| 1 | /* Cursor motion subroutines for GNU Emacs. |
| 2 | Copyright (C) 1985 Free Software Foundation, Inc. |
| 3 | based primarily on public domain code written by Chris Torek |
| 4 | |
| 5 | This file is part of GNU Emacs. |
| 6 | |
| 7 | GNU Emacs is free software; you can redistribute it and/or modify |
| 8 | it under the terms of the GNU General Public License as published by |
| 9 | the Free Software Foundation; either version 1, or (at your option) |
| 10 | any later version. |
| 11 | |
| 12 | GNU Emacs is distributed in the hope that it will be useful, |
| 13 | but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 14 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| 15 | GNU General Public License for more details. |
| 16 | |
| 17 | You should have received a copy of the GNU General Public License |
| 18 | along with GNU Emacs; see the file COPYING. If not, write to |
| 19 | the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA. */ |
| 20 | |
| 21 | |
| 22 | #include "config.h" |
| 23 | #include <stdio.h> |
| 24 | #include "cm.h" |
| 25 | #include "termhooks.h" |
| 26 | |
| 27 | #define BIG 9999 /* 9999 good on VAXen. For 16 bit machines |
| 28 | use about 2000.... */ |
| 29 | |
| 30 | char *tgoto (); |
| 31 | |
| 32 | extern char *BC, *UP; |
| 33 | |
| 34 | int cost; /* sums up costs */ |
| 35 | |
| 36 | /* ARGSUSED */ |
| 37 | evalcost (c) |
| 38 | char c; |
| 39 | { |
| 40 | cost++; |
| 41 | } |
| 42 | |
| 43 | void |
| 44 | cmputc (c) |
| 45 | char c; |
| 46 | { |
| 47 | if (termscript) |
| 48 | fputc (c & 0177, termscript); |
| 49 | putchar (c & 0177); |
| 50 | } |
| 51 | |
| 52 | /* NEXT TWO ARE DONE WITH MACROS */ |
| 53 | #if 0 |
| 54 | /* |
| 55 | * Assume the cursor is at row row, column col. Normally used only after |
| 56 | * clearing the screen, when the cursor is at (0, 0), but what the heck, |
| 57 | * let's let the guy put it anywhere. |
| 58 | */ |
| 59 | |
| 60 | static |
| 61 | at (row, col) { |
| 62 | curY = row; |
| 63 | curX = col; |
| 64 | } |
| 65 | |
| 66 | /* |
| 67 | * Add n columns to the current cursor position. |
| 68 | */ |
| 69 | |
| 70 | static |
| 71 | addcol (n) { |
| 72 | curX += n; |
| 73 | |
| 74 | /* |
| 75 | * If cursor hit edge of screen, what happened? |
| 76 | * N.B.: DO NOT!! write past edge of screen. If you do, you |
| 77 | * deserve what you get. Furthermore, on terminals with |
| 78 | * autowrap (but not magicwrap), don't write in the last column |
| 79 | * of the last line. |
| 80 | */ |
| 81 | |
| 82 | if (curX == Wcm.cm_cols) { |
| 83 | /* |
| 84 | * Well, if magicwrap, still there, past the edge of the |
| 85 | * screen (!). If autowrap, on the col 0 of the next line. |
| 86 | * Otherwise on last column. |
| 87 | */ |
| 88 | |
| 89 | if (Wcm.cm_magicwrap) |
| 90 | ; /* "limbo" */ |
| 91 | else if (Wcm.cm_autowrap) { |
| 92 | curX = 0; |
| 93 | curY++; /* Beware end of screen! */ |
| 94 | } |
| 95 | else |
| 96 | curX--; |
| 97 | } |
| 98 | } |
| 99 | #endif |
| 100 | |
| 101 | /* |
| 102 | * (Re)Initialize the cost factors, given the output speed of the terminal |
| 103 | * in the variable ospeed. (Note: this holds B300, B9600, etc -- ie stuff |
| 104 | * out of <sgtty.h>.) |
| 105 | */ |
| 106 | |
