59 PICTURETHIS "SHAREWARE" VERSION RELEASE 2.00 MAY 1, 1989 USER MANUAL, PART 4 OF 5 PARTS Copyright 1988, 1989 by Patricia Y. Williams and Gregory Williams, All Rights Reserved. 18.6 WRITING A POSTSCRIPT FILE At the file menu, the WriteEPS option (for saving an encapsulated PostScript file to disk for subsequent delivery to a laser printer, imagesetter, or page layout program) is accessed by pressing: W PictureThis allows a great deal of flexibility in specifying how the PostScript output will appear. One or multiple (tiled) pages are allowed. The printed drawing can be small or large, and it can be scaled irregularly. Also, the drawing can be placed anywhere on the page, in "portrait" or "landscape" orientation (see below). To specify these parameters, several prompts appear in succession. These prompts all have "current" values which are acceptable in many cases. If the "current" value is acceptable for a prompt, just press "ENTER." Changes to any parameter are made by typing a new value in. "Esc" will return the previous prompt (with its current value as you just set it), so you can go back and reset a parameter without starting from the beginning. The first four prompts request information about the size and margins of the physical page on which you are printing. Initially, the size is set to 8.5 inches by 11 inches, and the margins are set to .25" all around. It is important to note that changing these parameters does NOT set your laser printer to accept a different size paper or reset its margins; that has to be done independently, and the procedure varies depending on the printer. PictureThis uses the parameters to position drawings on individual pages, and to determine the printing area for multiple page drawings. The initial settings are probably acceptable in most cases, even if the margins on the laser printer you are using are slightly different. If you change any of these four parameters, the new values will remain for the rest of your PictureThis session, unless they are changed again. Next a prompt appears: "Landscape orientation? (Y/N/ESC)." "Landscape orientation" (chosen by pressing "Y") means that the printed output will have the drawing's WIDTH (whether or not it is longer than the drawing's height) oriented PARALLEL 60 to the paper's height. The WIDTH direction always corresponds to the HORIZONTAL direction on your monitor screen, and the HEIGHT direction always corresponds to the VERTICAL direction on your monitor screen. The alternative to "landscape orientation" is "portrait orientation," with the drawing's WIDTH oriented PARALLEL to the paper's width, which is chosen by pressing any other key (except "Esc"). See the diagrams below. LANDSCAPE ORIENTATION PORTRAIT ORIENTATION _____________________ _____________________ | _________ | | _____________ | || | | || | | || | | || | | || | | || DRAWING |___ | || DRAWING | | || | / | || |______ | ||_____________| / | || | / | | \ / | ||_________| / | | WIDTH HEIGHT | | \ / |<-PAGE | | | HEIGHT WIDTH | EDGES->| | | | | | | | | | | | | | | | | | |_____________________| |_____________________| NOTE: DRAWING WIDTH IS USUALLY, BUT NOT NECESSARILY, LONGER THAN DRAWING HEIGHT The next prompt requests the drawing width in inches. The first line of this prompt shows the current drawing width. Initially, it is set from your drawing's frame (see Section 21.1) and scale (see Section 21.2). (Remember that parts of your drawing outside of the frame will NOT print.) If you have not changed the frame or the drawing's scale, the width is 8.00 inches. If you want to change the drawing's width, enter a new value greater than 0 inches and less than 7500 inches. Obviously, you will seldom want to scale the drawing near either of the two extremes! If you do change the width of the drawing, another prompt will appear: "Scale line weights with width? (Y/N)"; otherwise, a box with instructions for changing the height appears (described in the next paragraph). Scaling line weights means that the thicknesses of curves on the printed output will be scaled proportionally to the width; they will have the values assigned when they were originally drawn using PictureThis if the width setting has not changed. To scale line weights with width, press "Y." To use the line weight values originally assigned when the curves were drawn using PictureThis, regardless of width setting, press any other key. Next, another prompt appears, requesting you to set the height of the drawing. The first line of the prompt ("Height if scaled uniformly: XXX.XX"), shows the height of the 61 drawing if it is scaled uniformly with the current width. (This depends on the drawing's frame (see Section 21.1) and the aspect ratio (see Section 23).) If you want to change the height setting for the printed drawing output (thus altering the proportional scaling of width to height), type in a new height. (Note: if you come back to this prompt via "escapes," the first line changes to "Current height of drawing:" followed by the height that you entered.) If you altered the height setting, another box with instructions ("Skew line weights irregularly? (Y/N)") appears. If you want curves to appear on the printed output with their thicknesses skewed in proportion to the scaling of width to height, press "Y"; press any other key if you don't want to skew curve thicknesses. Skewing curve thicknesses means that the thicknesses depend on the orientations of the curves. For example, if the printed drawing output