path: root/engines/glk/frotz/processor_objects.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 2
 * 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, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
 *
 */

#include "glk/frotz/processor.h"

namespace Glk {
namespace Frotz {

#define MAX_OBJECT 2000

enum O1 {
	O1_PARENT          = 4,
	O1_SIBLING         = 5,
	O1_CHILD           = 6,
	O1_PROPERTY_OFFSET = 7,
	O1_SIZE            = 9
};

enum O4 {
	O4_PARENT          = 6,
	O4_SIBLING         = 8,
	O4_CHILD           = 10,
	O4_PROPERTY_OFFSET = 12,
	O4_SIZE            = 14
};

zword Processor::object_address(zword obj) {
    // Check object number
    if (obj > ((h_version <= V3) ? 255 : MAX_OBJECT)) {
        print_string("@Attempt to address illegal object ");
        print_num(obj);
        print_string(".  This is normally fatal.");
        new_line();
        runtimeError(ERR_ILL_OBJ);
    }

    // Return object address
    if (h_version <= V3)
        return h_objects + ((obj - 1) * O1_SIZE + 62);
    else
        return h_objects + ((obj - 1) * O4_SIZE + 126);
}

zword Processor::object_name(zword object) {
    zword obj_addr;
    zword name_addr;

    obj_addr = object_address(object);

    // The object name address is found at the start of the properties
    if (h_version <= V3)
        obj_addr += O1_PROPERTY_OFFSET;
    else
        obj_addr += O4_PROPERTY_OFFSET;

	LOW_WORD(obj_addr, name_addr);

    return name_addr;
}

zword Processor::first_property(zword obj) {
    zword prop_addr;
    zbyte size;

    // Fetch address of object name
    prop_addr = object_name (obj);

    // Get length of object name
	LOW_BYTE(prop_addr, size);

    // Add name length to pointer
    return prop_addr + 1 + 2 * size;
}

zword Processor::next_property(zword prop_addr) {
    zbyte value;

    // Load the current property id
	LOW_BYTE(prop_addr, value);
    prop_addr++;

    // Calculate the length of this property
    if (h_version <= V3)
        value >>= 5;
    else if (!(value & 0x80))
        value >>= 6;
    else {
		LOW_BYTE(prop_addr, value);
        value &= 0x3f;

        if (value == 0)
			// demanded by Spec 1.0
			value = 64;
    }

    // Add property length to current property pointer
    return prop_addr + value + 1;
}

void Processor::unlink_object(zword object) {
    zword obj_addr;
    zword parent_addr;
    zword sibling_addr;

    if (object == 0) {
        runtimeError(ERR_REMOVE_OBJECT_0);
        return;
    }

    obj_addr = object_address(object);

    if (h_version <= V3) {

        zbyte parent;
        zbyte younger_sibling;
        zbyte older_sibling;
        zbyte zero = 0;

        // Get parent of object, and return if no parent
        obj_addr += O1_PARENT;
		LOW_BYTE(obj_addr, parent);
        if (!parent)
            return;

        // Get (older) sibling of object and set both parent and sibling pointers to 0
		SET_BYTE(obj_addr, zero);
        obj_addr += O1_SIBLING - O1_PARENT;
		LOW_BYTE(obj_addr, older_sibling);
		SET_BYTE(obj_addr, zero);

        // Get first child of parent (the youngest sibling of the object)
        parent_addr = object_address(parent) + O1_CHILD;
		LOW_BYTE(parent_addr, younger_sibling);

        // Remove object from the list of siblings
		if (younger_sibling == object)
			SET_BYTE(parent_addr, older_sibling);
        else {
            do {
                sibling_addr = object_address(younger_sibling) + O1_SIBLING;
				LOW_BYTE(sibling_addr, younger_sibling);
            } while (younger_sibling != object);
			SET_BYTE(sibling_addr, older_sibling);
        }
    } else {
        zword parent;
        zword younger_sibling;
        zword older_sibling;
        zword zero = 0;

        // Get parent of object, and return if no parent
        obj_addr += O4_PARENT;
		LOW_WORD(obj_addr, parent);
        if (!parent)
            return;

        // Get (older) sibling of object and set both parent and sibling pointers to 0
		SET_WORD(obj_addr, zero);
        obj_addr += O4_SIBLING - O4_PARENT;
		LOW_WORD(obj_addr, older_sibling);
		SET_WORD(obj_addr, zero);

        // Get first child of parent (the youngest sibling of the object)
        parent_addr = object_address(parent) + O4_CHILD;
		LOW_WORD(parent_addr, younger_sibling);

