C++ Game perspective - Standard RPG perspective

[kosamika]

Hello otlanders!

im trying to edit the game perspective, into an standard RPG style
this post explains perspective, as i understand, in case im not explaining myself.

this is what i have:


first image, red arrows represent the movements i cant make.
2nd , 3rd images, shows the building on RME, so you can get a visual representation



first image, you can get on the roof, but i can only assume the check is being done in the blue square instead.
second image, wont allow me to get on the roof, again, i assume check is being done on blue square instead.
third image, levitation spell

it looks to me as if these functions are all using the same mathematics, i could be wrong, tho
totaly speaking from ignorance

this is my game::internalmovecreature at game.cpp, actualy using tfs 1.4.2

ReturnValue Game::internalMoveCreature(Creature* creature, Direction direction, uint32_t flags /*= 0*/)
{
    creature->setLastPosition(creature->getPosition());
    const Position& currentPos = creature->getPosition();
    Position destPos = getNextPosition(direction, currentPos);
    Player* player = creature->getPlayer();


    bool diagonalMovement = (direction & DIRECTION_DIAGONAL_MASK) != 0;
    if (player && !diagonalMovement) {
        //try to go up
        if (currentPos.z != 8 && creature->getTile()->hasHeight(3)) {
            Tile* tmpTile = map.getTile(currentPos.x +1, currentPos.y, currentPos.getZ() - 1); // add +1 to currentPos.x
            if (tmpTile == nullptr || (tmpTile->getGround() == nullptr && !tmpTile->hasFlag(TILESTATE_BLOCKSOLID))) {
                tmpTile = map.getTile(destPos.x +1, destPos.y, destPos.getZ() - 1); //add +1 to destPos.x
                if (tmpTile && tmpTile->getGround() && !tmpTile->hasFlag(TILESTATE_IMMOVABLEBLOCKSOLID)) {
                    flags |= FLAG_IGNOREBLOCKITEM | FLAG_IGNOREBLOCKCREATURE;


                    if (!tmpTile->hasFlag(TILESTATE_FLOORCHANGE)) {
                        player->setDirection(direction);
                        destPos.x++; //add +1 to destPos.x
                        destPos.z--;
                    }
                }
            }
        }


        //try to go down
        if (currentPos.z != 7 && currentPos.z == destPos.z) {
            Tile* tmpTile = map.getTile(destPos.x, destPos.y, destPos.z);
            if (tmpTile == nullptr || (tmpTile->getGround() == nullptr && !tmpTile->hasFlag(TILESTATE_BLOCKSOLID))) {
                tmpTile = map.getTile(destPos.x -1, destPos.y, destPos.z + 1); //substract -1 to destPos.x
                if (tmpTile && tmpTile->hasHeight(3) && !tmpTile->hasFlag(TILESTATE_IMMOVABLEBLOCKSOLID)) {
                    flags |= FLAG_IGNOREBLOCKITEM | FLAG_IGNOREBLOCKCREATURE;
                    player->setDirection(direction);
                    destPos.x--; //substract -1 to destPos.x
                    destPos.z++;
                }
            }
        }
    }


    Tile* toTile = map.getTile(destPos);
    if (!toTile) {
        return RETURNVALUE_NOTPOSSIBLE;
    }
    return internalMoveCreature(*creature, *toTile, flags);
}

every change has a comment on it, i just moved out the destination a little bit, but the checks are still being done somewhere else

i can only assume getNextPosition(direction, currentPos); is my answer, but any shread of light will be highly appreciated.

Also, worth mentioning i do lack game mechanics knowledge, therefore im not completely sure, if tibia allows you to get on top of roofs from the north side/west side.
if someone can confirm this to me, that helps too.

Please, help this tiny necromancer get on the roof!
thanks for your time.