User manual HP LASERJET 1100 ALL-IN-ONE - PCL/PJL REFERENCE (PCL 5 PRINTER LANGUAGE) - TECHNICAL REFERENCE MANUAL PART II

Part II 17 An Introduction to HP-GL/2 Vector Graphics The PCL 5 printer provides the ability to print vector graphics using the HP-GL/2 graphics language. HP-GL/2 graphics may be created within application software, or imported from existing applications. For various types of images (many technical drawings and business graphics, for example), it is advantageous to use vector graphics instead of raster graphics. The advantages include faster I/O transfer of large images and smaller disk storage requirements. Note As a guideline, use raster graphics for small, complex images, or those images that cannot be accomplished with HP-GL/2 (such as scanned photographs). Use HP-GL/2 for images that would involve a large amount of I/O data transfer if printed using raster graphics, or for drawings that are already in HP-GL/2 format. If the image is easier to describe using vectors instead of raster lines, the image usually prints faster using HP-GL/2. Printing with HP-GL/2 requires leaving the PCL printer language mode and entering HP-GL/2 mode. Switching between modes involves only a few commands, and software applications easily switch between the two modes as needed. EN 17-1 Learning HP-GL/2 Read through this chapter and Chapter 18 for a general overview of the HP-GL/2 language and its relationship to the PCL printer language. Then, flip through the other HP-GL/2 chapters until you see an example that interests you or fits your objective. Read through the examples and try printing them using your choice of programming languages. If you need help converting the generic commands shown in the examples to a programming language, see "Using HP-GL/2 with Programming Languages" later in this chapter. As you see unfamiliar commands, find the page number of the command description in the index and read about the command. Think of an application that you would like to program and then look for an example that uses some of the elements you desire. After trying some examples and seeing how the commands interact, you should be well on your way to learning the HP-GL/2 language. This chapter describes the interaction between the PCL printer language and HP-GL/2 modes and introduces the following topics: HP-GL/2 Commands and Syntax Using HP-GL/2 with Programming Languages The HP-GL/2 Coordinate System HP-GL/2 and PCL Orientation Interactions The Vector Graphics Limits Units of Measure Pen Status and Location Defining the Image Area (PCL Picture Frame) Scaling Automatically Adjusting Image Size Absolute and Relative Pen Movement Chapter 18 covers more HP-GL/2 fundamentals, and Chapters 19 through 23 discuss HP-GL/2 commands and their syntax. 17-2 An Introduction to HP-GL/2 Vector Graphics EN HP-GL/2 Commands and Syntax There are two classes of commands used to print vector graphics: PCL printer language commands and HP-GL/2 commands. As the name implies, the PCL printer language commands are used when in the PCL printer language mode. They define the area on the page where HP-GL/2 graphics are printed and provide a means to enter HP-GL/2 mode. The HP-GL/2 commands are used within HP-GL/2 mode. They define the image that is printed, and allow you to return to the PCL printer language mode. The HP-GL/2 language has its own syntax, and each command is listed in this section of the manual. The vector graphics commands have been grouped into functional categories. The categories are designated as shown in Table 17-1 through . Each of the command categories is discussed in its own chapter, beginning with Chapter 19, The Configuration and Status Group. Table 17-1 The HP-GL/2 Commands by Group (1 of 5) CONFIGURATION GROUP CO DF IN IP IR IW PG1 RO RP1 SC Comment Default Values Initialize Input P1 and P2 Input Relative P1 and P2 Input Window Advance Page Rotate Coordinate System Replot Scale 1. Ignored by HP LaserJet printers. EN HP-GL/2 Commands and Syntax 17-3 Table 17-2 The HP-GL/2 Commands by Group (2 of 5) VECTOR GROUP AA AR AT BR BZ CI PA PD PE PR PU RT Arc Absolute Arc Relative Absolute Arc Three Point Bezier Relative Bezier Absolute Circle Plot Absolute Pen Down Polyline Encoded Plot Relative Pen Up Relative Arc Three Point Table 17-3 The HP-GL/2 Commands by Group (3 of 5) POLYGON GROUP EA EP ER EW FP PM RA RR WG Edge Rectangle Absolute Edge Polygon Edge Rectangle Relative Edge Wedge Fill Polygon Polygon Mode Fill Rectangle Absolute Fill Rectangle Relative Fill Wedge 17-4 An Introduction to HP-GL/2 Vector Graphics EN Table 17-4 The HP-GL/2 Commands by Group (4 of 5) CHARACTER GROUP AD CF CP DI DR DT DV ES FI1 FN1 LB LO SA SB SD SI SL SR SS TD Alternate Font Definition Character Fill Mode Character Plot Absolute Direction Relative Direction Define Label Terminator Define Variable Text Path Extra Space Select Primary Font Select Secondary Font Label Label Origin Select Alternate Font Scalable or Bitmap Fonts Standard Font Definition Absolute Character Size Character Slant Relative Character Size Select Standard font Transparent Data 1. These commands are part of HP-GL/2's Dual Context Extensions. EN HP-GL/2 Commands and Syntax 17-5 Table 17-5 The HP-GL/2 Commands by Group (5 of 5) LINE AND FILL ATTRIBUTES GROUP AC FT LA LT PW RF SM SP SV1 TR1 UL WU Anchor Corner Fill Type Line Attributes Line Type Pen Width Raster Fill Definition Symbol Mode Select Pen Screened Vectors Transparency Mode User-defined Line Type Pen Width Unit Selection 1. These commands are part of the Palette Extensions to HP-GL/2. As shown in the tables above, each HP-GL/2 command is a two-letter mnemonic code designed to remind you of its function. For example, IN is the Initialize command, SP is the Select Pen command, and CI is the Circle command. Parameters are used with certain HP-GL/2 commands to tell the printer to complete the command in a particular way. Understanding HP-GL/2 Syntax HP-GL/2 commands have four components: a mnemonic, parameter(s), separator(s), and a terminator. Refer to the following illustration of a typical HP-GL/2 command and the description of its components. 