FON File Format

FON File Format is a type of game file used for fonts in Fallout and Fallout 2.

Background
Fonts from FON files are used for displaying information on Fallout and Fallout 2 locations. All fonts are non-scalable, raster, and do not contain any anti-aliasing information. The names of the structures and their fields used in the program were received from the debugging information in the file Mapper2.exe.

Structure
The FON file format is given in Table 2.1.

To work with FON files,  and   use the following structure:

Header
typedef struct { int num; 				// The number of images of characters in the file int height; 			// height of the font in points int spacing; 			// The distance between adjacent symbols at the points FontInfo* info; 			// Pointer to the array structures, describing characters unsigned char* data;		// Pointer to the array structures, describing symbol) } Font;

Symbol descriptor
typedef struct { int width;		// width character's points int offset;		// The image characters in a block of data } FontInfo;

The size of the block of data depicting characters determined as follows: last = font.num-1;		// Index of last character in the font size = font.info[last].offset + (font.info[last].width + 7) / 8 * font.height;

Through Construction
(font.info[last].width + 7) / 8 determined by the number of bytes needed to store information on one line symbol image. Information on the image stored as a symbol bit matrix.

Example
Let there is a symbol of a size 8x16 points of the image which is described as follows block data 00 00 7e 81 a5 81 81 bd 99 81 81 7e 00 00 00 00 The number of bytes needed to store information on one line symbol image bytesPerLine = (8 + 7) / 8 = 1 Bit matrix takes the form of 00      00000000        ........ 00       00000000        ........  7e       01111110        .######. 81      10000001        #......#  a5       10100101        #.#..#.# 81      10000001        #......#  81       10000001        #......#  bd  ==>  10111101  ==>   #.####.# 99      10011001        #..##..#  81       10000001        #......#  81       10000001        #......#  7e       01111110        .######. 00      00000000        ........  00       00000000        ........  00       00000000        ........  00       00000000        ........

FON viewer source code
This program was written by Anchorite, and was compiled in MSVS 2003.NET.

// Fallout FON-file viewer
 * 1) include 
 * 2) include 


 * 1) pragma pack(1)       // Struct memory alignment - 1 bytes

typedef struct { int width; int offset; } FontInfo;

typedef struct { int num; int height; int spacing; FontInfo* info; unsigned char* data; } Font;

int main(int argc, char* argv[]) {   FILE* fp; Font font; int last; int size; int i;

printf("Fallout FON-files viewer, version 1.0\n"); printf("Copyright (C) Anchorite (TeamX), 2005\n"); printf("anchorite2001@yandex.ru\n"); printf("\n");

if (argc < 2) { printf("Usage: %s file.fon\n", argv[0]); return 1; }

// Read file fp = fopen(argv[1], "rb");

if (!fp) { printf("Error: Unable open %s\n", argv[1]); return -1; }

if (fread(&font, sizeof(font), 1, fp) != 1) { printf("Error: Unable read FON-file header\n"); fclose(fp); return -1; }

font.info = malloc(font.num * sizeof(FontInfo));

if (font.info == NULL) { printf("Error: Unable allocate memory for glyphs info\n"); fclose(fp); return -1; }

if (fread(font.info, sizeof(FontInfo), font.num, fp) != font.num) { printf("Error: Unable read info about glyphs\n"); free(font.info); fclose(fp); return -1; }

last = font.num - 1; size = font.info[last].offset + (font.info[last].width + 7) / 8 * font.height;

font.data = malloc(size);

if (font.data == NULL) { printf("Error: Unable allocate memory for glyphs\n"); free(font.info); fclose(fp); return -1; }

if (fread(font.data, 1, size, fp) != size) { printf("Error: Unable read glyphs\n"); free(font.data); free(font.info); fclose(fp); return -1; }

fclose(fp);

// Font info printf("Number of glyphs: %d\n", font.num); printf("Height: %d\n", font.height); printf("Spacing: %d\n", font.spacing); printf("\n");

// Glyphs for(i = 0; i < font.num; i++) { printf("Glyph %d (0x%02X)\n", i, i); printf("================\n");

printf("Width: %d\n", font.info[i].width); printf("Offset: 0x%08X (%d)\n", font.info[i].offset, font.info[i].offset); printf("Offset from begin of file: 0x%08X (%d)\n",              sizeof(font) + sizeof(FontInfo) * font.num + font.info[i].offset,               sizeof(font) + sizeof(FontInfo) * font.num + font.info[i].offset); printf("\n");

if (font.height * font.info[i].width != 0) { int offset = font.info[i].offset; int bytesPerLine = (font.info[i].width + 7) / 8; int j;           int h;

for(h = 0; h < font.height; h++) { for(j = 0; j < font.info[i].width; j++) { if (font.data[offset + h * bytesPerLine + (j / 8)] & (1 << (7 - (j % 8)))) { printf("#"); }                   else { printf("."); }               }

printf("\n"); }

printf("\n"); printf("\n"); }       else { printf("Empty\n"); printf("\n"); printf("\n"); }   }

// Free font data free(font.data); free(font.info);

return 0; }

Program update
The following code was 99.9% based on Anchorite's previous version. I (Ghouly89) have simply taken the liberty to update the code, and make this program more user-friendly. I do not claim any credit for the FON-viewer source code. This program was compiled in Dev-Cpp 4.9.9.2.

