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;
     23:   PetscErrorCode         ierr;

     26:   if (!curfont) { PetscDrawXiInitFonts(XBWin);}
     27:   PetscNew(&font);
     28:   PetscDrawXiMatchFontSize(font,w,h);
     29:   PetscDrawXiLoadFont(XBWin,font);

     31:   curfont  = font;
     32:   *outfont = curfont;
     33:   return(0);
     34: }

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

     43: /*
     44:   These routines determine the font to be used based on the requested size,
     45:   and load it if necessary
     46: */

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

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

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

     65:   XFreeFontInfo(NULL,FontInfo,1);

     67:   /* Set the current font in the CG */
     68:   values.font = font->fnt;
     69:   XChangeGC(XBWin->disp,XBWin->gc.set,GCFont,&values);
     70:   return(0);
     71: }

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

     81:   /* This just gets the most basic fixed-width fonts */
     82:   names = XListFontsWithInfo(XBWin->disp,"?x??",NFONTS,&cnt,&info);
     83:   j     = 0;
     84:   for (i=0; i<cnt; i++) {
     85:     names[i][1]       = '\0';
     86:     nfonts[j].w       = info[i].max_bounds.width;
     87:     nfonts[j].h       = info[i].ascent + info[i].descent;
     88:     nfonts[j].descent = info[i].descent;
     89:     if (nfonts[j].w <= 0 || nfonts[j].h <= 0) continue;
     90:     j++;
     91:     if (j >= NFONTS) break;
     92:   }
     93:   act_nfonts = j;
     94:   if (cnt > 0) XFreeFontInfo(names,info,cnt);

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

    105:       PetscStrlen(names[i],&len);
    106:       if (len != 2) continue;
    107:       names[i][1]       = '\0';
    108:       nfonts[j].w       = info[i].max_bounds.width;
    109:       /* nfonts[j].w         = info[i].max_bounds.lbearing + info[i].max_bounds.rbearing; */
    110:       nfonts[j].h       = info[i].ascent + info[i].descent;
    111:       nfonts[j].descent = info[i].descent;
    112:       if (nfonts[j].w <= 0 || nfonts[j].h <= 0) continue;
    113:       j++;
    114:       if (j >= NFONTS) break;
    115:     }
    116:     act_nfonts = j;
    117:     XFreeFontInfo(names,info,cnt);
    118:   }
    119:   return(0);
    120: }

    122: static PetscErrorCode PetscDrawXiMatchFontSize(PetscDrawXiFont *font,int w,int h)
    123: {
    124:   int i,max,imax,tmp;

    127:   for (i=0; i<act_nfonts; i++) {
    128:     if (nfonts[i].w == w && nfonts[i].h == h) {
    129:       font->font_w       = w;
    130:       font->font_h       = h;
    131:       font->font_descent = nfonts[i].descent;
    132:       return(0);
    133:     }
    134:   }

    136:   /* determine closest fit,per max. norm */
    137:   imax = 0;
    138:   max  = PetscMax(PetscAbsInt(nfonts[0].w - w),PetscAbsInt(nfonts[0].h - h));
    139:   for (i=1; i<act_nfonts; i++) {
    140:     tmp = PetscMax(PetscAbsInt(nfonts[i].w - w),PetscAbsInt(nfonts[i].h - h));
    141:     if (tmp < max) {max = tmp; imax = i;}
    142:   }

    144:   /* should use font with closest match */
    145:   font->font_w       = nfonts[imax].w;
    146:   font->font_h       = nfonts[imax].h;
    147:   font->font_descent = nfonts[imax].descent;
    148:   return(0);
    149: }