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1.1 ! root 1: .so ../ADM/mac ! 2: .XX cip 175 "Cip User's Manual" ! 3: ....TM 82-11276-1 11173 39199-11 ! 4: ....ND March 19, 1982 ! 5: .EQ ! 6: delim $$ ! 7: .EN ! 8: .TL ! 9: Cip User's Manual: ! 10: .br ! 11: One Picture is Worth a Thousand Words ! 12: .AU "MH 2C-510" 7448 ! 13: Sally A. Browning ! 14: .AI ! 15: .MH ! 16: .AB ! 17: .I Cip ! 18: is an interactive drawing system for the Blit ! 19: |reference(locanthi spe blit) ! 20: bitmap display terminal designed by Bart Locanthi and Robert Pike. ! 21: It provides a pallette of ! 22: .I pic ! 23: |reference(latest pic) ! 24: shapes (box, circle, ellipse, line, arc, spline, and text) ! 25: for drawing and editing pictures on a screen. There is a macro ! 26: facility for treating a collection of drawn shapes as a single entity. ! 27: The principal ! 28: input device is a ! 29: .I mouse ! 30: that provides positional information. It has three buttons that invoke ! 31: drawing, editing, and command functions. ! 32: The keyboard is used only for typing in text ! 33: strings and filenames. The pictures are saved as ! 34: .I pic ! 35: descriptions, and can be included with text, ! 36: tables, and equations as input to ! 37: .I troff |reference(latest reference troff). ! 38: Existing ! 39: .I pic ! 40: descriptions of pictures can be displayed and edited as well. The picture ! 41: below was drawn with ! 42: .I cip. ! 43: .PS <blit.pic ! 44: .AE ! 45: .2C ! 46: .NH ! 47: The Screen ! 48: .PP ! 49: The screen is divided into three areas. The pallette of ! 50: .I pic ! 51: shapes is shown at the top of the screen. The middle and major part of ! 52: the screen is the drawing arena. At the bottom of the screen, there is room ! 53: for typing text strings and error messages, and a ! 54: box describing the mouse button functions. There may be a ! 55: box showing edit depth: it appears only when you are editing a macro. ! 56: Figure 1 shows the screen immediately after ! 57: .I cip ! 58: has been loaded into the Blit. ! 59: (Figure 1 was drawn with ! 60: .I cip, ! 61: of course.) ! 62: .1C ! 63: .KF ! 64: .PS <screen.pic ! 65: .SP 0.2 exactly ! 66: .ce ! 67: \f3Figure 1.\fR The \fIcip\fP screen ! 68: .KE ! 69: .2C ! 70: .PP ! 71: The drawing area is about 8 inches square. In the spirit of "what you ! 72: see is what you get", ! 73: .I cip ! 74: scales the picture to appear on paper as it does on the screen. ! 75: The exception is text: the ! 76: font selection on the Blit ! 77: is meager compared to the typesetter, and I make ! 78: no attempt to understand ! 79: .I troff .* ! 80: .FS ! 81: *This paper describes early versions of ! 82: .I cip . ! 83: The latest version (3.0) of ! 84: .I cip , ! 85: widely known as ! 86: .I xcip , ! 87: does display and edit text in its ! 88: correct size and font. ! 89: .FE ! 90: Thus, ! 91: .I eqn ! 92: and ! 93: .I troff ! 94: commands appear ! 95: literally instead of as they will appear on paper, and all text appears ! 96: in the same boring font and size. If you want to shrink the picture after ! 97: drawing it to fill the screen, you need only change one number in the ! 98: .I pic ! 99: description. This, and other advantages of having a textual description of ! 100: the picture, are discussed later. ! 101: ........ ! 102: .NH ! 103: Using the Mouse ! 104: .PP ! 105: The mouse is the primary input device to ! 106: .I cip. ! 107: It is a red hemispheric device that fits comfortably into the ! 108: palm of your hand, with three fingers positioned on the function ! 109: buttons. The cursor displayed on the screen will move as you move the mouse. ! 110: The mouse reports ! 111: .I relative ! 112: positions based on the movements of the steel ball in the bottom that moves ! 113: along the table surface. If you pick up the mouse and put it down somewhere ! 114: else without causing the ball to rotate, the cursor won't move. This feature ! 115: is handy if you don't have much clear space on your desk. ! 116: In addition to providing positional information, the mouse has three buttons ! 117: that represent command functions. In general, the first (left) button is ! 118: used for selection, the second (middle) for drawing and editing shapes, ! 119: and the third (right) for menu selection. In each case, both the down and up ! 120: motions of the button are significant. When I describe button motions, I will ! 121: use ! 122: .I push ! 123: to describe the press and hold action and ! 124: .I release ! 125: to mean letting go of the button. ! 126: .I Clicking ! 