Using Xft Fonts on linux

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Recently I upgraded my X Window install and somehow managed to hose up my font configuration and broke torque in the process! I went digging and found the font code on linux was fragile at best. Here is my attempt to improve things a bit. This will require that you are using Xfree 4.0 or Xorg 6.0 or higher.

To install (on a fresh torque 1.3 install):
Copy the existing x86UNIXFont.cc somewhere (x86UNIXFont.cc.orig)

Replace it with the attached code file.

Edit the mk/conf.UNIX.mk file

CFLAGS.GENERAL    = -DUSE_FILE_REDIRECT -I/usr/X11R6/include/  -MD -march=i586 \

becomes

CFLAGS.GENERAL    = -DUSE_FILE_REDIRECT -I/usr/X11R6/include/ 'freetype-config --cflags' -MD -march=i586 \

and

LINK.LIBS.RELEASE = 
LINK.LIBS.DEBUG   =

becomes

LINK.LIBS.RELEASE = -lXft
LINK.LIBS.DEBUG   = -lXft

save that file and build the engine.

then from the example directory

torque-1.3/example $ rm common/ui/cache/*
torque-1.3/example $ ./torqueDemo.bin -nohomedir

Now enjoy your newly rendered fonts.

Here is the file:

//-----------------------------------------------------------------------------
// Torque Game Engine 
// Copyright (C) GarageGames.com, Inc.
//-----------------------------------------------------------------------------



#include "platformX86UNIX/platformX86UNIX.h"
#include "dgl/gFont.h"
#include "dgl/gBitmap.h"
#include "math/mRect.h"
#include "console/console.h"

// Needed by createFont
#include <X11/Xlib.h>
#include <X11/Xutil.h>
#include <X11/Xos.h>
#include <X11/Xatom.h>
#include <X11/Xft/Xft.h>
#include <X11/extensions/Xrender.h>      // For XRenderColor

// Needed for getenv in createFont
#include <stdlib.h>

XftFont *loadFont(const char *name, S32 size, Display *display)
{
  XftFont *fontInfo = NULL;
  char* fontname = const_cast<char*>(name);
  if (dStrlen(fontname)==0)
    fontname = "arial";
  else if (stristr(const_cast<char*>(name), "arial") != NULL)
    fontname = "arial";
  else if (stristr(const_cast<char*>(name), "lucida console") != NULL)
    fontname = "lucida console";
  
  char* weight = "medium";
  char* slant = "roman"; // no slant
  
  if (stristr(const_cast<char*>(name), "bold") != NULL)
    weight = "bold";
  if (stristr(const_cast<char*>(name), "italic") != NULL)
    slant = "italic";
  
  char xfontName[512];
  // We specify a lower DPI to get 'correct' looking fonts, if we go with the
  // native DPI the fonts are to big and don't fit the widgets.
  dSprintf(xfontName, 512, "%s-%d:%s:slant=%s:dpi=65", fontname, size, weight, slant);
  
  // Lets see if Xft can get a font for us.
  char xftname[1024];
  fontInfo = XftFontOpenName(display, DefaultScreen(display), xfontName);
  if (fontInfo)
    {
      XftNameUnparse(fontInfo->pattern, xftname, 1024);
      Con::printf("Font '%s %d' mapped to '%s'\n", name, size, xftname);
    }
  return fontInfo;
}
GFont *createFont(const char *name, dsize_t size)
{
  // Our connection to the X Server, can't do anything without this
  Display *display = XOpenDisplay(getenv("DISPLAY"));
  if (!display)
    AssertFatal(false, "createFont: cannot connect to X server");
  XftFont *font = loadFont(name, size, display);
  if (!font) // This should almost never trigger anymore.
    AssertFatal(false, "createFont: cannot load font");
  int screen = DefaultScreen(display);
  int width, height;
  width = font->max_advance_width;
  height = font->height;
  // Create the pixmap to draw on.
  Pixmap pixmap = XCreatePixmap(display, 
				DefaultRootWindow(display),
				width, 
				height,
				DefaultDepth(display, screen));
  // And the Xft wrapper around it.
  XftDraw *draw = XftDrawCreate(display, 
				pixmap,
				DefaultVisual(display, screen),
				DefaultColormap(display, screen));
  // Allocate some colors, we don't use XftColorAllocValue here as that
  // Don't appear to function correctly (or I'm using it wrong) As we only do
  // this twice per new un cached font it isn't that big of a penalty. (Each
  // call to XftColorAllocName involves a round trip to the X Server)
  XftColor black, white;
  XftColorAllocName(display,
		    DefaultVisual(display, screen),
		    DefaultColormap(display, screen),
		    "black",
		    &black);
  // White
  XftColorAllocName(display,
		    DefaultVisual(display, screen),
		    DefaultColormap(display, screen),
		    "white",
		    &white);
  
  // The font.
  GFont *retFont = new GFont;
  static U8 scratchPad[65536];
  int x = 0;
  int y = 0;
  // Build the bitmaps
  for (U16 i = 32; i < 256; i++)
    {
      XGlyphInfo extent;
      FT_UInt glyph;
      if (!XftCharExists(display, font, i))
	{
	  retFont->insertBitmap(i, scratchPad, 0, 0, 0, 0, 0, width);
	  continue;
	}
      // Get the glyph and its extents.
      glyph = XftCharIndex(display, font, i);
      XftGlyphExtents (display, font, &glyph, 1, &extent);
      // Clear the bounding box and draw the glyph
      XftDrawRect (draw, &black, 0, 0, width, height);
      XftDrawGlyphs (draw, &white, font, 0, font->ascent, &glyph, 1);
      // Grab the rendered image ...
      XImage *ximage = XGetImage(display, pixmap, 0, 0, 
				 extent.xOff, height, 
				 AllPlanes, XYPixmap);
      if (ximage == NULL)
	AssertFatal(false, "cannot get x image");
      // And store each pixel in the scratchPad for insertion into the bitmap.
      // We grab the full height of the pixmap.
      for(y = 0; y < height; y++)
	{
	  // and the width of the glyph and its padding.
	  for(x = 0; x < extent.xOff; x++)
	    {
	      U8 val = static_cast<U8>(XGetPixel(ximage, x, y));
	      scratchPad[y * extent.xOff + x] = val;
	    }
	}
      // Done with the image.
      XDestroyImage(ximage);
      // Add it to the bitmap.
      retFont->insertBitmap(i,                   // index
			    scratchPad,          // src
			    extent.xOff,         // stride
			    extent.xOff,         // width
			    height,              // height 
			    0,                   // xOrigin
			    font->ascent,        // yOrigin
			    extent.xOff);        // xIncrement

    }
  retFont->pack(height, font->ascent);
  XftColorFree(display, DefaultVisual(display, screen), 
	       DefaultColormap(display, screen), &black);
  XftColorFree(display, DefaultVisual(display, screen),
	       DefaultColormap(display, screen), &white);
  XftDrawDestroy(draw);
  XFreePixmap(display, pixmap);
  // XftFontClose(display, font); //-- Why do we crash on this?
  XCloseDisplay(display);
  return retFont;
}

Better screenshots:
Old XFLD rendering (Xlib) slyvester.gxsnmp.org/torque/screenshots/oldfont-screenshot.jpg
XFT Rendering slyvester.gxsnmp.org/torque/screenshots/font-screenshot.jpg