solids.cp

/****************************************************************************************/
/*                                     SOLIDS.CP                                        */
/****************************************************************************************/
/*          (c) 1995 by Magnet Interactive Studios, inc. All rights reserved.           */
/****************************************************************************************/
/*  Revision History:                                                                   */
/*           7/6/94   File first created. By Andrew Looney.                             */
/*  v1.0     8/4/94   First polished version. By Andrew Looney.                         */
/*           8/8/94   Started making changes for next version.                          */
/*  v2.0    8/24/94   Seven level version burned onto CD-ROM. By Andrew Looney.         */
/*  v2.1    8/29/94   Comments brought back up to date. By Andrew Looney.               */
/*  v2.2     9/7/94   Sixteen level version. By Andrew Looney.                          */
/*  v2.3    9/23/94   Thirty level version burned onto CD-ROM. By Andrew Looney.        */
/*  v2.4   10/19/94   Fifty level version. By Andrew Looney.                            */
/*  v2.5   10/31/94   Sixty level version burned onto CD-ROM. By Andrew Looney.         */
/*  v3.0   10/31/94   Began switching over to real artwork. By Andrew Looney.           */
/*  v3.1   11/11/94   COMDEX version. By Andrew Looney.                                 */
/*  v3.2    12/2/94   Seventy-five level version. By Andrew Looney.                     */
/*  v3.3   12/14/94   Ack! Zombies! By Andrew Looney.                                   */
/*  v3.4   12/23/94   Orange Meanies! By Andrew Looney.                                 */
/*  v3.5     1/3/95   100 Levels! By Andrew Looney.                                     */
/*  v3.6     1/5/95   101 Levels. By Andrew Looney.                                     */
/*  v3.7    1/16/95   New, improved Brainy Seeker logic! By Andrew Looney.              */
/*  v3.8    1/27/95   114 level version burned onto CD-ROM. By Andrew Looney.           */
/*  v3.9     2/3/95   New CD-ROM burned for shipment to 3DO. By Andrew Looney.          */
/*  v4.0     2/9/95   New CD-ROM featuring the big level grid. By Andrew Looney.        */
/*  v4.1    2/22/95   New CD-ROM with rough draft of full interface. By Andrew Looney.  */
/*  v4.2    3/17/95   The St. Patrick's Day Version. By Andrew Looney.                  */
/*  v4.3    3/20/95   The last version before the movies get added. By Andrew Looney.   */
/*  v4.4    3/21/95   First version with movies integrated. By Andrew Looney.           */
/*  v4.5    3/22/95   Second version with movies integrated. By Andrew Looney.          */
/*  v4.6    3/27/95   Third version with movies integrated. By Andrew Looney.           */
/*  v5.0    3/28/95   Newest version sent to QA. By Andrew Looney.                      */
/*  v5.1    3/28/95   Now, with Easter Eggs! By Andrew Looney.                          */
/*  v5.2    3/29/95   Could this be the final version? By Andrew Looney.                */
/*  v5.3    3/30/95   OK, now maybe THIS is the final version! By Andrew Looney.        */
/*  v5.4     4/3/95   Made a couple more minor changes. By Andrew Looney.               */
/****************************************************************************************/