17-6 An Introduction to HP-GL/2 Vector Graphics EN Figure 17-1 Typical HP-GL/2 Command Mnemonic--The two-letter mnemonic reminds you of the command's function. The mnemonic can be uppercase or lowercase. Parameter(s)--Some commands have no parameters; for those commands which have them, parameters can be either required or optional (as indicated in the description of that command). Separator(s)--When you use parameters, you must separate them with a comma or space, or in the case of a numeric parameter, with a + or - sign. (Commas are recommended because some computers eliminate spaces, especially when sending variables.) Terminator--All commands require a terminator. Most HP-GL/2 commands are terminated by a semicolon or the first letter of the next mnemonic, a white space, or a tab (exceptions: LB uses a user-defined terminator; PE cannot use the first letter of the next mnemonic). The last command prior to exiting HP-GL/2 mode must be terminated with a semicolon. The following illustration shows the flexibility of the syntax. Each variation of the two-command sequence is permissible; however, the method shown on the left is recommended in most instances. The recommended method uses the first letter of the next mnemonic to terminate commands, uses no space between the mnemonic and its parameters, and separates parameters with a comma. (For clarity, examples in this HP-GL/2 section of the manual use semicolons as terminators, as shown in the middle example below.) Figure 17-2 Illustration of Syntax Flexibility EN HP-GL/2 Commands and Syntax 17-7 The next section explains how the syntax of individual commands is presented. Notations Used to Express Syntax The following describes the notations used in the syntax section of each command description: Mnemonic For readability, the mnemonic is shown in uppercase and separated from the parameters and/or terminator. parameters Parameters are shown in italic. [] Parameters in square brackets are optional. [param1,param2...[,param1,param2]] These optional parameters must be paired. params...params These parameters may be given the number of times specified in the command description. text...text This parameter indicates that you can type in a range of ASCII characters, such as in the Label (LB) command. (....) Indicates that you can use a range of the previous parameter; however, all X coordinates must have a corresponding Y coordinate. 17-8 An Introduction to HP-GL/2 Vector Graphics EN Note Remember that while X,Y coordinates are shown in parentheses in text [for example (3,4) or (0,0)], the parentheses are not part of the syntax. Do not enter these parentheses in your commands. ; iCommand terminator. In most HP-GL/2 commands, a semicolon is optional, and is shown in parentheses in most command syntax. Notes Three exceptions to the optional use of the semicolon as a command terminator occur in the following commands: Polyline Encoded (PE), Label (LB), and Comment (CO). PE must be terminated by a semicolon. LB is terminated by the nonprinting end-of-text character (ETX - decimal 3), or a user-defined character. The comment string of the CO command must be delimited by double quotes. A semicolon terminator is always required following the last command prior to leaving HP-GL/2 mode. , A comma is always shown as the separator between parameters. A space, +, or - is also valid (although not preferred). (A + or - is a valid separator only for numeric parameters.) Omitting Optional Parameters Some commands have optional parameters that take on default values if they are omitted. When you omit a parameter, you must omit all subsequent parameters in the same command (the Define Label Terminator (DT) command is an exception). For example, the Line Type (LT) command has three optional parameters: type, pattern length, and mode. The following command shows all three being used (type = 6, pattern length = 25, mode = 1). LT6,25,1 EN HP-GL/2 Commands and Syntax 17-9 If you omit the second parameter you must also omit the third parameter, as shown below: LT6 The printer uses the most recently specified pattern length and mode. If you have not specified a length or mode since sending a Default Values (DF) or Initialize (IN) command, the printer uses the parameter's defaults. For example, if you send the following command (omitting the second parameter), the printer interprets the "1" as the second parameter: LT6,1 Parameter Formats You must give parameters in the format (type of units) required by each HP-GL/2 command. The required format is stated in the parameter table of each command's description, and is described as follows. 1 Integer--An integer from ­1,073,741,823 (­230 +1) to 1,073,741,823 (230 ­ 1). The printer automatically rounds fractional parameters to the nearest integer within the range. Sending a number outside the parameter range may produce unexpected results. Clamped Integer--An integer from ­32,768 (­215) to 32,767 (215 ­1). The printer automatically rounds fractional parameters to the nearest integer. Sending a number outside this range does not cause an error, but the number is "clamped" to the limits of the range. For example, when parsing a clamped integer, the printer treats all numbers above 32,767 as 32,767. 2 Certain commands have parameters which are restricted to a smaller range. These ranges are listed in the parameter tables for each command. Sending a number outside the reduced parameter range may produce unexpected results. 3 Real--A number with an integer portion from ­1,073,741,823 (­230 +1) to 1,073,741,823 (230 ­ 1). You are assured of at least 6 significant digits (including integer and fractional portion). You may omit the decimal point when no decimal fraction is specified. Sending a number outside the parameter range may produce unexpected results. EN 17-10 An Introduction to HP-GL/2 Vector Graphics 4 Clamped Real--A number with an integer portion from ­32,768 to 32,767; you are assured of at least 6 significant digits (including integer and fractional portion). You may omit the decimal point when no decimal fraction is specified. Sending a number outside this range does not cause an error, but the number is "clamped" to the limits of the range. For example, the printer treats all numbers above 32,767 as 32,767. Certain commands have parameters which are restricted to a smaller range. These ranges are listed in the parameter tables for each command. Sending a number outside the reduced parameter range may produce unexpected results. 5 Label--Any sequence of characters. In the HP-GL/2 language, text is described using the term "label." Refer to the Label (LB) command in Chapter 23 for a complete description. Note Numbers within the above-mentioned ranges do not cause errors; however, the range may exceed the printer's physical printing area. Numbers that move the pen position outside the effective window result in image clipping. This topic is discussed in more detail later in this chapter under "The Vector Graphics Limits." When you see the term "current units" in a parameter table, the unit system of that parameter depends on whether scaling is on or off. When scaling is on, the units are user-units; when scaling is off, the units are plotter units (described under "Units of Measure" later in this chapter). Notes The printer cannot use exponential format numbers (for example, 6.03E8). If you are using a computer or language that uses the exponential format, you must use integer variables or a formatting technique to output fixed-point real numbers. Parameter values less than the range maximum are passed by the parser; these values may subsequently be unscaled into resolution units (e.g. 7200 units-per-inch) that exceed the device-dependent internally representable number range. If this occurs, the device enters a LOST mode; all relative drawing commands are ignored until a command is received which specifies an absolute move to a point within the internally representable number range. EN HP-GL/2 Commands and Syntax 17-11 Notes When LOST mode is entered, the pen is raised and the following commands are ignored: AA, AR, AT, CI, CP, EA, ER, EW, LB, PE, PM, PR, RA, RR, RT, and WG. The commands allowed in LOST mode are: AC, AD, CF, CO, DF, DI, DR, DT, DV, ES, FT, IN, IP, IR, IW, LA, LO, LT, PA, PD, PG, PU, PW, RF, RO, RP, SA, SB, SC, SD, SI, SL, SM, SP, SR, SS, TD, UL, WU, and the PM1/PM2 forms of PM. The commands IN, PG, RP, and PA, with in-range parameters, clear LOST mode, PD and PU in absolute plotting mode, with in-range parameters, also clear LOST mode. When PD clears LOST mode, a line is drawn from the last valid current position to the first point in the PD parameter sequence. If PA clears LOST mode, the pen will not go down until a PD command is received. 