127: a button means pushing and releasing the button in quick succession. ! 128: .PP ! 129: At the bottom of the screen is a box labeled "Mouse Buttons". It contains ! 130: three smaller boxes that represent the three buttons on the mouse. The boxes ! 131: are labeled to reflect the ! 132: .I current ! 133: set of functions associated with the mouse buttons. For example, Figure 1 ! 134: shows the initial set: (select,,menu). Notice that the second button is ! 135: meaningless in this state. The second button invokes actions on a selected ! 136: object, and thus is meaningful only when something (either a template ! 137: from the top row of the display or a previously drawn object) has been selected. ! 138: There are other occasions when the right and left buttons are meaningless, and ! 139: even occasions when all of the buttons are ignored. Table 1 shows the ! 140: possible button function triples and what states they are associated with. ! 141: Figure 2 shows the possible transitions between triples of mouse button ! 142: functions. ! 143: .PP ! 144: The mouse button functions are displayed for at least two reasons. First, they ! 145: make it easier to get acclimated to ! 146: .I cip ! 147: and to using a pointing device as the primary input device. Second, they ! 148: help the more experienced user determine the current state. ! 149: .1C ! 150: .KF ! 151: .PS <mouse.pic ! 152: .RT ! 153: .SP 0.2 exactly ! 154: .ce ! 155: \fBFigure 2.\fR Transition graph for mouse button functions ! 156: .TS ! 157: center box; ! 158: c | l | l | c | l. ! 159: State Button Functions Menu Next State How to Get to Next State ! 160: = ! 161: 1 (select,,menu) command 4 select drawn object (not text or macro) ! 162: \^ \^ \^ _ _ ! 163: \^ \^ \^ 5 select a template ! 164: \^ \^ \^ _ _ ! 165: \^ \^ \^ 6 choose \fBdefine macro\fR ! 166: \^ \^ \^ _ _ ! 167: \^ \^ \^ 7 choose \fBget file\fR or \fBput file\fR ! 168: _ ! 169: 2 (select,copy,menu) object 1 select nothing ! 170: \^ \^ \^ _ _ ! 171: \^ \^ \^ 3 select a text string or a macro instance ! 172: \^ \^ \^ _ _ ! 173: \^ \^ \^ 4 select an object (not text or macro) ! 174: \^ \^ \^ _ _ ! 175: \^ \^ \^ 5 select a template ! 176: _ ! 177: 3 (select,move,menu) object 1 select nothing ! 178: \^ \^ \^ _ _ ! 179: \^ \^ \^ 2 choose \fBcopy\fR ! 180: \^ \^ \^ _ _ ! 181: \^ \^ \^ 4 select an object (not text or macro) ! 182: \^ \^ \^ _ _ ! 183: \^ \^ \^ 5 select a template ! 184: _ ! 185: 4 (select,edit,menu) object 1 select nothing ! 186: \^ \^ \^ _ _ ! 187: \^ \^ \^ 2 choose \fBcopy\fR ! 188: \^ \^ \^ _ _ ! 189: \^ \^ \^ 3 select a text string or a macro instance ! 190: \^ \^ \^ _ _ ! 191: \^ \^ \^ 5 select a template ! 192: _ ! 193: 5 (select,draw,menu) command 3 select a text string or a macro instance ! 194: \^ \^ \^ _ _ ! 195: \^ \^ \^ 4 select a drawn object (not text or macro) ! 196: \^ \^ \^ _ _ ! 197: \^ \^ \^ 6 choose \fBget file\fR or \fBput file\fR ! 198: \^ \^ \^ _ _ ! 199: \^ \^ \^ 7 choose \fBget file\fR or \fBput file\fR ! 200: \^ \^ \^ _ _ ! 201: \^ \^ \^ 8 start drawing a spline ! 202: _ ! 203: 6 (,draw box,) 1 finish drawing box around macro ! 204: _ ! 205: 7 (,,,) 1 finish reading or writing file ! 206: \^ \^ \^ _ _ ! 207: \^ \^ \^ 5 finish reading or writing file ! 208: _ ! 209: 8 (,draw,end spline) 5 finish drawing a spline ! 210: _ ! 211: .TE ! 212: .SP 0.2 exactly ! 213: .ce ! 214: \fBTable 1.\fR Mouse button functions ! 215: .KE ! 216: .2C ! 217: .NH ! 218: Selection ! 219: .PP ! 220: The leftmost button on the mouse selects either a template from the ! 221: row at the top of the screen or an object in the drawing arena. Templates are ! 222: selected by positioning the cursor inside the box surrounding the desired ! 223: shape, and clicking button 1. The selected shape will be ! 224: displayed in reverse video (light on black background) until something ! 225: else is selected. Drawn objects are selected by positioning the cursor within ! 226: the bounding box of the desired object, and pushing button 1. The selected ! 227: object will vanish as long as the button is held down, reappearing when the ! 228: button is released. This vanishing act alerts the user to which object has ! 229: been selected. If it is not the desired one, reposition the mouse and try ! 230: again. It may require several attempts to select an object, ! 231: particularly in an area of the screen that is congested. An object stays ! 232: selected until either another object or a template is selected. ! 233: .PP ! 234: To "unselect" an object, either select a template or move to a blank area of the ! 