Chapter 9: Utility Routines This chapter describes the utilities available to transform coordinates, sort data and calculate the lengths of numbers and character strings. 9.1 Transforming Coordinates The following functions and the subroutine TRFREL convert user coordinates to plot coordinates. The calls are: IXP = NXPOSN (X) level 2, 3 IYP = NYPOSN (Y) level 2, 3 Plot coordinates can also be returned as real numbers. The calls are: XP = XPOSN (X) level 2, 3 YP = YPOSN (Y) level 2, 3 The following two functions convert plot coordinates to user coordinates. The calls are: XW = XINVRS (NXP) level 2, 3 YW = YINVRS (NYP) level 2, 3 The functions NXPIXL and NYPIXL convert plot coordinates to pixel. The calls are: IXP = NXPIXL (IX, IY) level 1, 2, 3 IYP = NYPIXL (IX, IY) level 1, 2, 3 T R F R E L TRFREL converts user coordinates to plot coordinates. The call is: CALL TRFREL (XRAY, YRAY, N) level 2, 3 XRAY, YRAY are arrays containing the user coordinates. After the call, they contain the calculated plot coordinates. N is the number of points. Note: The routines above can be used for linear and logarithmic scaling. For polar scaling, TRFREL and POS2PT can be used for getting plot coor- dinates. T R F C O 1 The routine TRFCO1 converts one-dimensional coordinates. The call is: CALL TRFCO1 (XRAY, N, CFROM, CTO) level 0, 1, 2, 3 XRAY is an array containing angles expressed in radians or degrees. After a call to TRFCO1, XRAY contains the converted coordinates. N is the number of coordinates. CFROM, CTO are character strings that can have the values 'DEGREES' and 'RADIANS'. T R F C O 2 The routine TRFCO2 converts two-dimensional coordinates. The call is: CALL TRFCO2 (XRAY, YRAY, N, CFROM, CTO) level 0, 1, 2, 3 XRAY, YRAY are arrays containing rectangular or polar co- ordinates. For polar coordinates, XRAY con- tains the angles measured in degrees and YRAY the radii. N is the number of coordinates. CFROM, CTO are character strings that can have the values 'RECT' and 'POLAR'. T R F C O 3 The routine TRFCO3 converts three-dimensional coordinates. The call is: CALL TRFCO3 (XRAY, YRAY, ZRAY, N, CFROM, CTO) level 0, 1, 2, 3 XRAY, YRAY, are arrays containing rectangular, spherical ZRAY or cylindrical coordinates. Spherical coordi- nates must be in the form (longitude,latitude, radius) where 0 <= longitude <= 360 and -90 <= latitude <= 90. Cylindrical coordinates must be in the form (angle, radius, z). N is the number of coordinates. CFROM, CTO are character strings that can have the values 'RECT','SPHER' and 'CYLI'. T R F M A T The routine TRFMAT converts a matrix to another matrix by bilinear interpolation. The call is: CALL TRFMAT (ZMAT,NX,NY,ZMAT2,NX2,NY2) level 0, 1, 2, 3 ZMAT is the input matrix of the dimension (NX, NY). NX, NY are the dimensions of the matrix ZMAT. ZMAT2 is the calculated matrix of the dimension (NX2, NY2). NX2, NY2 are the dimensions of the matrix ZMAT2. 9.2 String Arithmetic N L M E S S The function NLMESS returns the length of text in plot coor- dinates. The call is: NL = NLMESS (CSTR) level 1, 2, 3 CSTR is a character string (<= 132 characters). NL is the length in plot coordinates. T R M L E N The function TRMLEN returns the number of characters in a character string. The call is: NL = TRMLEN (CSTR) level 0, 1, 2, 3 CSTR is a character string. NL is the number of characters. U P S T R UPSTR converts a character string to uppercase letters. The call is: CALL UPSTR (CSTR) level 0, 1, 2, 3 CSTR is a character string to be converted. U T F I N T UTFINT converts a UTF8 character string to Unicode numbers. The call is: CALL UTFINT (CSTR, IRAY, NRAY, N) level 0, 1, 2, 3 CSTR is a character string in UTF8 format. IRAY is the returned array of Unicode numbers. NRAY is the dimension of IRAY. N is the returned number of calculated Unicode numbers. If an error occurred, a negative num- ber is returned. I N T U T F INTUTF converts an array of Unicode number to a UTF8 char- acter string. The call is: CALL INTUTF (IRAY, NRAY, CSTR, NMAX, N) level 0, 1, 2, 3 IRAY is an integer array of Unicode numbers. NRAY is the number elements in IRAY. CSTR is the returned character string in UTF8 for- mat. For the programming language C the string is terminated by '\0'. NMAX is the maximal number of characters that CSTR can contain. N is the returned length of CSTR. If an error occurred, a negative number is returned. 