/***************************** WHAT THIS SOFTWARE DOES **********************************
   The solids class is designed to provide an easy system for managing a large number of 
solid objects (within the context of objects sitting on and moving around within a 
landscape as depicted by the landscape class). In particular, this includes:
   1) sorting the objects so that they are drawn to the screen in the correct order to
      create the sense that objects visually obstruct other objects that they are
      directly in front of
   2) comprehensive collision detection
   To understand the functions within this class, you must first understand the various 
data structures employed by this class.
   The first of these is the inanimates lookup table. Given that this class is meant to
be used in conjunction with the landscape class, we also make the assumption that the 
region will be populated with a collection of objects that each sit in the middle of a 
tile. Given this, then, we create a lookup table similar to the one in the landscape 
class, which specifies what type of object occupies each tile. (A value of NOTHING is 
acceptable.) Different populations for different levels can then easily be created just
by loading up a different lookup table at the start of a round.
   Once the lookup table is established, we can then use the table to create all of the 
objects in the landscape. This is done by creating a table of CCBs and then using the 
table to determine the appearance of each piece in the table.
   Once we have a collection of object images, we can then use them to create our sorted 
database of solid objects. This list is the heart of this software package. The solids 
list is a doubly-linked list, sorted by location on the screen, with each node containing 
an identifier that denotes the object type, a pointer to the solid's artwork, and 
collision detection parameters specific to the object. Once created, this list can easily 
be sorted through when wishing to check for collisions, and when moving all of the
objects at once, and when drawing the objects to the screen. When one object moves 
relative to the others, it can easily be pulled from the list and reinserted at the 
correct location. And when an object is destroyed, it is simply removed from the list 
altogether.
   Another data structure of note is the trash can. For efficiency's sake, it is
desirable to have external functions keep track of pointers to specific objects in the 
solids list themselves, since they can then reference a specific object on the list 
without forcing the functions in this class to traverse the list in order to locate the 
object they wish to deal with. But because of this, software elements beyond the scope
of this class will have their fingers pointing at objects in this list which we cannot 
know about. This in turn means that we have to be careful about deleting objects on this 
list. We can't just throw an object away without giving the external users a chance to 
realize the object has been destroyed. Therefore, whenever an object is about to be 
destroyed, it is transferred to another linked list called the trash can. The object's 
artwork pointer is cleared, to indicate to anyone accessing that object that it is no 
longer valid. After the application software feels anyone using the solids list has had 
enough time to realize that an object has been transferred to the trash can, it can then 
call a routine to empty the trash, which will destroy an object for good by deallocating 
its dynamic memory.
	Finally, there's the anisolid structure. This is used to keep track of and deal with
animated solids. For each animated solid in the universe, there will be an entry on the
solids list describing the solid itself, and an entry on the anisolids list which keeps
track of the animation information and has a pointer to the object's entry in the solids
list. This setup enables us to find and deal with animated solids in a fast and efficient
way, and without having to traverse the entire solids list just to deal with a small
number of animated solids.
   In addition to these structures, we also use a number of local, private variables. We
keep a set of master artwork element pointers, which will either point to the master copy
of a piece of artwork or be set to NULL. Rather than waste memory storing art we don't
currently need, we load only those art pieces we need for the given level. The value of
the pointer tells us if the artwork element is already in memory or if it needs to be
loaded.
   A final note is a symbol defined in the application's header file called FUDGE_FACTOR.
The application that this class was created for features objects that have long shadows
stretching out from them on one side. Because these shadows are insubstantial, they 
sometimes look odd when they fall across other objects. So, because of this, the sorting
routine uses a fudge factor to bring an object to the front if it's directly in the path 
of the shadow cast by a given object (i.e. to the right and slightly behind the shadow 
casting object).
	Here's how you go about adding a new type of object:
	 1.) Create a new symbol for the art element (for example, RED_PYRAMID) in the big art
	     elements list, and adjust the value of TOTAL_ART_ELEMENTS (in ICEBREAKER.H).
	 2.) Create a new symbol that defines the name of the art file(s) that are used for
	     display of the object, (for example, RED_PIECE_FILE and RED_DEATH_ANIM)
		  along with variables (for example, red_piece_cel and red_death) that will serve as
		  the master artwork element pointers for the object. (in LANDSCAPE.H).
    3.) Add initialization of the variables to BootSolids (in this file).
	 4.) Add a case to the switch statement in LoadArtwork to handle the new object.
	 5.) Add an if statement to ShutdownUnusedArtwork to handle the new object.
	 6.) Add an if statement to ShutdownForExit to handle the new object.
	 7.) Add a case to the switch statement in ChangeArt to handle the object.
	 8.) If the object is a BOULDER or other non-uniform object, add the custom collision
	     detection numbers for the object to InitializeSolids.
	 9.) If the object is an animated object, add a call to CreateAnimatedSolid for the
	     object in AddToList.
	10.) If the object can be destroyed by contact with the dudemeyer or is fatal to the
	     dudemeyer, add handling for this in the function Obstructed (in DUDEMEYER.CP).
	11.) If the object can be destroyed by the shots the dudemeyer fires, add handling
	     for this to the function DetectHit (in WEAPON.CP).
	12.) Add a case for the new object to the switch statement in the function
	     ArtworkMissing (in ICEBREAKER.CP).
	13.) Add a case for the new object's ascii code in the parsing of level parameters
	     in the fucntion LoadLevel (in LEVELS.CP).
	14.) If the object is a BOULDER, add an exemption for the object to the calculation
	     of the number of pyramids in the function LoadLevel (in LEVELS.CP).
*****************************************************************************************/

/***** regular includes *****/

#include "graphics.h"
#include "stdio.h"
#include "stdlib.h"
#include "mem.h"
#include "types.h"

#include "hardware.h"
#include "event.h"
#include "strings.h"
#include "access.h"
#include "UMemory.h"

#include "Form3DO.h"
#include "Init3DO.h"
#include "Parse3DO.h"
#include "Utils3DO.h"

#include "audio.h"
#include "music.h"

/***** magnet includes *****/

#include "icebreaker.h"
#include "animation.h"
#include "solids.h"
#include "seeker.h"
#include "landscape.h"

/***** special c++ include (this must be last) *****/

#include "CPlusSwiHack.h"

/***** global variables *****/

extern ScreenContext g_screen;
extern int32         g_total_pyramids;
extern bool				g_art_usage[TOTAL_ART_ELEMENTS];
extern int32			level_lookup_table [ROWS_IN_LANDSCAPE] [COLUMNS_IN_LANDSCAPE];
extern Item   			timer_request_item;
extern IOInfo 			timer_request_info;
extern struct 			timeval current_time;
extern seeker			enemies;
extern landscape 		pavement;

