Date: 2022-03-31T04:46:00+00:00

Actual source code: xtext.c

      2: /*
      3:    This file contains simple code to manage access to fonts, insuring that
      4:    library routines access/load fonts only once
      5:  */

      7: #include <../src/sys/classes/draw/impls/x/ximpl.h>

      9: static PetscErrorCode PetscDrawXiInitFonts(PetscDraw_X*);
     10: static PetscErrorCode PetscDrawXiLoadFont(PetscDraw_X*,PetscDrawXiFont*);
     11: static PetscErrorCode PetscDrawXiMatchFontSize(PetscDrawXiFont*,int,int);

     13: /*
     14:     PetscDrawXiFontFixed - Return a pointer to the selected font.

     16:     Warning: Loads a new font for each window. This should be
     17:    ok because there will never be many windows and the graphics
     18:    are not intended to be high performance.
     19: */
     20: PetscErrorCode PetscDrawXiFontFixed(PetscDraw_X *XBWin,int w,int h,PetscDrawXiFont **outfont)
     21: {
     22:   static PetscDrawXiFont *curfont = NULL,*font;

     24:   if (!curfont) PetscDrawXiInitFonts(XBWin);
     25:   PetscNew(&font);
     26:   PetscDrawXiMatchFontSize(font,w,h);
     27:   PetscDrawXiLoadFont(XBWin,font);

     29:   curfont  = font;
     30:   *outfont = curfont;
     31:   return 0;
     32: }

     34: /* this is set by XListFonts at startup */
     35: #define NFONTS 20
     36: static struct {
     37:   int w,h,descent;
     38: } nfonts[NFONTS];
     39: static int act_nfonts = 0;

     41: /*
     42:   These routines determine the font to be used based on the requested size,
     43:   and load it if necessary
     44: */

     46: static PetscErrorCode PetscDrawXiLoadFont(PetscDraw_X *XBWin,PetscDrawXiFont *font)
     47: {
     48:   char        font_name[100];
     49:   XFontStruct *FontInfo;
     50:   XGCValues   values;

     52:   (void) sprintf(font_name,"%dx%d",font->font_w,font->font_h);
     53:   font->fnt = XLoadFont(XBWin->disp,font_name);

     55:   /* The font->descent may not have been set correctly; get it now that
     56:       the font has been loaded */
     57:   FontInfo           = XQueryFont(XBWin->disp,font->fnt);
     58:   font->font_descent = FontInfo->descent;
     59:   font->font_w       = FontInfo->max_bounds.rbearing - FontInfo->min_bounds.lbearing;
     60:   font->font_h       = FontInfo->max_bounds.ascent + FontInfo->max_bounds.descent;

     62:   XFreeFontInfo(NULL,FontInfo,1);

     64:   /* Set the current font in the CG */
     65:   values.font = font->fnt;
     66:   XChangeGC(XBWin->disp,XBWin->gc.set,GCFont,&values);
     67:   return 0;
     68: }

     70: /* Code to find fonts and their characteristics */
     71: static PetscErrorCode PetscDrawXiInitFonts(PetscDraw_X *XBWin)
     72: {
     73:   char        **names;
     74:   int         cnt,i,j;
     75:   XFontStruct *info;

     77:   /* This just gets the most basic fixed-width fonts */
     78:   names = XListFontsWithInfo(XBWin->disp,"?x??",NFONTS,&cnt,&info);
     79:   j     = 0;
     80:   for (i=0; i<cnt; i++) {
     81:     names[i][1]       = '\0';
     82:     nfonts[j].w       = info[i].max_bounds.width;
     83:     nfonts[j].h       = info[i].ascent + info[i].descent;
     84:     nfonts[j].descent = info[i].descent;
     85:     if (nfonts[j].w <= 0 || nfonts[j].h <= 0) continue;
     86:     j++;
     87:     if (j >= NFONTS) break;
     88:   }
     89:   act_nfonts = j;
     90:   if (cnt > 0) XFreeFontInfo(names,info,cnt);

     92:   /* If the above fails,try this: */
     93:   if (!act_nfonts) {
     94:     /* This just gets the most basic fixed-width fonts */
     95:     names = XListFontsWithInfo(XBWin->disp,"?x",NFONTS,&cnt,&info);
     96:     j     = 0;
     97:     for (i=0; i<cnt; i++) {
     98:       size_t         len;

    100:       PetscStrlen(names[i],&len);
    101:       if (len != 2) continue;
    102:       names[i][1]       = '\0';
    103:       nfonts[j].w       = info[i].max_bounds.width;
    104:       /* nfonts[j].w         = info[i].max_bounds.lbearing + info[i].max_bounds.rbearing; */
    105:       nfonts[j].h       = info[i].ascent + info[i].descent;
    106:       nfonts[j].descent = info[i].descent;
    107:       if (nfonts[j].w <= 0 || nfonts[j].h <= 0) continue;
    108:       j++;
    109:       if (j >= NFONTS) break;
    110:     }
    111:     act_nfonts = j;
    112:     XFreeFontInfo(names,info,cnt);
    113:   }
    114:   return 0;
    115: }

    117: static PetscErrorCode PetscDrawXiMatchFontSize(PetscDrawXiFont *font,int w,int h)
    118: {
    119:   int i,max,imax,tmp;

    121:   for (i=0; i<act_nfonts; i++) {
    122:     if (nfonts[i].w == w && nfonts[i].h == h) {
    123:       font->font_w       = w;
    124:       font->font_h       = h;
    125:       font->font_descent = nfonts[i].descent;
    126:       return 0;
    127:     }
    128:   }

    130:   /* determine closest fit,per max. norm */
    131:   imax = 0;
    132:   max  = PetscMax(PetscAbsInt(nfonts[0].w - w),PetscAbsInt(nfonts[0].h - h));
    133:   for (i=1; i<act_nfonts; i++) {
    134:     tmp = PetscMax(PetscAbsInt(nfonts[i].w - w),PetscAbsInt(nfonts[i].h - h));
    135:     if (tmp < max) {max = tmp; imax = i;}
    136:   }

    138:   /* should use font with closest match */
    139:   font->font_w       = nfonts[imax].w;
    140:   font->font_h       = nfonts[imax].h;
    141:   font->font_descent = nfonts[imax].descent;
    142:   return 0;
    143: }