9.3 Number Arithmetic N L N U M B NLNUMB calculates the length of numbers in plot coordinates. The call is: NL = NLNUMB (X, NDIG) level 1, 2, 3 X is a real number. NDIG is the number of decimal places (>= -1). NL is the length in plot coordinates. I N T L E N INTLEN calculates the number of digits in integers. The call is: CALL INTLEN (NX, NL) level 0, 1, 2, 3 NX is an integer. NL is the number of digits. F L E N FLEN calculates the number of digits in real numbers. The call is: CALL FLEN (X, NDIG, NL) level 0, 1, 2, 3 X is a real number. NDIG is the number of decimal places (>= -1). NL is the number of digits including the decimal point. For negative numbers, it includes the minus sign. I N T C H A INTCHA converts integers to character strings. The call is: CALL INTCHA (NX, NL, CSTR) level 0, 1, 2, 3 NX is the integer to be converted. NL is the number of digits in NX returned by INT- CHA. CSTR is the character string containing the inte- ger. F C H A FCHA converts real numbers to character strings. The call is: CALL FCHA (X, NDIG, NL, CSTR) level 0, 1, 2, 3 X is the real number to be converted. NDIG is the number of decimal places to be conside- red (>= -1). The last digit will be rounded up. NL is the number of digits returned by FCHA. CSTR is the character string containing the real number. S O R T R 1 SORTR1 sorts real numbers. The call is: CALL SORTR1 (XRAY, N, COPT) level 0, 1, 2, 3 XRAY is an array containing real numbers. N is the dimension of XRAY. COPT defines the sorting direction. IF COPT = 'A', the numbers will be sorted in ascending order; if COPT = 'D', they will be sorted in descen- ding order. S O R T R 2 SORTR2 sorts two-dimensional points in the X-direction. The call is: CALL SORTR2 (XRAY, YRAY, N, COPT) level 0, 1, 2, 3 XRAY, YRAY are arrays containing the coordinates. N is the number of points. COPT defines the sorting direction. IF COPT = 'A', the numbers will be sorted in ascending order; if COPT = 'D', they will be sorted in descen- ding order. Note: The Shell-algorithm is used for sorting. S P L I N E SPLINE calculates splined points used in CURVE to plot a spline. The call is: CALL SPLINE (XRAY, YRAY, N, XSRAY, YSRAY,NSPL) level 1, 2, 3 XRAY, YRAY are arrays containing points of the curve. N is the dimension of XRAY and YRAY. XSRAY, YSRAY are the splined points returned by SPLINE. NSPL is the number of calculated splined points returned by SPLINE. By default, NSPL has the value 200. Note: The number of interpolated points and the order of the polynomials can be modified with SPLMOD. B E Z I E R The routine BEZIER calculates a Bezier interpolation. The call is: CALL BEZIER (XRAY, YRAY, N, XPRAY, YPRAY, NP) level 0, 1, 2, 3 XRAY, YRAY are arrays containing points of the curve. N is the dimension of XRAY and YRAY (1 < N < 21). XPRAY, YPRAY are the Bezier points returned by BEZIER. NP is the number of calculated points defined by the user. H I S T O G The routine HISTOG calculates a histogram. The call is: CALL HISTOG (XRAY, N, XHRAY, YHRAY, NH) level 0, 1, 2, 3 XRAY is an array containing floating point numbers. N is the dimension of XRAY. XHRAY, YHRAY are arrays containing the calculated histo- gram. XHRAY contains distinct values from XRAY sorted in ascending order. YHRAY contains the frequency of points. NH is the number of points in XHRAY und YHRAY re- turned by HISTOG. T R I A N G The routine TRIANG calculates the Delaunay triangulation of an arbitrary collection of points in the plane. The Delaunay triangulation can directly be used to display surfaces and contour lines of irregularly distributed data points. The call is: CALL TRIANG (XRAY, YRAY, N, I1RAY, I2RAY, I3RAY, NMAX, NTRI) level 0, 1, 2, 3 XRAY, YRAY are arrays containing floating point numbers. The dimension of XRAY and YRAY must be greater or equal N + 3. N is the number of points in XRAY and YRAY. I1RAY, I2RAY, are the returned vertices for each triangle in I3RAY a counter-clockwise order. NMAX is the dimension of I1RAY, I2RAY and I3RAY. NMAX must be greater of equal 2 * N + 1. NTRI is the returned number of triangles. Notes: - The Watson algorithm is used for calculating the Delaunay triangulation. The algorithm in- creases with the number of points as approxi- mately O(N^1.5). - Surfaces and contours can be directly plotted from the triangulation with the routines CRV- TRI, SURTRI and CONTRI. C I R C 3 P The routine CIRC3P calculates a circle specified by three points. The call is: CALL CIRC3P (X1, Y1, X2, Y2, X3, Y3, XM, YM, R) level 0, 1, 2, 3 X1, Y1 are the X- and Y-coordinates of the first point. X2, Y2 are the X- and Y-coordinates of the second point. X3, Y3 are the X- and Y-coordinates of the third point. XM, YM are the calculated coordinates of the centre point. R is the calculated radius of the circle. P O L C L P The routine POLCLP clips a polygon against a rectangle. The Sutherland-Hodman algorithm is used by POLCLP. This routine must be called four times to clip against all edges of the rectangle. The call is: CALL POLCLP (XRAY, YRAY, N, XRAY2, YRAY2, NMAX, NOUT, XV, CEDGE) level 0, 1, 2, 3 XRAY, YRAY are arrays containing the polygon vertices. N is the number of the polygon vertices. XRAY2, YRAY2 are the returned clipped polygon vertices. NMAX is the maximal number of allowed edges in XRAY2 and YRAY2. NOUT is the number of vertices in the clipped poly- gon. XV is the value of the current edge. CEDGE is a character string that defines the edge. CEDGE can have the values 'TOP', 'LEFT', 'BOT- TOM' and 'RIGHT'. 