235: screen, push button 1 and select nothing. The unselect was successful if the ! 236: middle mouse button function is either "draw" or null and the third button ! 237: function is "menu". A selected object must be unselected ! 238: (by selecting either nothing or a template) to invoke the command ! 239: menu rather than an object menu. Menus are described next. ! 240: .NH ! 241: Menus ! 242: .PP ! 243: The right button on the mouse displays menus of commands and ! 244: refinements. Before describing the contents of the menus, let me describe ! 245: how they work. ! 246: .PP ! 247: A menu is displayed at the location of the cursor when button 3 is pushed down. ! 248: The display is visible as long as the button is held down. The menu is a list ! 249: of words, each representing a command or transformation. When the menu appears ! 250: on the screen, one of the entries is highlighted in reverse video. If button ! 251: 3 were released, this is the menu item that would be selected. As the cursor ! 252: moves up and down in the menu, the highlighted entry changes. If the cursor ! 253: moves outside the menu, nothing is highlighted. The entry that is highlighted ! 254: when the third button is released is the chosen one. (If no item is chosen, ! 255: nothing happens. This allows you to leave a menu without choosing an entry.) ! 256: .PP ! 257: There are two classes of menus. The ! 258: .I ! 259: command menu ! 260: .R ! 261: appears whenever no drawn object is selected and button 3 is pushed. It ! 262: contains commands that affect the whole screen or some part of it, but not ! 263: a specific single object. For example, ! 264: .B ! 265: reverse video ! 266: .R ! 267: flips the sense of ! 268: the screen. If the screen showed black objects on a light background (the ! 269: initial state), it will be flipped to show light objects on black. This ! 270: entry is a flip flop: selecting it an even number of times is equivalent ! 271: to not selecting it at all. Another entry in the command menu is ! 272: .B grid. ! 273: Selecting this entry causes a grid of dots to be displayed on the screen, ! 274: and future drawing is constrained to the grid points. The command is also ! 275: a flip flop: to turn it off, select it again. Other commands are ! 276: .B ! 277: clear screen, redraw screen, define macro, get file, put file, ! 278: .R ! 279: and ! 280: .B ! 281: quit. ! 282: .R ! 283: The macro and file ! 284: commands are described later; the others are self-explanatory. ! 285: .PP ! 286: If a drawn object is selected when the menu button is pushed, a menu with ! 287: entries that in some way transform the selected object is displayed. The ! 288: contents of this menu are tailored to the class of object selected. For ! 289: example, instances of circles, ellipses, and text can be copied or deleted. ! 290: Arcs and splines can be copied, deleted, or reflected around either the ! 291: x or y axis of their bounding box. Boxes can be copied, deleted, ! 292: or have their boundary be dotted, dashed, or solid. Lines can be copied, ! 293: deleted, reflected, dotted, dashed, solid, or have an arrowhead attached to ! 294: the endpoint closest to the cursor. The arrow ! 295: option is a flip flop: if ! 296: the nearer endpoint already has an arrowhead, selecting ! 297: .B arrow ! 298: again will remove it. Splines can also have arrowheads attached to either or ! 299: both ends. ! 300: .PP ! 301: Remember, if the menu button is depressed accidentally, leave it down long enough ! 302: to move the cursor outside the menu! ! 303: .PP ! 304: Figure 3 shows both command and object menus being used. In the first three ! 305: frames, the menu associated with splines is displayed and the spline is reflected ! 306: around the y-axis. The command menu is invoked in the remaining five frames to ! 307: get a new file. The menu is initially displayed with ! 308: .B ! 309: define macro ! 310: .R ! 311: highlighted; the mouse is moved up to select ! 312: .B ! 313: get file ! 314: .R ! 315: before the third button is released. ! 316: .1C ! 317: .KF ! 318: .sp 1 ! 319: .PS <menus.pic ! 320: .SP 0.2 exactly ! 321: .ce ! 322: \fBFigure 3.\fR Using menus ! 323: .KE ! 324: .2C ! 325: .NH ! 326: Drawing ! 327: .PP ! 328: The ! 329: .I pic ! 330: language can describe and position ! 331: circles, boxes (solid, dotted, and dashed), ellipses, ! 332: lines (solid, dotted, dashed, with or without arrowheads), circular arcs, ! 333: splines, and text. In addition, there is a mechanism for treating a ! 334: .I collection ! 335: of objects as a single entity, hereafter called a ! 336: .B macro. ! 