____                _       __
    / __ )____  _____   | |     / /___ ___________
   / __  / __ \/ ___/   | | /| / / __ `/ ___/ ___/
  / /_/ / /_/ (__  )    | |/ |/ / /_/ / /  (__  )
 /_____/\____/____/     |__/|__/\__,_/_/  /____/

       A futuristic real-time strategy game.
          This file is part of Bos Wars.

(C) Copyright 2001-2007 by the Bos Wars and Stratagus Project. Distributed under the "GNU General Public License"

---

action_resource.cpp

Go to the documentation of this file.

//     ____                _       __               
//    / __ )____  _____   | |     / /___ ___________
//   / __  / __ \/ ___/   | | /| / / __ `/ ___/ ___/
//  / /_/ / /_/ (__  )    | |/ |/ / /_/ / /  (__  ) 
// /_____/\____/____/     |__/|__/\__,_/_/  /____/  
//                                              
//       A futuristic real-time strategy game.
//          This file is part of Bos Wars.
//
//
//      (c) Copyright 2001-2008 by Crestez Leonard and Jimmy Salmon
//
//      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; only version 2 of the License.
//
//      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., 59 Temple Place - Suite 330, Boston, MA
//      02111-1307, USA.
//


/*----------------------------------------------------------------------------
--  Includes
----------------------------------------------------------------------------*/

#include <stdio.h>
#include <stdlib.h>
#include <string.h>

#include "stratagus.h"
#include "player.h"
#include "unit.h"
#include "unittype.h"
#include "animation.h"
#include "actions.h"
#include "pathfinder.h"
#include "interface.h"
#include "sound.h"

/*----------------------------------------------------------------------------
--  Declarations
----------------------------------------------------------------------------*/

#define SUB_START_RESOURCE 0
#define SUB_MOVE_TO_RESOURCE 5
#define SUB_UNREACHABLE_RESOURCE 31
#define SUB_START_GATHERING 55
#define SUB_GATHER_RESOURCE 60

int AlliedUnitRecyclingEfficiency[MaxCosts] = {0, 50};
int EnemyUnitRecyclingEfficiency[MaxCosts] = {0, 40};

/*----------------------------------------------------------------------------
--  Functions
----------------------------------------------------------------------------*/

static int MoveToResource(CUnit *unit)
{
    switch (DoActionMove(unit)) { // reached end-point?
        case PF_UNREACHABLE:
            return -1;
        case PF_REACHED:
            break;
        default:
            // Goal gone or something.
            if (unit->Anim.Unbreakable || unit->Orders[0]->Goal->IsVisibleAsGoal(unit->Player)) {
                return 0;
            }
            break;
    }
    return 1;
}

static bool StartGathering(CUnit *unit)
{
    CUnit *goal = unit->Orders[0]->Goal;

    Assert(!unit->IX && !unit->IY);

    //
    // Target is gone, stop getting resources.
    //
    if (!goal->IsVisibleAsGoal(unit->Player)) {
        goal->RefsDecrease();
        // Find an alternative, but don't look too far.
        unit->Orders[0]->X = unit->Orders[0]->Y = -1;
        if ((goal = UnitFindResource(unit, unit->X, unit->Y, 10))) {
            unit->SubAction = SUB_START_RESOURCE;
            unit->Orders[0]->Goal = goal;
            goal->RefsIncrease();
        } else {
            unit->ClearAction();
            unit->Orders[0]->Goal = NoUnitP;
        }
        return false;
    }

    // 0 can happen, for example with flying units.
    Assert(MapDistanceBetweenUnits(unit, goal) <= 1);

    //
    // Update the heading of a harvesting unit to look straight at the resource.
    //
    UnitHeadingFromDeltaXY(unit,
        goal->X + (goal->Type->TileWidth - 1) / 2 - unit->X,
        goal->Y + (goal->Type->TileHeight - 1) / 2 - unit->Y);

    return true;
}

static void AnimateActionHarvest(CUnit *unit)
{
    Assert(unit->Type->Animations->Harvest);
    UnitShowAnimation(unit, unit->Type->Animations->Harvest);
}

static void FindNewResource(CUnit *unit)
{
    unit->Orders[0]->Goal->RefsDecrease();
    unit->Orders[0]->Goal = NoUnitP;

    unit->Orders[0]->X = unit->Orders[0]->Y = -1;
    if ((unit->Orders[0]->Goal = UnitFindResource(unit, unit->X, unit->Y, 10))) {
        DebugPrint("Unit %d found another resource.\n" _C_ unit->Slot);
        unit->SubAction = SUB_START_RESOURCE;
        unit->State = 0;
        unit->Orders[0]->Goal->RefsIncrease();
    } else {
        DebugPrint("Unit %d did not find another resource.\n" _C_ unit->Slot);
        unit->ClearAction();
        unit->State = 0;
    }
}

static void GatherResource(CUnit *unit)
{
    CUnit *source = unit->Orders[0]->Goal;
    int amount[MaxCosts] = {1, 1};
    bool visible = source->IsAliveOnMap();
    int i;
    const int totalEfficiency[MaxCosts] = {100, 100};
    const int *efficiency = totalEfficiency;

