Actual source code: text.c

  1: #define PETSC_DLL

  3: /*
  4:    This file contains simple code to manage access to fonts, insuring that
  5:    library routines access/load fonts only once
  6:  */

 8:  #include src/sys/draw/impls/x/ximpl.h


 11: PetscErrorCode XiInitFonts(PetscDraw_X *);
 12: PetscErrorCode XiMatchFontSize(XiFont*,int,int);
 13: PetscErrorCode XiLoadFont(PetscDraw_X*,XiFont*);
 14: /*
 15:     XiFontFixed - Return a pointer to the selected font.

 17:     Warning: Loads a new font for each window. This should be 
 18:    ok because there will never be many windows and the graphics
 19:    are not intended to be high performance.
 20: */
 23: PetscErrorCode XiFontFixed(PetscDraw_X *XBWin,int w,int h,XiFont **outfont)
 24: {
 25:   static XiFont *curfont = 0,*font;

 29:   if (!curfont) { XiInitFonts(XBWin);}
 30:   PetscNew(XiFont,&font);
 31:   XiMatchFontSize(font,w,h);
 32:   XiLoadFont(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: PetscErrorCode XiLoadFont(PetscDraw_X *XBWin,XiFont *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;

 67:   /* Storage leak; should probably just free FontInfo? */
 68:   /* XFreeFontInfo(FontInfo); */

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

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

 86:   /* This just gets the most basic fixed-width fonts */
 87:   names   = XListFontsWithInfo(XBWin->disp,"?x??",NFONTS,&cnt,&info);
 88:   j       = 0;
 89:   for (i=0; i<cnt; i++) {
 90:     names[i][1]         = '\0';
 91:     nfonts[j].w         = info[i].max_bounds.width ;
 92:     nfonts[j].h         = info[i].ascent + info[i].descent;
 93:     nfonts[j].descent   = info[i].descent;
 94:     if (nfonts[j].w <= 0 || nfonts[j].h <= 0) continue;
 95:     j++;
 96:     if (j >= NFONTS) break;
 97:   }
 98:   act_nfonts    = j;
 99:   if (cnt > 0)  {
100:     XFreeFontInfo(names,info,cnt);
101:   }
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 +
116:                                     info[i].max_bounds.rbearing; */
117:         nfonts[j].h         = info[i].ascent + info[i].descent;
118:         nfonts[j].descent   = info[i].descent;
119:         if (nfonts[j].w <= 0 || nfonts[j].h <= 0) continue;
120:         j++;
121:         if (j >= NFONTS) break;
122:     }
123:     act_nfonts    = j;
124:     XFreeFontInfo(names,info,cnt);
125:   }
126:   return(0);
127: }

131: PetscErrorCode XiMatchFontSize(XiFont *font,int w,int h)
132: {
133:   int i,max,imax,tmp;

136:   for (i=0; i<act_nfonts; i++) {
137:     if (nfonts[i].w == w && nfonts[i].h == h) {
138:         font->font_w        = w;
139:         font->font_h        = h;
140:         font->font_descent  = nfonts[i].descent;
141:         return(0);
142:     }
143:   }

145:   /* determine closest fit,per max. norm */
146:   imax = 0;
147:   max  = PetscMax(PetscAbsInt(nfonts[0].w - w),PetscAbsInt(nfonts[0].h - h));
148:   for (i=1; i<act_nfonts; i++) {
149:     tmp = PetscMax(PetscAbsInt(nfonts[i].w - w),PetscAbsInt(nfonts[i].h - h));
150:     if (tmp < max) {max = tmp; imax = i;}
151:   }

153:   /* should use font with closest match */
154:   font->font_w        = nfonts[imax].w;
155:   font->font_h        = nfonts[imax].h;
156:   font->font_descent  = nfonts[imax].descent;
157:   return(0);
158: }