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/* 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/>.
*
*/
#include "glk/zcode/processor.h"
namespace Glk {
namespace ZCode {
void Processor::z_copy_table() {
zword addr;
zword size = zargs[2];
zbyte value;
int i;
if (zargs[1] == 0) {
// zero table
for (i = 0; i < size; i++)
storeb((zword)(zargs[0] + i), 0);
} else if ((short) size < 0 || zargs[0] > zargs[1]) {
// copy forwards
for (i = 0; i < (((short)size < 0) ? -(short)size : size); i++) {
addr = zargs[0] + i;
LOW_BYTE(addr, value);
storeb((zword)(zargs[1] + i), value);
}
} else {
// copy backwards
for (i = size - 1; i >= 0; i--) {
addr = zargs[0] + i;
LOW_BYTE(addr, value);
storeb((zword)(zargs[1] + i), value);
}
}
}
void Processor::z_loadb() {
zword addr = zargs[0] + zargs[1];
zbyte value;
LOW_BYTE(addr, value);
store(value);
}
void Processor::z_loadw() {
zword addr = zargs[0] + 2 * zargs[1];
zword value;
LOW_WORD(addr, value);
store(value);
}
void Processor::z_scan_table() {
zword addr = zargs[1];
int i;
// Supply default arguments
if (zargc < 4)
zargs[3] = 0x82;
// Scan byte or word array
for (i = 0; i < zargs[2]; i++) {
if (zargs[3] & 0x80) {
// scan word array
zword wvalue;
LOW_WORD(addr, wvalue);
if (wvalue == zargs[0])
goto finished;
} else {
// scan byte array
zbyte bvalue;
LOW_BYTE(addr, bvalue);
if (bvalue == zargs[0])
goto finished;
}
addr += zargs[3] & 0x7f;
}
addr = 0;
finished:
store(addr);
branch(addr);
}
void Processor::z_storeb() {
storeb((zword)(zargs[0] + zargs[1]), zargs[2]);
}
void Processor::z_storew() {
storew((zword)(zargs[0] + 2 * zargs[1]), zargs[2]);
}
} // End of namespace ZCode
} // End of namespace Glk
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