/********************************  solids::BootSolids  ***********************************
	This function simply sets all of the artwork element pointer values to NULL. This is
important because artwork is only loaded if the pointer is set to NULL, and on bootup we
can't really be certain that these pointers will be pre-initialized to the value NULL.
*****************************************************************************************/

void solids::BootSolids(void)
{
	red_piece_cel    = (CCB *) NULL;
	blue_piece_cel   = (CCB *) NULL;
	green_piece_cel  = (CCB *) NULL;
	purple_piece_cel = (CCB *) NULL;
	boulder0_cel     = (CCB *) NULL;
	boulder1_cel     = (CCB *) NULL;
	boulder2_cel     = (CCB *) NULL;
	boulder3_cel     = (CCB *) NULL;
	boulder4_cel     = (CCB *) NULL;
	boulder5_cel     = (CCB *) NULL;
	boulder6_cel     = (CCB *) NULL;
	boulder7_cel     = (CCB *) NULL;
	boulder8_cel     = (CCB *) NULL;
	boulder9_cel     = (CCB *) NULL;
	boulderA_cel     = (CCB *) NULL;
	boulderD_cel     = (CCB *) NULL;
	blue_death.anim_pointer          = (ANIM *) NULL;
	red_death.anim_pointer           = (ANIM *) NULL;
	purple_death.anim_pointer        = (ANIM *) NULL;
	green_death.anim_pointer         = (ANIM *) NULL;
	concrete_death.anim_pointer      = (ANIM *) NULL;
	concrete_puff[0].anim_pointer    = (ANIM *) NULL;
	concrete_puff[1].anim_pointer    = (ANIM *) NULL;
	concrete_puff[2].anim_pointer    = (ANIM *) NULL;
	rainbow_piece_anim.anim_pointer  = (ANIM *) NULL;
	concrete_piece_anim.anim_pointer = (ANIM *) NULL;
}

/******************************  solids::LoadArtwork  ***********************************
   This function is called whenever the software determines that it needs a given artwork
element but that this element has not been loaded into memory (i.e. the pointer to that
element is set to NULL.) This function takes as input the symbol which uniquely identifies
this piece of artwork, and loads it into memory. If the file could not be found, this
function calls the routine ArtworkMissing, which will identify the missing art and abort
the program. (It is assumed that such problems will occur only during testing.)
	Note that in some cases, a call to load a given piece of art may result in loading
several pieces of art. For example, if we are called upon to load the red pyramid art,
we automatically also load the animation for the destruction of the red pyramid, since
we know it will also be needed.
*****************************************************************************************/

