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Length: 20610 (0x5082) Types: TextFile Names: »display.c«
└─⟦a0efdde77⟧ Bits:30001252 EUUGD11 Tape, 1987 Spring Conference Helsinki └─ ⟦this⟧ »EUUGD11/euug-87hel/sec1/micrognu/display.c«
/* * The functions in this file handle redisplay. The * redisplay system knows almost nothing about the editing * process; the editing functions do, however, set some * hints to eliminate a lot of the grinding. There is more * that can be done; the "vtputc" interface is a real * pig. Two conditional compilation flags; the GOSLING * flag enables dynamic programming redisplay, using the * algorithm published by Jim Gosling in SIGOA. The MEMMAP * changes things around for memory mapped video. With * both off, the terminal is a VT52. */ #include "def.h" /* * You can change these back to the types * implied by the name if you get tight for space. If you * make both of them "int" you get better code on the VAX. * They do nothing if this is not Gosling redisplay, except * for change the size of a structure that isn't used. * A bit of a cheat. */ /* These defines really belong in sysdef.h */ #ifndef XCHAR # define XCHAR int # define XSHORT int #endif #ifdef STANDOUT_GLITCH extern int SG; /* number of standout glitches */ #endif /* * A video structure always holds * an array of characters whose length is equal to * the longest line possible. Only some of this is * used if "ncol" isn't the same as "NCOL". */ typedef struct { short v_hash; /* Hash code, for compares. */ short v_flag; /* Flag word. */ short v_color; /* Color of the line. */ XSHORT v_cost; /* Cost of display. */ char v_text[NCOL]; /* The actual characters. */ } VIDEO; #define VFCHG 0x0001 /* Changed. */ #define VFHBAD 0x0002 /* Hash and cost are bad. */ /* * SCORE structures hold the optimal * trace trajectory, and the cost of redisplay, when * the dynamic programming redisplay code is used. * If no fancy redisplay, this isn't used. The trace index * fields can be "char", and the score a "short", but * this makes the code worse on the VAX. */ typedef struct { XCHAR s_itrace; /* "i" index for track back. */ XCHAR s_jtrace; /* "j" index for trace back. */ XSHORT s_cost; /* Display cost. */ } SCORE; int sgarbf = TRUE; /* TRUE if screen is garbage. */ int vtrow = 0; /* Virtual cursor row. */ int vtcol = 0; /* Virtual cursor column. */ int tthue = CNONE; /* Current color. */ int ttrow = HUGE; /* Physical cursor row. */ int ttcol = HUGE; /* Physical cursor column. */ int tttop = HUGE; /* Top of scroll region. */ int ttbot = HUGE; /* Bottom of scroll region. */ VIDEO *vscreen[NROW-1]; /* Edge vector, virtual. */ VIDEO *pscreen[NROW-1]; /* Edge vector, physical. */ VIDEO video[2*(NROW-1)]; /* Actual screen data. */ VIDEO blanks; /* Blank line image. */ #ifdef GOSLING /* * This matrix is written as an array because * we do funny things in the "setscores" routine, which * is very compute intensive, to make the subscripts go away. * It would be "SCORE score[NROW][NROW]" in old speak. * Look at "setscores" to understand what is up. */ SCORE score[NROW*NROW]; #endif /* * Initialize the data structures used * by the display code. The edge vectors used * to access the screens are set up. The operating * system's terminal I/O channel is set up. Fill the * "blanks" array with ASCII blanks. The rest is done * at compile time. The original window is marked * as needing full update, and the physical screen * is marked as garbage, so all the right stuff happens * on the first call to redisplay. */ vtinit() { register VIDEO *vp; register int i; ttopen(); ttinit(); vp = &video[0]; for (i=0; i<NROW-1; ++i) { vscreen[i] = vp; ++vp; pscreen[i] = vp; ++vp; } blanks.v_color = CTEXT; for (i=0; i<NCOL; ++i) blanks.v_text[i] = ' '; } /* * Tidy up the virtual display system * in anticipation of a return back to the host * operating system. Right now all we do is position * the cursor to the last line, erase the line, and * close the terminal channel. */ vttidy() { ttcolor(CTEXT); ttnowindow(); /* No scroll window. */ ttmove(nrow-1, 0); /* Echo line. */ tteeol(); tttidy(); ttflush(); ttclose(); } /* * Move the virtual cursor to an origin * 0 spot on the virtual display screen. I could * store the column as a character pointer to the spot * on the line, which would make "vtputc" a little bit * more efficient. No checking for errors. */ vtmove(row, col) { vtrow = row; vtcol = col; } /* * Write a character to the virtual display, * dealing with long lines and the display of unprintable * things like control characters. Also expand tabs every 8 * columns. This code only puts printing characters into * the virtual display image. Special care must be taken when * expanding tabs. On a screen whose width is not a multiple * of 8, it is possible for the virtual cursor to hit the * right margin before the next tab stop is reached. This * makes the tab code loop if you are not careful. * Three guesses how we found this. */ vtputc(c) register int c; { register VIDEO *vp; vp = vscreen[vtrow]; if (vtcol >= ncol) vp->v_text[ncol-1] = '$'; else if (c == '\t') { do { vtputc(' '); } while (vtcol<ncol && (vtcol&0x07)!=0); } else if (ISCTRL(c) != FALSE) { vtputc('^'); vtputc(c ^ 0x40); } else vp->v_text[vtcol++] = c; } /* * Erase from the end of the * software cursor to the end of the * line on which the software cursor is * located. The display routines will decide * if a hardware erase to end of line command * should be used to display this. */ vteeol() { register VIDEO *vp; vp = vscreen[vtrow]; while (vtcol < ncol) vp->v_text[vtcol++] = ' '; } /* * Make sure that the display is * right. This is a three part process. First, * scan through all of the windows looking for dirty * ones. Check the framing, and refresh the screen. * Second, make sure that "currow" and "curcol" are * correct for the current window. Third, make the * virtual and physical screens the same. */ VOID update() { register LINE *lp; register WINDOW *wp; register VIDEO *vp1; register VIDEO *vp2; register int i; register int j; register int c; register int hflag; register int currow; register int curcol; register int offs; register int size; VOID traceback (); VOID uline (); if (typeahead()) return; if (sgarbf) { /* must update everything */ wp = wheadp; while(wp != NULL) { wp->w_flag |= WFMODE | WFHARD; wp = wp->w_wndp; } } hflag = FALSE; /* Not hard. */ wp = wheadp; while (wp != NULL) { if (wp->w_flag != 0) { /* Need update. */ if ((wp->w_flag&WFFORCE) == 0) { lp = wp->w_linep; for (i=0; i<wp->w_ntrows; ++i) { if (lp == wp->w_dotp) goto out; if (lp == wp->w_bufp->b_linep) break; lp = lforw(lp); } } i = wp->w_force; /* Reframe this one. */ if (i > 0) { --i; if (i >= wp->w_ntrows) i = wp->w_ntrows-1; } else if (i < 0) { i += wp->w_ntrows; if (i < 0) i = 0; } else i = wp->w_ntrows/2; lp = wp->w_dotp; while (i!