    AnimateActionHarvest(unit);

    // Calculate how much we can harvest.
    if (visible && UnitHoldsResources(source)) {
        // Determine efficiency of recycling buildings
        if (unit->Player == source->Player || unit->Player->IsAllied(source)) {
            efficiency = AlliedUnitRecyclingEfficiency;
        } else if (unit->Player->IsEnemy(source)) {
            efficiency = EnemyUnitRecyclingEfficiency;
        }

        // Update ResourcesHeld based on HP
        // Source might have been healed or attacked
        // Is this the best place for this?
        if (efficiency != totalEfficiency) {
            int hp = source->Variable[HP_INDEX].Max *
                source->ResourcesHeld[1] / source->Type->ProductionCosts[1];
            if (hp != 0 && hp != source->Variable[HP_INDEX].Value) {
                for (i = 0; i < MaxCosts; ++i) {
                    source->ResourcesHeld[i] = source->Type->ProductionCosts[i] *
                        source->Variable[HP_INDEX].Value / source->Variable[HP_INDEX].Max;
                }
            }
        }

        // Calculate new resource amounts
        CalculateRequestedAmount(unit->Type, source->ResourcesHeld, amount);
        for (i = 0; i < MaxCosts; ++i) {
            unit->Player->ProductionRate[i] -= unit->Data.Harvest.CurrentProduction[i];
            unit->Data.Harvest.CurrentProduction[i] = amount[i] * efficiency[i] / 100;
            unit->Player->ProductionRate[i] += unit->Data.Harvest.CurrentProduction[i];
            source->ResourcesHeld[i] -= amount[i];
        }

        // Recycling loses hit points
        if (efficiency != totalEfficiency) {
            source->Variable[HP_INDEX].Value = source->Variable[HP_INDEX].Max *
                source->ResourcesHeld[1] / source->Type->ProductionCosts[1];
            if (source->Variable[HP_INDEX].Value == 0 && source->ResourcesHeld[1] != 0) {
                source->Variable[HP_INDEX].Value = 1;
            }
        }
    }

    //
    // End of resource: destroy the resource.
    //
    if (!visible || !UnitHoldsResources(source)) {
        if (unit->Anim.Unbreakable) {
            // Wait until the animation finishes
            return;
        }

        DebugPrint("Resource is destroyed for unit %d\n" _C_ unit->Slot);

        for (i = 0; i < MaxCosts; ++i) {
            unit->Player->ProductionRate[i] -= unit->Data.Harvest.CurrentProduction[i];
            unit->Data.Harvest.CurrentProduction[i] = 0;
        }

        if (unit->OrderCount == 1) {
            // Find a new resource to harvest
            FindNewResource(unit);
        } else {
            unit->Orders[0]->Goal->RefsDecrease();
            unit->Orders[0]->Goal = NoUnitP;
            unit->ClearAction();
        }

        // Don't destroy the resource twice.
        // This only happens when it's empty.
        if (visible) {
            LetUnitDie(source);
        }
    }
}

static void ResourceGiveUp(CUnit *unit)
{
    DebugPrint("Unit %d gave up on resource gathering.\n" _C_ unit->Slot);
    if (unit->Orders[0]->Goal) {
        unit->Orders[0]->Goal->RefsDecrease();
        unit->Orders[0]->Goal = NULL;
    }
    unit->ClearAction();
}

void HandleActionResource(CUnit *unit)
{
    if (unit->Wait) {
        unit->Wait--;
        return;
    }

    // Let's start mining.
    if (unit->SubAction == SUB_START_RESOURCE) {
        if (unit->Orders[0]->Goal->Type->CanHarvestFrom) {
            NewResetPath(unit);
            unit->SubAction = SUB_MOVE_TO_RESOURCE;
        } else {
            ResourceGiveUp(unit);
            return;
        }
    }

    // Move to the resource location.
    if (unit->SubAction >= SUB_MOVE_TO_RESOURCE &&
            unit->SubAction < SUB_UNREACHABLE_RESOURCE) {
        int ret = MoveToResource(unit);
        // -1 failure, 0 not yet reached, 1 reached
        if (ret == -1) {
            // Can't Reach
            unit->SubAction++;
            unit->Wait = 10;
            return;
        } else if (ret == 1) {
            // Reached
            unit->SubAction = SUB_START_GATHERING;
            memset(unit->Data.Harvest.CurrentProduction, 0, sizeof(unit->Data.Harvest.CurrentProduction));
        } else {
            // Move along.
            return;
        }
    }

    // Resource seems to be unreachable
    if (unit->SubAction == SUB_UNREACHABLE_RESOURCE) {
        ResourceGiveUp(unit);
        return;
    }

    // Start gathering the resource
    if (unit->SubAction == SUB_START_GATHERING) {
        if (StartGathering(unit)) {
            unit->SubAction = SUB_GATHER_RESOURCE;
        } else {
            return;
        }
    }

    // Gather the resource.
    if (unit->SubAction == SUB_GATHER_RESOURCE) {
        GatherResource(unit);
        return;
    }
}

---