337: .NH 2 ! 338: Drawing New Shapes ! 339: .PP ! 340: There are two ways to draw shapes on the screen. First, select a template with ! 341: button 1. ! 342: Button 2 can be used ! 343: to draw objects of the selected shape on the screen. The location and size of ! 344: the drawn object is determined by the down and up motions of the button. For ! 345: example, to draw a circle, select the circle template, move the cursor to the desired position for ! 346: the ! 347: .I center ! 348: of the circle, and push down on the middle button. As long the button is ! 349: depressed, the trial radius of the circle will track the mouse movement: ! 350: as the mouse moves away from the origin, the circle will expand and ! 351: vise versa. When button 2 is released, the circle radius is fixed as ! 352: the distance between the origin and mouse position. ! 353: Table 2 defines the points fixed by button 2 motions for all the ! 354: shapes. ! 355: .KF ! 356: .SP 1 ! 357: .ps -1 ! 358: .vs -1p ! 359: .TS ! 360: box center ; ! 361: c | l | l. ! 362: Object Push Release ! 363: _ ! 364: _ ! 365: circle center radius = distance(push,release) ! 366: _ ! 367: box a corner opposite corner ! 368: _ ! 369: ellipse center height = $| roman "push" .y - roman "release" .y|$ ! 370: width = $| roman "push" .x - roman "release" .x|$ ! 371: _ ! 372: line endpoint endpoint ! 373: _ ! 374: arc endpoint endpoint ! 375: center ! 376: _ ! 377: spline endpoint point ! 378: (subsequent releases define ! 379: another point, until button 3) ! 380: _ ! 381: text center of ! 382: baseline ! 383: .TE ! 384: .ps +1 ! 385: .vs +1p ! 386: .SP 0.2 exactly ! 387: .ce ! 388: \fBTable 2.\fR Using button 2 for drawing shapes ! 389: .KE ! 390: .PP ! 391: Arcs are drawn counter-clockwise. When an arc is drawn, it will be ! 392: either one quarter or three quarters of a circle (in imitation of ! 393: .I pic ! 394: defaults). If you want something else, select and edit the arc once it is ! 395: drawn. The picture below shows the default arcs; the order that the endpoints ! 396: are entered determines whether one fourth or three fourths of a circle is ! 397: drawn. ! 398: .KS ! 399: .PS <arcs.pic ! 400: .KE ! 401: .PP ! 402: Two of the shapes, splines and text, require a few more words to explain ! 403: how to draw them. Splines are curves that ! 404: shape themselves to a framework of line segments and are drawn with repetitive ! 405: pushes of the middle button. ! 406: Each click adds a line segment to the framework of the spline. ! 407: .I Pic , ! 408: and thus ! 409: .I cip , ! 410: splines will contain the first and last points entered and will be tangent to ! 411: the midpoint of ! 412: each line segment in the framework. The spline will be ! 413: .I near ! 414: the endpoints of each line segment. ! 415: Only the framework is shown on the screen while you are entering the spline. ! 416: To terminate and draw the spline, push the third button. Figure 4 shows the process ! 417: of drawing a spline. ! 418: .1C ! 419: .KF ! 420: .PS <spline.pic ! 421: .SP 0.2 exactly ! 422: .ce ! 423: \fBFigure 4.\fR Drawing a spline ! 424: .KE ! 425: .2C ! 426: .PP ! 427: To add some text to the picture, move to the desired position for the ! 428: .I center ! 429: of the text string ! 430: and push and release button 2. Now type the text. It will ! 431: appear on the lower left portion of the screen, just below the drawing arena. ! 432: The backspace key can be used to make minor corrections. As soon as, and ! 433: not until, you push carriage return, the string will be displayed in the ! 434: drawing arena, centered at the selected location. Figure 5 pictures the ! 435: stages of drawing text.* ! 436: .FS ! 437: *At least, in older versions of ! 438: .I cip . ! 439: In version 3.0, text appears as you type it. ! 440: .FE ! 441: .1C ! 442: .KF ! 443: .PS <text.pic ! 444: .SP 0.2 exactly ! 445: .ce ! 446: \fBFigure 5.\fR Drawing text ! 447: .KE ! 448: .2C ! 449: .NH 2 ! 450: Copying Existing Shapes ! 451: .PP ! 452: The second way to draw shapes on the screen is by copying previously drawn ! 453: things. First use button 1 to select a specific drawn object ! 454: rather than a template. ! 455: Then push button 3 to get a menu pertinent to the selected object. ! 456: Select the menu entry ! 457: .B copy. ! 458: Now, button 2 can be used to position exact copies of ! 459: the selected object. The ! 460: .I origin ! 461: of the object (see Table 3) will be located at the cursor position when ! 462: button 2 is pushed. In this case, the release of button 2 is necessary but ! 