| 107 | cmcostinit () |
| 108 | { |
| 109 | char *p; |
| 110 | |
| 111 | #define COST(x,e) (x ? (cost = 0, tputs (x, 1, e), cost) : BIG) |
| 112 | #define CMCOST(x,e) ((x == 0) ? BIG : (p = tgoto(x, 0, 0), COST(p ,e))) |
| 113 | |
| 114 | Wcm.cc_up = COST (Wcm.cm_up, evalcost); |
| 115 | Wcm.cc_down = COST (Wcm.cm_down, evalcost); |
| 116 | Wcm.cc_left = COST (Wcm.cm_left, evalcost); |
| 117 | Wcm.cc_right = COST (Wcm.cm_right, evalcost); |
| 118 | Wcm.cc_home = COST (Wcm.cm_home, evalcost); |
| 119 | Wcm.cc_cr = COST (Wcm.cm_cr, evalcost); |
| 120 | Wcm.cc_ll = COST (Wcm.cm_ll, evalcost); |
| 121 | Wcm.cc_tab = Wcm.cm_tabwidth ? COST (Wcm.cm_tab, evalcost) : BIG; |
| 122 | |
| 123 | /* |
| 124 | * These last three are actually minimum costs. When (if) they are |
| 125 | * candidates for the least-cost motion, the real cost is computed. |
| 126 | * (Note that "0" is the assumed to generate the minimum cost. |
| 127 | * While this is not necessarily true, I have yet to see a terminal |
| 128 | * for which is not; all the terminals that have variable-cost |
| 129 | * cursor motion seem to take straight numeric values. --ACT) |
| 130 | */ |
| 131 | |
| 132 | Wcm.cc_abs = CMCOST (Wcm.cm_abs, evalcost); |
| 133 | Wcm.cc_habs = CMCOST (Wcm.cm_habs, evalcost); |
| 134 | Wcm.cc_vabs = CMCOST (Wcm.cm_vabs, evalcost); |
| 135 | |
| 136 | #undef CMCOST |
| 137 | #undef COST |
| 138 | } |
| 139 | |
| 140 | /* |
| 141 | * Calculate the cost to move from (srcy, srcx) to (dsty, dstx) using |
| 142 | * up and down, and left and right, motions, and tabs. If doit is set |
| 143 | * actually perform the motion. |
| 144 | */ |
| 145 | |
| 146 | static |
| 147 | calccost (srcy, srcx, dsty, dstx, doit) |
| 148 | { |
| 149 | register int deltay, |
| 150 | deltax, |
| 151 | c, |
| 152 | totalcost; |
| 153 | int ntabs, |
| 154 | n2tabs, |
| 155 | tabx, |
| 156 | tab2x, |
| 157 | tabcost; |
| 158 | register char *p; |
| 159 | |
| 160 | /* If have just wrapped on a terminal with xn, |
| 161 | don't believe the cursor position: give up here |
| 162 | and force use of absolute positioning. */ |
| 163 | |
| 164 | if (curX == Wcm.cm_cols) |
| 165 | goto fail; |
| 166 | |
| 167 | totalcost = 0; |
| 168 | if ((deltay = dsty - srcy) == 0) |
| 169 | goto x; |
| 170 | if (deltay < 0) |
| 171 | p = Wcm.cm_up, c = Wcm.cc_up, deltay = -deltay; |
| 172 | else |
| 173 | p = Wcm.cm_down, c = Wcm.cc_down; |
| 174 | if (c == BIG) { /* caint get thar from here */ |
| 175 | if (doit) |
| 176 | printf ("OOPS"); |
| 177 | return c; |
| 178 | } |
| 179 | totalcost = c * deltay; |
| 180 | if (doit) |
| 181 | while (--deltay >= 0) |
| 182 | tputs (p, 1, cmputc); |
| 183 | x: |
| 184 | if ((deltax = dstx - srcx) == 0) |
| 185 | goto done; |
| 186 | if (deltax < 0) { |
| 187 | p = Wcm.cm_left, c = Wcm.cc_left, deltax = -deltax; |
| 188 | goto dodelta; /* skip all the tab junk */ |
| 189 | } |
| 190 | /* Tabs (the toughie) */ |
| 191 | if (Wcm.cc_tab >= BIG || !Wcm.cm_usetabs) |
| 192 | goto olddelta; /* forget it! */ |
| 193 | |
| 194 | /* |
| 195 | * ntabs is # tabs towards but not past dstx; n2tabs is one more |
| 196 | * (ie past dstx), but this is only valid if that is not past the |
| 197 | * right edge of the screen. We can check that at the same time |