void solids::LoadArtwork (int32 element_to_load)
{
	switch(element_to_load)
	{
		case RED_PYRAMID:			red_piece_cel = LoadCel(RED_PIECE_FILE, MEMTYPE_CEL);
										if (red_piece_cel == NULL)
											ArtworkMissing(RED_PYRAMID);
										if (!(red_death.LoadArtwork (RED_DEATH_ANIM)))
											ArtworkMissing(RED_PYRAMID);
										break;
		case BLUE_PYRAMID:		blue_piece_cel = LoadCel(BLUE_PIECE_FILE, MEMTYPE_CEL);
										if (blue_piece_cel == NULL)
											ArtworkMissing(BLUE_PYRAMID);
										if (!(blue_death.LoadArtwork (BLUE_DEATH_ANIM)))
											ArtworkMissing(BLUE_PYRAMID);
										break;
		case GREEN_PYRAMID:		green_piece_cel = LoadCel(GREEN_PIECE_FILE, MEMTYPE_CEL);
										if (green_piece_cel == NULL)
											ArtworkMissing(GREEN_PYRAMID);
										if (!(green_death.LoadArtwork (GREEN_DEATH_ANIM)))
											ArtworkMissing(GREEN_PYRAMID);
										break;
		case RAINBOW_PYRAMID:	if (!(rainbow_piece_anim.LoadArtwork(RAINBOW_ANIM)))
											ArtworkMissing(RAINBOW_PYRAMID);
										break;
		case PURPLE_PYRAMID:		purple_piece_cel = LoadCel(PURPLE_PIECE_FILE, MEMTYPE_CEL);
										if (purple_piece_cel == NULL)
											ArtworkMissing(PURPLE_PYRAMID);
										if (!(purple_death.LoadArtwork (PURPLE_DEATH_ANIM)))
											ArtworkMissing(PURPLE_PYRAMID);
										break;
		case BOULDER0:				boulder0_cel = LoadCel(BOULDER0_FILE, MEMTYPE_CEL);
										if (boulder0_cel == NULL)
											ArtworkMissing(BOULDER0);
										break;
		case BOULDER1:				boulder1_cel = LoadCel(BOULDER1_FILE, MEMTYPE_CEL);
										if (boulder1_cel == NULL)
											ArtworkMissing(BOULDER1);
										break;
		case BOULDER2:				boulder2_cel = LoadCel(BOULDER2_FILE, MEMTYPE_CEL);
										if (boulder2_cel == NULL)
											ArtworkMissing(BOULDER2);
										break;
		case BOULDER3:				boulder3_cel = LoadCel(BOULDER3_FILE, MEMTYPE_CEL);
										if (boulder3_cel == NULL)
											ArtworkMissing(BOULDER3);
										break;
		case BOULDER4:				boulder4_cel = LoadCel(BOULDER4_FILE, MEMTYPE_CEL);
										if (boulder4_cel == NULL)
											ArtworkMissing(BOULDER4);
										break;
		case BOULDER5:				boulder5_cel = LoadCel(BOULDER5_FILE, MEMTYPE_CEL);
										if (boulder5_cel == NULL)
											ArtworkMissing(BOULDER5);
										break;
		case BOULDER6:				boulder6_cel = LoadCel(BOULDER6_FILE, MEMTYPE_CEL);
										if (boulder6_cel == NULL)
											ArtworkMissing(BOULDER6);
										break;
		case BOULDER7:				boulder7_cel = LoadCel(BOULDER7_FILE, MEMTYPE_CEL);
										if (boulder7_cel == NULL)
											ArtworkMissing(BOULDER7);
										break;
		case BOULDER8:				boulder8_cel = LoadCel(BOULDER8_FILE, MEMTYPE_CEL);
										if (boulder8_cel == NULL)
											ArtworkMissing(BOULDER8);
										break;
		case BOULDER9:				boulder9_cel = LoadCel(BOULDER9_FILE, MEMTYPE_CEL);
										if (boulder9_cel == NULL)
											ArtworkMissing(BOULDER9);
										break;
		case BOULDERA:				boulderA_cel = LoadCel(BOULDERA_FILE, MEMTYPE_CEL);
										if (boulderA_cel == NULL)
											ArtworkMissing(BOULDERA);
										break;
		case BOULDERD:				boulderD_cel = LoadCel(BOULDERD_FILE, MEMTYPE_CEL);
										if (boulderD_cel == NULL)
											ArtworkMissing(BOULDERD);
										break;
		case CONCRETE_PYRAMID:	if (!(concrete_piece_anim.LoadArtwork(CONCRETE_ANIM)))
											ArtworkMissing(CONCRETE_PYRAMID);
										if (!(concrete_death.LoadArtwork (CONCRETE_DEATH_ANIM)))
											ArtworkMissing(CONCRETE_PYRAMID);
										if (!(concrete_puff[0].LoadArtwork (CONCRETE_PUFF_1)))
											ArtworkMissing(CONCRETE_PYRAMID);
										if (!(concrete_puff[1].LoadArtwork (CONCRETE_PUFF_2)))
											ArtworkMissing(CONCRETE_PYRAMID);
										if (!(concrete_puff[2].LoadArtwork (CONCRETE_PUFF_3)))
											ArtworkMissing(CONCRETE_PYRAMID);
										break;
	}
}

/*********************  solids::PlaceSolidsInStartingPositions  *************************
   This function is based on the assumption that users of this class will be interested 
in a universe of solitary solid objects each resting upon a single tile (as implemented 
by the landscape class). Given this, we use the same method of positioning objects on
the screen that the landscape class uses to lay out the tiles. This works fine since
we are using the same size cel for our solid objects that we use for tiles (although 
this does usually leaves a lot of empty space around the object).
*****************************************************************************************/

void  solids::PlaceSolidsInStartingPositions (void)
{
	int32 i,j;

	if (red_piece_cel == NULL)
		LoadArtwork(RED_PYRAMID);
	if (blue_piece_cel == NULL)
		LoadArtwork(BLUE_PYRAMID);
	if (green_piece_cel == NULL)
		LoadArtwork(GREEN_PYRAMID);

	/* create CCBs for all static solids */
	for (i = 0; i < ROWS_IN_LANDSCAPE; i++)
		for (j = 0; j < COLUMNS_IN_LANDSCAPE; j++)
		{
			inanimates_cel_database[i][j] = new(CCB);
			memcpy(inanimates_cel_database[i][j],green_piece_cel,sizeof(CCB));
		}

	/* position the first ccb, from which all others derive */
	inanimates_cel_database[0][0]->ccb_XPos = INITIAL_UPPER_LEFT_X;
	inanimates_cel_database[0][0]->ccb_YPos = INITIAL_UPPER_LEFT_Y;
	ChangeArt(inanimates_cel_database[0][0],level_lookup_table[0][0]);

	/* position the first ccb in each row */
	for (i = 1; i < ROWS_IN_LANDSCAPE; i++)
	{
		inanimates_cel_database[i][0]->ccb_XPos = inanimates_cel_database[0][0]->ccb_XPos;
		inanimates_cel_database[i][0]->ccb_YPos = inanimates_cel_database[i-1][0]->ccb_YPos
		                                     	 + (TILE_HEIGHT << 16);
		ChangeArt(inanimates_cel_database[i][0],level_lookup_table[i][0]);
	}