463: meaningless. ! 464: .KF ! 465: .SP ! 466: .TS ! 467: center allbox; ! 468: c l. ! 469: Object Origin ! 470: _ ! 471: circle center ! 472: box upper left corner ! 473: ellipse center ! 474: line first drawn point ! 475: arc first drawn point ! 476: spline first drawn point ! 477: text center of baseline ! 478: macro upper left corner ! 479: .TE ! 480: .SP 0.2 exactly ! 481: .ce ! 482: \fBTable 3.\fR The origins of objects ! 483: .KE ! 484: .NH 2 ! 485: Alignment Aids ! 486: .PP ! 487: .I Cip ! 488: has a few features built in to make positioning objects easier. First, lines ! 489: that are drawn ! 490: .I nearly ! 491: horizontal or vertical will be made exactly so. Also, each of the basic shapes ! 492: has a number of points designated ! 493: .I sticky. ! 494: As you move the cursor near these special points, it will tend to stick to them ! 495: until you move sufficiently far away. Figure 6 shows the sticky points for ! 496: each shape. The corners of the ! 497: .I ! 498: bounding box ! 499: .R ! 500: of a macro instance are sticky as well. ! 501: The final alignment aid is the grid. When the grid is turned on, drawn ! 502: objects will rachet from grid point to grid point as you move the cursor. ! 503: The cursor is prejudiced in favor of sticky points: it will move to the ! 504: nearest grid point only when there is no close sticky point. ! 505: .1C ! 506: .KF ! 507: .PS <sticky.pic ! 508: .SP 0.2 exactly ! 509: .ce ! 510: \fBFigure 6.\fR Sticky points ! 511: .KE ! 512: .2C ! 513: .NH ! 514: Editing ! 515: .PP ! 516: The editing facilities of ! 517: .I cip ! 518: allow both the position and size of previously drawn objects to be changed. The ! 519: basic mechanism is to ! 520: .I select ! 521: the object with button 1, and then use button 2 for the actual editing. The ! 522: position of the cursor when button 2 is depressed and the shape of the selected ! 523: object determine the editing action. For example, suppose a circle ! 524: has been selected. If the cursor is near the origin of the circle when ! 525: the middle button is pushed, the origin of the circle will track the cursor ! 526: as long as the button is depressed. Its new location will be the cursor ! 527: position when the button is released, and the radius will be unchanged. ! 528: If, instead, the cursor is near the edge of the circle when the middle button ! 529: is depressed, the center of the circle will remain fixed, and the radius of ! 530: the circle will track the cursor. The other objects are edited in the same ! 531: manner: near the center moves the object, near the edge (or corner, or ! 532: endpoint) changes the size, with the exception of arcs, splines, text, and macros. ! 533: .PP ! 534: Arcs have three interesting points: the two endpoints, and the center of ! 535: the circle that contains the arc. The point nearest the cursor when ! 536: button 2 is depressed will track the cursor. (There is no way to ! 537: reposition the arc.) This includes the center of the circle, which is shown ! 538: with a pair of lines when the arc is selected. ! 539: .PP ! 540: Splines have a variable number of ! 541: .I ! 542: guiding points ! 543: .R ! 544: that can be changed. Lines between the ! 545: guiding points are drawn to help in locating them when the spline is selected. ! 546: The point ! 547: nearest the cursor when the middle button is depressed will track the mouse ! 548: motions, becoming fixed at the cursor position when the button is released. ! 549: Again, there is no way to move the whole spline. ! 550: .PP ! 551: It doesn't make sense in ! 552: .I cip's ! 553: world to change the size of text. Accordingly, it can only be moved. After ! 554: the text is selected and button 2 is pushed, the text string will track ! 555: the cursor, coming to rest when the button is released. ! 556: The ! 557: .I contents ! 558: of a text string are changed by deleting the string and re-entering it ! 559: correctly.* ! 560: .FS ! 561: *In version 3.0, the size, font, vertical spacing and adjustment ! 562: (left justified, right justified or centered) can be changed from the button 3 menu. ! 563: .FE ! 564: .PP ! 565: Macro editing is more complex. An instance of a macro can be repositioned ! 566: by selecting the instance and pushing the second button. The entire macro ! 567: will track the mouse movements until the button is released. Changing the ! 568: .I components ! 569: of the macro will be discussed in the next section. ! 570: .PP ! 571: The editing facilities of ! 572: .I cip ! 573: are summarized below. Figure 7 shows the process of editing ! 