Actual source code: xtext.c
petsc-3.7.1 2016-05-15
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      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: */
     22: PetscErrorCode PetscDrawXiFontFixed(PetscDraw_X *XBWin,int w,int h,PetscDrawXiFont **outfont)
     23: {
     24:   static PetscDrawXiFont *curfont = 0,*font;
     25:   PetscErrorCode         ierr;

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

     33:   curfont  = font;
     34:   *outfont = curfont;
     35:   return(0);
     36: }

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

     45: /*
     46:   These routines determine the font to be used based on the requested size,
     47:   and load it if necessary
     48: */

     52: static PetscErrorCode PetscDrawXiLoadFont(PetscDraw_X *XBWin,PetscDrawXiFont *font)
     53: {
     54:   char        font_name[100];
     55:   XFontStruct *FontInfo;
     56:   XGCValues   values;

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

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

     69:   XFreeFontInfo(0,FontInfo,1);

     71:   /* Set the current font in the CG */
     72:   values.font = font->fnt;
     73:   XChangeGC(XBWin->disp,XBWin->gc.set,GCFont,&values);
     74:   return(0);
     75: }

     77: /* Code to find fonts and their characteristics */
     80: static PetscErrorCode PetscDrawXiInitFonts(PetscDraw_X *XBWin)
     81: {
     82:   char        **names;
     83:   int         cnt,i,j;
     84:   XFontStruct *info;

     87:   /* This just gets the most basic fixed-width fonts */
     88:   names = XListFontsWithInfo(XBWin->disp,"?x??",NFONTS,&cnt,&info);
     89:   j     = 0;
     90:   for (i=0; i<cnt; i++) {
     91:     names[i][1]       = '\0';
     92:     nfonts[j].w       = info[i].max_bounds.width;
     93:     nfonts[j].h       = info[i].ascent + info[i].descent;
     94:     nfonts[j].descent = info[i].descent;
     95:     if (nfonts[j].w <= 0 || nfonts[j].h <= 0) continue;
     96:     j++;
     97:     if (j >= NFONTS) break;
     98:   }
     99:   act_nfonts = j;
    100:   if (cnt > 0) XFreeFontInfo(names,info,cnt);

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

    111:       PetscStrlen(names[i],&len);
    112:       if (len != 2) continue;
    113:       names[i][1]       = '\0';
    114:       nfonts[j].w       = info[i].max_bounds.width;
    115:       /* nfonts[j].w         = info[i].max_bounds.lbearing + info[i].max_bounds.rbearing; */
    116:       nfonts[j].h       = info[i].ascent + info[i].descent;
    117:       nfonts[j].descent = info[i].descent;
    118:       if (nfonts[j].w <= 0 || nfonts[j].h <= 0) continue;
    119:       j++;
    120:       if (j >= NFONTS) break;
    121:     }
    122:     act_nfonts = j;
    123:     XFreeFontInfo(names,info,cnt);
    124:   }
    125:   return(0);
    126: }

    130: static PetscErrorCode PetscDrawXiMatchFontSize(PetscDrawXiFont *font,int w,int h)
    131: {
    132:   int i,max,imax,tmp;

    135:   for (i=0; i<act_nfonts; i++) {
    136:     if (nfonts[i].w == w && nfonts[i].h == h) {
    137:       font->font_w       = w;
    138:       font->font_h       = h;
    139:       font->font_descent = nfonts[i].descent;
    140:       return(0);
    141:     }
    142:   }

    144:   /* determine closest fit,per max. norm */
    145:   imax = 0;
    146:   max  = PetscMax(PetscAbsInt(nfonts[0].w - w),PetscAbsInt(nfonts[0].h - h));
    147:   for (i=1; i<act_nfonts; i++) {
    148:     tmp = PetscMax(PetscAbsInt(nfonts[i].w - w),PetscAbsInt(nfonts[i].h - h));
    149:     if (tmp < max) {max = tmp; imax = i;}
    150:   }

    152:   /* should use font with closest match */
    153:   font->font_w       = nfonts[imax].w;
    154:   font->font_h       = nfonts[imax].h;
    155:   font->font_descent = nfonts[imax].descent;
    156:   return(0);
    157: }