17-12 An Introduction to HP-GL/2 Vector Graphics EN Using HP-GL/2 With Programming Languages The HP-GL/2 examples included in this manual are given in a "generic" format (they show the commands required to perform a specific function but usually do not use a specific programming language). In most cases, the commands are accompanied by a brief description of the command being used. To see how HP-GL/2 commands are used in BASIC and the C programming language, see the following examples. Example:BASIC This example uses BASIC to print three lines forming a simple triangle (shown below). 10 20 30 40 50 60 70 LPRINT LPRINT LPRINT LPRINT LPRINT LPRINT LPRINT CHR$(27);"E"; :REM Reset the printer CHR$(27);"%0B"; :REM Enter HP-GL/2 Mode "IN"; :REM Initialize HP-GL/2 Mode "SP1PA10,10"; :REM Select Pen & move to 10,10 "PD2500,10,10,1500,10,10;"; :REM Pen down & draw CHR$(27);"%0A"; :REM Enter PCL Mode CHR$(27);"E"; :REM Reset to end job/eject page Figure 17-3 EN Using HP-GL/2 With Programming Languages 17-13 Example:C Programming Language This example uses the C programming language to print the same three lines shown on the previous page. Table 17-6 #include main() { FILE *prn; prn = fopen("PRN","wb"); fprintf(prn,"033E"); fprintf(prn,"033%%>0B"); fprintf(prn,"IN"); fprintf(prn,"SP1PA10,10"); fprintf(prn,"PD2500,10,10,1500,10,10;"); fprintf(prn,"033%%0A"); fprintf(prn,"033E"); } /* open the printer */ /* EC E to reset printer */ /* Enter HP-GL/2 */ /* Initialize HP-GL/2 Mode */ /* Select pen 1 & move to 10,10 */ /* Pen down & draw */ /* enter PCL at previous CAP */ /* Reset to end job/eject page */ 17-14 An Introduction to HP-GL/2 Vector Graphics EN The HP-GL/2 Coordinate System Both PCL and HP-GL/2 use a Cartesian Coordinate System. The Cartesian coordinate system is a grid formed by two perpendicular axes, usually called the X-axis and Y-axis (refer to Figure 17-4). The intersection of the axes is called the origin of the system and has a location of (0,0). The default HP-GL/2 coordinate system is different than the PCL coordinate system; +Y is down in PCL and up in HP-GL/2. In addition, the default origin is at the lower left in HP-GL/2 and at the upper left in PCL. Note The HP-GL/2 coordinate system can be set up to match the PCL coordinate system. See the example entitled "Adapting the HP-GL/2 Coordinate System to Match the PCL System" in Chapter 19. Figure 17-4 The HP-GL/2 Coordinate System To locate any point on the grid (the printing area within the PCL Picture Frame), move from the origin a number of units along the X-axis, then move a number of units parallel to the Y-axis. The number of units you move matches a coordinate location. Each point is designated by the combination of its X-coordinate and Y-coordinate, known as an X,Y coordinate pair. In , positive X values are plotted to the right of the origin, and positive Y values are plotted above the origin. EN The HP-GL/2 Coordinate System 17-15 Study Figure 17-4 to locate these points: (0,0); (-2,2); (6,2); (6,3); (10,0); (6,-3); (6,-2); (-2,-2); (0,0). Draw a straight line between each point in the order listed. (You should have drawn an arrow.) This is a simple demonstration of defining a vector image when in HP-GL/2 mode. Note To specify a point when programming an application, you must always give a complete X,Y coordinate pair; the X coordinate is first and the Y coordinate second. This manual shows coordinate pairs in parentheses (X,Y) for clarity. Do not use parentheses in your command sequence. Using the default HP-GL/2 coordinate system, the origin is in the lower left corner of the PCL Picture Frame, as shown in Figure 17-5. Using the IP or IR commands, you can move the origin to other locations. Then, using the SC command, you can define practically any unit coordinate system. (This process is discussed in more detail later in this chapter under "Scaling," and also in Chapter 19.) Figure 17-5 The Default HP-GL/2 Coordinate System 17-16 An Introduction to HP-GL/2 Vector Graphics EN HP-GL/2 & PCL Orientation Interactions The relationship between the orientation of the HP-GL/2 coordinate system and the PCL coordinate system is important. Figure 17-6 illustrates this relationship for the default HP-GL/2 orientation (RO 0) and the PCL logical page orientation. As shown in the illustration, in the default HP-GL/2 orientation, the origin of the HP-GL/2 coordinate system defaults to the lower-left corner of the PCL Picture Frame. (HP-GL/2 and PCL X-coordinates increase in the same direction, but the Y-coordinates increase in opposite directions.) Notice that a change in the PCL logical page orientation changes the orientation of the PCL coordinate system and the HP-GL/2 coordinate system. Figure 17-6 Orientation Interactions Between PCL and HP-GL/2 The relationship between the coordinate systems can be changed using the HP-GL/2 Rotate (RO) command. Rotations specified by the RO command are relative to the default HP-GL/2 orientation (which matches the PCL orientation). Figure 17-7 shows how the RO command modifies the default HP-GL/2 orientation. Note A change in PCL print direction has no effect on the HP-GL/2 orientation, the physical position of the picture frame, or the picture frame anchor point. EN HP-GL/2 & PCL Orientation Interactions 17-17 Figure 17-7 Modifying HP-GL/2 Orientation on a Portrait Page 17-18 An Introduction to HP-GL/2 Vector Graphics EN The Vector Graphics Limits The area on the page where a vector graphics image can be printed is determined by the intersection of the following four boundaries: Hard-clip Limits Soft-clip Window PCL Logical Page PCL Picture Frame The hard-clip limit refers to the boundaries resulting from the physical limits of the printer (in PCL mode, this is referred to as the printable area). The soft-clip limit refers to the area defined using the HP-GL/2 Input Window (IW) command. The intersection of all these areas is the effective window. An HP-GL/2 graphic appears on the page only if it falls within the effective window. Figure 17-8 The Effective Window Note For more information on the PCL coordinate system and the PCL 5 printer's printable limits, see Chapter 2. EN The Vector Graphics Limits 17-19 HP-GL/2 Units of Measure In HP-GL/2 mode, you can measure along the X,Y axes and express coordinates using two types of units: plotter units and user-units. Plotter Units One plotter unit equals 0.025 mm. When specifying distances in plotter units, the printer converts the number of plotter units to equivalent dot coordinates before printing. Under default conditions, the printer uses plotter units. The following table lists equivalent measurements for plotter units. Table 17-7 PlotterUnits 1 plu = 40 plu = 1016 plu = 3.39 plu = EquivalentValue 0.025 mm ( 0.00098 in.) 1 mm 1 in. 1 dot @ 300 dpi User-units The size of units along the X and Y axes may be redefined using the Scale (SC) command. User-units allow you to customize the coordinate system to represent any value. For example, you could plot the moon cycle for the year by dividing the X-axis into 31 units for days of the month and the Y-axis into 12 units for months of the year. To mark a point on December 25, you would give the coordinate (25,12) rather than calculating the exact location in plotter units. Before printing, the printer internally converts user-units to dot locations. 