| 198 | * as we figure out where we would be if we use the tabs (which |
| 199 | * we will put into tabx (for ntabs) and tab2x (for n2tabs)). |
| 200 | */ |
| 201 | |
| 202 | ntabs = (deltax + srcx % Wcm.cm_tabwidth) / Wcm.cm_tabwidth; |
| 203 | n2tabs = ntabs + 1; |
| 204 | tabx = (srcx / Wcm.cm_tabwidth + ntabs) * Wcm.cm_tabwidth; |
| 205 | tab2x = tabx + Wcm.cm_tabwidth; |
| 206 | |
| 207 | if (tab2x >= Wcm.cm_cols) /* too far (past edge) */ |
| 208 | n2tabs = 0; |
| 209 | |
| 210 | /* |
| 211 | * Now set tabcost to the cost for using ntabs, and c to the cost |
| 212 | * for using n2tabs, then pick the minimum. |
| 213 | */ |
| 214 | |
| 215 | /* cost for ntabs + cost for right motion */ |
| 216 | tabcost = ntabs ? ntabs * Wcm.cc_tab + (dstx - tabx) * Wcm.cc_right |
| 217 | : BIG; |
| 218 | |
| 219 | /* cost for n2tabs + cost for left motion */ |
| 220 | c = n2tabs ? n2tabs * Wcm.cc_tab + (tab2x - dstx) * Wcm.cc_left |
| 221 | : BIG; |
| 222 | |
| 223 | if (c < tabcost) /* then cheaper to overshoot & back up */ |
| 224 | ntabs = n2tabs, tabcost = c, tabx = tab2x; |
| 225 | |
| 226 | if (tabcost >= BIG) /* caint use tabs */ |
| 227 | goto newdelta; |
| 228 | |
| 229 | /* |
| 230 | * See if tabcost is less than just moving right |
| 231 | */ |
| 232 | |
| 233 | if (tabcost < (deltax * Wcm.cc_right)) { |
| 234 | totalcost += tabcost; /* use the tabs */ |
| 235 | if (doit) |
| 236 | while (--ntabs >= 0) |
| 237 | tputs (Wcm.cm_tab, 1, cmputc); |
| 238 | srcx = tabx; |
| 239 | } |
| 240 | |
| 241 | /* |
| 242 | * Now might as well just recompute the delta. |
| 243 | */ |
| 244 | |
| 245 | newdelta: |
| 246 | if ((deltax = dstx - srcx) == 0) |
| 247 | goto done; |
| 248 | olddelta: |
| 249 | if (deltax > 0) |
| 250 | p = Wcm.cm_right, c = Wcm.cc_right; |
| 251 | else |
| 252 | p = Wcm.cm_left, c = Wcm.cc_left, deltax = -deltax; |
| 253 | |
| 254 | dodelta: |
| 255 | if (c == BIG) { /* caint get thar from here */ |
| 256 | fail: |
| 257 | if (doit) |
| 258 | printf ("OOPS"); |
| 259 | return BIG; |
| 260 | } |
| 261 | totalcost += c * deltax; |
| 262 | if (doit) |
| 263 | while (--deltax >= 0) |
| 264 | tputs (p, 1, cmputc); |
| 265 | done: |
| 266 | return totalcost; |
| 267 | } |
| 268 | |
| 269 | #if 0 |
| 270 | losecursor () |
| 271 | { |
| 272 | curY = -1; |
| 273 | } |
| 274 | #endif |
| 275 | |
| 276 | #define USEREL 0 |
| 277 | #define USEHOME 1 |
| 278 | #define USELL 2 |
| 279 | #define USECR 3 |
| 280 | |
| 281 | cmgoto (row, col) |
| 282 | { |
| 283 | int homecost, |
| 284 | crcost, |
| 285 | llcost, |
| 286 | relcost, |
| 287 | directcost; |
| 288 | int use; |
| 289 | char *p, |
| 290 | *dcm; |
| 291 | |
| 292 | /* First the degenerate case */ |
| 293 | if (row == curY && col == curX) /* already there */ |
| 294 | return; |
| 295 | |
| 296 | if (curY >= 0 && curX >= 0) |
| 297 | { |
| 298 | /* We may have quick ways to go to the upper-left, bottom-left, |
| 299 | * start-of-line, or start-of-next-line. Or it might be best to |
| 300 | * start where we are. Examine the options, and pick the cheapest. |
| 301 | */ |
| 302 | |
| 303 | relcost = calccost (curY, curX, row, col, 0); |
| 304 | use = USEREL; |
| 305 | if ((homecost = Wcm.cc_home) < BIG) |