        // Remove object from the list of siblings
		if (younger_sibling == object) {
			SET_WORD(parent_addr, older_sibling);
		} else {
            do {
                sibling_addr = object_address(younger_sibling) + O4_SIBLING;
				LOW_WORD(sibling_addr, younger_sibling);
            } while (younger_sibling != object);
			SET_WORD(sibling_addr, older_sibling);
        }
    }
}

void Processor::z_clear_attr() {
    zword obj_addr;
    zbyte value;

    if (_storyId == SHERLOCK)
        if (zargs[1] == 48)
            return;

    if (zargs[1] > ((h_version <= V3) ? 31 : 47))
        runtimeError(ERR_ILL_ATTR);

    // If we are monitoring attribute assignment display a short note
    if (_attribute_assignment) {
        stream_mssg_on();
        print_string("@clear_attr ");
        print_object(zargs[0]);
        print_string(" ");
        print_num(zargs[1]);
        stream_mssg_off();
    }

    if (zargs[0] == 0) {
        runtimeError(ERR_CLEAR_ATTR_0);
        return;
    }

    // Get attribute address
    obj_addr = object_address(zargs[0]) + zargs[1] / 8;

    // Clear attribute bit
	LOW_BYTE(obj_addr, value);
    value &= ~(0x80 >> (zargs[1] & 7));
	SET_BYTE(obj_addr, value);
}

void Processor::z_jin() {
    zword obj_addr;

    // If we are monitoring object locating display a short note
    if (_object_locating) {
        stream_mssg_on();
        print_string("@jin ");
        print_object(zargs[0]);
        print_string(" ");
        print_object(zargs[1]);
        stream_mssg_off();
    }

    if (zargs[0] == 0) {
        runtimeError(ERR_JIN_0);
        branch(0 == zargs[1]);
        return;
    }

    obj_addr = object_address(zargs[0]);

    if (h_version <= V3) {
        zbyte parent;

        // Get parent id from object
        obj_addr += O1_PARENT;
		LOW_BYTE(obj_addr, parent);

        // Branch if the parent is obj2
        branch(parent == zargs[1]);

    } else {
        zword parent;

        // Get parent id from object
        obj_addr += O4_PARENT;
		LOW_WORD(obj_addr, parent);

        // Branch if the parent is obj2
        branch(parent == zargs[1]);
    }
}

void Processor::z_get_child() {
    zword obj_addr;

    // If we are monitoring object locating display a short note
    if (_object_locating) {
        stream_mssg_on();
        print_string("@get_child ");
        print_object(zargs[0]);
        stream_mssg_off();
    }

    if (zargs[0] == 0) {
        runtimeError(ERR_GET_CHILD_0);
        store(0);
        branch(false);
        return;
    }

    obj_addr = object_address(zargs[0]);

    if (h_version <= V3) {
        zbyte child;

        // Get child id from object
        obj_addr += O1_CHILD;
		LOW_BYTE(obj_addr, child);

        // Store child id and branch
        store(child);
        branch(child);
    } else {
        zword child;

        // Get child id from object
        obj_addr += O4_CHILD;
		LOW_WORD(obj_addr, child);

        // Store child id and branch
        store(child);
        branch(child);
    }
}

void Processor::z_get_next_prop() {
    zword prop_addr;
    zbyte value;
    zbyte mask;

    if (zargs[0] == 0) {
        runtimeError(ERR_GET_NEXT_PROP_0);
        store(0);
        return;
    }

    // Property id is in bottom five (six) bits
    mask = (h_version <= V3) ? 0x1f : 0x3f;

    // Load address of first property
    prop_addr = first_property(zargs[0]);

    if (zargs[1] != 0) {
        // Scan down the property list
        do {
			LOW_BYTE(prop_addr, value);
            prop_addr = next_property(prop_addr);
        } while ((value & mask) > zargs[1]);

        // Exit if the property does not exist
        if ((value & mask) != zargs[1])
            runtimeError(ERR_NO_PROP);
    }

    // Return the property id
	LOW_BYTE(prop_addr, value);
    store((zword) (value & mask));
}

void Processor::z_get_parent() {
    zword obj_addr;

    // If we are monitoring object locating display a short note
    if (_object_locating) {
        stream_mssg_on();
        print_string("@get_parent ");
        print_object(zargs[0]);
        stream_mssg_off();
    }

    if (zargs[0] == 0) {
        runtimeError(ERR_GET_PARENT_0);
        store(0);
        return;
    }

    obj_addr = object_address(zargs[0]);

    if (h_version <= V3) {
        zbyte parent;