17-20 An Introduction to HP-GL/2 Vector Graphics EN Pen Status and Location Since printing vector graphics has traditionally been performed with plotters, the terms pen and pen position are used to described the HP-GL/2 cursor, the current active position (CAP) when in HP-GL/2 mode. Like a physical pen, this imaginary pen must be selected if you want to draw images. Commands such as Pen Up (PU) or Pen Down (PD), and phrases such as "current pen position" or "moving the pen" apply to the imaginary pen just as they would a physical pen on a plotter. Pen Status Pen status refers to whether the "pen" is up or down. Use the Pen Up (PU) command with X,Y coordinates to move the pen to the desired printing location without drawing a line. Use the Pen Down (PD) command with X,Y coordinates to lower the pen and begin drawing from the current location to the first specified X,Y coordinate. Upon entering HP-GL/2 mode for the first time following a reset (ECE) command, no pen has been selected and the pen is up. This means that no lines are drawn when HP-GL commands are given until a pen is selected. This can be done using the Select Pen (SP) command. Most drawing commands require that the pen be lowered to produce marks on the page. Once lowered with a Pen Down (PD) command, the pen remains down for subsequent HP-GL/2 printing commands until a Pen Up (PU) or Initialize (IN) command is issued. The pen remains selected until a new SP command is received. You must be aware of the pen's up/down status to avoid drawing stray lines between parts of your picture. Note Upon entry into HP-GL/2 mode, a good programming practice is to select a pen and command a pen-up move to the initial starting position. This ensures that a pen is selected and is in the proper position to begin drawing. Every time you use a PU or PD command, the printer updates the pen up/down status. The following table shows the commands that include an automatic PD command as part of their function. After performing their complete function, they return the pen to its previous up/down state. EN Pen Status and Location 17-21 Table 17-8 Command CI EA EP ER EW FP RA RR WG LB SM Circle Commands That Include an Automatic Pen Down Group The Vector Group The Polygon Group Edge Rectangle Absolute Edge Polygon Edge Rectangle Relative Edge Wedge Fill Polygon Fill Rectangle Absolute Fill Rectangle Relative Fill Wedge Label Symbol Mode The Character Group The Line and Fill Attributes Group Notes Whenever the printer receives a Pen Down command, it produces a dot at the current pen location. If the pen is already down when the printer receives a command with an automatic Pen Down, the unnecessary dot can mar your final output. For best results, include a Pen Up (PU) command before any command with an automatic Pen Down. Only the portion of the pen falling within the effective window is printed. The pen is centered on a line between the beginning and end points, with half of the pen width falling on either side of this line. The definition of each command tells you whether it has an automatic pen down. If you find that part of your image is not drawn, make sure your command sequence uses the PD command before the affected commands. 17-22 An Introduction to HP-GL/2 Vector Graphics EN Pen Location Pen location refers to the X,Y coordinates of the current active position (CAP -- the point at which the next HP-GL/2 command begins). Most commands, when completed, update the pen location. The next command then begins at that location. Some commands do not update the current pen location. The definition of each command tells you whether the current pen location is updated or restored. Use the Pen Up (PU) command with the desired X,Y coordinates to lift the pen and move it to a new location. The Default Values (DF) command does not reset the current pen location; the Initialize (IN) command moves it to the lower-left corner of the PCL Picture Frame. You should specify your beginning pen location for each HP-GL/2 drawing. EN Pen Status and Location 17-23 Scaling When you scale a drawing, you define your own units of measurement instead of using plotter units; the printer converts your units (user-units) to dot positions for placing the image on the page. Scaling allows control of the printer using units that are easy for you to work with. For example, you can scale your drawing to divide the drawing area into 100 squares. As you plan the drawing, you can think in terms of 100 squares rather than plotter units. Here is another example of scaling: since 400 plotter units equals 1 centimeter, you can establish this scale to print in user-units equal to 1 centimeter each. Scaling begins with the scaling points, P1 and P2. P1 and P2 act as two points marking opposite corners of a rectangle. You can make this rectangle any size and place it anywhere in relation to the origin, depending on the plotter unit coordinates you specify for P1 and P2. (P1 and P2 default to the lower left and upper right corners of the picture frame, respectively, but you can change their locations using the Input P1 and P2 (IP) or Input Relative P1 and P2 (IR) commands.) After you have defined the positions for P1 and P2, or have accepted the default, use this imaginary rectangle to set up scaling for your drawing. With the Scale (SC) command you specify how many sections the rectangle divides into horizontally (the X-axis) and how many sections the rectangle divides into vertically (the Y-axis). With this process you have created your user-units. Scaling also allows you to enlarge or reduce your image by changing the locations of P1 and P2. P1 and P2 represent physical locations in relation to the PCL Picture Frame. When the imaginary rectangle formed by P1 and P2 is enlarged or reduced with the IP or IR commands, the HP-GL/2 image is also enlarged or reduced to fit the new P1/P2 rectangle. (For a more detailed explanation of scaling and the Scale (SC) command, see Chapter 19.) For importing existing HP-GL/2 images, another method of enlarging or reducing drawings exists. It involves varying the size of the PCL Picture Frame and is described next. This method allows you to scale an image while maintaining the aspect ratio of all elements (including fonts). The Scale command does not affect the size of fonts. 