	/* Now position the other elements in each row */
	for (i = 0; i < ROWS_IN_LANDSCAPE; i++)
	{
		for (j = 1; j < COLUMNS_IN_LANDSCAPE; j++)
		{
			inanimates_cel_database[i][j]->ccb_XPos
			       = inanimates_cel_database[i][j-1]->ccb_XPos + (HALF_TILE_WIDTH << 16);
			if (j % 2)
			   inanimates_cel_database[i][j]->ccb_YPos
				       = inanimates_cel_database[i][j-1]->ccb_YPos - (HALF_TILE_HEIGHT << 16);
			else
			   inanimates_cel_database[i][j]->ccb_YPos
				       = inanimates_cel_database[i][j-1]->ccb_YPos + (HALF_TILE_HEIGHT << 16);
			ChangeArt(inanimates_cel_database[i][j],level_lookup_table[i][j]);
		}
	}
}

/****************************  solids::InitializeSolids  ********************************
   This function performs all of the steps needed to fully initialize the universe of
solid objects and to set things up so that objects can easily be added to and removed
from the universe. It is meant to be called prior to each new round that uses a set of
solid objects.
*****************************************************************************************/

void  solids::InitializeSolids (void)		
{
	int32 i,j;
	CCB   *temp;

	solids_list = (solid_object *) NULL;
	trash_can = (solid_object *) NULL;
	anisolid_list = (anisolid *) NULL;

	ShutdownUnusedArtwork();
	PlaceSolidsInStartingPositions();
	for (i = 0; i < ROWS_IN_LANDSCAPE; i++)
	{
		for (j = 0; j < COLUMNS_IN_LANDSCAPE; j++)
		{
			if (level_lookup_table[i][j] != NOTHING)
			{
				switch (level_lookup_table[i][j])
				{
					case BOULDER0:	AddToList(inanimates_cel_database[i][j], BOULDER0, 27, 4);
										temp = new(CCB);
										memcpy(temp,inanimates_cel_database[i][j],sizeof(CCB));
										AddToList(temp, PHANTOM_BOULDER, 15, 11);
										break;
					case BOULDER1:	AddToList(inanimates_cel_database[i][j], BOULDER1, 26, 3);
										temp = new(CCB);
										memcpy(temp,inanimates_cel_database[i][j],sizeof(CCB));
										AddToList(temp, PHANTOM_BOULDER, 10, 11);
										break;
					case BOULDER2:	AddToList(inanimates_cel_database[i][j], BOULDER2, 27, 4);
										temp = new(CCB);
										memcpy(temp,inanimates_cel_database[i][j],sizeof(CCB));
										AddToList(temp, PHANTOM_BOULDER, 10, 11);
										break;
					case BOULDER3:	AddToList(inanimates_cel_database[i][j], BOULDER3, 24, 3);
										temp = new(CCB);
										memcpy(temp,inanimates_cel_database[i][j],sizeof(CCB));
										AddToList(temp, PHANTOM_BOULDER, 10, 10);
										break;
					case BOULDER4:	AddToList(inanimates_cel_database[i][j], BOULDER4, 23, 2);
										temp = new(CCB);
										memcpy(temp,inanimates_cel_database[i][j],sizeof(CCB));
										AddToList(temp, PHANTOM_BOULDER, 10, 10);
										break;
					case BOULDER5:	AddToList(inanimates_cel_database[i][j], BOULDER5, 27, 4);
										temp = new(CCB);
										memcpy(temp,inanimates_cel_database[i][j],sizeof(CCB));
										AddToList(temp, PHANTOM_BOULDER, 15, 11);
										break;
					case BOULDER6:	AddToList(inanimates_cel_database[i][j], BOULDER6, 27, 4);
										temp = new(CCB);
										memcpy(temp,inanimates_cel_database[i][j],sizeof(CCB));
										AddToList(temp, PHANTOM_BOULDER, 13, 11);
										break;
					case BOULDER7:	AddToList(inanimates_cel_database[i][j], BOULDER7, 27, 4);
										temp = new(CCB);
										memcpy(temp,inanimates_cel_database[i][j],sizeof(CCB));
										AddToList(temp, PHANTOM_BOULDER, 10, 11);
										break;
					case BOULDER8:	AddToList(inanimates_cel_database[i][j], BOULDER8, 24, 2);
										temp = new(CCB);
										memcpy(temp,inanimates_cel_database[i][j],sizeof(CCB));
										AddToList(temp, PHANTOM_BOULDER, 9, 10);
										break;
					case BOULDER9:	AddToList(inanimates_cel_database[i][j], BOULDER9, 26, 3);
										temp = new(CCB);
										memcpy(temp,inanimates_cel_database[i][j],sizeof(CCB));
										AddToList(temp, PHANTOM_BOULDER, 8, 10);
										break;
					case BOULDERA:	AddToList(inanimates_cel_database[i][j], BOULDERA, 27, 3);
										temp = new(CCB);
										memcpy(temp,inanimates_cel_database[i][j],sizeof(CCB));
										AddToList(temp, PHANTOM_BOULDER, 9, 12);
										break;
					case BOULDERD:	AddToList(inanimates_cel_database[i][j], BOULDERD, 27, 4);
										temp = new(CCB);
										memcpy(temp,inanimates_cel_database[i][j],sizeof(CCB));
										AddToList(temp, PHANTOM_BOULDER, 13, 10);
										break;
					default:			AddToList(inanimates_cel_database[i][j],
					                         level_lookup_table[i][j],
				   	                      PYRAMID_COL_DETECT_X, PYRAMID_COL_DETECT_Y);
										break;
				}
			}
		}
	}
}