574: a spline; the technique is similar for all simple shapes. ! 575: .KS ! 576: .PS ! 577: scale=100 ! 578: box ht 40 wid 60 with .nw at 70,650 dashed ! 579: box ht 80 wid 120 with .nw at 40,670 ! 580: box ht 40 wid 60 with .nw at 10,610 dotted ! 581: box ht 40 wid 60 with .nw at 10,690 dotted ! 582: box ht 40 wid 60 with .nw at 130,690 dotted ! 583: box ht 40 wid 60 with .nw at 130,610 dotted ! 584: .PE ! 585: .KE ! 586: .de XY ! 587: .ti 0 ! 588: .. ! 589: .de XX ! 590: .br ! 591: .. ! 592: .in 5n ! 593: .XY ! 594: To edit solid box: ! 595: .XX ! 596: a) cursor inside a dotted box: move corner ! 597: .XX ! 598: b) cursor inside dashed box: move box ! 599: .KS ! 600: .PS ! 601: scale=100 ! 602: circle rad 29 at 96,458 ! 603: circle rad 65 at 96,458 ! 604: .PE ! 605: .KE ! 606: .XY ! 607: To edit outer circle: ! 608: .XX ! 609: a) cursor inside inner circle: move circle ! 610: .XX ! 611: b) cursor in ring between circles: change radius ! 612: .KS ! 613: .PS ! 614: scale=100 ! 615: ellipse ht 120 wid 216 at 116,257 ! 616: box ht 51 wid 65 with .nw at 6,283 dotted ! 617: box ht 51 wid 65 with .nw at 161,283 dotted ! 618: box ht 36 wid 90 with .nw at 71,232 dashed ! 619: box ht 36 wid 90 with .nw at 71,319 dashed ! 620: .PE ! 621: .KE ! 622: .XY ! 623: To edit ellipse: ! 624: .XX ! 625: a) cursor in a dashed box: change height ! 626: .XX ! 627: b) cursor in a dotted box: change width ! 628: .XX ! 629: c) cursor anywhere else in ellipse: move ellipse ! 630: .KS ! 631: .PS ! 632: scale=100 ! 633: line from 104,0 to 0,60 dotted ! 634: line from 104,119 to 209,60 dotted ! 635: line from 0,0 to 209,119 ! 636: box ht 119 wid 209 with .nw at 0,119 dotted ! 637: .PE ! 638: .KE ! 639: .XY ! 640: To edit solid line: ! 641: .XX ! 642: a) cursor in the dotted box and between the dotted lines: move line ! 643: .XX ! 644: b) cursor in a dotted triangle: move endpoint ! 645: .KS ! 646: .PS ! 647: scale=100 ! 648: box ht 128 wid 128 with .nw at 20,702 dashed ! 649: line from 84,574 to 84,606 dashed ! 650: line from 84,670 to 84,702 dashed ! 651: circle rad 32 at 84,638 ! 652: line from 129,683 to 84,638 dotted ! 653: line from 39,683 to 84,638 dotted ! 654: arc from 129,683 to 39,683 at 84,638 ! 655: .PE ! 656: .KE ! 657: .XY ! 658: To edit arc: (dotted lines appear (solid) when arc is selected) ! 659: .XX ! 660: a) cursor inside circle: move origin ! 661: .XX ! 662: b) cursor outside circle, inside left dashed box: move endpoint ! 663: .XX ! 664: c) cursor outside circle, inside right dashed box: move startpoint ! 665: .XX ! 666: .KS ! 667: .PS ! 668: scale=100 ! 669: box ht 173 wid 179 with .nw at 0,485 dotted ! 670: line from 179,372 to 104,355 dotted ! 671: line from 98,338 to 104,355 dotted ! 672: line from 148,448 to 74,410 dotted ! 673: line from 179,464 to 148,448 dotted ! 674: line from 80,453 to 64,428 dotted ! 675: line from 64,428 to 7,424 dotted ! 676: line from 93,485 to 80,453 dotted ! 677: line from 85,391 to 104,355 dotted ! 678: line from 64,428 to 85,391 dotted ! 679: line from 85,312 to 98,338 dotted ! 680: line from 0,485 to 140,475 dashed ! 681: line from 170,417 to 0,485 dashed ! 682: line from 13,369 to 179,312 dashed ! 683: line from 170,417 to 13,369 dashed ! 684: spline from 140,475\ ! 685: to 0,485\ ! 686: to 170,417\ ! 687: to 13,369\ ! 688: to 179,312 ! 689: "\(bu" at 0,485 ! 690: "\(bu" at 179,312 ! 691: "\(bu" at 13,369 ! 692: "\(bu" at 170,417 ! 693: "\(bu" at 140,475 ! 694: .PE ! 695: .KE ! 696: .XY ! 697: To edit spline: (dashed lines appear (solid) when spline is selected) ! 698: .XX ! 699: a) cursor inside a dotted region: move guiding point (large dot) ! 700: .KS ! 701: .PS ! 702: scale=100 ! 703: box ht 18 wid 92 with .nw at 36,254 dotted ! 704: "Text String" at 79,241 ! 705: .PE ! 706: .KE ! 707: .XY ! 708: To edit text: ! 709: .XX ! 710: a) cursor anywhere: move text ! 711: (To change the contents of the string, delete it ! 712: and re-type it correctly.)* ! 713: .FS ! 714: *In version 3.0, you can change the point size, vertical spacing, ! 715: font and adjustment of text from the menu. ! 716: .FE ! 717: .KS ! 718: .PS ! 719: scale=100 ! 720: box ht 130 wid 139 with .nw at 19,130 dotted ! 721: line from 58,71 to 92,96 ! 722: line from 92,96 to 123,73 ! 723: line from 43,32 to 58,51 ! 724: line from 58,51 to 71,32 ! 725: line from 110,33 to 123,53 ! 726: line from 123,53 to 138,34 ! 727: circle rad 10 at 92,106 ! 728: circle rad 10 at 58,61 ! 729: circle rad 10 at 123,63 ! 730: circle rad 10 at 43,22 ! 731: circle rad 10 at 71,22 ! 732: circle rad 10 at 110,23 ! 733: circle rad 10 at 138,24 ! 