crx = (1 - fx) / dx ELSE IF dx < 0 THEN crx = -fx / dx ELSE crx = 100
IF dz > 0 THEN cry = (1 - fy) / dz ELSE IF dz < 0 THEN cry = -fy / dz ELSE cry = 100
IF crx < cry THEN
z = z + crx
fy = fy + crx * dz
IF dx > 0 THEN intx = intx + 1: fx = 0 ELSE intx = intx - 1: fx = 1
bounce = 0
ELSE
z = z + cry
fx = fx + cry * dx
IF dz > 0 THEN inty = inty + 1: fy = 0 ELSE inty = inty - 1: fy = 1
bounce = 1
END IF
IF map(inty, intx) = 1 THEN
h = 100 / z
LINE (160 + x, 100 - h)-(160 + x, 100 + h), 1 + bounce
EXIT FOR
END IF
NEXT
NEXT