9.4 Date Routine B A S D A T The routine BASDAT defines the base date. This routine is necessary for plotting date labels and data containing date coordinates. The call is: CALL BASDAT (IDAY, IMONTH, IYEAR) level 0, 1, 2, 3 IDAY is the day number of the date between 1 and 31. IMONTH is the month number of the date between 1 and 12. IYEAR is the four digit year number of the date. I N C D A T The function INCDAT returns the number of days between a specified date and the base date. These calculated days can be passed as parameters to the routine GRAF and as coordina- tes to data plotting routines such as CURVE. The call is: N = INCDAT (IDAY, IMONTH, IYEAR) level 0, 1, 2, 3 N is the returned number of calculated days. IDAY is the day number of the date between 1 and 31. IMONTH is the month number of the date between 1 and 12. IYEAR is the four digit year number of the date. T R F D A T The routine TRFDAT calculates for a number of days the cor- responding date. The call is: CALL TRFDAT (N, IDAY, IMONTH, IYEAR) level 0, 1, 2, 3 N is the number of days. IDAY is the returned day number. IMONTH is the returned month number. IYEAR is the returned four digit year number. N W K D A Y The function NWKDAY returns the weekday for a given date. The call is: N = NWKDAY (IDAY, IMONTH, IYEAR) level 0, 1, 2, 3 N is the returned weekday between 1 and 7 (1 = Monday, 2 = Tuesday, ...). IDAY is the day number of the date between 1 and 31. IMONTH is the month number of the date between 1 and 12. IYEAR is the four digit year number of the date. 9.5 Bit Manipulation B I T S I 2 The routine BITSI2 allows bit manipulation on 16 bit variab- les. The call is: CALL BITSI2 (NBITS, NINP, IINP, NOUT, IOUT, IOPT) level 0, 1, 2, 3 NBITS is the number of bits to be shifted. NINP is a 16 bit variable from which to extract the bit field. IINP is the bit position of the leftmost bit of the bit field. The bits are numbered 0 - 15 where 0 is the most significant bit. NOUT is a 16 bit variable into which the bit field is placed. IOUT is the bit position where to put the bit field. IOPT controls whether the bits outside of the field are set to zero or not. If IOPT equal 0, the bits are set to zero. If IOPT not equal 0, the bits are left as they are. For this case, NOUT is also used as input parameter. In the C function, IOPT is missing in the parameter list and internally used with the value 1. B I T S I 4 The routine BITSI4 allows bit manipulation on 32 bit variab- les. The call is: CALL BITSI4 (NBITS, NINP, IINP, NOUT, IOUT, IOPT) level 0, 1, 2, 3 NBITS is the number of bits to be shifted. NINP is a 32 bit variable from which to extract the bit field. IINP is the bit position of the leftmost bit of the bit field. The bits are numbered 0 - 31 where 0 is the most significant bit. NOUT is a 32 bit variable into which the bit field is placed. IOUT is the bit position where to put the bit field. IOPT controls whether the bits outside of the field are set to zero or not. If IOPT equal 0, the bits are set to zero. If IOPT not equal 0, the bits are left as they are. For this case, NOUT is also used as input parameter. In the C function, IOPT is missing in the parameter list and internally used with the value 1. 9.6 Byte Swapping S W A P I 2 The routine SWAPI2 swaps the bytes of 16 bit integer variab- les. The call is: CALL SWAPI2 (IRAY, N) level 0, 1, 2, 3 IRAY is an array containing the 16 bit variables. N is the number of variables. S W A P I 4 The routine SWAPI4 swaps the bytes of 32 bit integer variab- les. The call is: CALL SWAPI4 (IRAY, N) level 0, 1, 2, 3 IRAY is an array containing the 32 bit variables. N is the number of variables. 