        // Get parent id from object
        obj_addr += O1_PARENT;
		LOW_BYTE(obj_addr, parent);

        // Store parent
        store(parent);

	} else {
        zword parent;

        // Get parent id from object
        obj_addr += O4_PARENT;
		LOW_WORD(obj_addr, parent);

        // Store parent
        store(parent);
    }
}

void Processor::z_get_prop() {
    zword prop_addr;
    zword wprop_val;
    zbyte bprop_val;
    zbyte value;
    zbyte mask;

    if (zargs[0] == 0) {
        runtimeError(ERR_GET_PROP_0);
        store(0);
        return;
    }

    // Property id is in bottom five (six) bits
    mask = (h_version <= V3) ? 0x1f : 0x3f;

    // Load address of first property
    prop_addr = first_property(zargs[0]);

    // Scan down the property list
    for (;;) {
		LOW_BYTE(prop_addr, value);
        if ((value & mask) <= zargs[1])
            break;
        prop_addr = next_property(prop_addr);
    }

    if ((value & mask) == zargs[1]) {
		// property found

        // Load property(byte or word sized)
        prop_addr++;

        if ((h_version <= V3 && !(value & 0xe0)) || (h_version >= V4 && !(value & 0xc0))) {
			LOW_BYTE(prop_addr, bprop_val);
            wprop_val = bprop_val;
		} else {
			LOW_WORD(prop_addr, wprop_val);
		}
    } else {
		// property not found

        // Load default value
        prop_addr = h_objects + 2 * (zargs[1] - 1);
		LOW_WORD(prop_addr, wprop_val);
    }

    // Store the property value
    store(wprop_val);
}

void Processor::z_get_prop_addr() {
    zword prop_addr;
    zbyte value;
    zbyte mask;

    if (zargs[0] == 0) {
        runtimeError(ERR_GET_PROP_ADDR_0);
        store(0);
        return;
    }

    if (_storyId == BEYOND_ZORK)
        if (zargs[0] > MAX_OBJECT)
            { store(0); return; }

    // Property id is in bottom five (six) bits
    mask = (h_version <= V3) ? 0x1f : 0x3f;

    // Load address of first property
    prop_addr = first_property(zargs[0]);

    // Scan down the property list
    for (;;) {
		LOW_BYTE(prop_addr, value);
        if ((value & mask) <= zargs[1])
            break;
        prop_addr = next_property(prop_addr);
    }

    // Calculate the property address or return zero
    if ((value & mask) == zargs[1]) {

        if (h_version >= V4 && (value & 0x80))
            prop_addr++;
        store((zword) (prop_addr + 1));

    } else {
		store(0);
	}
}

void Processor::z_get_prop_len() {
    zword addr;
    zbyte value;

    // Back up the property pointer to the property id
    addr = zargs[0] - 1;
	LOW_BYTE(addr, value);

    // Calculate length of property
    if (h_version <= V3)
        value = (value >> 5) + 1;
    else if (!(value & 0x80))
        value = (value >> 6) + 1;
    else {
        value &= 0x3f;

        if (value == 0)
			value = 64;        // demanded by Spec 1.0
    }

    // Store length of property
    store(value);
}

void Processor::z_get_sibling() {
    zword obj_addr;

    if (zargs[0] == 0) {
        runtimeError(ERR_GET_SIBLING_0);
        store(0);
        branch(false);
        return;
    }

    obj_addr = object_address(zargs[0]);

    if (h_version <= V3) {
        zbyte sibling;

        // Get sibling id from object
        obj_addr += O1_SIBLING;
		LOW_BYTE(obj_addr, sibling);

        // Store sibling and branch
        store(sibling);
        branch(sibling);

	} else {
        zword sibling;

        // Get sibling id from object
        obj_addr += O4_SIBLING;
		LOW_WORD(obj_addr, sibling);

        // Store sibling and branch
        store(sibling);
        branch(sibling);
    }
}

void Processor::z_insert_obj() {
    zword obj1 = zargs[0];
    zword obj2 = zargs[1];
    zword obj1_addr;
    zword obj2_addr;

    // If we are monitoring object movements display a short note
    if (_object_movement) {
        stream_mssg_on();
        print_string("@move_obj ");
        print_object(obj1);
        print_string(" ");
        print_object(obj2);
        stream_mssg_off();
    }

    if (obj1 == 0) {
        runtimeError(ERR_MOVE_OBJECT_0);
        return;
    }

    if (obj2 == 0) {
        runtimeError(ERR_MOVE_OBJECT_TO_0);
        return;
    }

