Developer CD Series 2000 November: Tool Chest/Dev.CD Nov 00 TC Disk 1.toast/Sample Code/Games/SprocketInvaders/Source/GameObject.c

Text File | 2000-09-28 | 5.8 KB | 292 lines | [TEXT/MPS ]

//•    ------------------------------------------------------------------------------------------    •
//•
//•    Copyright © 1996 Apple Computer, Inc., All Rights Reserved
//•
//•
//•        You may incorporate this sample code into your applications without
//•        restriction, though the sample code has been provided "AS IS" and the
//•        responsibility for its operation is 100% yours.  However, what you are
//•        not permitted to do is to redistribute the source as "DSC Sample Code"
//•        after having made changes. If you're going to re-distribute the source,
//•        we require that you make it clear in the source that the code was
//•        descended from Apple Sample Code, but that you've made changes.
//•
//•        Authors:
//•            Chris De Salvo
//•
//•    ------------------------------------------------------------------------------------------    •

//•    ------------------------------    Includes

#include "GameObject.h"
#include "Graphics.h"
#include "MemoryHandler.h"
#include "ObjectActions.h"

//•    ------------------------------    Private Definitions
//•    ------------------------------    Private Types
//•    ------------------------------    Private Variables

static UInt32    gNumGameObjectsEver = 0;

//•    ------------------------------    Private Functions
//•    ------------------------------    Public Variables

UInt32    gNumGameObjects = 0;

//•    --------------------    GameObjectAllocate

GameObjectPtr
GameObjectAllocate(void)
{
GameObjectPtr    go;

    //•    Allocate memory for this object
    go = (GameObjectPtr) NewTaggedPtrClear(sizeof (GameObject), 'GObj', gNumGameObjectsEver++);
    if (! go)
        return (nil);

    gNumGameObjects++;

    go->action = ObjectIdle;
    SetRect(&go->screenRect, 0, 0, 0, 0);
    SetRect(&go->oldScreenRect, 0, 0, 0, 0);

    return (go);
}

//•    --------------------    GameObjectDispose

void
GameObjectDispose(GameObjectPtr go)
{
    if (! go)
        return;

    switch (go->kind)
    {
        case objectEnemyParticles:
        case objectPlayerParticles:
        case objectPlasmaParticles:
        case objectMissileParticles:
            ParticlesDispose(&go->objectData.particles);
            break;
    }

    DisposeTaggedPtrZ((Ptr *) &go);
    gNumGameObjects--;
}

//•    --------------------    GameObjectAddToList

void
GameObjectAddToList(GameObjectPtr *list, GameObjectPtr go)
{
    if (! go)
        return;

    //•    Handle the case of this being the only item
    if (*list == nil)
    {
        *list = go;
        go->next = nil;
        go->prev = nil;

        return;
    }

    //•    Otherwise, just add it to the top
    go->next = *list;            //•    Have the new object point down to the old front
    go->prev = nil;                //•    Point up to nothing
    go->next->prev = go;        //•    Have the next item point back up to the new object

    *list = go;                    //•    Update the global list head pointer
}

//•    --------------------    GameObjectRemoveFromList

void
GameObjectRemoveFromList(GameObjectPtr *list, GameObjectPtr go)
{
    if (! go)
        return;

    if (! *list)
        return;

    //•    Adjust the back link
    if (go->prev)
        go->prev->next = go->next;

    //•    Adjust the forward link
    if (go->next)
        go->next->prev = go->prev;

    //•    Handle the case of it being the first item
    if (go == *list)
    {
        if (go->next)
            *list = go->next;
        else
            *list = nil;
    }
}

//•    --------------------    GameObjectDisposeList

void
GameObjectDisposeList(GameObjectPtr *list)
{
GameObjectPtr    next;
GameObjectPtr    current;

    if (! *list)
        return;

    current = *list;

    do
    {
        next = current->next;
        GameObjectDispose(current);
        current = next;
    } while (next);

    *list = nil;
}

//•    --------------------    GameObjectSetSprite

void
GameObjectSetSprite(GameObjectPtr go, SpritePtr sprite)
{
    if (go && sprite)
        go->objectData.sprite = sprite;
}

//•    --------------------    GameObjectGetSprite

SpritePtr
GameObjectGetSprite(GameObjectPtr go)
{
    if (! go)
        return (nil);

    return (go->objectData.sprite);
}

//•    --------------------    GameObjectSetParticles

void
GameObjectSetParticles(GameObjectPtr go, ParticlesPtr particles)
{
    if (go && particles)
    {
        go->objectData.particles = particles;
        go->objectData.particles->bounds = go->bounds;
    }
}

//•    --------------------    GameObjectGetParticles

ParticlesPtr
GameObjectGetParticles(GameObjectPtr go)
{
    if (! go)
        return (nil);

    return (go->objectData.particles);
}

//•    --------------------    GameObjectSetBounds

void
GameObjectSetBounds(GameObjectPtr go, RectPtr r)
{
    if (go && r)
        go->bounds = *r;
}

//•    --------------------    GameObjectGetBounds

RectPtr
GameObjectGetBounds(GameObjectPtr go)
{
    if (! go)
        return (nil);

    return (&go->bounds);
}

//•    --------------------    GameObjectListAdvance

void
GameObjectListAdvance(GameObjectPtr list)
{
GameObjectPtr    next;
GameObjectPtr    current;

    if (! list)
        return;

    current = list;

    //•    We need to iterate over the list in this manner because
    //•    objects might remove themselves from the list as part of their action
    do
    {
        next = current->next;
        current->action(current);
        current = next;
    } while (next);
}

//•    --------------------    GameObjectListDraw

void
GameObjectListDraw(GameObjectPtr list, CGrafPtr dest)
{
GameObjectPtr    index;

    for (index = list; index; index = index->next)
    {
        switch (index->kind)
        {
            case objectEnemy:
            case objectEnemyShot:
            case objectGreenPlayer:
            case objectGreenPlayerShot:
            case objectRedPlayer:
            case objectRedPlayerShot:
                index->screenRect = SpriteDraw(index->objectData.sprite, index->frame, dest, index->screenX, index->screenY);
                break;

            case objectEnemyParticles:
            case objectPlayerParticles:
            case objectPlasmaParticles:
            case objectMissileParticles:
                index->screenRect = ParticlesDraw(index->objectData.particles, dest);
                break;
        }

        if (! EmptyRect(&index->screenRect))
            GraphicsSetRectDirty(&index->screenRect);

        index->oldScreenRect = index->screenRect;
    }
}

//•    --------------------    GameObjectListCount

UInt32
GameObjectListCount(GameObjectPtr list)
{
GameObjectPtr    index;
UInt32        count = 0;

    for (index = list; index; index = index->next)
        count++;

    return (count);
}