halflife-photomode/common/parsemsg.cpp

/***
*
*	Copyright (c) 1999, Valve LLC. All rights reserved.
*	
*	This product contains software technology licensed from Id 
*	Software, Inc. ("Id Technology").  Id Technology (c) 1996 Id Software, Inc. 
*	All Rights Reserved.
*
*   Use, distribution, and modification of this source code and/or resulting
*   object code is restricted to non-commercial enhancements to products from
*   Valve LLC.  All other use, distribution, or modification is prohibited
*   without written permission from Valve LLC.
*
****/
//
//  parsemsg.cpp
//
//--------------------------------------------------------------------------------------------------------------
#include "extdll.h"
#include "parsemsg.h"

static byte* gpBuf;
static int giSize;
static int giRead;
static bool giBadRead;

bool READ_OK()
{
	return !giBadRead;
}

void BEGIN_READ(void* buf, int size)
{
	giRead = 0;
	giBadRead = false;
	giSize = size;
	gpBuf = (byte*)buf;
}


int READ_CHAR()
{
	int c;

	if (giRead + 1 > giSize)
	{
		giBadRead = true;
		return -1;
	}

	c = (signed char)gpBuf[giRead];
	giRead++;

	return c;
}

int READ_BYTE()
{
	int c;

	if (giRead + 1 > giSize)
	{
		giBadRead = true;
		return -1;
	}

	c = (unsigned char)gpBuf[giRead];
	giRead++;

	return c;
}

int READ_SHORT()
{
	int c;

	if (giRead + 2 > giSize)
	{
		giBadRead = true;
		return -1;
	}

	c = (short)(gpBuf[giRead] + (gpBuf[giRead + 1] << 8));

	giRead += 2;

	return c;
}

int READ_WORD()
{
	return READ_SHORT();
}


int READ_LONG()
{
	int c;

	if (giRead + 4 > giSize)
	{
		giBadRead = true;
		return -1;
	}

	c = gpBuf[giRead] + (gpBuf[giRead + 1] << 8) + (gpBuf[giRead + 2] << 16) + (gpBuf[giRead + 3] << 24);

	giRead += 4;

	return c;
}

float READ_FLOAT()
{
	union
	{
		byte b[4];
		float f;
		int l;
	} dat;

	dat.b[0] = gpBuf[giRead];
	dat.b[1] = gpBuf[giRead + 1];
	dat.b[2] = gpBuf[giRead + 2];
	dat.b[3] = gpBuf[giRead + 3];
	giRead += 4;

	//	dat.l = LittleLong (dat.l);

	return dat.f;
}

char* READ_STRING()
{
	static char string[2048];
	int l, c;

	string[0] = 0;

	l = 0;
	do
	{
		if (giRead + 1 > giSize)
			break; // no more characters

		c = READ_CHAR();
		if (c == -1 || c == 0)
			break;
		string[l] = c;
		l++;
	} while (l < sizeof(string) - 1);

	string[l] = 0;

	return string;
}

float READ_COORD()
{
	return (float)(READ_SHORT() * (1.0 / 8));
}

float READ_ANGLE()
{
	return (float)(READ_CHAR() * (360.0 / 256));
}

float READ_HIRESANGLE()
{
	return (float)(READ_SHORT() * (360.0 / 65536));
}

//--------------------------------------------------------------------------------------------------------------
BufferWriter::BufferWriter()
{
	Init(NULL, 0);
}

//--------------------------------------------------------------------------------------------------------------
BufferWriter::BufferWriter(unsigned char* buffer, int bufferLen)
{
	Init(buffer, bufferLen);
}

//--------------------------------------------------------------------------------------------------------------
void BufferWriter::Init(unsigned char* buffer, int bufferLen)
{
	m_overflow = false;
	m_buffer = buffer;
	m_remaining = bufferLen;
	m_overallLength = bufferLen;
}

//--------------------------------------------------------------------------------------------------------------
void BufferWriter::WriteByte(unsigned char data)
{
	if (!m_buffer || 0 == m_remaining)
	{
		m_overflow = true;
		return;
	}

	*m_buffer = data;
	++m_buffer;
	--m_remaining;
}

//--------------------------------------------------------------------------------------------------------------
void BufferWriter::WriteLong(int data)
{
	if (!m_buffer || m_remaining < 4)
	{
		m_overflow = true;
		return;
	}

	m_buffer[0] = data & 0xff;
	m_buffer[1] = (data >> 8) & 0xff;
	m_buffer[2] = (data >> 16) & 0xff;
	m_buffer[3] = data >> 24;
	m_buffer += 4;
	m_remaining -= 4;
}

//--------------------------------------------------------------------------------------------------------------
void BufferWriter::WriteString(const char* str)
{
	if (!m_buffer || 0 == m_remaining)
	{
		m_overflow = true;
		return;
	}

	if (!str)
		str = "";

	int len = strlen(str) + 1;
	if (len > m_remaining)
	{
		m_overflow = true;
		str = "";
		len = 1;
	}

	strcpy((char*)m_buffer, str);
	m_remaining -= len;
	m_buffer += len;
}

//--------------------------------------------------------------------------------------------------------------
int BufferWriter::GetSpaceUsed()
{
	return m_overallLength - m_remaining;
}

//--------------------------------------------------------------------------------------------------------------