height is set to be much greater than the width, a curve oriented along the height direction will have a much smaller thickness than will a curve oriented along the width direction, even though both curves were assigned the same lineweight when they were originally drawn using PictureThis. You might want to experiment with skewing to gain a better understanding of how it works. The next two prompts allow you to specify where the top left corner of the drawing's frame will appear on the paper. The first prompt requests the "horizontal indent": how far the left edge of the drawing's frame will be from the left edge of the paper. The initial value is the left margin of the paper (as set above). You can change this value to be anywhere between the left and right margins. The second prompt requests the "vertical indent": how far the top edge of the drawing's frame will be from the top edge of the paper. The initial value is the top margin of the paper (as set above). You can change this value to be anywhere between the top and bottom margins. (Note that if you indent too much, a drawing that would normally fit on one page will extend to two or four pages.) From the settings, PictureThis calculates how many physical pages will be required for the drawing. If the result is more than one page, two more prompts appear. The first prompt asks if you want to overlap the page margins. If you answer "Y," the separate page outputs will have a .25 inch overlap - the last 1/4 inch of the page will also be the first 1/4 inch on the next page, both horizontally and vertically. If you press any other key (except "Esc"), there will be no overlap. Experiment to find which method is preferable to you for assembling multiple page drawings. After this prompt is answered, another prompt appears stating how many pages wide and high your output will be. It also warns you that the PostScript output will NOT be an Encapsulated PostScript file. Only drawing outputs that fit on a single page are made into EPSFs that can be incorporated into other programs. Drawings that are require multiple pages are simple, but not Encapsulated, PostScript programs that can be sent to any PostScript printer. (Of course, you can make a separate EPSF 62 file from the same drawing.) You are now asked if you want to continue. If the number of pages is satisfactory, press "Y." Otherwise, press any other key, and you will be taken back to the drawing width prompt, so you can respecify the parameters. Finally, the prompt for a file specification for a PostScript file appears. If you have previously saved an EPS file in the current PictureThis session, you will be asked if you want to use the last entered file specification. If you answer "Y," that file will be used again. If you answer "N" or if this is the first EPS file saved, you will see a prompt asking you to enter a file specification. The second line of this prompt is a file specification with the current directory, "*" for the filename, and "EPS" for the extension. (We strongly recommend using the extension "EPS" for your Encapsulated PostScript files.) If you press "ENTER," a directory will appear for the file specification on the second line. Select the filename by using the cursor keys to change the highlighted filename and press "ENTER" when the filename that you wish to use is highlighted. If you press "Esc" you will return to the last prompt. If you wish to see the directory for a different "wild card" file specification, type that specification in and its directory will appear. The path that you type in will be used as the "current path" in subsequent EPS file saves. You may also directly type in the the desired name (with an extension and the appropriate operating system path specification if necessary) with which the Encapsulated PostScript file for the current drawing is to be saved. If this file already exists, you will be asked if you want to write over it. An "Esc" from the file specification takes you all the way back to the files menu. After the file specification is selected in one of the above ways, three more prompts appear. "Created by?" is the first. Key in an appropriate response, then press "ENTER." "Title?" is the next prompt that appears. Key in a title for your drawing, and press "ENTER." A final prompt appears: "Date: XX-XX-XXXX (Press ENTER or revise)." Press "ENTER" to accept the displayed date (the current system date) or key in a different date (no special format is required) and then press "ENTER." These last three prompt answers have no effect on your printed drawing. They are put in the "comments" section at the beginning of the file you are saving, and they are sometimes used by page layout programs to aid in file identification. Wait until all disk activity has stopped before you continue. (If you get an error message, you should attempt to correct the problem and then try again.) Encapsulated PostScript files (EPSFs) produced by PictureThis contain only ASCII characters, so they can be viewed with the operating system "TYPE" command, and they can be edited with most word processing programs; also, they can be merged with other PostScript files, such as those produced by page layout programs (some of which have the ability to recognize EPSFs for positioning and scaling). If you don't have access to an EPSF-recognizing page layout program, 63 PostScript files created by PictureThis can be delivered directly to PostScript-compatible output devices to produce printed output. (If you know how to program in PostScript, you can modify the output by appropriate editing of the PostScript files. PictureThis-produced PostScript files are quite straightforward. In particular, text can be added. A future version of PictureThis will incorporate text editing, but until then, you'll find that it isn't very hard to add simple text by merging files created by PictureThis and files created by page layout programs.) For best results, you'll need to experiment with the page layout program(s) and/or PostScript compatible output devices to which you have access. 