    // Get addresses of both objects
    obj1_addr = object_address(obj1);
    obj2_addr = object_address(obj2);

    // Remove object 1 from current parent
    unlink_object(obj1);

    // Make object 1 first child of object 2
    if (h_version <= V3) {
        zbyte child;

        obj1_addr += O1_PARENT;
		SET_BYTE(obj1_addr, obj2);
        obj2_addr += O1_CHILD;
		LOW_BYTE(obj2_addr, child);
		SET_BYTE(obj2_addr, obj1);
        obj1_addr += O1_SIBLING - O1_PARENT;
		SET_BYTE(obj1_addr, child);

    } else {
        zword child;

        obj1_addr += O4_PARENT;
		SET_WORD(obj1_addr, obj2);
        obj2_addr += O4_CHILD;
		LOW_WORD(obj2_addr, child);
		SET_WORD(obj2_addr, obj1);
        obj1_addr += O4_SIBLING - O4_PARENT;
		SET_WORD(obj1_addr, child);
    }
}

void Processor::z_put_prop() {
    zword prop_addr;
    zword value;
    zbyte mask;

    if (zargs[0] == 0) {
        runtimeError(ERR_PUT_PROP_0);
        return;
    }

    // Property id is in bottom five or six bits
    mask = (h_version <= V3) ? 0x1f : 0x3f;

    // Load address of first property
    prop_addr = first_property(zargs[0]);

    // Scan down the property list
    for (;;) {
		LOW_BYTE(prop_addr, value);
        if ((value & mask) <= zargs[1])
            break;

        prop_addr = next_property(prop_addr);
    }

    // Exit if the property does not exist
    if ((value & mask) != zargs[1])
        runtimeError(ERR_NO_PROP);

    // Store the new property value (byte or word sized)
    prop_addr++;

    if ((h_version <= V3 && !(value & 0xe0)) || (h_version >= V4 && !(value & 0xc0))) {
        zbyte v = zargs[2];
		SET_BYTE(prop_addr, v);
    } else {
        zword v = zargs[2];
		SET_WORD(prop_addr, v);
    }
}

void Processor::z_remove_obj() {
    // If we are monitoring object movements display a short note
    if (_object_movement) {
        stream_mssg_on();
        print_string("@remove_obj ");
        print_object(zargs[0]);
        stream_mssg_off();
    }

    // Call unlink_object to do the job
    unlink_object(zargs[0]);
}

void Processor::z_set_attr() {
    zword obj_addr;
    zbyte value;

    if (_storyId == SHERLOCK)
        if (zargs[1] == 48)
            return;

    if (zargs[1] > ((h_version <= V3) ? 31 : 47))
        runtimeError(ERR_ILL_ATTR);

    // If we are monitoring attribute assignment display a short note
    if (_attribute_assignment) {
        stream_mssg_on();
        print_string("@set_attr ");
        print_object(zargs[0]);
        print_string(" ");
        print_num(zargs[1]);
        stream_mssg_off();
    }

    if (zargs[0] == 0) {
        runtimeError(ERR_SET_ATTR_0);
        return;
    }

    // Get attribute address
    obj_addr = object_address(zargs[0]) + zargs[1] / 8;

    // Load attribute byte
	LOW_BYTE(obj_addr, value);

    // Set attribute bit
    value |= 0x80 >> (zargs[1] & 7);

    // Store attribute byte
	SET_BYTE(obj_addr, value);
}

void Processor::z_test_attr() {
    zword obj_addr;
    zbyte value;

    if (zargs[1] > ((h_version <= V3) ? 31 : 47))
        runtimeError(ERR_ILL_ATTR);

    // If we are monitoring attribute testing display a short note
    if (_attribute_testing) {
        stream_mssg_on();
        print_string("@test_attr ");
        print_object(zargs[0]);
        print_string(" ");
        print_num(zargs[1]);
        stream_mssg_off();
    }

    if (zargs[0] == 0) {
        runtimeError(ERR_TEST_ATTR_0);
        branch(false);
        return;
    }

    // Get attribute address
    obj_addr = object_address(zargs[0]) + zargs[1] / 8;

    // Load attribute byte
	LOW_BYTE(obj_addr, value);

    // Test attribute
    branch(value & (0x80 >> (zargs[1] & 7)));
}

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