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-rw-r--r--app/mpg/2.2/src/matrix printer130
1 files changed, 130 insertions, 0 deletions
diff --git a/app/mpg/2.2/src/matrix printer b/app/mpg/2.2/src/matrix printer
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+(* Version vom 21.10.87 BJ *)
+(* Standardoperationen *)
+(* printer line - Linienalgorithmus *)
+(* printer fill - Fuellalgorithmus *)
+
+PROC printer line (INT CONST x1,y1,x2,y2,
+ PROC (INT CONST, INT CONST) p set pixel):
+ INT VAR x,y,z,
+ a,b,d,
+ dx :: abs(x2-x1),
+ dy :: abs(y2-y1),
+ dp,dq;
+ IF dx <> 0 AND dy <> 0
+ THEN IF dy <= dx
+ THEN draw line 1
+ ELSE draw line 2
+ FI
+ ELSE IF dx = 0 AND dy <> 0
+ THEN draw vertical line
+ ELSE draw horizontal line
+ FI
+ FI.
+
+ draw line 1:
+ x := x1;
+ y := y1;
+ z := x2;
+ a := sign(x2-x1);
+ b := sign(y2-y1);
+ dp := dy * 2;
+ d := dp - dx;
+ dq := dp - 2 * dx;
+ setpoint;
+ WHILE x <> z REP
+ x := x + a;
+ IF d < 0
+ THEN d := d + dp
+ ELSE y := y + b;
+ d := d + dq
+ FI;
+ setpoint
+ PER.
+
+ draw line 2:
+ x := x1;
+ y := y1;
+ z := y2;
+ b := sign(x2-x1);
+ a := sign(y2-y1);
+ dp := dx * 2;
+ d := dp - dy;
+ dq := dp - 2 * dy;
+ setpoint;
+ WHILE y <> z REP
+ y := y + a;
+ IF d < 0
+ THEN d := d + dp
+ ELSE x := x + b;
+ d := d + dq
+ FI;
+ setpoint
+ PER.
+
+ draw vertical line:
+ a := sign(y2-y1);
+ x := x1;
+ y := y1;
+ z := y2;
+ setpoint;
+ WHILE y <> z REP
+ y := y + a;
+ setpoint
+ PER.
+
+ draw horizontal line:
+ a := sign(x2-x1);
+ x := x1;
+ y := y1;
+ z := x2;
+ setpoint;
+ WHILE x <> z REP
+ x := x + a;
+ setpoint
+ PER.
+
+ setpoint:
+ p set pixel (x,y)
+END PROC printer line;
+
+PROC printer fill (INT CONST xl, xr, y, dir,
+ BOOL PROC (INT CONST, INT CONST) point,
+ PROC (INT CONST, INT CONST) pset):
+ INT VAR xl1 :: xl;
+ WHILE point(xl1,y) REP
+ xl1 INCR 1;
+ IF xl1 >= xr
+ THEN LEAVE printer fill
+ FI
+ PER;
+ INT VAR xrn :: xl1+1,
+ xln :: xl1;
+ WHILE NOT point(xrn,y) REP
+ pset(xrn,y);
+ xrn INCR 1
+ PER;
+ WHILE NOT point(xln,y) REP
+ pset(xln,y);
+ xln DECR 1
+ PER;
+ IF xrn > xr
+ THEN printer fill (xr, xrn-1,y-dir,-dir,
+ BOOL PROC (INT CONST, INT CONST) point,
+ PROC (INT CONST, INT CONST) pset)
+ ELSE printer fill (xrn, xr, y, dir,
+ BOOL PROC (INT CONST, INT CONST) point,
+ PROC (INT CONST, INT CONST) pset)
+ FI;
+ IF xln < xl
+ THEN printer fill (xln+1,xl, y-dir,-dir,
+ BOOL PROC (INT CONST, INT CONST) point,
+ PROC (INT CONST, INT CONST) pset)
+ ELSE printer fill (xl,xln, y, dir,
+ BOOL PROC (INT CONST, INT CONST) point,
+ PROC (INT CONST, INT CONST) pset)
+ FI;
+ printer fill(xln+1, xrn-1, y+dir, dir,
+ BOOL PROC (INT CONST, INT CONST) point,
+ PROC (INT CONST, INT CONST) pset)
+END PROC printer fill;
+