/********************************  solids::AddToList  ***********************************
	As the name suggests, this function adds a new solid to the solid objects list. Doing 
this requires dynamically allocating memory to store the list entry. If the object is an 
animated solid, this function also makes the appropriate calls needed to add the object
to the animated solids list as well as the regular solids list.
*****************************************************************************************/

void  solids::AddToList (CCB *target, int32 object_type, int32 cd_x, int32 cd_y)
{
	register solid_object	*new_solid;

	new_solid = new(solid_object);
	new_solid->cel = target;
	new_solid->object_type = object_type;
	new_solid->col_detect_x = cd_x;
	new_solid->col_detect_y = cd_y;
	new_solid->next = (solid_object *) NULL;
	new_solid->previous = (solid_object *) NULL;

	if (object_type == RAINBOW_PYRAMID)
	{
		if (rainbow_piece_anim.anim_pointer == NULL)
			LoadArtwork(RAINBOW_PYRAMID);
		CreateAnimatedSolid (&rainbow_piece_anim,STANDARD_FRAME_RATE >> (RandomNumber(0,0)),
		                     new_solid, TRUE);
		if (purple_piece_cel == NULL)
			LoadArtwork(PURPLE_PYRAMID);
	}
	
	if (object_type == CONCRETE_PYRAMID)
	{
		if (concrete_piece_anim.anim_pointer == NULL)
			LoadArtwork(CONCRETE_PYRAMID);
		CreateAnimatedSolid (&concrete_piece_anim, STANDARD_FRAME_RATE, new_solid, FALSE);
	}

	if (solids_list == (solid_object *) NULL)
		solids_list = new_solid;
	else
		InsertAtProperPointInList(new_solid);
}

/**********************  solids::InsertAtProperPointInList  *****************************
   This function takes as input a pointer to a solid object record, then it figures out 
where in the solids list it belongs and inserts it at that point. The objects are sorted 
such that the first one in the list is the object farthest up and to the left on the 
field of solid objects.
   It is important to understand that all objects in the linked list must be drawn in a 
cel of the same size, with center of the base of the object centered within the cel.
*****************************************************************************************/

void solids::InsertAtProperPointInList (solid_object	*new_solid)
{
	register solid_object	*traversal_ptr;

	traversal_ptr = solids_list;

	/* first, find out if this object ought to be first on the list: */
	if ( (((ABS(new_solid->cel->ccb_YPos - traversal_ptr->cel->ccb_YPos)) <= FUDGE_FACTOR)
 	       && (new_solid->cel->ccb_XPos < traversal_ptr->cel->ccb_XPos))
		|| (new_solid->cel->ccb_YPos + FUDGE_FACTOR < traversal_ptr->cel->ccb_YPos) )
	{
		new_solid->next = solids_list;
		new_solid->previous = (solid_object *) NULL;
		solids_list->previous = new_solid;
		solids_list = new_solid;
		return;
	}

	/* now traverse the list and insert the object in front of the first object that     */
	/* we encounter with x and y coordinates lower and further right on the screen       */
	/* than our own:                                                                     */
	while (traversal_ptr->next != (solid_object *) NULL)
	{
		if ( (((ABS(new_solid->cel->ccb_YPos-traversal_ptr->cel->ccb_YPos)) <= FUDGE_FACTOR)
	 	       && (new_solid->cel->ccb_XPos < traversal_ptr->cel->ccb_XPos))
			|| (new_solid->cel->ccb_YPos + FUDGE_FACTOR < traversal_ptr->cel->ccb_YPos) )
		{
			new_solid->next = traversal_ptr;
			new_solid->previous = traversal_ptr->previous;
			traversal_ptr->previous = new_solid;
			new_solid->previous->next = new_solid;
			return;
		}
		traversal_ptr = traversal_ptr->next;
	}
	