18.7 SHELLING TO DOS PictureThis allows you to shell to DOS and use the normal DOS facilities without exiting PictureThis. While in the "FILES" state, press: D When you do this, one of two error messages may appear. If the valid COMMAND.COM file is not in the current directory or in a path specified in your PATH specification (see your DOS manual), you will get an error message, and you will not be allowed to shell to DOS. If COMMAND.COM is found, but there is insufficient memory to shell, you get an error message, and you will not be allowed to shell to DOS. If no problems are encountered, the DOS prompt will appear and you will be able to carry out normal DOS functions. When you want to return to PictureThis, type "EXIT" (or "exit"), then press "ENTER" at the DOS prompt. PictureThis will return in the "FREE" state. 19. UNITS AND POSITION BOXES PictureThis allows you to specify the units you want to work in. When PictureThis is loaded, the units are initially pixels, which are screen units directly related to the screen AND to the "internal units" in which PictureThis information is stored internally (see Section 19.3). Pixels are the best units to work in if you are drawing "visually" and do not require "real-world" measurements. If you need to relate your drawing to "real" measurements, you should change the current units (see Section 19.1). PictureThis provides two position boxes to tell you the distance of the cursor from the corner of the frame (see Section 19.2) and the relative position of the cursor to some previously specified point (see Section 19.4). 19.1 CHANGING THE CURRENT UNIT To change the current unit, press: 64 F9 The state changes to "MISC," and the miscellaneous menu appears. To change the current unit, press: U The unit menu appears. The first element in the menu shows the current units (abbreviated). To choose new units, press one of the following: "X" for pixels (PX), "I" for inches (IN), "P" for picas and points (PP), "T" for points (PT), "C" for centimeters (CM), or "M" for millimeters (MM). (For those unfamiliar with typographical units, a (PostScript) point is EXACTLY 1/72"; a (PostScript) pica is 12 points or EXACTLY 1/6".) If the chosen units are NOT pixels, you will see a further prompt asking if you want to measure from the top or the bottom of the frame (the horizontal measurement is always from the left edge of the frame). Pixels are always measured from the top of the frame. Press "T" if you want to measure the vertical units from the top of the frame, "B" if you want to measure from the bottom of the frame. The "FREE" state returns, and measurements in the position boxes are in the new units. If you have toggled the status box on (see Section 4.3), the current units (abbreviated) will appear as the rightmost element in the box.. Not only will the measurements be shown in the current units, but also the cursor also move in increments related to the units. If the units are pixels, the cursor moves in pixels (the CGA screen is 320 pixels horizontally and 200 pixels vertically): either one pixel or n pixels, where n is the current fast cursor speed (see Section 20.1). The cursor will move the same distance when a particular cursor key is pressed at any magnification, but it will move different distances for a cursor press in the horizontal direction than in the vertical direction, because CGA screen pixels are not square (see Section 23). For units other than pixels, the cursor moves in real units (or a multiple of real units), so the actual movement depends on the current magnification (see Section 6.1), the drawing scale (see Section 21.2), and the aspect ratio (see Section 23). Because of this, for one cursor press, the cursor will move three times as far on the 300% screen and one-half as far on the 50% screen as it moves on the 100% screen. The cursor movement for one cursor press at the slow cursor speed is shown in the following table: UNIT CURSOR MOVEMENT INCREMENT inches 1/100 inch points 1 point (1/72") picas & points 1 point (1/72") centimeters 1/10 cm (1 mm) millimeters 1 mm 65 If the fast cursor speed is toggled on (see Section 5), one cursor press will move the cursor n times the "cursor movement increment" in the above table, where n is the fast cursor speed (see Section 20.1). For example, the frame when PictureThis is started is 8 inches wide, and the fast cursor speed is 10. If you toggle the fast cursor speed on and change the unit to inches, it will require 80 presses of the right cursor key to move from the left side of the frame to the right. (Of course, there are faster ways to get there!) 