// Fallout FON-file viewer
 * 1) include 
 * 2) include 
 * 3) include 


 * 1) pragma pack(1)       // Struct memory alignment - 1 bytes

/*   Changes by Ghouly89: * Removed argument counter / argument string array variables so user can deal straight through the program console * Added character string "fileName" to hold the .FON file name to be opened and read * Made all text output to a local (same directory) file titled "font.txt"

typedef struct { int width; int offset; } FontInfo;

typedef struct { int num; int height; int spacing; FontInfo* info; unsigned char* data; } Font;

int main {   FILE* fontFile; FILE* fontText; Font font; int last; int size; int i;   char fileName[100];

system("TITLE Fallout font viewer"); system("COLOR 0A"); printf("Enter the name of the .FON file to open (output can be found in font.txt) : "); printf("\n\n\n\t"); gets(fileName);

fontText = fopen("font.txt", "w"); fprintf(fontText, "Fallout FON-files viewer, version 1.0\n"); fprintf(fontText, "Copyright (C) Anchorite (TeamX), 2005\n"); fprintf(fontText, "anchorite2001@yandex.ru\n"); fprintf(fontText, "\n");

// Read file fontFile = fopen(fileName, "rb");

if (!fontFile) { fprintf(fontText, "Error: Unable to open %s\n", fileName); return -1; }

if (fread(&font, sizeof(font), 1, fontFile) != 1) { fprintf(fontText, "Error: Unable to read FON-file header\n"); fclose(fontFile); fclose(fontText); return -1; }

font.info = malloc(font.num * sizeof(FontInfo));

if (font.info == NULL) { fprintf(fontText, "Error: Unable to allocate memory for glyphs info\n"); fclose(fontFile); fclose(fontText); return -1; }

if (fread(font.info, sizeof(FontInfo), font.num, fontFile) != font.num) { fprintf(fontText, "Error: Unable to read info about glyphs\n"); free(font.info); fclose(fontFile); fclose(fontText); return -1; }

last = font.num - 1; size = font.info[last].offset + (font.info[last].width + 7) / 8 * font.height;

font.data = malloc(size);

if (font.data == NULL) { fprintf(fontText, "Error: Unable to allocate memory for glyphs\n"); free(font.info); fclose(fontFile); fclose(fontText); return -1; }

if (fread(font.data, 1, size, fontFile) != size) { fprintf(fontText, "Error: Unable to read glyphs\n"); free(font.data); free(font.info); fclose(fontFile); fclose(fontText); return -1; }

fclose(fontFile);

// Font info fprintf(fontText, "Number of glyphs: %d\n", font.num); fprintf(fontText, "Height: %d\n", font.height); fprintf(fontText, "Spacing: %d\n", font.spacing); fprintf(fontText, "\n");

// Glyphs for(i = 0; i < font.num; i++) { fprintf(fontText, "Glyph %d (0x%02X)\n", i, i); fprintf(fontText, "================\n");

fprintf(fontText, "Width: %d\n", font.info[i].width); fprintf(fontText, "Offset: 0x%08X (%d)\n", font.info[i].offset, font.info[i].offset); fprintf(fontText, "Offset from beginning of file: 0x%08X (%d)\n",              sizeof(font) + sizeof(FontInfo) * font.num + font.info[i].offset,               sizeof(font) + sizeof(FontInfo) * font.num + font.info[i].offset); fprintf(fontText, "\n");

if (font.height * font.info[i].width != 0) { int offset = font.info[i].offset; int bytesPerLine = (font.info[i].width + 7) / 8; int j;           int h;

for(h = 0; h < font.height; h++) { for(j = 0; j < font.info[i].width; j++) { if (font.data[offset + h * bytesPerLine + (j / 8)] & (1 << (7 - (j % 8)))) { fprintf(fontText, "#"); }                   else { fprintf(fontText, "."); }               }

fprintf(fontText, "\n"); }

fprintf(fontText, "\n"); fprintf(fontText, "\n"); }       else { fprintf(fontText, "Empty\n"); fprintf(fontText, "\n"); fprintf(fontText, "\n"); }   }    printf("\n\n"); printf("Font data read to file."); getch; // Close the .FON file and the "font.txt" file fclose(fontFile); fclose(fontText);

// Free font data free(font.data); free(font.info);

return 0; }