	/* if we still haven't returned, then we've reached the end of the list. The         */
	/* traversal_ptr is pointing to the last element in the list, but the comparison of  */
	/* this element to the new object has not yet been made. The question we now have to */
	/* answer is, does the new object get placed before or after the final object?       */

	if ( (((ABS(new_solid->cel->ccb_YPos - traversal_ptr->cel->ccb_YPos)) <= FUDGE_FACTOR)
	       && (new_solid->cel->ccb_XPos < traversal_ptr->cel->ccb_XPos))
		|| (new_solid->cel->ccb_YPos + FUDGE_FACTOR < traversal_ptr->cel->ccb_YPos) )
	{
		new_solid->next = traversal_ptr;
		new_solid->previous = traversal_ptr->previous;
		traversal_ptr->previous = new_solid;
		new_solid->previous->next = new_solid;
	}
	else
	{
		/* add new object at end of list */
		new_solid->previous = traversal_ptr;
		new_solid->next = (solid_object *) NULL;
		traversal_ptr->next = new_solid;
	}
	/* Note: Yes, there's some redundancy here... but the other choice is to keep going  */
	/* in the while loop until traversal_ptr == NULL, after which we would know that the */
	/* new object gets placed at the end of the list, but in that case, traversal_ptr    */
	/* would have been set to NULL and we'd have to retraverse the entire list just to   */
	/* get that pointer value back. Another alternative would be to keep a second        */
	/* pointer going, lagging one node behind traversal_ptr, but that wastes a lot of    */
	/* processing time in all of the cases except for when we get near to the end of     */
	/* the list. So, this seemed like the best approach.                                 */
}

/*************************  solids::TamperWithSorting  **********************************
   In some cases, the way we sort objects in InsertAtProperPointInList may not quite be
satisfactory. For such cases, this function was created. If two objects are not in the 
desired order on the list, this function will place them in the desired positions
relative to each other.
*****************************************************************************************/

void solids::TamperWithSorting (solid_object *first_solid, solid_object *second_solid,
                                bool second_first)
{
	if (second_first)
	{
		RemoveFromList(second_solid);
		if (solids_list == first_solid)
		{
			solids_list = second_solid;
			second_solid->next = first_solid;
			second_solid->previous = (solid_object *) NULL;
			first_solid->previous = second_solid;
		}
		else
		{
			second_solid->previous = first_solid->previous;
			first_solid->previous = second_solid;
			second_solid->previous->next = second_solid;
			second_solid->next = first_solid;
		}
	}
	else
	{
		RemoveFromList(second_solid);
		if (first_solid->next != (solid_object *) NULL)
			first_solid->next->previous = second_solid;
		second_solid->next = first_solid->next;
		second_solid->previous = first_solid;
		first_solid->next = second_solid;
	}
}

/*****************************  solids::RemoveFromList  *********************************
   This function removes an object from a doubly linked list of solid objects and
corrects the pointers around it to cope with the object's removal. It does not, however, 
deallocate the memory used by the object, nor change the object in any way.
*****************************************************************************************/

void  solids::RemoveFromList (solid_object *target_solid)
{
	/* if object is at head of list, adjust master list pointer */
	if (target_solid == solids_list)
	{
		solids_list = target_solid->next;
		/* then adjust new first element, unless element being remove was last one */
		if (solids_list != (solid_object *) NULL)
			solids_list->previous = (solid_object *) NULL;
	}
	/* now handle removing any elements other than first one */
	else
	{
		target_solid->previous->next = target_solid->next;
		/* correct next element's previous pointer, unless there is no next element */
		if (target_solid->next != (solid_object *) NULL)
			target_solid->next->previous = target_solid->previous;
	}
}

/**************************  solids::FindPointerIntoList  *******************************
   This function searches through a list of solid objects until it finds an object with
a cel pointer that matches the one passed in. The main purpose of this function is to 
allow external users to learn where their object of interest is on the solids list so
that they can refer to their own object directly, rather than allowing them to be lazy
and force us to traverse the solids list more often than we need to.
*****************************************************************************************/

solid_object*  solids::FindPointerIntoList (CCB *target)
{
	register solid_object	*traversal_ptr;

	traversal_ptr = solids_list;
	while (traversal_ptr != (solid_object *) NULL)
	{
		if (traversal_ptr->cel == target)
			return(traversal_ptr);
		traversal_ptr = traversal_ptr->next;
	}
	printf("MAJOR BUMMER: target object not found by solids::FindPointerIntoList().\n");
	return(traversal_ptr);
}

/***************************  solids::EliminateObject  **********************************
   There are two versions of the EliminateObject function. The first is meant for lazy
users who wish to destroy a solid object but know it only by its picture; the second is 
for users who are able to provide a pointer to the actual object structure that they 
wish to destroy.
   This is the first of these functions. It first calls FindPointerIntoList to get the 
pointer, and then it simply calls the other version of EliminateObject.
*****************************************************************************************/

void  solids::EliminateObject (CCB *cel_to_eliminate)
{
	solid_object *object_to_eliminate;

	object_to_eliminate = FindPointerIntoList(cel_to_eliminate);
	EliminateObject(object_to_eliminate);
}

