COMMENT ⊗   VALID 00002 PAGES
C REC  PAGE   DESCRIPTION
C00001 00001
C00002 00002	BEGIN "PGTST"  INTEGER CH
C00004 ENDMK
C⊗;
BEGIN "PGTST"  INTEGER CH;
REQUIRE "PGHDR.SAI[VIS,HPM]" SOURCE_FILE;
REQUIRE "VIXHDR.SAI[VIS,HPM]" SOURCE_FILE;

PRINT("channel ",CVOS(CH←GDDCHN(-1)),'15&'12);
WHILE TRUE DO
   BEGIN
   INTEGER ARRAY PIC[0:PIXDIM(480,512,1)]; REAL X1,Y1,X2,Y2; STRING S; INTEGER FOO;

   MAKPIX(480,512,1,PIC[0]);
   PDDINI(PIC[0],10,10,470,470);  PSCREE(-4/3,-1,4/3,1);

   PRINT("X1,Y1, X2,Y2:"); S←INCHWL;
   X1←REALSCAN(S,FOO);  Y1←REALSCAN(S,FOO);
   X2←REALSCAN(S,FOO);  Y2←REALSCAN(S,FOO);

   IF ¬PPICFT(X1,Y1,X2,Y2,"DSK:SF2.ENH[PIC,HE]") 
       THEN PRINT("Picture file not found",'15&'12);

   PLINE(X1,Y1,X1,Y2);   PLINE(X2,Y2,X1,Y2);
   PLINE(X2,Y2,X2,Y1);   PLINE(X1,Y1,X2,Y1);

   DDINIT; VIDONE(PIC[0],1); DPYUP(CH);
   END;

END;