734: .PE ! 735: .KE ! 736: .XY ! 737: To move an instance of a macro: ! 738: .XX ! 739: a) cursor anywhere: move macro ! 740: .br ! 741: (Changing the components of a macro is discussed elsewhere) ! 742: .in 0 ! 743: .1C ! 744: .KF ! 745: .PS <editSpline.pic ! 746: .SP 0.2 exactly ! 747: .ce ! 748: \fBFigure 7.\fR Editing a spline ! 749: .KE ! 750: .2C ! 751: .NH ! 752: Macros ! 753: .PP ! 754: .I Cip ! 755: has a macro facility that allows objects to be grouped together and treated ! 756: as a single entity. The aggregate can be moved, reflected, copied, or deleted. ! 757: In addition, components of the macro can be modified, deleted, or added. ! 758: Changes made to the components will be reflected in ! 759: .I all ! 760: instances of the macro, except those that have been reflected. ! 761: .PP ! 762: A group of objects is collected into a macro by selecting the ! 763: .B ! 764: define macro ! 765: .R ! 766: option in the command menu. A bounding box is drawn around the desired ! 767: objects using button 2. Any object that is completely contained in the ! 768: bounding box will be included in the aggregate. ! 769: .PP ! 770: Once the definition is complete, the macro instance can be selected in the ! 771: usual manner. ! 772: The object menu for macros has entries for deleting, copying, and reflecting ! 773: the macro instance. It can be repositioned by holding the middle button down. ! 774: The center of the bounding box will track the cursor until the button is ! 775: released. ! 776: .PP ! 777: The macro object menu has a fifth entry that allows the components of the ! 778: macro to be modified, deleted, or added. Selection, drawing, editing, and ! 779: menus work exactly as described before except that they operate within ! 780: the context of the macro. When editing begins, a small box appears on the ! 781: screen to the left of the Mouse Buttons box. It shows the current depth of ! 782: macro editing. (Yes, Virginia, macros can be nested.) To terminate the ! 783: editing, move the cursor inside the Edit Depth box and click the ! 784: selection button, decrementing the depth count. When the ! 785: count goes to zero, the screen will be redrawn to reflect the changes. ! 786: Modifications to macros affect ! 787: .I all ! 788: instances of the macro. ! 789: .PP ! 790: Detail can be added to a single instance of a macro by drawing ! 791: over it. Components of an individual ! 792: instance cannot be deleted or modified without changing all instances. ! 793: .PP ! 794: Suppose you define a macro that contains a circle in a box. After ! 795: replicating it several times, you decide that one instance should not ! 796: have the circle. The sixth entry in the macro menu, ! 797: .B separate, ! 798: will separate the aggregate back into individual objects. That is, for a ! 799: .I ! 800: selected instance ! 801: .R ! 802: of a macro, the ! 803: .B ! 804: define macro ! 805: .R ! 806: operation will be undone. Now you can select the offending circle and ! 807: delete it without changing the other instances of the macro. However, ! 808: changes made to the macro will no longer affect the separated objects. ! 809: .NH ! 810: Saving Pictures ! 811: .PP ! 812: The command menu has two entries that involve file operations. ! 813: .B ! 814: Put file ! 815: .R ! 816: converts the picture on the screen into ! 817: .I pic ! 818: and saves it in a file on the host machine. Similarly, ! 819: .B ! 820: get file ! 821: .R ! 822: reads a file, presumed to be ! 823: .I pic, ! 824: and draws the resulting picture on the screen. Both commands ask for a ! 825: file name: the prompt ! 826: .CW FILE? ! 827: appears in the lower left part of the screen, ! 828: just below the drawing arena (see Figure 3g). ! 829: The filename from the previous get or put ! 830: command will be automatically displayed to reduce the amount of typing ! 831: necessary. Typing <CR> (carriage return) uses the default filename. ! 832: .PP ! 833: There are four error conditions that may arise following a file operation. ! 834: Attempts to put a file are the least error prone: the only error, ! 835: besides the host being down, is that you don't have the right to ! 836: write the file in question. Get file commands are subject to ! 837: errors involving access rights to the file, problems opening a pipe to ! 838: parse the pic, and having a picture that is too ! 839: complicated to fit within the available memory of the Blit. ! 840: Errors are reported in the lower left portion of the screen, just below ! 841: the drawing arena. ! 842: .NH ! 843: Commentary ! 