17-24 An Introduction to HP-GL/2 Vector Graphics EN Absolute and Relative Pen Movement The Plot Absolute (PA) and Plot Relative (PR) commands allow you to set whether you want to draw using absolute or relative "pen" moves. Absolute pen movement uses X,Y coordinates to specify an exact, fixed point relative to the origin (0,0). In Figure 17-9, the coordinates (3,8), (5,4), and (8,1) are always in the same place with respect to the origin, no matter where the pen is when the coordinates are issued. Figure 17-9 Absolute Coordinates Relative pen movement uses X,Y increments to specify the number of units the pen moves from its current pen location. All commands that use relative increments include "relative" in their name (except the PE command). (An example is the Edge Rectangle Relative (ER) command. In Figure 17-10 for example, assume that the pen is currently at the origin (0,0). To move to the absolute points shown in Figure 17-9 using relative coordinates, count 3 units to the right and 8 units up from the current pen location; these are both positive directions with respect to the origin. This is the relative location (3,8). Now move 5 positive X-units and 7 negative Y-units from this location to the lower point; this is the relative location (5,-7). From this location, move to the last point by moving 3 negative X-units and 3 positive Y-units (-3,3). EN Absolute and Relative Pen Movement 17-25 Figure 17-10Relative Coordinates Relative movement is useful in many applications where you know the dimensions of the shape you want, but do not want to calculate the absolute coordinates. For example, if you want a box 4 X-units by 8 Y-units, you can use the Edge Rectangle Relative (ER) command to draw the box without having to calculate the absolute coordinates of the opposite corner. (The ER command draws a rectangle using the current pen location as one corner, and the specified relative coordinates as the opposite corner.) Absolute pen movement is the default mode; coordinates received within a PU (Pen Up) or PD (Pen Down) command are interpreted as absolute plotter units unless a PR (Plot Relative) command establishes relative mode. As with absolute coordinates, the relative units can be either user-units or plotter units, depending on whether the SC command is in effect. Note Relative increments add to the current pen location. The printer automatically converts the new relative location to absolute coordinates and updates the current pen location. Using relative coordinates can be faster in cases where the I/O speed limits your print speed, since relative coordinates are generally smaller numbers and therefore transmit less data over the I/O. 17-26 An Introduction to HP-GL/2 Vector Graphics EN 18 The Picture Frame Introduction When importing an existing HP-GL/2 file, or creating an HP-GL/2 image within an application, you use several PCL commands to set up the picture frame size, choose the picture frame location, and enter and exit HP-GL/2 mode. This chapter explains these PCL commands. The following terms are used in this discussion: Picture presentation directives are a group of PCL commands which: Provide the means to enter and exit HP-GL/2 context. Define a delimiting rectangle for the graphic image. Specify a scaling factor so existing HP-GL/2 graphics can be scaled and placed anywhere on the PCL logical page. Picture frame refers to the destination rectangle when transferring HP-GL/2 graphics into the PCL logical page. The PCL picture frame size commands specify the size of the destination rectangle. Picture frame scaling factor is the ratio of the size of the picture frame to the size of the source HP-GL/2 plot. There may actually be two scaling factors, one for the x direction and one for the y direction. Picture frame anchor point refers to the upper left corner of the picture frame, which is set to the current active position (CAP) in the PCL environment at the time the picture frame anchor point command is executed. EN Introduction 18-1 Defining the Image Area(PCL Picture Frame) There is a group of commands that allows you to specify an area on the page for placing an HP-GL/2 graphic image. These commands are the Picture Presentation Directives and are used to define a bounding rectangle to contain the HP-GL/2 image. Figure 18-1 illustrates the Picture Presentation Directives. The rectangular area surrounding the image is the PCL Picture Frame and the location on the page of the PCL Picture Frame is determined by the picture frame anchor point. Refer to Figures 2-3 and 2-4 for the default picture frame size. Figure 18-1 The Picture Presentation Directives 18-2 The Picture Frame EN Automatically Adjusting Image Size to Fit the PCL Picture Frame FrameImported HP-GL/2 drawings can be adjusted automatically to fit the size of the PCL Picture Frame without changing the locations of P1 and P2 (in Scale mode, as described earlier). This is called picture frame scaling. When using picture frame scaling, specify the HP-GL/2 plot size unless the drawing is page size-independent (described below). If a drawing is not page size-independent, the printer will not adjust the size of the image to fit the picture frame without the HP-GL/2 plot size command; the drawing and the picture frame are assumed to be the same size. If a drawing is page size-independent, it automatically enlarges or reduces to fit within the picture frame without specifying an HP-GL/2 plot size. Creating a Page Size-Independent Plot As mentioned, if an imported HP-GL/2 drawing is page sizeindependent, it is adjusted automatically to fit different page sizes without specifying the HP-GL/2 plot size. For a drawing to be page size-independent, it must not specify any parameters in absolute units. This implies that: No parameter of any command is in plotter units. The scaled mode (SC command) must be used exclusively; either the default locations of P1 and P2 are used, or their positions are specified with the IR (Input Relative P1 and P2) command. The default window is used, or the window is specified in user-units (using the IW command). For labels, only the SR (Relative Character Size) mode is used; the SI (Absolute Character Size) mode is not used. The Pen Width selection mode (WU) is specified as relative instead of metric. The pattern length for the Line Type (LT) is specified as relative instead of metric. Scalable fonts are used exclusively. The default window is used, or the window is specified in user-units. The DR command (relative direction) is used for label direction (not DI -- absolute direction). EN Automatically Adjusting Image Size to Fit the PCL Picture Frame 18-3 If a drawing does not meet the above criteria and the drawing is not the same size as the picture frame, the HP-GL/2 plot size must be specified to accomplish the desired scaling. If it is not specified, the image is clipped to the effective window and no scaling occurs. Note The above bulleted items are required for automatic scaling when the picture frame size changes, without specifying the HP-GL/2 plot size. However, if