19.2 CURRENT POSITION BOX The current position box can be toggled on by pressing: P (If you press P again, the relative position box will also be toggled on (see Section 19.4). A third press will turn both boxes off.) The current position box appears at the lower right corner of the screen with two numbers in it. The left number is the horizontal distance of the cursor from the left edge of the frame, specified in the current units; the right number is the vertical distance of the cursor from the frame origin (top or bottom (see Section 19.1)), also specified in the current units. (Unless the current units are pixels, in which case the position box numbers are in "internal units" (see Section 19.3).) If the current units are picas and points, the numbers are displayed as XXX&YY, where XXX is picas and YY is points (example: 12&11 means 12 picas and 11 points; remember, 1 pica equals 12 points). Note: the information displayed in the position box is calculated using floating point calculations for all units except pixels. If you do not have a math coprocessor, calculations might be considerably slower when the current position box is toggled on; if you are not using the information, toggle the position box off for more speed. 19.3 INTERNAL UNITS What are "internal units"? PictureThis saves the position of the cursor and all other elements in internal units (ius). These are integer values, so most calculations are done with integers instead of floating point numbers (making the calculations faster and the drawing files smaller). Ius have much finer resolution than the screen, allowing high resolution in the final output and precise cutting, smoothing, and object manipulations (scaling, rotation, etc.). Cursor jumps are stored as internal units. Ius are quite simply related to pixels: each cursor jump when the current units are pixels is an exact number of ius: 48 ius per pixel on the 50% screen, 24 ius per pixel on the 100% screen, and 8 ius per pixel on the 300% screen. The relationships between other units and ius depend on the drawing scale (see Section 66 21.2), the magnification (see Section 6.1), and the aspect ratio (see Section 23). A cursor jump when the current units are inches, for example, is stored as a certain number of ius, which might not be exactly 1/100 inch (.01"), but, perhaps, .0105". This matters little in practice (can you see .0005"?), but it needs to be recognized, since you will notice that the numbers in the position box do not always change by the exact amounts given in the cursor jump table in Section 19.1. (Note: If the fast cursor speed is toggled on, cursor jumps are more accurate.) You can always move the cursor to a more exact location, if necessary, by moving in internal units. To move in internal units, press: I The cursor now moves in 1 or n internal unit jumps (where n is the fast cursor speed). To return to "external units," press "I" again. The fourth character from the right in the status box is an "I" if the cursor is moving in ius; it is an "E" if the cursor is moving in external units; it is a "G" if the grid is active (see Section 20.3)). The number following this indicator is 1 if the slow cursor speed is toggled, or n (2 - 99) if the fast cursor speed is toggled. When "I" is toggled, the numbers in the position box still are in the current units. 19.4 RELATIVE POSITION BOX The relative position box gives information about the position of the cursor RELATIVE to a previously set point (which depends on the current state). It can be toggled on when the current position box is on by pressing "P," and it can be toggled off again (along with the current position box) by pressing "P" again. ("P" is a 3-way toggle.) There are four standard components of the relative position box: horizontal difference, vertical difference, distance, and angle (measured in degrees clockwise from a conceptual horizontal line extending to the right of the previously specified point). These numbers are all expressed in the current units. (The distance for pixels is expressed in HORIZONTAL internal units; vertical ius do NOT equal horizontal ius.) The previously specified point for each state is as shown in the following table. STATE POINT MEASURED FROM LINE first endpoint CURVE endpoint associated with current control point CHANGE endpoint associated with current control point BOX original box corner SQUARE original square corner OVAL center of oval FRAME original frame corner GRID current grid origin 67 MOVE start point COPY start point SCALE anchor point until "F2" ROTATE anchor point until "F2" FLIP 1st flipline point MEASUR point at which you pressed "M" TMPMOV start point For states not included in the table, the relative position box is empty. There are three special relative position box values. If the relative position box is on while scaling, after you press "F2" to set the 100% scaling line, the horizontal and vertical scale factors are shown (see Section 17.3). During rotation, the rotation angle is shown (see Section 17.4), and during inclination the inclination angle is shown (see Section 1.6). Note: the information displayed in the relative position box is calculated using floating point calculations for all units. If you do not have a math coprocessor, calculations will be slower when the relative position box is toggled on. If you are not using the information, toggle the box off for more speed. 