844: .PP ! 845: .I Cip ! 846: grew out of my experience with ! 847: .I pic. ! 848: It is wonderful to be able to describe and draw pictures that can included ! 849: right along with text in a document. However, words are not always the ! 850: best form of expression. It is easy to spend an afternoon ! 851: turning a five minute sketch into a ! 852: .I pic ! 853: description. ! 854: .I Cip ! 855: allows you to do the sketch online and get the ! 856: .I pic ! 857: description as a bonus. ! 858: .PP ! 859: I have put most of my efforts into the user interface. There is a minimum of ! 860: typing: only file names and text strings are entered from the keyboard. There ! 861: are alignment aids: sticky points, help with vertical and horizontal lines, ! 862: and a grid option. The current meaning of the mouse buttons is displayed. ! 863: Only use will tell if these aids are enough. ! 864: .PP ! 865: Before going on to a discussion of the limitations of ! 866: .I cip, ! 867: let me mention a ! 868: .I good ! 869: thing about saving the picture as readable text. The ! 870: .I pic ! 871: produced by ! 872: .I cip ! 873: is full of numbers, including the line ! 874: .CW scale=100 . ! 875: The resolution on the Blit ! 876: is 100 pixels/inch, and this command is necessary for the picture ! 877: to be the same size on both the screen and a piece of paper. ! 878: Thus, the size of the picture can be changed ! 879: by changing the scale. For example, all of the miniature ! 880: .I cip ! 881: screens that appear in this document originated from the big version in ! 882: Figure 1. The screens in Figures 3, 4, 5, and 7 were created with ! 883: .CW scale=300 ! 884: and are roughly one ninth the size of the original; the one ! 885: on the cover page had ! 886: .CW scale=450 . ! 887: Ragged edges and small imperfections ! 888: in the picture can be removed by twiddling the position and size of ! 889: objects. One common way to use ! 890: .I cip ! 891: is to draw a rough version on the screen, and refine it by using a ! 892: combination of ! 893: .I cip ! 894: editing and ! 895: .I pic ! 896: editing. ! 897: .PP ! 898: .I Cip ! 899: resides almost entirely in the Blit. ! 900: (Implementations also exist for the DMD5620 and 630MTG terminals.) ! 901: The host machine provides ! 902: the file system and parses ! 903: .I pic; ! 904: everything else is done in the terminal. While this approach is ! 905: not subject to the delays in response time that plague timesharing users, ! 906: it does require a large program (50K bytes) to be downloaded into the ! 907: terminal through a serial connection. It should be interesting to compare this ! 908: approach to one in which the major part of the program runs in the host, with ! 909: the terminal providing only the graphic support. ! 910: .PP ! 911: There are some things that can be expressed in a textual language like ! 912: .I pic ! 913: that are difficult to describe graphically. Examples are relationships between ! 914: objects (text centered in a box that is somehow part of the box and should ! 915: move with it), shortening a line between two circles by the radius of the ! 916: circle, naming objects and referring to them. Ivan Sutherland's thesis, ! 917: Sketchpad|reference(sutherland sketchpad) ! 918: dealt with the problem of expressing constraints between objects; his techniques ! 919: will be incorporated into ! 920: .I cip ! 921: at some point in the future. ! 922: .PP ! 923: Adding functionality to ! 924: .I cip ! 925: is constrained by having ! 926: .I pic ! 927: as the output form. ! 928: Potentially interesting extensions like arbitrary rotation of objects, ! 929: shapes that are solid or shaded rather than outlined, shapes that ! 930: obscure things that are behind them, and so on, are ruled out ! 931: because they cannot be described in ! 932: .I pic. ! 933: Chris Van Wyk's ! 934: .I ideal |reference(latest ideal) ! 935: .I does ! 936: allow these extensions. It might be interesting to do a drawing system ! 937: for it. ! 938: .PP ! 939: Brian Kernighan, in addition to his role as ! 940: .I pic ! 941: oracle, provided the program that runs on the host, parses ! 942: .I pic ! 943: files, and sends a simplified form of the picture to the Blit. ! 944: Bart Locanthi and Rob Pike built the Blit ! 945: and wrote the graphics support and file system access routines. And finally, ! 946: my first and most enthusiastic user was Norm Schryer. My thanks to them all. ! 947: .NH 1 ! 948: References ! 949: .LP ! 950: |reference_placement
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