=0 && lback(lp)!=wp->w_bufp->b_linep) { --i; lp = lback(lp); } wp->w_linep = lp; wp->w_flag |= WFHARD; /* Force full. */ out: lp = wp->w_linep; /* Try reduced update. */ i = wp->w_toprow; if ((wp->w_flag&~WFMODE) == WFEDIT) { while (lp != wp->w_dotp) { ++i; lp = lforw(lp); } vscreen[i]->v_color = CTEXT; vscreen[i]->v_flag |= (VFCHG|VFHBAD); vtmove(i, 0); for (j=0; j<llength(lp); ++j) vtputc(lgetc(lp, j)); vteeol(); } else if ((wp->w_flag&(WFEDIT|WFHARD)) != 0) { hflag = TRUE; while (i < wp->w_toprow+wp->w_ntrows) { vscreen[i]->v_color = CTEXT; vscreen[i]->v_flag |= (VFCHG|VFHBAD); vtmove(i, 0); if (lp != wp->w_bufp->b_linep) { for (j=0; j<llength(lp); ++j) vtputc(lgetc(lp, j)); lp = lforw(lp); } vteeol(); ++i; } } if ((wp->w_flag&WFMODE) != 0) modeline(wp); wp->w_flag = 0; wp->w_force = 0; } wp = wp->w_wndp; } lp = curwp->w_linep; /* Cursor location. */ currow = curwp->w_toprow; while (lp != curwp->w_dotp) { ++currow; lp = lforw(lp); } curcol = 0; i = 0; while (i < curwp->w_doto) { c = lgetc(lp, i++); if (c == '\t') curcol |= 0x07; else if (ISCTRL(c) != FALSE) ++curcol; ++curcol; } if (curcol >= ncol) /* Long line. */ curcol = ncol-1; if (sgarbf != FALSE) { /* Screen is garbage. */ sgarbf = FALSE; /* Erase-page clears */ epresf = FALSE; /* the message area. */ tttop = HUGE; /* Forget where you set */ ttbot = HUGE; /* scroll region. */ tthue = CNONE; /* Color unknown. */ ttmove(0, 0); tteeop(); for (i=0; i<nrow-1; ++i) { uline(i, vscreen[i], &blanks); ucopy(vscreen[i], pscreen[i]); } ttmove(currow, curcol); ttflush(); return; } #ifdef GOSLING if (hflag != FALSE) { /* Hard update? */ for (i=0; i<nrow-1; ++i) { /* Compute hash data. */ hash(vscreen[i]); hash(pscreen[i]); } offs = 0; /* Get top match. */ while (offs != nrow-1) { vp1 = vscreen[offs]; vp2 = pscreen[offs]; if (vp1->v_color != vp2->v_color || vp1->v_hash != vp2->v_hash) break; uline(offs, vp1, vp2); ucopy(vp1, vp2); ++offs; } if (offs == nrow-1) { /* Might get it all. */ ttmove(currow, curcol); ttflush(); return; } size = nrow-1; /* Get bottom match. */ while (size != offs) { vp1 = vscreen[size-1]; vp2 = pscreen[size-1]; if (vp1->v_color != vp2->v_color || vp1->v_hash != vp2->v_hash) break; uline(size-1, vp1, vp2); ucopy(vp1, vp2); --size; } if ((size -= offs) == 0) /* Get screen size. */ panic("Illegal screen size in update"); setscores(offs, size); /* Do hard update. */ traceback(offs, size, size, size); for (i=0; i<size; ++i) ucopy(vscreen[offs+i], pscreen[offs+i]); ttmove(currow, curcol); ttflush(); return; } #endif for (i=0; i<nrow-1; ++i) { /* Easy update. */ vp1 = vscreen[i]; vp2 = pscreen[i]; if ((vp1->v_flag&VFCHG) != 0) { uline(i, vp1, vp2); ucopy(vp1, vp2); } } ttmove(currow, curcol); ttflush(); } /* * Update a saved copy of a line, * kept in a VIDEO structure. The "vvp" is * the one in the "vscreen". The "pvp" is the one * in