an HP-GL/2 plot size is specified, any unscaled HP-GL/2 image (any image created without the SC command) is automatically enlarged or reduced to fit the PCL Picture Frame; the amount of enlargement or reduction is determined by the picture frame scaling factor (the ratio of the HP-GL/2 plot size to the PCL Picture Frame size). See Chapter 19 to specify an HP-GL/2 plot size. 18-4 The Picture Frame EN Typical HP-GL/2 PlotCommand Sequence Before we discuss the actual commands and how they operate, we will demonstrate the general sequence in which these commands are used to print HP-GL/2 files. The following command sequence is usually followed when creating HP-GL/2 images: Send the job control and page control commands, and any other PCL commands that you wish to send before drawing the HP-GL/2 image. (See Chapters 3, 4, and 5 for job control and page control information.) Specify the PCL Picture Frame dimensions using the EC*c#X (Picture Frame Horizontal Size) and EC*c#Y (Picture Frame Vertical Size) commands. These commands determine the boundary of the window in which you place or draw your image. The PCL Picture Frame represents the maximum boundary for your HP-GL/2 drawing. Specify the picture frame anchor point using the EC*c0T (Set Picture Frame Anchor Point) command. This command determines the position on the logical page where the upper left corner of the PCL Picture Frame is placed. Receipt of this command establishes the PCL picture frame anchor point at the PCL current cursor position. If importing an existing plot, defined in absolute units, specify the HP-GL/2 plot size using the ECEC*c#K (Horizontal HP-GL/2 Plot Size) and EC*c#L (Vertical HP-GL/2 Plot Size). This plot size represents the size of the original HP-GL/2 image. If you are creating a drawing within an application, do not send these commands. Enter HP-GL/2 mode using the EC%#B command. Send HP-GL/2 commands (IN;SP1;. . .). Exit HP-GL/2 mode by sending the EC%#A (Enter PCL Mode) command. Send more PCL commands if desired or issue an ECE command to end the job and eject the page. Note Whenever a printer reset (ECE) is sent at the beginning of a job, precede it with a UEL (EC%­12345X) command; whenever a printer reset is sent at the end of a job, follow it with a UEL command. EN Typical HP-GL/2 PlotCommand Sequence 18-5 Table 18-1 E CE Example: Creating and Using a PCL Picture Frame Reset the printer. E C&l2A E C&l0O E C*c3060x3960Y Set the page size to letter. Specify portrait orientation. Specify a 4.25-inch wide by 5.5-inch high PCL Picture Frame (4.25in. x 720 decipoints/in. = 3060 decipoints; 5.5in. x 720 decipoints/in. = 3960 decipoints). Move the cursor to the point you desire as the picture frame anchor point. Set the picture frame anchor point to the current cursor position. Specify that the original HP-GL/2 plot size is 8.5 inches wide by 11 inches high. This sets up a scaling factor of 2:1 because the original HP-GL/2 plot size is twice as large as the PCL Picture Frame (4.25 x 5.5 inches). (If you are creating a drawing within an application instead of importing an existing plot, do not send this command.) Enter HP-GL/2 mode with the pen (HP-GL/2 cursor) at the PCL cursor position. In this example, the cursor would be at the picture frame anchor point (600 PCL Units down from the top of the logical page and 565 PCL Units to the right of the left logical page boundary). E C*p565x600Y E *c0T C E C*c8.5k11L E C%1B 18-6 The Picture Frame EN Table 18-1 Example: Creating and Using a PCL Picture Frame Send the HP-GL/2 commands you desire to send. (The IN command defaults the pen position to the HP-GL/2 origin, the lower-left corner of the PCL Picture Frame.) Enter the PCL mode with the cursor at the current HP-GL/2 pen position. Send some text or more PCL commands. Reset the printer to end the job and eject a page. IN;SP1;PU50,50; E C%1A TextTextText E CE Figure 18-2 The previous example provides an idea of the commands involved in printing an HP-GL/2 plot, whether importing an existing drawing or creating one within an application. The example describes one way to print a plot, but many things can be varied such as the picture frame size and location, and the cursor position when entering and leaving HP-GL/2 mode. EN Typical HP-GL/2 PlotCommand Sequence 18-7 Note If you have a page size-independent HP-GL/2 image, there is no need to set plot size, otherwise it is good practice to set plot size. The commands that allow you to set up a PCL Picture Frame and enter/exit HP-GL/2 mode are discussed in detail in the rest of this chapter. By reading the following command descriptions, you can see how changing command parameters can affect your printed output. Horizontal Picture Frame Size This PCL command specifies the horizontal dimension of the window to be used for printing an HP-GL/2 plot. E C*c#X # Default Range Note =Horizontal size in decipoints (1/720th inch) = width of the current logical page = 0 - 32767 (valid to 4 decimal places) The horizontal dimension specified is parallel to the PCL X-axis when the print direction is set to 0 degrees (the default). Using this command defaults the location of P1 to the lower left corner of the picture frame, and P2 to the upper right corner of the picture frame. It also resets the soft-clip window to the PCL Picture Frame boundaries, clears the polygon buffer, and updates the HP-GL/2 pen position to the lower-left corner of the picture frame (P1), as viewed from the current orientation. If no horizontal picture frame size command is used, the printer defaults the picture frame size to the logical page width. A parameter value of 0 or the PCL reset, UEL, page length, paper size, or orientation commands default the horizontal picture frame size. If an HP-GL/2 plot size is specified, the horizontal picture frame size is used to determine the horizontal scaling factor used for scaling the image to fit in the picture frame. 18-8 The Picture Frame EN Example: To specify a horizontal picture frame size of 5 inches, send: E C*c3600X (5 in. x 720 decipoints/in. = 3600 decipoints). Vertical Picture Frame Size (Decipoints) This PCL command specifies the vertical dimension of the window used for printing an HP-GL/2 plot. E C*c#Y # Default Range Note =Vertical size in decipoints (1/720th inch) = The distance between the default top and bottom margins (the default text length) = 0 - 32767 (valid to 4 decimal places) The vertical dimension specified is parallel to the PCL Y-axis when the print direction is set to 0 degrees (the default). Example:To specify a vertical picture frame size of 6.5 inches, send: E C*c4680Y (6.5 in. x 720 decipoints/in. = 4680 decipoints) EN Vertical Picture Frame Size (Decipoints) 18-9 Set Picture Frame Anchor Point This command sets the location of the PCL Picture Frame anchor point to the PCL cursor position. E C*c0T Default Range =0 =0 The position of the picture frame anchor point defines the location of the upper left corner of the PCL Picture Frame. The "upper left" refers to the corner for which X and Y coordinates are minimized when the print direction is 0. A parameter value of