//initialize
var x_temp, y_temp, x_target, y_target, h_collision_list, v_collision_list, _c, i, _n, _n2;

x_prev = x + x_slop;
y_prev = y + y_slop;
x_temp = x_prev;
y_temp = y_prev;
x_target = x_prev + x_speed;
y_target = y_prev + y_speed;
h_collision_list = ds_list_create();
v_collision_list = ds_list_create();

//get h_collision_list
if x_speed < 0 and bool( collision_rectangle( bbox_left + x_slop + x_speed, bbox_top, bbox_left + x_slop, bbox_bottom, tmp_block, 0, 1 ) ) {

    _c = 0;
    while _c != noone {

        _c = collision_rectangle( bbox_left + x_slop + x_speed, bbox_top, bbox_left + x_slop, bbox_bottom, tmp_block, 0, 1 );
        if _c != noone {

            ds_list_add( h_collision_list, _c );
            instance_deactivate_object( _c );

        }

    }

    //truncate x_speed to nearest obstacle if needed
    if ds_list_size( h_collision_list ) > 0 {

        _n = x_target;
        for ( i = 0; i < ds_list_size( h_collision_list ); i++ ) {

            instance_activate_object( ds_list_find_value( h_collision_list, i ) );
            _n2 = ds_list_find_value( h_collision_list, i ).bbox_right;
            if _n2 > _n _n = _n2;

        }

        x_target = _n;

    }

}

if x_speed > 0 and bool( collision_rectangle( bbox_right + x_slop, bbox_top, bbox_left + x_slop + x_speed, bbox_bottom, tmp_block, 0, 1 ) ) {

    _c = 0;
    while _c != noone {

        _c = collision_rectangle( bbox_right + x_slop, bbox_top, bbox_left + x_slop + x_speed, bbox_bottom, tmp_block, 0, 1 );
        if _c != noone {

            ds_list_add( h_collision_list, _c );
            instance_deactivate_object( _c )

        }

    }

    //truncate x_speed to nearest obstacle if needed
    if ds_list_size( h_collision_list ) > 0 {

        _n = x_target;
        for ( i = 0; i < ds_list_size( h_collision_list ); i++ ) {

            instance_activate_object( ds_list_find_value( h_collision_list, i ) );
            _n2 = ds_list_find_value( h_collision_list, i ).bbox_left;
            if _n2 < _n _n = _n2;

        }

        x_target = _n;

    }

}

//resolve horizontal movement
x = x_target div 1;
x_slop = x_target mod 1;

if y_speed < 0 and bool( collision_rectangle( bbox_right, bbox_top + y_slop + y_speed, bbox_left, bbox_top + y_slop, tmp_block, 0, 1 ) ) {

    _c = 0;
    while _c != noone {

        _c = collision_rectangle( bbox_right, bbox_top + y_slop + y_speed, bbox_left, bbox_top + y_slop, tmp_block, 0, 1 );
        if _c != noone {

            ds_list_add( v_collision_list, _c );
            instance_deactivate_object( _c );

        }

    }

    if ds_list_size( v_collision_list ) > 0 {

        _n = y_target;
        for ( i = 0; i < ds_list_size( v_collision_list ); i++; ) {

            instance_activate_object( ds_list_find_value( v_collision_list, i ) );
            _n2 = ds_list_find_value( h_collision_list, i ).bbox_bottom;
            if _n2 > _n _n = _n2;

        }

        y_target = _n;

    }

}

if y_speed > 0 and bool( collision_rectangle( bbox_right, bbox_bottom + y_slop, bbox_left, bbox_bottom + y_slop + y_speed, tmp_block, 0, 1 ) ) {

    _c = 0;
    while _c != noone {

        _c = collision_rectangle( bbox_right, bbox_bottom + y_slop, bbox_left, bbox_bottom + y_slop + y_speed, tmp_block, 0, 1 );
        if _c != noone {

            ds_list_add( v_collision_list, _c );
            instance_deactivate_object( _c );

        }

    }

    while _c != noone {

        _c = collision_rectangle( bbox_right, bbox_bottom + y_slop, bbox_left, bbox_bottom + y_slop + y_speed, tmp_platform, 0, 1 );
        if _c != noone {

            ds_list_add( v_collision_list, _c );
            instance_deactivate_object( _c );

        }

    }

    if ds_list_size( v_collision_list ) > 0 {

        _n = y_target;
        for ( i = 0; i < ds_list_size( v_collision_list ); i++; ) {

            instance_activate_object( ds_list_find_value( v_collision_list, i ) );
            _n2 = ds_list_find_value( h_collision_list, i ).bbox_bottom;
            if _n2 < _n _n = _n2;

        }

        y_target = _n;

    }

}

//resolve vertical movement
y = y_target div 1;
y_slop = y_target mod 1;

//memory cleanup
ds_list_destroy( h_collision_list );
ds_list_destroy( v_collision_list );