the "pscreen". This is called to make the * virtual and physical screens the same when * display has done an update. */ ucopy(vvp, pvp) register VIDEO *vvp; register VIDEO *pvp; { vvp->v_flag &= ~VFCHG; /* Changes done. */ pvp->v_flag = vvp->v_flag; /* Update model. */ pvp->v_hash = vvp->v_hash; pvp->v_cost = vvp->v_cost; pvp->v_color = vvp->v_color; bcopy(vvp->v_text, pvp->v_text, ncol); } /* * Update a single line. This routine only * uses basic functionality (no insert and delete character, * but erase to end of line). The "vvp" points at the VIDEO * structure for the line on the virtual screen, and the "pvp" * is the same for the physical screen. Avoid erase to end of * line when updating CMODE color lines, because of the way that * reverse video works on most terminals. */ VOID uline(row, vvp, pvp) VIDEO *vvp; VIDEO *pvp; { #ifdef MEMMAP putline(row+1, 1, &vvp->v_text[0]); #else register char *cp1; register char *cp2; register char *cp3; register char *cp4; register char *cp5; register int nbflag; if (vvp->v_color != pvp->v_color) { /* Wrong color, do a */ ttmove(row, 0); /* full redraw. */ #ifdef STANDOUT_GLITCH if (pvp->v_color != CTEXT && SG >= 0) tteeol(); #endif ttcolor(vvp->v_color); #ifdef STANDOUT_GLITCH cp1 = &vvp->v_text[SG > 0 ? SG : 0]; /* the odd code for SG==0 is to avoid putting the invisable * glitch character on the next line. * (Hazeltine executive 80 model 30) */ cp2 = &vvp->v_text[ncol - (SG >= 0 ? (SG!=0 ? SG : 1) : 0)]; #else cp1 = &vvp->v_text[0]; cp2 = &vvp->v_text[ncol]; #endif while (cp1 != cp2) { ttputc(*cp1++); ++ttcol; } #ifndef MOVE_STANDOUT ttcolor(CTEXT); #endif return; } cp1 = &vvp->v_text[0]; /* Compute left match. */ cp2 = &pvp->v_text[0]; while (cp1!=&vvp->v_text[ncol] && cp1[0]==cp2[0]) { ++cp1; ++cp2; } if (cp1 == &vvp->v_text[ncol]) /* All equal. */ return; nbflag = FALSE; cp3 = &vvp->v_text[ncol]; /* Compute right match. */ cp4 = &pvp->v_text[ncol]; while (cp3[-1] == cp4[-1]) { --cp3; --cp4; if (cp3[0] != ' ') /* Note non-blanks in */ nbflag = TRUE; /* the right match. */ } cp5 = cp3; /* Is erase good? */ if (nbflag==FALSE && vvp->v_color==CTEXT) { while (cp5!=cp1 && cp5[-1]==' ') --cp5; /* Alcyon hack */ if ((int)(cp3-cp5) <= tceeol) cp5 = cp3; } /* Alcyon hack */ ttmove(row, (int)(cp1-&vvp->v_text[0])); #ifdef STANDOUT_GLITCH if (vvp->v_color != CTEXT && SG > 0) { if(cp1 < &vvp->v_text[SG]) cp1 = &vvp->v_text[SG]; if(cp5 > &vvp->v_text[ncol-SG]) cp5 = &vvp->v_text[ncol-SG]; } else if (SG < 0) #endif ttcolor(vvp->v_color); while (cp1 != cp5) { ttputc(*cp1++); ++ttcol; } if (cp5 != cp3) /* Do erase. */ tteeol(); #endif } /* * Redisplay the mode line for * the window pointed to by the "wp". * This is the only routine that has any idea * of how the modeline is formatted. You can * change the modeline format by hacking at * this routine. Called by "update" any time * there is a dirty window. * Note that if STANDOUT_GLITCH is defined, first and last SG characters * may never be seen. */ modeline(wp) register WINDOW *wp; { register int n; register BUFFER *bp; n = wp->w_toprow+wp->w_ntrows; /* Location. */ vscreen[n]->v_color = CMODE; /* Mode line color. */ vscreen[n]->v_flag |= (VFCHG|VFHBAD); /* Recompute, display. */ vtmove(n, 