TEXT902.f90

	!THIS PROGRAM DRAWS CONTOUR USING GRID DATA
	!BUILD AS QUICKWIN OR STANDARD GRAPHICS
	!APPLICATION.
	!THIS PROGRAM IS DESIGNED TO DRAW
	!CONTOUR WITH THE GRID DATA
	!
	USE MSFLIB
	REAL(8) STATUS
	TYPE(WXYCOORD) XY
	PARAMETER(JJ=24,II=40,XSC=15.0,YSC=15.5)
	REAL(8) X(4),Y(4),F(4),T(II,JJ)
	REAL(8) X2(II),Y2(II),F2(II)
	LOGICAL L(4),L2(II),LL
	!READ THE GRID DATA IN THIS PROGRAM
	!WE CONSTRUCT A IDEAL TEMPERATURE DATA
	TX=40.0
	TN=40.0
	DO 100 J=1,JJ
		DO 100 I=1,II
			T(I,J)=40.0-1.2*J+I+.06*(J-15)**2+.04*(I-20)**2
			T(I,J)=T(I,J)+10*COS(.325*J)*SIN(.325*I)
			IF (TX .LT. T(I,J)) THEN
				TX=T(I,J)
			ENDIF
			IF(TN .GT. T(I,J)) THEN
				TN=T(I,J)
			ENDIF
100	CONTINUE
	!BEGIN THE CONTOUR
	DO 200 TC=INT(TN+1)+.5,INT(TX)+.5,4
		DO 300 J=0,JJ-1
			DO 400 I=0,II-1
				NK=0
				IF(I.GT.0)THEN
					L(4)=L2(I)
				ENDIF
				IF(L(4))THEN
					NK=NK+1
					X(4)=X2(I)
					Y(4)=Y2(I)
					F(4)=F2(I)
				ENDIF
				TA=T(I,J+1)
				TB=T(I+1,J+1)
				L10=(TC.GE.TA).AND.(TC.LT.TB)
				L20=(TC.LT.TA).AND.(TC.GE.TB)
				LL=L10.OR.L20
				IF(LL) THEN
					FF=(TC-TA)/(TB-TA)
				ENDIF
				L(2)=LL
				IF(L(2)) THEN
					NK=NK+1
					F(2)=FF
					X(2)=(I+FF)*XSC
					Y(2)=(J+FF)*YSC
				ENDIF
				L2(I)=L(2)
				IF(L(2)) THEN
					X2(I)=X(2)
					Y2(I)=Y(2)
					F2(I)=F(2)
				ENDIF
				IF(J.GT.0) THEN
					L(1)=L(3)
					IF(L(1))THEN
						NK=NK+1
						X(1)=X(3)
						Y(1)=Y(3)
						F(1)=F(3)
					ENDIF
					IF((NK.EQ.1).OR.(NK.EQ.3).OR.(I.EQ.0))THEN
						TA=T(I+1,J)
						TB=T(I+1,J+1)
						L10=(TC.GE.TA).AND.(TC.LT.TB)
						L20=(TC.LT.TA).AND.(TC.GE.TB)
						LL=L10.OR.L20
						IF(LL) THEN
							FF=(TC-TA)/(TB-TA)
						ENDIF
						L(3)=LL
						IF(L(3)) THEN
							NK=NK+1
							F(3)=FF
							X(3)=(I+1)*XSC
							Y(3)=(J+FF)*YSC
						ENDIF
					ELSE
						L(3)=0
					ENDIF
				ENDIF
				IF((J.GT.0).AND.(I.GT.0).AND.(NK.GT.0)) THEN
					IF(NK.EQ.2) THEN
						DO M1=1,3
							IF(L(M1)) THEN
								DO M2=M1+1,4
									IF(L(M2)) THEN
										CALL MOVETO_W(X(M1),479-Y(M1),XY)
										STATUS=LINETO_W(X(M2),479-Y(M2))
									ENDIF
								ENDDO
							ENDIF
						ENDDO
					ELSE
						CALL MOVETO_W(X(1),479-Y(1),XY)
						STATUS=LINETO_W(X(2),479-Y(2))
						CALL MOVETO_W(X(3),479-Y(3),XY)
						STATUS=LINETO_W(X(4),479-Y(4))
					ENDIF
				ENDIF
400			CONTINUE
300		CONTINUE
200	CONTINUE
	END