RosettaCodeData/Task/Bitmap-Flood-fill/XPL0/bitmap-flood-fill.xpl0
2023-07-01 13:44:08 -04:00

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include c:\cxpl\codes;
proc Flood(X, Y, C, C0); \Fill an area of color C0 with color C
int X, Y, \seed coordinate (where to start)
C, C0; \color to fill with and color to replace
def S=8000; \size of queue (must be an even number)
int Q(S), \queue (FIFO)
F, E; \fill and empty indexes
proc EnQ(X, Y); \Enqueue coordinate
int X, Y;
[Q(F):= X;
F:= F+1;
Q(F):= Y;
F:= F+1;
if F >= S then F:= 0;
]; \EnQ
proc DeQ; \Dequeue coordinate
[X:= Q(E);
E:= E+1;
Y:= Q(E);
E:= E+1;
if E >= S then E:= 0;
]; \DeQ
[F:= 0; E:= 0;
EnQ(X, Y);
while E # F do
[DeQ;
if ReadPix(X, Y) = C0 then
[Point(X, Y, C);
EnQ(X+1, Y); \enqueue adjacent pixels
EnQ(X-1, Y);
EnQ(X, Y+1);
EnQ(X, Y-1);
];
];
]; \Flood
def Size = 30.0;
int X, Y;
real Ang, Dist;
[SetVid($101); \set 640x480 graphics with 256 colors
Ang:= 0.0; \draw some flower petals
repeat Dist:= Size*(Cos(Ang*3.0) - 1.0);
X:= fix(Dist*Cos(Ang));
Y:= fix(Dist*Sin(Ang));
Point(X+320, 240-Y, $F);
Ang:= Ang + 0.001; \draw dots close together to prevent leaks
until Ang >= 2.0*3.14159;
Flood(330, 240, $2A, 0); \color the petals
Flood(310, 230, $2C, 0);
Flood(310, 250, $2E, 0);
if ChIn(1) then []; \wait for keystroke
SetVid(3); \restore normal text mode
]