9.7 Binary I/O This chapter describes the utilities available to transform Binary I/O from Fortran can cause some problems: unformatted IO in Fortran is system-dependent and direct access I/O needs a fixed record length. Therefore, DISLIN offers some C routines callable from Fortran. O P E N F L The routine OPENFL opens a file for binary I/O. The call is: CALL OPENFL (CFILE, NLU, IRW, ISTAT) level 0, 1, 2, 3 CFILE is a character string containing the file name. NLU is the logical unit for the I/O (0 <= NLU <= 99). The units 15 and 16 are reserved for DIS- LIN. IRW defines the file access mode (0: READ, 1: WRITE, 2: APPEND). ISTAT is the returned status (0: no errors). C L O S F L The routine CLOSFL closes a file. The call is: CALL CLOSFL (NLU) level 0, 1, 2, 3 NLU is the logical unit. R E A D F L The routine READFL reads a given number of bytes. The call is: CALL READFL (NLU, IBUF, NBYT, ISTAT) level 0, 1, 2, 3 NLU is the logical unit. IBUF is an array where to read the bytes. NBYT is the number of bytes. ISTAT is the number of bytes read (0 means end of file). W R I T F L The routine WRITFL writes a number of bytes. The call is: CALL WRITFL (NLU, IBUF, NBYT, ISTAT) level 0, 1, 2, 3 NLU is the logical unit. IBUF is an array containing the bytes. NBYT is the number of bytes. ISTAT is the number of bytes written (0 means an er- ror). S K I P F L The routine SKIPFL skips a number of bytes from the current position. The call is: CALL SKIPFL (NLU, NBYT, ISTAT) level 0, 1, 2, 3 NLU is the logical unit. NBYT is the number of bytes. ISTAT is the returned status (0: OK). T E L L F L The routine TELLFL returns the current position in bytes. The call is: CALL TELLFL (NLU, NBYT) level 0, 1, 2, 3 NLU is the logical unit. NBYT is the returned position in bytes where byte numbering begins with zero. NBYT = -1, if an error occurs. P O S I F L The routine POSIFL skips to a certain position relative to the start. The call is: CALL POSIFL (NLU, NBYT, ISTAT) level 0, 1, 2, 3 NLU is the logical unit. NBYT defines the position. Byte numbering begins with zero. ISTAT is the returned status (0: OK). 9.8 Window Terminals 9.8.1 Clearing the Screen E R A S E The routine ERASE clears the screen, a graphics window or the page of a raster format such as TIFF, PNG, PPM and BMP. In general, this is done by DISINI at the beginning of a plot. The call is: CALL ERASE level 1, 2, 3 Note: If backing store is enabled in DISLIN with the routine X11Mod, the routine ERASE clears just the pixmap and not directly the graphics win- dow. Clearing just the pixmap has the advan- tage that a new plot can be created on the pixmap while the graphics window remains un- changed. The pixmap can then be copied to the graphics window with the routine SENDBF. This double frame buffer effect avoids flickering. 9.8.2 Clearing the Output Buffer S E N D B F Normally, the graphical output to the screen is buffered. To send the buffer to the screen, the routine SENDBF can be used. The call is: CALL SENDBF level 1, 2, 3 Note: SENDBF updates also a graphics window with the current pixmap if backing store is enabled in the routine X11MOD. SENDBF can be used after DISFIN if there is still a graphics win- dow (i.e. after WINMOD ('NONE')). B U F M O D The routine BUFMOD changes the behaviour of SENDBF. The call is: CALL BUFMOD (CMOD, CKEY) level 1, 2, 3 CMOD is a character string that can have the values 'ON' and 'OFF'. CKEY is a character string that can have the value 'SENDBF'. This keyword enables or disables the internal calls of SENDBF in DISLIN routines such as ENDGRF. Default: ('ON', 'SENDBF'). 9.8.3 Multiple Windows The following routines allow programs to create up to 8 win- dows for graphics output on X11 and Windows terminals. Note, that multiple windows can be used with graphic windows but are not compatible with other file formats in DISLIN. O P N W I N The routine OPNWIN creates a new window for graphics output on the screen. The call is: CALL OPNWIN (ID) level 1, 2, 3 ID is the window number between 1 and 8. Notes: - The file format must be set to X Window emula- tion in the routine METAFL (i.e. with the key- word 'XWIN'). - The size and position of windows can be chan- ged with the routines WINDOW and WINSIZ. - An individual page size can be defined for the window with the routine PAGWIN. - Windows can be closed and selected with the routines CLSWIN and SELWIN. - A created window with OPNWIN is selected auto- matically for graphics output. - External windows can also be used with OPNWIN if the routine SETXID is called before. - The routine WINMOD affects the handling of windows in the termination routine DISFIN. C L S W I N The routine CLSWIN closes a window created with OPNWIN. The call is: CALL CLSWIN (ID) level 1, 2, 3 ID is the window number between 1 and 8. S E L W I N The routine SELWIN selects a window on the screen where the following graphics output will be sent to. The call is: CALL SELWIN (ID) level 1, 2, 3 ID is the window number between 1 and 8. P A G W I N PAGWIN defines the page size for multiple windows. If PAGWIN is not called, the current page size defined by PAGE or SET- PAG is used. The call is: CALL PAGWIN (NXP, NYP) level 1, 2, 3 NXP, NYP are the length and height of the page in plot coordinates. The lower right corner of the page is the point (NXP-1, NYP-1). W I N I D The routine WINID returns the ID of the currently selected window. The call is: CALL WINID (ID) level 1, 2, 3 ID is the returned window number. W I N T I T The routine WINTIT changes the window title of the currently selected window. The call is: CALL WINTIT (CSTR) level 1, 2, 3 CSTR is a character string containing the new window title. 