zero (EC*c0T) specifies that the picture frame anchor point should be set to the cursor position. Sending a cursor move command prior to sending this command places the picture frame anchor in the desired location. All parameter values other than zero are ignored, but if you do not send a Set Picture Frame Anchor command, the printer defaults the anchor point to the left edge of the logical page and the default top margin. Note The print direction command does not affect the physical location of the anchor point or the picture frame. Using this command defaults the location of P1 and P2, resets the soft-clip window to the PCL Picture Frame boundaries, clears the polygon buffer, and updates the HP-GL/2 pen position to the lower left corner of the picture frame (if entered with EC%0B), as viewed from the current orientation. Example: To set the picture frame anchor point to a position 6 inches from the left logical page boundary and 5 inches below the top margin, send: E E C*p1800x1500Y C*c0T In this example, the cursor is first moved to the desired location (6 inches x 300 dots/inch = 1800 dots; 5 inches x 300 dots/inch = 1500 dots). Then the EC*c0T command sets the picture frame anchor point to that location. 18-10 The Picture Frame EN HP-GL/2 Plot Horizontal Size This command specifies the horizontal size of the HP-GL/2 drawing being imported. E C*c#K # Default Range =The horizontal size in inches = width of the currently selected picture frame = 0 to 32767 (valid to 4 decimal places) The horizontal HP-GL/2 plot size determines the horizontal scaling factor used to fit the drawing into the PCL Picture Frame. For example, if the horizontal HP-GL/2 plot size is specified as 12 inches and the PCL Picture Frame width is 4 inches, the horizontal scaling factor would be 3:1; the horizontal component of the image would be reduced to one-third its original size to fit into the PCL Picture Frame. A parameter value of zero or a reset, page length, paper size, or orientation command defaults the HP-GL/2 plot size to the width of the currently selected picture frame, resulting in no scaling. Example: If the original HP-GL/2 drawing is 8.5 inches wide, send: E *c8.5K C EN HP-GL/2 Plot Horizontal Size 18-11 HP-GL/2 Plot Vertical Size This command specifies the vertical size of the HP-GL/2 drawing being imported. E C*c#L # Default Range =The vertical size in inches = height of the currently selected picture frame = 0 to 32767 (valid to 4 decimal places) The vertical HP-GL/2 plot size value determines the vertical scaling factor used to fit the drawing into the PCL Picture Frame. For example, if the vertical HP-GL/2 plot size is specified as 7 inches and the PCL Picture Frame height is 14 inches, the vertical scaling factor would be 1:2; the vertical component of the image would be enlarged to twice its original size to fit into the PCL Picture Frame. A parameter value of zero or a reset, page length, paper size, or orientation command defaults the HP-GL/2 plot size to the height of the currently selected picture frame, resulting in no scaling. Example: If the original HP-GL/2 drawing is 7 inches tall, send: E *c7L C 18-12 The Picture Frame EN Enter HP-GL/2 Mode This command causes the printer to interpret subsequent commands as HP-GL/2 commands, instead of PCL printer language commands. E C%#B # Default Range =0-- Position pen at previous HP-GL/2 pen position 1 -- Position pen at current PCL cursor position =0 = 0, 1 (even values are mapped to 0; odd values are mapped to 1; EC%B is the same as EC%0B) As soon as the printer receives this command, it switches to HP-GL/2 mode, interpreting commands as HP-GL/2 commands until it receives an Enter PCL Mode, ECE, or UEL command, or until the printer power is switched off and on. (For information on the effect of PCL settings on HP-GL/2 mode, see "Default Settings" later in this chapter.) The value field (#) determines the cursor position once HP-GL/2 mode is entered. 0-- This parameter option (EC%0B) sets the pen position to the previous HP-GL/2 position; if this is the first time HP-GL/2 mode is entered in the present print job (assuming an ECE has been sent), the pen position is at the lower left corner of the PCL Picture Frame (0,0). 1-- This parameter option (EC%1B) specifies that the pen position be the same as the current PCL cursor position. Example: To set the pen position to the current PCL cursor position, send: E C%1B EN Enter HP-GL/2 Mode 18-13 Enter PCL Mode This command causes the printer to return to PCL mode from HP-GL/2 mode. E C%#A # Default Range =0-- Position cursor at previous PCL cursor position. 1 -- Position cursor at current HP-GL/2 pen position. =0 = 0, 1 (even values are mapped to 0; odd values are mapped to 1) Sending the Enter PCL Mode command causes the printer to stop interpreting the incoming data as HP-GL/2 commands and to begin interpreting the data as PCL commands. The value field (#) specifies the cursor position when PCL mode is entered. 0-- A 0 parameter (EC%0A) sets the pen position to the previous PCL position (the cursor position before entering HP-GL/2 mode). 1-- A 1 parameter (EC%1A) sets the cursor position to the current HP-GL/2 pen position. If the current HP-GL/2 pen position is outside the bounds of the PCL logical page, the nearest point on the logical page boundary becomes the new PCL cursor position. No PCL variables except the cursor position are affected by entering and exiting HP-GL/2 mode. Example: To exit HP-GL/2 mode using the current active cursor position (CAP) that existed before entering HP-GL/2 mode, send: E C%0A 18-14 The Picture Frame EN Default Settings When you enter HP-GL/2 mode, most vector graphics variables retain their previous HP-GL/2 value. However, the following changes in the PCL environment can affect the HP-GL/2 environment: Resetting the printer (ECE or control panel reset): · Executes an IN (Initialize) command · Defaults the PCL Picture Frame size · Defaults the PCL Picture Frame anchor point · Defaults the HP-GL/2 plot size · Defaults the PCL logical page orientation A page size, page length, or orientation command: · Defaults the PCL Picture Frame anchor point · Defaults the PCL Picture Frame · Defaults the HP-GL/2 plot size · Defaults P1 and P2 (IP,IR commands) · Resets the soft-clip window to the PCL Picture Frame boundaries (IW command) · Clears the polygon buffer (PM0,PM2) · Updates the cursor to the lower-left corner of the picture frame (P1). Redefining the PCL Picture Frame: · Defaults P1 and P2 (IP,IR commands) · Resets the soft-clip window (IW) to the PCL Picture Frame boundaries. · Clears the polygon buffer (PM0,PM2) · Updates the current pen position to the lower-left corner of the picture frame (P1) Setting the picture frame anchor point: · Defaults P1 and P2 (IP,IR commands) · Resets the soft-clip window to the PCL Picture Frame boundaries (IW command) · Clears the polygon buffer (PM0,PM2) · Updates the current pen position to the lower-left corner of the picture frame (P1) Setting an HP-GL/2 plot size: · Changes the picture frame scaling factor EN Default Settings 18-15 As the printer enters HP-GL/2 mode for the first time since ECE, power-on, or control panel reset, all HP-GL/2 variables are at their default settings, as determined by the Picture Presentation Directives (the PCL Picture Frame Size, Picture Frame Anchor Point, and HP-GL/2 Plot Size commands). Table 18-2 E CE E C&&l2A E C&&l0O E *c3600x3600Y C Example: Creating a Simple Drawing Reset the printer. Set the page size to letter. Specify portrait orientation. Specify a 5-inch wide by 5-inch high PCL Picture Frame (5in. x 720 decipoints/in. = 3600 decipoints). Move the cursor to the point you desire as the picture frame anchor point. E C*p450x675Y E C*c0T Set the picture frame anchor point to the cursor position. 