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 = 0,*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(0,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: }