9.8.4 Cursor Routines The following routines allow a user to collect some X- and Y-coordinates in a graphics window with the mouse. The coor- dinates can be returned in pixels and in DISLIN plot coordi- nates. All routines are also available in DISLIN draw wid- gets. C S R P O S The routine CSRPOS sets the position of the mouse pointer and returns the position if a character key or a mouse but- ton is pressed. This routine can be used for cursor naviga- tion. The call is: CALL CSRPOS (NX, NY, IKEY) level 1, 2, 3 NX, NY are integer coordinates. On entry, the mouse pointer is set to the position (NX, NY). If a character key is pressed, the position of the mouse is returned in NX and NY. IKEY is the returned ASCII code for the pressed key. The cursor keys can also be used where the following values are returned: 1 for cur- sor left, 2 for cursor up, 3 for cursor right, 4 for cursor down. The value 5 is returned if the left mouse button is clicked, and the value 6 for the right mouse button. The value -1 is returned if an error occurred and the value 0 if no key is pressed. Note: The behaviour of CSRPOS can be modified with the routine CSRMOD. C S R K E Y The routine CSRKEY returns a character key. If no character key is pressed, the value 0 is returned. The call is: CALL CSRKEY (IKEY) level 1, 2, 3 IKEY is the returned ASCII code for the pressed key. The cursor keys can also be used where the following values are returned: 1 for cur- sor left, 2 for cursor up, 3 for cursor right, 4 for cursor down. The value 0 is returned if no key is pressed. C S R P T 1 The routine CSRPT1 returns the position of the mouse pointer if the mouse button 1 is pressed. The mouse pointer is changed to a cross hair pointer in the graphics window if CSRPT1 is active. The call is: CALL CSRPT1 (NX, NY) level 1, 2, 3 NX, NY are the returned coordinates of the pressed mouse pointer. C S R R E C The routine CSRREC returns two opposite corners of a rect- angle created with mouse button 1. A rubber band is plotted around the rectangle. The call is: CALL CSRREC (NX1, NY1, NX2, NY2) level 1, 2, 3 NX1, NY1, are the returned coordinates of two opposide NX2, NY2 rectangle corners. C S R L I N The routine CSRLIN is similar to CSRREC and returns the end points of a line created with mouse button 1. The call is: CALL CSRLIN (NX1, NY1, NX2, NY2) level 1, 2, 3 NX1, NY1, are the returned coordinates of the line end NX2, NY2 points. C S R P T S The routine CSRPTS returns an array of mouse positions. The routine is waiting for mouse button 1 clicks and terminates if mouse button 2 is pressed. The mouse pointer is changed to a cross hair pointer in the graphics window. The call is: CALL CSRPTS (NXRAY, NYRAY, NMAX, N, IRET) level 1, 2, 3 NXRAY, NYRAY are the returned coordinates of the collected mouse positions. NMAX is the dimension of NXRAY and NYRAY and de- fines the maximal number of points that will be stored in NXRAY and NYRAY. N is the number of points that are returned in NXRAY and NYRAY. IRET is a returned status. IRET not equal 0 means that not all mouse movements could be stored in NXRAY and NYRAY. C S R M O V The routine CSRMOV returns an array of mouse movements. The routine collects the mouse movements of mouse button 1 and terminates if mouse button 1 is released. The mouse pointer is changed to a cross hair pointer in the graphics window. The call is: CALL CSRMOV (NXRAY, NYRAY, NMAX, N, IRET) level 1, 2, 3 NXRAY, NYRAY are the returned coordinates of the collected mouse movements. NMAX is the dimension of NXRAY and NYRAY and de- fines the maximal number of points that will be stored in NXRAY and NYRAY. N is the number of points that are returned in NXRAY and NYRAY. IRET is a returned status. IRET not equal 0 means that not all mouse positions could be stored in NXRAY and NYRAY. C S R M O D The routine CSRMOD modifies the behaviour of CSRPOS. The call is: CALL CSRMOD (CMOD, CKEY) level 1, 2, 3 CMOD is a character string that can have the values 'STANDARD', 'SET', 'GET' and 'READ'. With the keywords 'SET' and 'GET' the cursor position can be defined or requested without waiting for a user event. The value 'READ' means that the cursor position is not set at the entry of CSRPOS. The value 'STANDARD' means the default behaviour of CSRPOS. CKEY is a character string that can have the value 'POS'. Default: ('STANDARD', 'POS'). C S R U N I The routine CSRUNI defines if pixels or plot coordinates are returned by the cursor routines. The call is: CALL CSRUNI (COPT) level 1, 2, 3 COPT is a character string that can have the values 'PIXEL' and 'PLOT'. Default: COPT = 'PLOT'. Note: Plot coordinates can be converted to user co- ordinates with the routines XINVRS and YINVRS. C S R T Y P The routine CSRTYP defines the cursor used by the cursor routine. The call is: CALL CSRTYP (COPT) level 1, 2, 3 COPT is a character string that can have the values 'NONE', 'CROSS', 'ARROW' and 'VARROW'. 