20. CURSOR SPEED AND GRID Cursor movements can be changed in two more ways. The fast cursor speed can be changed, and the cursor can be restricted to snap-to a user-settable grid. 20.1 SETTING THE FAST CURSOR SPEED The cursor can move at the slow cursor speed of 1 cursor jump per press or at the fast cursor speed of n cursor jumps per press. You can toggle between these two speeds with the "Ins" key. The fast cursor speed is initially set to 10, but it can be changed to any integer between 2 and 99. To change the fast cursor speed, press "F9" to get to the miscellaneous menu. Then press: C A prompt appears with the current fast cursor speed shown on its first line. To change the fast cursor speed, enter an integer between 2 and 99. The next-to-last element of the status box is the current cursor speed, either 1 or the fast cursor speed you have set. 20.2 SETTING THE GRID The cursor can be constrained to move on a user-settable grid. To set the grid, press "F9" to get to the miscellaneous menu. Then press: G 68 The state changes from "MISC" to "GRID," and a prompt appears asking if you want to change the grid origin (the origin is a point which the grid goes through and other grid points are calculated from). The grid origin is initially set to be the top left corner of the initial frame, but it can be set to any on-screen point. (Note: Changing the frame does NOT change the grid origin.) If the current grid origin is satisfactory, press any key except "Y" or "Esc." If you want to change the grid origin, press "Y". A prompt will appear (if "H+" is toggled): "Move then F3 to set grid origin," and a dotted line will be drawn from the current grid origin to the cursor. Move the cursor to a new grid origin (the dotted line will follow) and press "F3." ("Esc" will bring up the prompt asking if you want to change the grid origin.) After you have established the grid origin (either by setting it or accepting the old one), a grid menu appears. The top line of this menu shows the grid parameters that you can change (the spacing of the grid, its form, and its color), and the word "Keep". The second line lists the current parameters. 20.2.1 CHANGING THE SPACING OF THE GRID To change the spacing of the grid, press: S A prompt appears, showing the current horizontal spacing of the grid in the current units (i.e., pixels, inches, etc.) and requesting that you enter a new horizontal spacing. (The initial spacing is one inch by one inch.) If the horizontal spacing is satisfactory, press "ENTER." If you want to change it, type in a new spacing in the current unit and then press "ENTER." "Esc" will return the grid menu. A new prompt appears, asking if you want square spacing. (Square spacing means that the distance in the horizontal and vertical direction are the same, but the number of internal units can be different in the two directions, depending on the aspect ratio (see Section 23).) If you answer "Y," the vertical spacing will be automatically calculated to be square, and the grid menu will reappear with the new spacing in the second line. If you press any other key (except "Esc"), a prompt will appear showing the current vertical spacing in the current unit, and requesting that you enter a new vertical spacing. Press "ENTER" if the current vertical spacing is acceptable, or type in a new vertical spacing and press "ENTER." The grid menu will reappear with the new horizontal and vertical spacings on the second line. (Note that the spacings are saved in internal units, so the actual spacing may be slightly off your entered value (see Section 19.3).) 20.2.2 CHANGING THE FORM OF THE GRID The grid can be invisible (its initial form), or it can 69 show as dots on the screen at each grid point or as horizontal and vertical dotted lines intersecting at each grid point (mesh). To change the form of the grid, while in the grid menu, press: F A grid form menu appears. If you want the grid to be invisible, press "N" for none. If you want the grid to appear as dots, press "D." If you want the grid to appear as a mesh, press "M." The grid menu reappears with the new form on the second line. Pressing "Esc" returns the grid menu with no change in form. 20.2.3 CHANGING THE COLOR OF THE GRID The color of a visible grid can be any of four colors. To change the color of the grid, while at the grid menu, press: C A grid color menu appears. If you want the grid to show in the background color (black, sometimes useful with a template), press "B." If you want the grid to show in the foreground color (the color in which curves and endpoints are drawn), press "F." If you want the grid to be shown in one of the two template colors, press "1" or "2." The initial color is template1. The grid menu will reappear with the new color indicated. "Esc" will return the grid menu with no changes. 20.2.4 SAVING THE GRID PARAMETERS To save the grid parameters entered (including the grid origin), press "K" for keep. The entered grid parameters become the current ones, the screen is redrawn with the new grid (even if invisible), and the state returns to "FREE." If you press "Esc" while on the grid menu, any changes to the grid (including a new grid origin) will NOT be saved, the state will return to "MISC," and the miscellaneous menu will reappear. The current grid parameters are saved with the current drawing (see Section 18.3), so when you retrieve a drawing, the grid will be reset to that associated with the drawing. 