#ifndef _NET_GUI_HXX
#define _NET_GUI_HXX
+#include <simgear/misc/stdint.hxx>
// NOTE: this file defines an external interface structure. Due to
// variability between platforms and architectures, we only used fixed
// I am not aware of any platforms that don't use 4 bytes for float
// and 8 bytes for double.
-#ifdef HAVE_STDINT_H
-# include <stdint.h>
-#elif defined( _MSC_VER ) || defined(__MINGW32__)
-typedef signed char int8_t;
-typedef signed short int16_t;
-typedef signed int int32_t;
-typedef signed __int64 int64_t;
-typedef unsigned char uint8_t;
-typedef unsigned short uint16_t;
-typedef unsigned int uint32_t;
-typedef unsigned __int64 uint64_t;
-#else
-# error "Port me! Platforms that don't have <stdint.h> need to define int8_t, et. al."
-#endif
-const uint32_t FG_NET_GUI_VERSION = 7;
+const uint32_t FG_NET_GUI_VERSION = 8;
// Define a structure containing the top level flight dynamics model
FG_MAX_TANKS = 4
};
- uint32_t version; // increment when data values change
+// Note: align fields properly and manually to avoid incompatibilities
+// between 32bit and 64bit CPUs. Make sure that each field is already
+// placed on an offset which is a multiple of the size of its data
+// type, i.e. uint32/float need to have on offset of 4, doubles need
+// an offset of 8. This guarantees that compilers will _not_ add
+// CPU-specific padding bytes. Whenever in doubt about padding rules,
+// check "data structure alignment" in Wikipedia/Google :).
- // Positions
- double longitude; // geodetic (radians)
- double latitude; // geodetic (radians)
- float altitude; // above sea level (meters)
- float agl; // above ground level (meters)
- float phi; // roll (radians)
- float theta; // pitch (radians)
- float psi; // yaw or true heading (radians)
+ uint32_t version; // increment when data values change
+ uint32_t padding1; // 4 padding bytes, so the next (64bit) var is aligned to 8
+
+ // Positions (note: offset for these doubles is already aligned to 8 - to avoid architecture specific alignments)
+ double longitude; // geodetic (radians)
+ double latitude; // geodetic (radians)
+
+ float altitude; // above sea level (meters)
+ float agl; // above ground level (meters)
+ float phi; // roll (radians)
+ float theta; // pitch (radians)
+ float psi; // yaw or true heading (radians)
// Velocities
float vcas;
- float climb_rate; // feet per second
+ float climb_rate; // feet per second
// Consumables
- uint32_t num_tanks; // Max number of fuel tanks
+ uint32_t num_tanks; // Max number of fuel tanks
float fuel_quantity[FG_MAX_TANKS];
// Environment