'NONE' means that the current cursor is not changed. Default: COPT = 'CROSS'. S E T C S R The routine SETCSR defines the cursor that is used by the DISLIN graphics window. The call is: CALL SETCSR (COPT) level 1, 2, 3 COPT is a character string that can have the values 'ARROW', 'CROSS' and 'VARROW'. Default: COPT = 'ARROW'. 9.9 Elementary Image Routines The following routines allow transferring of image data bet- ween windows, files and arrays. The output format must be an image format such as CONS, TIFF, PNG, BMP and PPM, but the writing of image data to PostScript and PDF files is also supported. If the output format is PostScript or PDF, the size of images and the position of an image on the output page can be defined with the routines IMGSIZ and IMGBOX. I M G I N I The routine IMGINI initializes transferring of image data with the routines RPIXEL, RPIXLS, RPXROW, WPIXEL, WPIXLS and WPXROW. If the output format is PostScript or PDF, IMGINI creates a virtual image where image data can be written to. WPXROW. The call is: CALL IMGINI level 1, 2, 3 I M G F I N The routine IMGFIN terminates transferring of image data with the routines RPIXEL, RPIXLS, RPXROW, WPIXEL, WPIXLS and WPXROW. If the output format is PostScript or PDF, the vir- tual image created in IMGINI is copied to the PostScript or PDF file. The call is: CALL IMGFIN level 1, 2, 3 R P I X E L The routine RPIXEL reads one pixel from memory. The call is: CALL RPIXEL (IX, IY, ICLR) level 1, 2, 3 IX, IY is the position of the pixel in screen coordi- nates. ICLR is the returned colour value of the pixel. W P I X E L The routine WPIXEL writes one pixel into memory. The call is: CALL WPIXEL (IX, IY, ICLR) level 1, 2, 3 IX, IY is the position of the pixel in screen coordi- nates. ICLR is the new colour value of the pixel. R P I X L S The routine RPIXLS copies colour values from a rectangle in memory to an array. The call is: CALL RPIXLS (IRAY, IX, IY, NW, NH) level 1, 2, 3 IRAY is a byte array containing the returned colour values. IX, IY contain the starting point in screen coordina- tes. NW, NH are the width and height of the rectangle in screen coordinates. W P I X L S The routine WPIXLS copies colour values from an array to a rectangle in memory. The call is: CALL WPIXLS (IRAY, IX, IY, NW, NH) level 1, 2, 3 IRAY is a byte array containing the colour values. IX, IY contain the starting point in screen coordina- tes. NW, NH are the width and height of the rectangle in screen coordinates. R P X R O W The routine RPXROW copies one line of colour values from memory to an array. The call is: CALL RPXROW (IRAY, IX, IY, N) level 1, 2, 3 IRAY is a byte array containing the returned colour values. IX, IY contain the starting point in screen coordina- tes. N is the number of pixels. W P X R O W The routine WPXROW copies colour values from an array to a line in memory. The call is: CALL WPXROW (IRAY, IX, IY, N) level 1, 2, 3 IRAY is a byte array containing the colour values. IX, IY contain the starting point in screen coordina- tes. N is the number of pixels. Note: IMGINI and IMGFIN must be used with the rou- tines RPIXEL, WPIXEL, RPIXLS, WPIXLS, RPXROW and WPXROW. I M G M O D The routine IMGMOD defines palette or true colour mode for the routines RPIXLS, WPIXLS, RPXROW and WPXROW. For palette mode, the byte arrays in the routines above must contain colour indices between 0 and 255. For true colour mode, the byte arrays must contain RGB values (8 bit for each value). The call is: CALL IMGMOD (CMOD) level 1, 2, 3 CMOD is a character string that can have the values 'INDEX' and 'RGB'. Default: CMOD = 'INDEX'. I M G S I Z If the output format is PostScript or PDF, the size of images can be defined with the routine IMGSIZ. The routine must be called before IMGINI. The call is: CALL IMGSIZ (NW, NH) level 1, 2, 3 NW, NH are the image width and height in pixels. Default: (853, 603). I M G B O X If the output format is PostScript or PDF, a rectangle on the output page can be specified where the image is copied to. The routine IMGBOX must be called before IMGINI. The call is: CALL IMGBOX (NX, NY, NW, NH) level 1, 2, 3 NX, NY is the upper left corner of the rectangle on the page in plot coordinates. NW, NH are the width and