tr_font.c

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/*
===========================================================================
Copyright (C) 1999-2005 Id Software, Inc.

This file is part of Quake III Arena source code.

Quake III Arena source code is free software; you can redistribute it
and/or modify it under the terms of the GNU General Public License as
published by the Free Software Foundation; either version 2 of the License,
or (at your option) any later version.

Quake III Arena source code is distributed in the hope that it will be
useful, but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
GNU General Public License for more details.

You should have received a copy of the GNU General Public License
along with Foobar; if not, write to the Free Software
Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
===========================================================================
*/
// tr_font.c
// 
//
// The font system uses FreeType 2.x to render TrueType fonts for use within the game.
// As of this writing ( Nov, 2000 ) Team Arena uses these fonts for all of the ui and 
// about 90% of the cgame presentation. A few areas of the CGAME were left uses the old 
// fonts since the code is shared with standard Q3A.
//
// If you include this font rendering code in a commercial product you MUST include the
// following somewhere with your product, see www.freetype.org for specifics or changes.
// The Freetype code also uses some hinting techniques that MIGHT infringe on patents 
// held by apple so be aware of that also.
//
// As of Q3A 1.25+ and Team Arena, we are shipping the game with the font rendering code
// disabled. This removes any potential patent issues and it keeps us from having to 
// distribute an actual TrueTrype font which is 1. expensive to do and 2. seems to require
// an act of god to accomplish. 
//
// What we did was pre-render the fonts using FreeType ( which is why we leave the FreeType
// credit in the credits ) and then saved off the glyph data and then hand touched up the 
// font bitmaps so they scale a bit better in GL.
//
// There are limitations in the way fonts are saved and reloaded in that it is based on 
// point size and not name. So if you pre-render Helvetica in 18 point and Impact in 18 point
// you will end up with a single 18 point data file and image set. Typically you will want to 
// choose 3 sizes to best approximate the scaling you will be doing in the ui scripting system
// 
// In the UI Scripting code, a scale of 1.0 is equal to a 48 point font. In Team Arena, we
// use three or four scales, most of them exactly equaling the specific rendered size. We 
// rendered three sizes in Team Arena, 12, 16, and 20. 
//
// To generate new font data you need to go through the following steps.
// 1. delete the fontImage_x_xx.tga files and fontImage_xx.dat files from the fonts path.
// 2. in a ui script, specificy a font, smallFont, and bigFont keyword with font name and 
//    point size. the original TrueType fonts must exist in fonts at this point.
// 3. run the game, you should see things normally.
// 4. Exit the game and there will be three dat files and at least three tga files. The 
//    tga's are in 256x256 pages so if it takes three images to render a 24 point font you 
//    will end up with fontImage_0_24.tga through fontImage_2_24.tga
// 5. You will need to flip the tga's in Photoshop as the tga output code writes them upside
//    down.
// 6. In future runs of the game, the system looks for these images and data files when a s
//    specific point sized font is rendered and loads them for use. 
// 7. Because of the original beta nature of the FreeType code you will probably want to hand
//    touch the font bitmaps.
// 
// Currently a define in the project turns on or off the FreeType code which is currently 
// defined out. To pre-render new fonts you need enable the define ( BUILD_FREETYPE ) and 
// uncheck the exclude from build check box in the FreeType2 area of the Renderer project. 


#include "tr_local.h"
#include "../qcommon/qcommon.h"

#ifdef BUILD_FREETYPE
#include "../ft2/fterrors.h"
#include "../ft2/ftsystem.h"
#include "../ft2/ftimage.h"
#include "../ft2/freetype.h"
#include "../ft2/ftoutln.h"

#define _FLOOR(x)  ((x) & -64)
#define _CEIL(x)   (((x)+63) & -64)
#define _TRUNC(x)  ((x) >> 6)

FT_Library ftLibrary = NULL;  
#endif

#define MAX_FONTS 6
static int registeredFontCount = 0;
static fontInfo_t registeredFont[MAX_FONTS];

#ifdef BUILD_FREETYPE
void R_GetGlyphInfo(FT_GlyphSlot glyph, int *left, int *right, int *width, int *top, int *bottom, int *height, int *pitch) {

  *left  = _FLOOR( glyph->metrics.horiBearingX );
  *right = _CEIL( glyph->metrics.horiBearingX + glyph->metrics.width );
  *width = _TRUNC(*right - *left);
    
  *top    = _CEIL( glyph->metrics.horiBearingY );
  *bottom = _FLOOR( glyph->metrics.horiBearingY - glyph->metrics.height );
  *height = _TRUNC( *top - *bottom );
  *pitch  = ( qtrue ? (*width+3) & -4 : (*width+7) >> 3 );
}


FT_Bitmap *R_RenderGlyph(FT_GlyphSlot glyph, glyphInfo_t* glyphOut) {

  FT_Bitmap  *bit2;
  int left, right, width, top, bottom, height, pitch, size;