| 306 | homecost += calccost (0, 0, row, col, 0); |
| 307 | if (homecost < relcost) |
| 308 | relcost = homecost, use = USEHOME; |
| 309 | if ((llcost = Wcm.cc_ll) < BIG) |
| 310 | llcost += calccost (Wcm.cm_rows - 1, 0, row, col, 0); |
| 311 | if (llcost < relcost) |
| 312 | relcost = llcost, use = USELL; |
| 313 | if ((crcost = Wcm.cc_cr) < BIG) { |
| 314 | if (Wcm.cm_autolf) |
| 315 | if (curY + 1 >= Wcm.cm_rows) |
| 316 | crcost = BIG; |
| 317 | else |
| 318 | crcost += calccost (curY + 1, 0, row, col, 0); |
| 319 | else |
| 320 | crcost += calccost (curY, 0, row, col, 0); |
| 321 | } |
| 322 | if (crcost < relcost) |
| 323 | relcost = crcost, use = USECR; |
| 324 | directcost = Wcm.cc_abs, dcm = Wcm.cm_abs; |
| 325 | if (row == curY && Wcm.cc_habs < BIG) |
| 326 | directcost = Wcm.cc_habs, dcm = Wcm.cm_habs; |
| 327 | else if (col == curX && Wcm.cc_vabs < BIG) |
| 328 | directcost = Wcm.cc_vabs, dcm = Wcm.cm_vabs; |
| 329 | } |
| 330 | else |
| 331 | { |
| 332 | directcost = 0, relcost = 100000; |
| 333 | dcm = Wcm.cm_abs; |
| 334 | } |
| 335 | |
| 336 | /* |
| 337 | * In the following comparison, the = in <= is because when the costs |
| 338 | * are the same, it looks nicer (I think) to move directly there. |
| 339 | */ |
| 340 | if (directcost <= relcost) |
| 341 | { |
| 342 | /* compute REAL direct cost */ |
| 343 | cost = 0; |
| 344 | p = dcm == Wcm.cm_habs ? tgoto (dcm, row, col) : |
| 345 | tgoto (dcm, col, row); |
| 346 | tputs (p, 1, evalcost); |
| 347 | if (cost <= relcost) |
| 348 | { /* really is cheaper */ |
| 349 | tputs (p, 1, cmputc); |
| 350 | curY = row, curX = col; |
| 351 | return; |
| 352 | } |
| 353 | } |
| 354 | |
| 355 | switch (use) |
| 356 | { |
| 357 | case USEHOME: |
| 358 | tputs (Wcm.cm_home, 1, cmputc); |
| 359 | curY = 0, curX = 0; |
| 360 | break; |
| 361 | |
| 362 | case USELL: |
| 363 | tputs (Wcm.cm_ll, 1, cmputc); |
| 364 | curY = Wcm.cm_rows - 1, curX = 0; |
| 365 | break; |
| 366 | |
| 367 | case USECR: |
| 368 | tputs (Wcm.cm_cr, 1, cmputc); |
| 369 | if (Wcm.cm_autolf) |
| 370 | curY++; |
| 371 | curX = 0; |
| 372 | break; |
| 373 | } |
| 374 | |
| 375 | (void) calccost (curY, curX, row, col, 1); |
| 376 | curY = row, curX = col; |
| 377 | } |
| 378 | |
| 379 | /* Clear out all terminal info. |
| 380 | Used before copying into it the info on the actual terminal. |
| 381 | */ |
| 382 | |
| 383 | Wcm_clear () |
| 384 | { |
| 385 | bzero (&Wcm, sizeof Wcm); |
| 386 | UP = 0; |
| 387 | BC = 0; |
| 388 | } |
| 389 | |
| 390 | /* |
| 391 | * Initialized stuff |
| 392 | * Return 0 if can do CM. |
| 393 | * Return -1 if cannot. |
| 394 | * Return -2 if size not specified. |
| 395 | */ |
| 396 | |
| 397 | Wcm_init () |
| 398 | { |
| 399 | #if 0 |
| 400 | if (Wcm.cm_abs && !Wcm.cm_ds) |
| 401 | return 0; |
| 402 | #endif |
| 403 | if (Wcm.cm_abs) |
| 404 | return 0; |
| 405 | /* Require up and left, and, if no absolute, down and right */ |
| 406 | if (!Wcm.cm_up || !Wcm.cm_left) |
| 407 | return - 1; |
| 408 | if (!Wcm.cm_abs && (!Wcm.cm_down || !Wcm.cm_right)) |
| 409 | return - 1; |
| 410 | /* Check that we know the size of the screen.... */ |
| 411 | if (Wcm.cm_rows <= 0 || Wcm.cm_cols <= 0) |
| 412 | return - 2; |
| 413 | return 0; |
| 414 | } |