height of the rectangle in plot coordinates. NW and NH should have the same ratio as the image that is copied to the rectangle. The default rectangle is the full page. I M G T P R The routine IMGTPR defines a transparency colour for copying image pixels to memory. Pixels that have the same colour as the colour defined by IMGTPR are not copied to memory. The call is: CALL IMGTPR (NCLR) level 1, 2, 3 NCLR is a colour value. If NCLR = -1, the transpar- ency colour will be ignored. Default: NCLR = -1 R I M A G E The routine RIMAGE copies an image from memory to a file. The call is: CALL RIMAGE (CFIL) level 1, 2, 3 CFIL is the name of the output file. A new file version will be created for existing files (see FILMOD). Notes: - Images are stored with an ASCII header of 80 bytes length followed by the binary image data. The format of the image data depends on the video mode and is therefore system-depen- dent. - A single image file can be displayed with the routine WIMAGE or with the utility program DISIMG. A sequence of image files can be dis- played with the utility program DISMOV. W I M A G E The routine WIMAGE copies an image from a file to memory. The call is: CALL WIMAGE (CFIL) level 1, 2, 3 CFIL is the name of the input file. R T I F F The routine RTIFF copies an image from memory to a file. The image is stored in the device-independent TIFF format. The call is: CALL RTIFF (CFIL) level 1, 2, 3 CFIL is the name of the output file. A new file version will be created for existing files (see FILMOD). Notes: - This image format can be used to export images created with DISLIN into other software pack- ages or to transfer them to other computer systems. - A TIFF file created by DISLIN can be displayed with the routine WTIFF or with the utility program DISTIF. W T I F F The routine WTIFF copies an TIFF file created by DISLIN from a file to memory. The call is: CALL WTIFF (CFIL) level 1, 2, 3 CFIL is the name of the input file. Note: The position of the TIFF file and a clipping window can be defined with the routines TIFORG and TIFWIN. T I F O R G The routine TIFORG defines the upper left corner of the screen where the TIFF file is copied to. The call is: CALL TIFORG (NX, NY) level 1, 2, 3 NX, NY is the upper left corner in screen coordina- tes. T I F W I N The routine TIFWIN defines a clipping window of the TIFF file that can be copied with the routine WTIFF to the screen. The call is: CALL TIFWIN (NX, NY, NW, NH) level 1, 2, 3 NX, NY is the upper left corner of the clipping win- dow in pixels. NW, NH are the width and height of the clipping win- dow in pixels. R G I F The routine RGIF copies an image from memory to a GIF file. The call is: CALL RGIF (CFIL) level 1, 2, 3 CFIL is the name of the output file. A new file version will be created for existing files (see FILMOD). R P N G The routine RPNG copies an image from memory to a PNG file. The call is: CALL RPNG (CFIL) level 1, 2, 3 CFIL is the name of the output file. A new file version will be created for existing files (see FILMOD). R B F P N G The routine RBFPNG copies an image from memory as a PNG file to a buffer. The call is: CALL RBFPNG (CBUF, NMAX, N) level 1, 2, 3 CBUF is a character buffer where the image is copied to in PNG format. NMAX defines how many bytes can be copied to CBUF. If NMAX = 0, the size of the PNG file is re- turned in N without copying the PNG file to CBUF. N is the returned length of the buffer. N <= 0, if an error occurs. R P P M The routine RPPM copies an image from memory to a PPM file. The call is: CALL RPPM (CFIL) level 1, 2, 3 CFIL is the name of the output file. A new file version will be created for existing files (see FILMOD). R M B P The routine RBMP copies an image from memory to a BMP file. The call is: CALL RBMP (CFIL) level 1, 2, 3 CFIL is the name of the output file. A new file version will be created for existing files (see FILMOD). E X P I M G The routine EXPIMG copies an image from memory to a file. The call is: CALL EXPIMG (CFIL, COPT) level 1, 2, 3 CFIL is the name of the output file. A new file version will be created for existing files (see FILMOD). COPT defines the file format and can have the values 'PS', 'PDF', 'PNG', 'GIF', 'TIFF', 'PPM' and 'BMP'. Note: For the options 'PNG', 'GIF', 'TIFF', 'PPM' and 'BMP', EXPIMG has the same meaning as the routines RPNG, RGIF, RTIFF, RPPM, and RBMP. I M G C L P The routine IMGCLP defines a clipping region for the rou- tines RTIFF, RGIF, RPNG, RPPM and RBMP for copying the graphics window to an output file. The call is: CALL IMGCLP (NX, NY, NW, NH) level 1, 2, 3 NX, NY is the upper left corner of the rectangle in pixels. NW, NH are the width and height of the rectangle in pixels. P D F B U F The routine PDFBUF