scummvm-cursorfix/engines/glk/scott/unp64/exo_util.cpp

/* ScummVM - Graphic Adventure Engine
 *
 * ScummVM is the legal property of its developers, whose names
 * are too numerous to list here. Please refer to the COPYRIGHT
 * file distributed with this source distribution.
 *
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
 *
 */

/*
 * Copyright (c) 2002 - 2023 Magnus Lind.
 *
 *
 * This software is provided 'as-is', without any express or implied
 * warranty. In no event will the authors be held liable for any damages
 * arising from the use of this software.
 *
 * Permission is granted to anyone to use this software for any purpose,
 * including commercial applications, and to alter it and redistribute it
 * freely, subject to the following restrictions:
 *
 * 1. The origin of this software must not be misrepresented; you must not
 * claim that you wrote the original software. If you use this software
 * in a product, an acknowledgment in the product documentation would be
 * appreciated but is not required.
 * 2. Altered source versions must be plainly marked as such, and must not be
 * misrepresented as being the original software.
 * 3. This notice may not be removed or altered from any source distribution.
 *
 */

#include "common/util.h"
#include "glk/scott/unp64/exo_util.h"

namespace Glk {
namespace Scott {

int findSys(const byte *buf, int target) {
	int outstart = -1;
	int state = 1;
	int i = 0;
	/* skip link and line number */
	buf += 4;
	/* iAN: workaround for hidden sysline (1001 cruncher, CFB, etc)*/
	if (buf[0] == 0) {
		for (i = 5; i < 32; i++)
			if (buf[i] == 0x9e && (((buf[i + 1] & 0x30) == 0x30) || ((buf[i + 2] & 0x30) == 0x30)))
				break;
	}
	/* exit loop at line end */
	while (i < 1000 && buf[i] != '\0') {
		byte *sysEnd;
		int c = buf[i];
		switch (state) {
			/* look for and consume sys token */
		case 1:
			if ((target == -1 && (c == 0x9e)) || c == target) {
				state = 2;
			}
			break;
			/* skip spaces and left parenthesis, if any */
		case 2:
			if (strchr(" (", c) != nullptr)
				break;
			// fallthrough
			/* convert string number to int */
		case 3:
			outstart = (int)strtol((const char *)(buf + i), (char **)&sysEnd, 10);
			if ((buf + i) == sysEnd) {
				/* we got nothing */
				outstart = -1;
			} else {
				c = *sysEnd;
				if ((c >= 0xaa) && (c <= 0xae)) {
					i = (int)strtol((char *)(sysEnd + 1), (char **)&sysEnd, 10);
					switch (c) {
					case 0xaa:
						outstart += i;
						break;
					case 0xab:
						outstart -= i;
						break;
					case 0xac:
						outstart *= i;
						break;
					case 0xad:
						if (i > 0)
							outstart /= i;
						break;
					case 0xae:
						c = outstart;
						while (--i)
							outstart *= c;
						break;
					}
				} else if (c == 'E') {
					i = (int)strtol((char *)(sysEnd + 1), (char **)&sysEnd, 10);
					i++;
					while (--i)
						outstart *= 10;
				}
			}
			state = 4;
			break;
		case 4:
			break;
		}
		++i;
	}

	return outstart;
}

static void loadPrgData(byte mem[65536], uint8_t *data, size_t dataLength, LoadInfo *info) {
	int len = MIN(65536 - info->_start, static_cast<int>(dataLength));
	memcpy(mem + info->_start, data, (size_t)len);

	info->_end = info->_start + len;
	info->_basicVarStart = -1;
	info->_run = -1;
	if (info->_basicTxtStart >= info->_start && info->_basicTxtStart < info->_end) {
		info->_basicVarStart = info->_end;
	}
}

void loadData(uint8_t *data, size_t dataLength, byte mem[65536], LoadInfo *info) {
	int load = data[0] + data[1] * 0x100;

	info->_start = load;
	loadPrgData(mem, data + 2, dataLength - 2, info);
}

int strToInt(const char *str, int *value) {
	int status = 0;
	do {
		char *strEnd;
		long lval;

		/* base 0 is auto detect */
		int base = 0;

		if (*str == '\0') {
			/* no string to parse */
			status = 1;
			break;
		}

		if (*str == '$') {
			/* a $ prefix specifies base 16 */
			++str;
			base = 16;
		}

		lval = strtol(str, &strEnd, base);

		if (*strEnd != '\0') {
			/* there is garbage in the string */
			status = 1;
			break;
		}

		if (value != nullptr) {
			/* all is well, set the out parameter */
			*value = static_cast<int>(lval);
		}
	} while (0);

	return status;
}

bool u32eq(const unsigned char *addr, uint32_t val)
{
	return addr[3] == (val >> 24) &&
	addr[2] == ((val >> 16) & 0xff) &&
	addr[1] == ((val >>	 8) & 0xff) &&
	addr[0] == (val & 0xff);
}

bool u32eqmasked(const unsigned char *addr, uint32_t mask, uint32_t val)
{
	uint32_t val1 = addr[0] | (addr[1] << 8) | (addr[2] << 16) | (addr[3] << 24);
	return (val1 & mask) == val;
}

bool u32eqxored(const unsigned char *addr, uint32_t xormask, uint32_t val)
{
	uint32_t val1 = addr[0] | (addr[1] << 8) | (addr[2] << 16) | (addr[3] << 24);
	return (val1 ^ xormask) == val;
}

bool u16eqmasked(const unsigned char *addr, uint16_t mask, uint16_t val)
{
	uint16_t val1 = addr[0] | (addr[1] << 8);
	return (val1 & mask) == val;
}


bool u16eq(const unsigned char *addr, uint16_t val)
{
	return addr[1] == (val >> 8) &&
	addr[0] == (val & 0xff);
}

bool u16noteq(const unsigned char *addr, uint16_t val)
{
	return addr[1] != (val >> 8) ||
	addr[0] != (val & 0xff);
}

bool u16gteq(const unsigned char *addr, uint16_t val)
{
	uint16_t val2 = addr[0] | (addr[1] << 8);
	return val2 >= val;
}

bool u16lteq(const unsigned char *addr, uint16_t val)
{
	uint16_t val2 = addr[0] | (addr[1] << 8);
	return val2 <= val;
}

} // End of namespace Scott
} // End of namespace Glk