0); /* Seek to right line. */ bp = wp->w_bufp; vtputc('-'); vtputc('-'); if ((bp->b_flag&BFCHG) != 0) { /* "*" if changed. */ vtputc('*'); vtputc('*'); } else { vtputc('-'); vtputc('-'); } vtputc('-'); n = 5; n += vtputs("MicroGnuEmacs:"); if (bp->b_bname[0] != 0) { vtputc(' '); ++n; n += vtputs(&(bp->b_bname[0])); } while (n < 42) { /* Pad out with blanks */ vtputc(' '); ++n; } vtputc('('); ++n; if (mode == 0) n += vtputs("Fundamental"); else { if ((mode&MBSMAP) != 0) { n += vtputs("bsmap"); if ((mode&~MBSMAP) != 0) { vtputc('-'); ++n; } } if ((mode&MFLOW) != 0) { n += vtputs("flow"); if ((mode&~(MFLOW|MBSMAP)) != 0) { vtputc('-'); ++n; } } if ((mode&MINDENT) != 0) { n += vtputs("indent"); if ((mode&~(MINDENT|MFLOW|MBSMAP)) != 0) { vtputc('-'); ++n; } } if ((mode&MFILL) != 0) n += vtputs("fill"); } vtputc(')'); ++n; while (n < ncol) { /* Pad out. */ vtputc('-'); ++n; } } /* * output a string to the mode line, report how long it was. */ vtputs(s) register char *s; { register int n = 0; while (*s != '\0') { vtputc(*s++); ++n; } return n; } #ifdef GOSLING /* * Compute the hash code for * the line pointed to by the "vp". Recompute * it if necessary. Also set the approximate redisplay * cost. The validity of the hash code is marked by * a flag bit. The cost understand the advantages * of erase to end of line. Tuned for the VAX * by Bob McNamara; better than it used to be on * just about any machine. */ hash(vp) register VIDEO *vp; { register int i; register int n; register char *s; if ((vp->v_flag&VFHBAD) != 0) { /* Hash bad. */ s = &vp->v_text[ncol-1]; for (i=ncol; i!=0; --i, --s) if (*s != ' ') break; n = ncol-i; /* Erase cheaper? */ if (n > tceeol) n = tceeol; vp->v_cost = i+n; /* Bytes + blanks. */ for (n=0; i!=0; --i, --s) n = (n<<5) + n + *s; vp->v_hash = n; /* Hash code. */ vp->v_flag &= ~VFHBAD; /* Flag as all done. */ } } /* * Compute the Insert-Delete * cost matrix. The dynamic programming algorithm * described by James Gosling is used. This code assumes * that the line above the echo line is the last line involved * in the scroll region. This is easy to arrange on the VT100 * because of the scrolling region. The "offs" is the origin 0 * offset of the first row in the virtual/physical screen that * is being updated; the "size" is the length of the chunk of * screen being updated. For a full screen update, use offs=0 * and size=nrow-1. * * Older versions of this code implemented the score matrix by * a two dimensional array of SCORE nodes. This put all kinds of * multiply instructions in the code! This version is written to * use a linear array and pointers, and contains no multiplication * at all. The code has been carefully looked at on the VAX, with * only marginal checking on other machines for efficiency. In * fact, this has been tuned twice! Bob McNamara tuned it even * more for the VAX, which is a big issue for him because of * the 66 line X displays. * * On some machines, replacing the "for (i=1; i<=size; ++i)" with * i = 1; do { } while (++i <=size)" will make the code quite a * bit better; but it looks ugly. */ setscores(offs, size) { register SCORE *sp; SCORE *sp1; register int tempcost; register int bestcost; register int j; register int i; register VIDEO **vp; VIDEO **pp, **vbase, **pbase; vbase = &vscreen[offs-1]; /* By hand CSE's. */ pbase = &pscreen[offs-1]; score[0].s_itrace = 0; /* [0, 0] */ score[0].s_jtrace = 0; score[0].s_cost = 0; sp = &score[1]; /* Row 0, inserts. */ tempcost = 0; vp = &vbase[1]; for (j=1; j<=size; ++j) { sp->s_itrace = 0; sp->s_jtrace = j-1; tempcost += tcinsl; tempcost += (*vp)->v_cost; sp->s_cost = tempcost; ++vp; ++sp; } sp = &score[NROW]; /* Column 0, deletes. */ tempcost = 0; for (i=1; i<=size; ++i) { sp->s_itrace = i-1; sp->s_jtrace = 0; tempcost += tcdell; sp->s_cost = tempcost; sp += NROW; } sp1 = &score[NROW+1]; /* [1, 1]. */ pp = &pbase[1]; for (i=1; i<=size; ++i) { sp = sp1; vp = &vbase[1]; for (j=1; j<=size; ++j) { sp->s_itrace = i-1; sp->s_jtrace = j; bestcost = (sp-NROW)->s_cost; if (j != size) /* Cd(A[i])=0 @ Dis. */ bestcost += tcdell; tempcost = (sp-1)->s_cost; tempcost += (*vp)->v_cost; if (i != size) /* Ci(B[j])=0 @ Dsj. */ tempcost += tcinsl; if (tempcost < bestcost) { sp->s_itrace = i; sp->s_jtrace = j-1; bestcost = tempcost; } tempcost = (sp-NROW-1)->s_cost; if ((*pp)->v_color != (*vp)->v_color || (*pp)->v_hash != (*vp)->v_hash) tempcost += (*vp)->v_cost; if (tempcost < bestcost) { sp->s_itrace = i-1; sp->s_jtrace = j-1; bestcost = tempcost; } sp->s_cost = bestcost; ++sp; /* Next column. */ ++vp; } ++pp; sp1 += NROW; /* Next row. */ } } /* * Trace back through the dynamic programming cost * matrix, and update the screen using an optimal sequence * of redraws, insert lines, and delete lines. The "offs" is * the origin 0 offset of the chunk of the screen we are about to * update. The "i" and "j" are always started in the lower right * corner of the matrix, and imply the size of the screen. * A full screen traceback is called with offs=0 and i=j=nrow-1. * There is some do-it-yourself double subscripting here, * which is acceptable because this routine is much less compute * intensive then the code that builds the score matrix! */ VOID traceback(offs, size, i, j) { register int itrace; register int jtrace; register int k; register int ninsl; register int ndraw; register int ndell; if (i==0 && j==0) /* End of update. */ return; itrace = score[(NROW*i) + j].s_itrace; jtrace = score[(NROW*i) + j].s_jtrace; if (itrace == i) { /* [i, j-1] */ ninsl = 0; /* Collect inserts. */ if (i != size) ninsl = 1; ndraw = 1; while (itrace!=0 || jtrace!=0) { if (score[(NROW*itrace) + jtrace].s_itrace != itrace) break; jtrace = score[(NROW*itrace) + jtrace].s_jtrace; if (i != size) ++ninsl; ++ndraw; } traceback(offs, size, itrace, jtrace); if (ninsl != 0) { ttcolor(CTEXT); ttinsl(offs+j-ninsl, offs+size-1, ninsl); } do { /* B[j], A[j] blank. */ k = offs+j-ndraw; uline(k, vscreen[k], &blanks); } while (--ndraw); return; } if (jtrace == j) { /* [i-1, j] */ ndell = 0; /* Collect deletes. */ if (j != size) ndell = 1; while (itrace!=0 || jtrace!=0) { if (score[(NROW*itrace) + jtrace].s_jtrace != jtrace) break; itrace = score[(NROW*itrace) + jtrace].s_itrace; if (j != size) ++ndell; } if (ndell != 0) { ttcolor(CTEXT); ttdell(offs+i-ndell, offs+size-1, ndell); } traceback(offs, size, itrace, jtrace); return; } traceback(offs, size, itrace, jtrace); k = offs+j-1; uline(k, vscreen[k], pscreen[offs+i-1]); } #endif