copies a PDF file from memory to a user buffer. The routine must be called after DISFIN and PDF buf- fer output must be enabled with the statement CALL PDFMOD ('ON', 'BUFFER') before DISINI. The call is: CALL PDFBUF (CBUF, NMAX, N) level 0 CBUF is a character buffer where the PDF format is copied to. NMAX defines how many bytes can be copied to CBUF. If NMAX = 0, the size of the PDF file is re- turned in N without copying the PDF file to CBUF. N is the returned length of the buffer. N <= 0, if an error occurs. Note: The PDF file is deleted in memory after it is copied to the buffer. L D I M G The routine LDIMG loads an PNG, BMP, GIF or TIFF image from a file into an array. RapidEye satellite TIFF images are also supported by LDIMG. The call is: CALL LDIMG (CFIL, IRAY, NMAX, NC, N) level 0, 1, 2, 3 CFIL is a character string that contains the file- name. IRAY is an INTEGER*2 array containing the image data after the call to LDIMG. NMAX is the number of elements in IRAY. If NMAX = 0, just the needed number of elements is returned in the variable N. NC is the channel number. Normally, the red compo- nents are returned for NC = 1, the green values for NC = 2 and the blue values for NC = 3. RapidEye TIFF images contain 5 channels. If NC = 0, all channels are returned, stored after each other in IRAY. For NC = -1, the image is packed as byte values in IRAY. Three bytes contain the RGB values of a pixel. N is the returned number of elements used in IRAY. 9.10 Transparency The following routines allow transparency effects in DISLIN by using alpha blending. Alpha blending is only possible if the output format is a raster format such as screen output or plotting to an image file like PNG and TIFF. A second restriction is that the output device must support the full range of RGB colours. This means that you have to enable the option IMGFMT ('RGB') for image files. T P R I N I The routine TPRINI initializes transparency. All following plotting output until TPRFIN is going to a separate frame buffer. The call is: CALL TPRINI level 1, 2, 3 T P R F I N The routine TPRFIN terminates transparency. The separate frame buffer is mixed with the real frame buffer by using alpha blending. The call is: CALL TPRFIN level 1, 2, 3 T P R V A L The routine TPRVAL defines the alpha value. The call is: CALL TPRVAL (X) level 1, 2, 3 X is a floating point value in the range from 0.0 to 1.0, where 0.0 means a fully transpar- ent colour and 1.0 means a fully opaque col- our. Default: 1.0 The following program code plots three circles with alpha blending: CALL TPRVAL(0.5) CALL COLOR('RED') CALL TPRINI CALL CIRCLE(500,500,500) CALL TPRFIN CALL COLOR('GREEN') CALL TPRINI CALL CIRCLE(750,750,500) CALL TPRFIN CALL COLOR('BLUE') CALL TPRINI CALL CIRCLE(1000,500,500) CALL TPRFIN T P R M O D The routine TPRMOD defines additional options for transpar- ency. The call is: CALL TPRMOD (CMOD, CKEY) level 1, 2, 3 CMOD is a character string defining an option. CKEY is a character string that can have the val- ues 'BACK' and 'FIGURE'. For CKEY = 'BACK', the parameter CMOD can have the values 'O- PAQUE' and 'NOOPAQUE'. 'OPAQUE' means that a transparent figure maybe mixed with the back- ground colour black or white. 'NOOPAQUE' means that the background colour is defined as fully transparent. The elementary figures in DISLIN such as circles, rectangles and polygons contain already a TPRINI/TPRFIN en- vironment that can be enabled with the key 'FIGURES' and the mode 'AUTO'. Default: ('OPAQUE', 'BACK'), ('NOAUTO', 'FIGURES'). The example above can also be written as: CALL TPRVAL(0.5) CALL TPRMOD('AUTO','FIGURES') CALL COLOR('RED') CALL CIRCLE(500,500,500) CALL COLOR('GREEN') CALL CIRCLE(750,750,500) CALL COLOR('BLUE') CALL CIRCLE(1000,500,500) 9.11 Using Threads T H R I N I The routine THRINI initializes threads. THRINI must be called before any other DISLIN routine. The call is: CALL THRINI (N) N is the number of threads that are used by the program. T H R F I N The routine THRFIN terminates threads. THRFIN should be called after any other DISLIN routine. The call is: CALL THRFIN Notes: - The thread routines above are only available for the DISLIN C libraries. - On Unix systems, thread programs must be linked with a DISLIN library that is compiled for Posix threads. This library may not be included in all DISLIN distributions. 9.12 Plotting the MPS Logo M P S L O G O The routine MPSLOGO plots the MPS logo. The call is: CALL MPSLOGO (NX, NY, ISIZE, COPT) NX, NY are plot coordinates that define the upper left corner of the logo. ISIZE defines the size of the logo in pixels. ISIZE can have the values 100, 125, 150, 175, 200 and 300. COPT is a character string that can have the values 'TEXT' and 'NOTEXT'.