  R_GetGlyphInfo(glyph, &left, &right, &width, &top, &bottom, &height, &pitch);

  if ( glyph->format == ft_glyph_format_outline ) {
    size   = pitch*height; 

    bit2 = Z_Malloc(sizeof(FT_Bitmap));

    bit2->width      = width;
    bit2->rows       = height;
    bit2->pitch      = pitch;
    bit2->pixel_mode = ft_pixel_mode_grays;
    //bit2->pixel_mode = ft_pixel_mode_mono;
    bit2->buffer     = Z_Malloc(pitch*height);
    bit2->num_grays = 256;

    Com_Memset( bit2->buffer, 0, size );

    FT_Outline_Translate( &glyph->outline, -left, -bottom );

    FT_Outline_Get_Bitmap( ftLibrary, &glyph->outline, bit2 );

    glyphOut->height = height;
    glyphOut->pitch = pitch;
    glyphOut->top = (glyph->metrics.horiBearingY >> 6) + 1;
    glyphOut->bottom = bottom;
    
    return bit2;
  }
  else {
    ri.Printf(PRINT_ALL, "Non-outline fonts are not supported\n");
  }
  return NULL;
}

void WriteTGA (char *filename, byte *data, int width, int height) {
	byte	*buffer;
	int		i, c;

	buffer = Z_Malloc(width*height*4 + 18);
	Com_Memset (buffer, 0, 18);
	buffer[2] = 2;		// uncompressed type
	buffer[12] = width&255;
	buffer[13] = width>>8;
	buffer[14] = height&255;
	buffer[15] = height>>8;
	buffer[16] = 32;	// pixel size

	// swap rgb to bgr
	c = 18 + width * height * 4;
	for (i=18 ; i<c ; i+=4)
	{
		buffer[i] = data[i-18+2];		// blue
		buffer[i+1] = data[i-18+1];		// green
		buffer[i+2] = data[i-18+0];		// red
		buffer[i+3] = data[i-18+3];		// alpha
	}

	ri.FS_WriteFile(filename, buffer, c);

	//f = fopen (filename, "wb");
	//fwrite (buffer, 1, c, f);
	//fclose (f);

	Z_Free (buffer);
}

static glyphInfo_t *RE_ConstructGlyphInfo(unsigned char *imageOut, int *xOut, int *yOut, int *maxHeight, FT_Face face, const unsigned char c, qboolean calcHeight) {
  int i;
  static glyphInfo_t glyph;
  unsigned char *src, *dst;
  float scaled_width, scaled_height;
  FT_Bitmap *bitmap = NULL;

  Com_Memset(&glyph, 0, sizeof(glyphInfo_t));
  // make sure everything is here
  if (face != NULL) {
    FT_Load_Glyph(face, FT_Get_Char_Index( face, c), FT_LOAD_DEFAULT );
    bitmap = R_RenderGlyph(face->glyph, &glyph);
    if (bitmap) {
      glyph.xSkip = (face->glyph->metrics.horiAdvance >> 6) + 1;
    } else {
      return &glyph;
    }

    if (glyph.height > *maxHeight) {
      *maxHeight = glyph.height;
    }

    if (calcHeight) {
      Z_Free(bitmap->buffer);
      Z_Free(bitmap);
      return &glyph;
    }

/*
    // need to convert to power of 2 sizes so we do not get 
    // any scaling from the gl upload
  	for (scaled_width = 1 ; scaled_width < glyph.pitch ; scaled_width<<=1)
	  	;
  	for (scaled_height = 1 ; scaled_height < glyph.height ; scaled_height<<=1)
	  	;
*/

    scaled_width = glyph.pitch;
    scaled_height = glyph.height;

    // we need to make sure we fit
    if (*xOut + scaled_width + 1 >= 255) {
      if (*yOut + *maxHeight + 1 >= 255) {
        *yOut = -1;
        *xOut = -1;
        Z_Free(bitmap->buffer);
        Z_Free(bitmap);
        return &glyph;
      } else {
        *xOut = 0;
        *yOut += *maxHeight + 1;
      }
    } else if (*yOut + *maxHeight + 1 >= 255) {
      *yOut = -1;
      *xOut = -1;
      Z_Free(bitmap->buffer);
      Z_Free(bitmap);
      return &glyph;
    }


    src = bitmap->buffer;
    dst = imageOut + (*yOut * 256) + *xOut;

		if (bitmap->pixel_mode == ft_pixel_mode_mono) {
			for (i = 0; i < glyph.height; i++) {
				int j;
				unsigned char *_src = src;
				unsigned char *_dst = dst;
				unsigned char mask = 0x80;
				unsigned char val = *_src;
				for (j = 0; j < glyph.pitch; j++) {
					if (mask == 0x80) {
						val = *_src++;
					}
					if (val & mask) {
						*_dst = 0xff;
					}
					mask >>= 1;
        
					if ( mask == 0 ) {
						mask = 0x80;
					}
					_dst++;
				}

				src += glyph.pitch;
				dst += 256;

			}
		} else {
	    for (i = 0; i < glyph.height; i++) {
		    Com_Memcpy(dst, src, glyph.pitch);
			  src += glyph.pitch;