engine/fteqtv/msg.c

#include "qtv.h"

void InitNetMsg(netmsg_t *b, void *buffer, int bufferlength)
{
	b->data = buffer;
	b->maxsize = bufferlength;
	b->readpos = 0;
	b->cursize = 0;
}

unsigned char ReadByte(netmsg_t *b)
{
	if (b->readpos >= b->cursize)
	{
		b->readpos = b->cursize+1;
		return 0;
	}
	return ((unsigned char *)b->data)[b->readpos++];
}
unsigned short ReadShort(netmsg_t *b)
{
	int b1, b2;
	b1 = ReadByte(b);
	b2 = ReadByte(b);

	return b1 | (b2<<8);
}
unsigned int ReadLong(netmsg_t *b)
{
	int s1, s2;
	s1 = ReadShort(b);
	s2 = ReadShort(b);

	return s1 | (s2<<16);
}

unsigned int BigLong(unsigned int val)
{
	union {
		unsigned int i;
		unsigned char c[4];
	} v;

	v.i = val;
	return (v.c[0]<<24) | (v.c[1] << 16) | (v.c[2] << 8) | (v.c[3] << 0);
}

unsigned int SwapLong(unsigned int val)
{
	union {
		unsigned int i;
		unsigned char c[4];
	} v;
	unsigned char s;

	v.i = val;
	s = v.c[0];
	v.c[0] = v.c[3];
	v.c[3] = s;
	s = v.c[1];
	v.c[1] = v.c[2];
	v.c[2] = s;

	return v.i;
}

float ReadFloat(netmsg_t *b)
{
	union {
		unsigned int i;
		float f;
	} u;

	u.i = ReadLong(b);
	return u.f;
}
void ReadString(netmsg_t *b, char *string, int maxlen)
{
	maxlen--;	//for null terminator
	while(maxlen)
	{
		*string = ReadByte(b);
		if (!*string)
			return;
		string++;
		maxlen--;
	}
	*string++ = '\0';	//add the null

	printf("ReadString: buffer is too small\n");
	while(ReadByte(b))	//finish reading the string, even if we will loose part of it
		;
}
float ReadCoord(netmsg_t *b, unsigned int pext1)
{
	if (pext1 & PEXT_FLOATCOORDS)
		return ReadFloat(b);
	else
		return (short)ReadShort(b) / 8.0;
}
float ReadAngle(netmsg_t *b, unsigned int pext1)
{
	if (pext1 & PEXT_FLOATCOORDS)
		return (ReadShort(b) * 360.0) / 0x10000;
	else
		return (ReadByte(b) * 360.0) / 0x100;
}

void WriteByte(netmsg_t *b, unsigned char c)
{
	if (b->cursize>=b->maxsize)
		return;
	((unsigned char*)b->data)[b->cursize++] = c;
}
void WriteShort(netmsg_t *b, unsigned short l)
{
	WriteByte(b, (l&0x00ff)>>0);
	WriteByte(b, (l&0xff00)>>8);
}
void WriteLong(netmsg_t *b, unsigned int l)
{
	WriteByte(b, (l&0x000000ff)>>0);
	WriteByte(b, (l&0x0000ff00)>>8);
	WriteByte(b, (l&0x00ff0000)>>16);
	WriteByte(b, (l&0xff000000)>>24);
}
void WriteFloat(netmsg_t *b, float f)
{
	union {
		unsigned int i;
		float f;
	} u;

	u.f = f;
	WriteLong(b, u.i);
}
void WriteCoord(netmsg_t *b, float c, unsigned int pext)
{
	if (pext & PEXT_FLOATCOORDS)
		WriteFloat(b, c);
	else
		WriteShort(b, (short)(c*8));
}
void WriteAngle(netmsg_t *b, float a, unsigned int pext)
{
	if (pext & PEXT_FLOATCOORDS)
		WriteShort(b, (a/360.0)*0x10000);
	else
		WriteByte(b, (a/360.0)*0x100 + 0.49);	//round better, to avoid rounding bias
}
void WriteString2(netmsg_t *b, const char *str)
{	//no null terminator, convienience function.
	while(*str)
		WriteByte(b, *str++);
}
void WriteString(netmsg_t *b, const char *str)
{
	while(*str)
		WriteByte(b, *str++);
	WriteByte(b, 0);
}
void WriteData(netmsg_t *b, const void *data, int length)
{
	int i;
	unsigned char *buf;

	if (b->cursize + length > b->maxsize)	//urm, that's just too big. :(
		return;
	buf = (unsigned char*)b->data+b->cursize;
	for (i = 0; i < length; i++)
		*buf++ = ((unsigned char*)data)[i];
	b->cursize+=length;
}
void WriteCoordf(netmsg_t *b, unsigned int pext, float fl)
{
	if (pext & PEXT_FLOATCOORDS)
		WriteFloat(b, fl);
	else
		WriteShort(b, fl*8);
}
void WriteAnglef(netmsg_t *b, unsigned int pext, float fl)
{
	if (pext & PEXT_FLOATCOORDS)
		WriteShort(b, (fl/360)*0x10000);
	else
		WriteByte(b, (fl/360)*0x100);
}