Truetype header struct description

gistfile1.c

	typedef int32_t Fixed;
	typedef int16_t FWord;
	
	typedef struct   
	{   
		Fixed   Table;              // version number 0x00010000 for version 1.0.    
		Fixed   fontRevision;       // Set by font manufacturer.    
		uint32_t  checkSumAdjustment; // To compute: set it to 0, sum the entire font as ULONG, then store 0xB1B0AFBA - sum.    
		uint32_t  magicNumber;        // Set to 0x5F0F3CF5.    
		uint16_t  flags;              // Bit 0 - baseline for font at y=0;    
									// Bit 1 - left sidebearing at x=0;   
									// Bit 2 - instructions may depend on point size;    
									// Bit 3 - force ppem to integer values for all internal scaler math; may use fractional ppem sizes if this bit is clear;    
									// Bit 4 - instructions may alter advance width (the advance widths might not scale linearly);    
									// Bits 5-10 - defined by Apple;    
									// Bit 11 - font compressed with Agfa MicroType Compression.    
									// Note: All other bits must be zero.    
		uint16_t  unitsPerEm;         // Valid range is from 16 to 16384    
		uint64_t  created;            // International date (8-byte field).    
		uint64_t  modified;           // International date (8-byte field).    
		FWord   xMin;               // For all glyph bounding boxes.    
		FWord   yMin;               // For all glyph bounding boxes.    
		FWord   xMax;               // For all glyph bounding boxes.    
		FWord   yMax;               // For all glyph bounding boxes.    
		uint16_t  macStyle;           // Bit 0 bold (if set to 1); Bit 1 italic (if set to 1)    
									// Bits 2-15 reserved (set to 0).    
		uint16_t  lowestRecPPEM;      // Smallest readable size in pixels.    
		int16_t   fontDirectionHint;  //  0 Fully mixed directional glyphs;    
									//  1 Only strongly left to right;    
									//  2 Like 1 but also contains neutrals;    
									// -1 Only strongly right to left;    
									// -2 Like -1 but also contains neutrals.    
		int16_t   indexToLocFormat;   // 0 for short offsets, 1 for long.    
		int16_t   glyphDataFormat;    // 0 for current format.    
	} truetype_head;