20.3 USING THE GRID The grid's main purpose is to restrict cursor movements to the grid points. To toggle the snap-to grid on, press: G The cursor moves to the nearest grid point (visible or invisible). If the status box is on, the third indicator from the left changes to "G." While the snap-to grid toggle is on, the cursor will move ONLY to grid points. Pressing a cursor 70 key will move the cursor one grid point in that direction. The fast cursor speed toggle ("Ins") and the internal unit movement toggle ("I") have no effect while the snap-to grid is toggled, except to change the cursor movements when the snap-to grid is toggled off again. While the snap-to grid is toggled on, the cursor will not move in any direction beyond the grid point closest to the edge of the screen in that direction. If you move the cursor off the grid by cursor movements not tied to the grid (finding endpoints, going to frame corners, etc.), PictureThis will check your position at the END of the movement, and automatically toggle the snap-to grid OFF if the cursor is not on a grid point. To toggle the snap-to grid off, press "G" again. 21. CHANGING THE FRAME AND SCALING THE DRAWING The size and shape of the rectangular frame determines which portion of your drawing is printed (and shown on the Quickshow screen). This frame can be changed at any time. The scale of the frame in "real-world" coordinates can also be changed. This means that you can set the width or height of the frame to represent a different size in the current unit. A frame that is 8 inches wide can be set to 4 inches wide. It will still look the same on the screen, but moving an "inch" on the screen will move the cursor twice as far as before. 21.1 CHANGING THE FRAME To change the frame (only when in the state "FREE"), move the cursor to the desired position for any corner of the new frame (unless you want the default frame (see below)) and press: F The state becomes "FRAME", and a prompt appears asking if you would like the default frame. (The default frame is the initial frame when PictureThis is started. It is as large as the 100% screen, and is in the middle of the 50% screen.) If you answer "Esc", the state returns to "FREE" with no change to the frame. If you answer "Y", the current frame is erased, the default frame is drawn, and the state returns to "FREE." If you press any other key, the old frame is erased, and a prompt (if "H+" is toggled) appears: "Move then F3 to set frame." Move the cursor to the diagonally opposite corner of your new frame. A dotted box follows the cursor. Notice that you can still use the "Ctrl + Home," "Ctrl + PgUp," etc., keys to jump to the corners of the old frame, even though it is not visible. When the new frame is satisfactory, press "F3." The new frame is established and the state returns to "FREE." If the current position box is toggled on, the numbers in it will change, since the position is measured from the frame origin (top or bottom left corner of the frame). Pressing "Esc" while changing the frame returns the 71 old frame and returns the state to "FREE." Changing the frame does NOT change the drawing scale: the distance on the screen that represented an inch before the frame change will still represent an inch. To change the drawing scale, see Section 21.2. The frame is saved with a drawing (see Section 18.2), so if you retrieve a drawing, the frame will change to that saved with the drawing. 21.2 SCALING THE DRAWING To change the scale of the drawing, press "F9" to bring up the miscellaneous menu. The state becomes "MISC." Then press: S A menu appears, asking you to choose whether you want to set the horizontal or vertical frame size. (You can only scale one of these; the other will automatically be scaled proportionally.) After you press "H" or "V" to choose which frame dimension you want to scale, a prompt appears that shows the current frame size (in the chosen direction and in the current units (inches are used if the current units are pixels)) and requests that you enter a new frame size (in the current units). If you are satisfied with the current frame dimension, press "ENTER" and the "FREE" state will return. If you want to change the frame size enter a new size and press "ENTER." (If you enter an illegal number, you will be given another chance.) Another prompt will appear, asking if you want to scale the line weights. If you answer "Y", the line weights will change in proportion to the difference between the previous size and the new size. For example, if the previous frame width was 8 inches, and you change it to 4 inches, a 10 point curve will change to a 5 point curve. It will look exactly as it did before on the Quickshow screen. (The frame now represents 4 inches, so 5 point curves now appear the same as 10 point curves did before.) If you press any other key, the line weights will not change. In the above example, the curves will now appear twice as thick on the Quickshow screen. You should not change the scale of the drawing frivolously. The only good reason to change the scale is to enable you to work on a drawing that you need to be a specific size, in units that represent that specific size. If your final drawing is to be 5 inches wide, and you have specific measurements for parts of your drawing, it is convenient to set the frame size to 5 inches wide. Of course, an inch on the screen will be larger than a real inch unless you have a very small screen or unless the frame is smaller than the 100% screen's width. (The initial frame is 8 inches wide and goes all the way across a screen which is typically about 8 inches wide, so an inch on the 100% screen represents an inch on the drawing.) If you change the scale in the middle of a drawing, two endpoints that were a certain distance apart will now be a DIFFERENT distance apart. It is generally best 72 to change the scale BEFORE you