18-16 The Picture Frame EN Table 18-2 Example: Creating a Simple Drawing (continued) Enter HP-GL/2 mode with the cursor (pen) at the PCL cursor position. In this example, the cursor is at the picture frame anchor point (450 dots [1.5 in.] down from the top margin and 675 dots [2.25 in.] to the right of the left logical page boundary). Initialize HP-GL/2 command values and select pen number 1 (black). (The IN command moves the pen position from the anchor point to the HP-GL/2 origin, the lower-left corner of the PCL Picture Frame.) Set up user scaling so that P1 is (0,0) and P2 is (100,100) (these points are the lower-left and upper-right corners of the PCL Picture Frame, respectively). E C%1B IN;SP1; SC0,100,0,100; PD100,0,100, 100,0,100,0,0; Draw a box marking the perimeter of the PCL Picture Frame. EN Default Settings 18-17 Table 18-2 Example: Creating a Simple Drawing (continued) PU50,50;CI25; Lift the pen and move to the center of the PCL Picture Frame (50,50); draw a circle with a radius that is 25% of the picture frame width. Enter the PCL mode with the cursor at the current HP-GL/2 pen position. Reset the printer to end the job and eject a page. E C%1A EE C Note Any line drawn along the border of the effective window will cause the line to be clipped, producing a line width one-half of the defined pen width. For example, all the lines drawn in the above example are half the width of the other lines since they are clipped at the window borders. 18-18 The Picture Frame EN 19 The Configuration and Status Group Introduction The configuration and status group commands help you: Establish default conditions and values for HP-GL/2 features. Scale images in the dimensional units you want to use. Enlarge/reduce images for different media sizes. Establish a window (soft-clip limits). Draw equal-sized and mirror-imaged drawings. Rotate the HP-GL/2 coordinate system. Add comments to your HP-GL/2 command sequence. Table 19-1 lists the commands described in this chapter. EN Introduction 19-1 Table 19-1 Command The Configuration and Status Group Commands Summary Allows comments to be included in an HP-GL/2 command sequence. Sets most programmable HP-GL/2 features to their default conditions. Sets all programmable HP-GL/2 features to their default conditions. Establishes new or default locations for the scaling points P1 and P2. Establishes P1 and P2 locations as a percentage of the PCL Picture Frame. Sets up a window (soft-clip limits). This command is ignored.1 Rotates the HP-GL/2 coordinate system. This command is ignored. Establishes a user-unit coordinate system. CO, Comment DF, Default IN,Initialize IP, Input P1 and P2 IR, Input Relative P1 and P2 IW, Input Window PG, Advance Full Page RO, Rotate Coordinate System RP, Replot SC, Scale 1. These commands, useful in plotter applications, are not the optimal solution for PCL 5 printers. Other PCL commands perform similar functions (see the Number of Copies and Form Feed command descriptions). 19-2 The Configuration and Status Group EN Establishing Default Conditions Whether you are using HP-GL/2 mode or strictly the PCL printer language mode, you should establish default conditions at the beginning of each print job to prevent unexpected results due to "leftover" command parameters from a previous job. From within HP-GL/2 mode there are two ways to establish default conditions: using the Initialize (IN) command or using the Default (DF) command. Using the IN command sets the printer to its user-selected defaults. This process is called initialization. The reset command (ECE) executes an Initialize (IN) command automatically, so if a reset was sent at the beginning of your print job, HP-GL/2 command parameters are at their user-selected default state when HP-GL/2 mode is first entered. (See Chapter 3 for a more thorough discussion of the printer environment and how it is affected by the reset command.) Note HP-GL/2 command parameters are set to their default values the first time HP-GL/2 mode is entered during a print job (assuming that an E CE reset is sent at the beginning of the job). After commands have been sent to modify the current print environment, the command parameters are no longer set to their defaults. When re-entering HP-GL/2 mode, immediately sending an IN command ensures that HP-GL/2 features are set to their default conditions (if that is desired). The DF command is not as powerful as the IN command. The conditions set by the DF and IN commands are described later in this chapter. EN Establishing Default Conditions 19-3 The Scaling Points P1 and P2 When you scale a drawing, you define your own units of measurement, which the printer then converts to plotter units. Scaling relies on the relationship between two points: P1 and P2. These two points are called the scaling points because they take on the user-unit values that you specify with the Scale (SC) command. You can change the locations of P1 and P2 using either the Input P1 and P2 (IP), or Input Relative P1 and P2 (IR) command. P1 and P2 always represent an absolute location in relation to the PCL Picture Frame, defined in plotter-units. They designate opposite corners of a rectangular printing area within the picture frame. You can change the size of the rectangular printing area and move it anywhere within the picture frame, or even outside the picture frame, depending on the plotter-unit coordinates you specify using the IP or IR commands. Using the Scale Command Scaling allows you to establish units of measure with which you are familiar, or which are more logical to your drawing. The Scale command (SC) determines the number of user-units along the Xand Y-axes between P1 and P2. The actual size of the units depends on the locations of P1 and P2 and the range of user-units set up by the SC command. There are three types of scaling: Anisotropic Isotropic Point-factor Anisotropic scaling indicates that the size of the units along the X-axis may be different than the size of the units on the Y-axis. Isotropic scaling, then, indicates that the units are the same size on both axes. Point-factor scaling sets up a ratio of plotter units to user-units. The Scale command does not change the locations of P1 and P2, only their coordinate values. Also, scaling is not limited to the rectangular area defined by P1 and P2, but extends across the entire printing area within the PCL Picture Frame. 19-4 The Configuration and Status Group EN