move_list.h

/* 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/>.
 *
 */

#ifndef AGS_ENGINE_AC_MOVE_LIST_H
#define AGS_ENGINE_AC_MOVE_LIST_H

#include "ags/lib/allegro.h" // fixed math
#include "ags/engine/game/savegame.h"
#include "ags/shared/util/geometry.h"

namespace AGS3 {

// Forward declaration
namespace AGS {
namespace Shared {
class Stream;
}
}
using namespace AGS; // FIXME later

#define MAXNEEDSTAGES 256
#define MAXNEEDSTAGES_LEGACY 40

enum MoveListDoneFlags {
    kMoveListDone_X = 0x01,
    kMoveListDone_Y = 0x02,
    kMoveListDone_XY = kMoveListDone_X | kMoveListDone_Y
};

enum MoveListSvgVersion {
    kMoveSvgVersion_Initial = 0, // [UNSUPPORTED] from 3.5.0 pre-alpha
    kMoveSvgVersion_350,   // new pathfinder, arbitrary number of stages
    kMoveSvgVersion_36109, // skip empty lists, progress as float
};

struct MoveList {
    int     numstage = 0;
    // Waypoints, per stage
    Point   pos[MAXNEEDSTAGES];
    // xpermove and ypermove contain number of pixels done per a single step
    // along x and y axes; i.e. this is a movement vector, per path stage
    fixed   xpermove[MAXNEEDSTAGES]{};
    fixed   ypermove[MAXNEEDSTAGES]{};
    int     onstage = 0; // current path stage
    Point   from;  // current stage's starting position
    // Steps made during current stage;
    // distance passed is calculated as xpermove[onstage] * onpart;
    // made a fractional value to let recalculate movelist dynamically
    float   onpart = 0.f;
    uint8_t doneflag = 0u;
    uint8_t direct = 0; // MoveCharDirect was used or not

    // Dynamic fixups, not serialized
    // Final section move speed and steps, used when an object
    // finishes one of the axes sooner than the other
    fixed   fin_move = 0;
    float   fin_from_part = 0.f;

    const Point &GetLastPos() const { return numstage > 0 ? pos[numstage - 1] : pos[0]; }

    // Gets a movelist's step length, in coordinate units
    // (normally the coord unit is a game pixel)
    float GetStepLength() const;
    // Gets a fraction of a coordinate unit that is in progress of stepping over;
    // (normally the coord unit is a game pixel)
    float GetPixelUnitFraction() const;
    // Sets a step progress to this fraction of a coordinate unit
    void SetPixelUnitFraction(float frac);

    void ReadFromSavegame_Legacy(Shared::Stream *in);
    AGS::Engine::HSaveError ReadFromSavegame(Shared::Stream *in, int32_t cmp_ver);
    void WriteToSavegame(Shared::Stream *out) const;
};

} // namespace AGS3

#endif