begin a drawing, if at all. When you change the drawing's scale, the grid does NOT change in appearance, but it represents a different size. Scaling the drawing is not the only way to change the size of the final output. When you create a PostScript file for the drawing (see Section 18.6), the default size will be determined from the drawing scale and frame size, but you can change the size as you wish. When you save a drawing (see Section 18.2), the frame and drawing scale are saved with it. When you retrieve a drawing, the drawing brings this information with it. 22. NOTING POINTS AND MEASURING DISTANCES Sometimes it is useful to mark a point on the screen to which you want to return later, but the point is not an endpoint. It is also sometimes useful to be able to measure the distance between two arbitrary points or to move to a position that is a certain proportion of the distance between two points. PictureThis has two facilities to help. 22.1 NOTED POINTS To "note" a point to which you can return later, move the cursor to the point and press "N." A small cross appears at the cursor's position (you must to move the cursor to see the cross). Up to 25 points can be noted. To return to a noted point, press (simultaneously) "SHIFT" and "Del." The cursor jumps to the nearest noted point. You can then jump to other noted points using "SPACE," "+," and "-," just as when you are finding endpoints. Pressing "Esc" gets you back to your original cursor position. Pressing "ENTER" stops the cursor at the noted point it is on. Any other key stops at the noted point AND carries out whatever operation the key would normally carry out (e.g., "F1" would create an endpoint). To erase an individual noted point, move the cursor to the noted point (as above) and press "N" again. The noted point will be erased. To erase ALL currently noted points, press "0" (zero; NOT on the numeric keypad). A prompt appears, asking if you want to erase all the noted points. Answer "Y" if you want to erase all noted points, or press any other key if you do not want to erase all noted points. Noted points are saved with drawings, and they are retrieved with drawings. 22.2 MEASURING DISTANCES The current position box and (especially) the relative position box give you information about distances when you are drawing curves, moving objects, etc. Sometimes you need this information when you are performing an operation that doesn't register on the relative position box, such as noting points. Or you might like to move to the midpoint between two arbitrary points without doing any calculations. To perform these operations, while in the "FREE" state, move the cursor 73 to the point you wish to measure from and press: M Now move the cursor; a dotted line follows. If you have the relative position box toggled on, the horizontal and vertical differences, the distance, and the angle from the point at which you pressed "M" all are shown. When you reach the point to which you wish to measure from (the measuring point), press "F3." A prompt appears: the first line states the current percentage distance from the first point; the second line requests that you enter a percentage distance. If you press "ENTER", the current percentage will be used; or you may key in a different percentage. The cursor will move to the percentage distance "between" the two points and will be saved as the current percentage to be used the next time you measure. For example, 100% will leave the cursor at its current position; 50% will move the cursor to half way between the two points. Percentages greater than 100 are legal. For example, 200% will move the cursor along the line from the initial point to the measuring point twice as far as the measuring point. Negative percentages are also legal. A -100% will move the cursor in the OPPOSITE direction from the measuring point, on the same line, the same distance as the first point is from the measuring point. Try it. If the cursor would end up off the screen, you will hear a beep, see an error message (if toggled on), and get another chance to enter a percentage. Pressing "Esc" gives you another chance to set the measuring point. If the cursor is successfully moved, the state returns to "FREE" and the dotted line is erased. 23. ASPECT RATIO Pixels on a typical CGA medium resolution screen are not square. The ratio of the height to the width of a pixel is usually about 1.20 to 1. This ratio is called the aspect ratio. The initial aspect ratio for PictureThis is set to 1.20. Some screens are adjusted to have a different aspect ratio. If your circles or squares drawn with PictureThis are not the proper shape, then your screen's aspect ratio is not 1.20. Not only will your circles and squares appear distorted on the screen, but also the PostScript output will be distorted in relation to the screen representation. To reset the aspect ratio, press "F9" to access the miscellaneous menu and change the state to "MISC." Then press: A A menu appears in which you can choose to set the aspect ratio by cursor movement or direct entry. The first time you perform the operation, you should set it by cursor movement, to determine the correct aspect ratio for your screen. To do this, press "C." The screen will be cleared and a large oval with a rectangle around it will appear in the middle of the 74 screen. The current aspect ratio will appear in a small box in the bottom left corner. If the oval is indeed a circle, and the rectangle is square (you can measure to be sure), the current aspect ratio is correct for your screen. Otherwise, adjust the aspect ratio by moving the cursor at the top of the oval either up or down. The oval and rectangle will be adjusted with the cursor movement, and the aspect ratio in the box will change. When the oval is a true circle, and the rectangle is a square (measure the rectangle if you want precision), note the aspect ratio in the box and press "F3". Alternately, you may directly enter the correct aspect ratio (if you know it) by pressing "D" at the menu. You will then see a prompt that informs you of the current aspect ratio and asks you to enter a new one. After you have set the aspect ratio with either method, a prompt asks you if you want the aspect ratio saved in the configuration file (PICTHIS.CFG) that is read when you start up PictureThis. If you want the aspect ratio automatically set to the new value when you start PictureThis, answer "Y"; otherwise, press any other key. 24. VIEWSCREEN, PALETTE, AND SCREEN TOGGLES There are several ways to manipulate the appearance of the PictureThis screen. These include the viewscreen, changing the palette, and various screen toggles. 24.1 VIEWSCREEN To view the entire drawing at any magnification WITHOUT the endpoints and frame showing, press: V To return to the drawing screen, press "Esc." It is not possible to draw on the viewscreen: there's no cursor! The viewscreen is NOT clipped at the frame, but you may scroll and "zoom" the viewscreen (see Section 6). The template shows on the viewscreen, but it can be toggled off. The main use of the viewscreen is to check how full the PictureThis memory areas are (see Section 27.2). Another use is for low- resolution screen "dumps" (say, to a dot-matrix printer) of a drawing in progress. Drawings can be saved and retrieved while on the viewscreen (see Section 18). 24.2 CHANGING THE PALETTE You might prefer to use PictureThis with a screen palette other than the default (light gray, magenta, and cyan). You can do this by pressing "F9" to bring up the miscellaneous menu. Then press: P 75 A palette menu appears, showing the current palette number (the initial setting is 1). For the default palette (gray, magenta, cyan), press "1." For the second palette (brown, red, green), press "2." For the third palette (gray, red, blue), press "3." (Use the main keyboard number keys.) For the corresponding palettes at high intensity, press the appropriate number keys simultaneously with the "SHIFT" key. Some EGA video boards and monitors don't show all of the palettes differently. You'll need to experiment to determine which palettes are best with your equipment. 24.3 SCREEN TOGGLES To PERMANENTLY erase ALL curves comprising the current drawing, press: C A prompt appears ("Clear current drawing? (Y/N)"). If you DO want to erase the current drawing (IRRETRIEVABLY, unless the drawing was previously saved, as described in Section 18.2) press "Y." If you DON'T want to erase the drawing, press any other key. To redraw the current screen, press: D This redraws the screen without changing anything. This is useful when aesthetically unpleasing "garbage" appears on the screen. Most PictureThis operations leave no garbage, but sometimes extra or missing dots can result from an operation (especially when manipulating objects). "Garbage" can also appear when the position boxes (see Section 19) or the status box (see Section 4.3) is on the screen and a curve is drawn through parts of them. If the box is then removed, parts of the curve can disappear. On the 50% screen, the template is "compressed" to fit in the available space: one pixel on the 50% screen corresponds to four pixels on the 100% screen. The compression algorithm used by PictureThis is very simple: the 100% screen is divided into boxes with four pixels each (two across by two down), and the color of ONE pixel in each box is used to determine the color of the pixel on the 50% screen which corresponds to that box. You can choose the position (top left, top right, bottom left, or bottom right) of the pixel in each box used for determining colors during compression by repeatedly pressing: D while at the 50% screen. At each press, the screen is redrawn with a different "compression color pixel" position used for producing the template. Since there are four possible positions for the "compression color pixel" used, four 76 successive presses of the "D" key will return the template to the way it started. If you change to another view and then return, the template will appear the way it did when you left the 50% screen. Being able to choose between the differently compressed templates can be useful when some features appear only on some of them. To remove the drawing TEMPORARILY, press: R This redraws the screen with the curves removed, allowing a better view of the template. To restore the drawing, press "R" again. The "R" key won't remove and restore a drawing on the viewscreen, but you can press "R" while the viewscreen is on so that curves will be removed when you return to the drawing screen; this can be useful to avoid exceeding the pixel memory limit with complex drawings (see Section 27.2 for more information). To remove the template TEMPORARILY, press: T To restore the template, press "T" again. This works on the drawing screen and the viewscreen. Note: all of the features described in this section require redrawing of the screen, and they can only be carried out in the "FREE" state.