/***************************  solids::EliminateObject  **********************************
   There are two versions of the EliminateObject function. The first is meant for lazy
users who wish to destroy a solid object but know it only by its picture; the second is 
for users who are able to provide a pointer to the actual object structure that they 
wish to destroy.
   This is the second of these functions. It pulls the object out of the solids list, and 
then alters it to indicate that the object is being destroyed, and finally places the 
object in the trash can.
*****************************************************************************************/

void  solids::EliminateObject (solid_object *object_to_eliminate)
{
	/* set the cel pointer of this object to NULL, to alert anyone who might be holding  */
	/* a pointer to this object to the fact that it's been destroyed, then add it        */
	/* to the list of objects to be thrown away:                                         */
	object_to_eliminate->cel = (CCB *) NULL;
	RemoveFromList(object_to_eliminate);
	object_to_eliminate->next = trash_can;
	trash_can = object_to_eliminate;
}

/*****************************  solids::EmptyTrash  *************************************
   This function is the final stage in the destruction of a solid object. Assuming the
object was first transferred onto the trash can list, and then allowed to stay there
long enough for all routines that use objects externally to have executed at least once,
and thereby realize the object was being destroyed, this function can then be called to 
remove all items on the trash can list and deallocate their memory.
*****************************************************************************************/

void  solids::EmptyTrash (void)
{
	solid_object	*traversal_ptr,*vanguard_pointer;

	traversal_ptr = trash_can;
	while (traversal_ptr != (solid_object *) NULL)
	{
		vanguard_pointer = traversal_ptr->next;
		if ((traversal_ptr->object_type == PHANTOM_BOULDER))
			delete(traversal_ptr->cel);
		delete(traversal_ptr);
		traversal_ptr = vanguard_pointer;
	}
	trash_can = (solid_object *) NULL;
}

/****************************  solids::DisplaySolids  ***********************************
   This function traverses the entire solids list and draws everything thereon into the 
screen buffer indicated by the external global variable g_screen. Well, not quite 
everything. To save time, anything that isn't visible isn't drawn.
*****************************************************************************************/

void  solids::DisplaySolids (void)
{
	register solid_object	*traversal_ptr;
	         CCB	         *draw_me;
	register CCB            *draw_me_next;

	MaintainAnimatedObjects();

	draw_me = (CCB *) NULL;
	draw_me_next = draw_me;
	traversal_ptr = solids_list;
	while (traversal_ptr != (solid_object *) NULL)
	{
		traversal_ptr->cel->ccb_NextPtr = (CCB *) NULL;
		traversal_ptr->cel->ccb_Flags &= ~CCB_LAST;
		if ((traversal_ptr->cel->ccb_XPos + (traversal_ptr->cel->ccb_Width << 16) >=  0)
	 	 && (traversal_ptr->cel->ccb_XPos <= (SCREEN_WIDTH << 16))
		 && (traversal_ptr->cel->ccb_YPos + (traversal_ptr->cel->ccb_Height << 16) >=  0)
	 	 && (traversal_ptr->cel->ccb_YPos <= (SCREEN_HEIGHT << 16))
		 && (traversal_ptr->object_type != PHANTOM_BOULDER))
		{
			if (draw_me == (CCB *) NULL)
			{
				draw_me = traversal_ptr->cel;
				draw_me_next = draw_me;
			}
			else
			{
				draw_me_next->ccb_NextPtr = traversal_ptr->cel;
				draw_me_next = traversal_ptr->cel;
			}
		}
		traversal_ptr = traversal_ptr->next;
	}
	/* draw_me and draw_me next will be NULL if no objects are visible at all on the     */
	/* screen, which can happen if you destroy all pyramids on screen and fall into a    */
	/* pit before any new seekers reappear on screen. For this rather rare case, we need */
	/* to make sure that draw_me isn't NULL.                                             */
	if (draw_me == NULL)
		return;
	draw_me_next->ccb_Flags |= CCB_LAST;
	DrawScreenCels(g_screen.sc_Screens[g_screen.sc_curScreen],draw_me);
}

/***************************  solids::FixPositionOnList  ********************************
   As with EliminateObject, there are two versions of this function, one for those who 
know the object in question only by its cel pointer, and one for those who know the
object pointer. This is the first version, and it just gets the pointer it needs and
then calls the other version.
*****************************************************************************************/

void	solids::FixPositionOnList (CCB *target_cel)
{
	solid_object	*target;

	target = FindPointerIntoList(target_cel);
	FixPositionOnList(target);
}

/***************************  solids::FixPositionOnList  ********************************
   As with EliminateObject, there are two versions of this function, one for those who 
know the object in question only by its cel pointer, and one for those who know the
object pointer. This is the second version.
   This function is used to make sure that an object which has moved relative to other 
objects is still in the right spot on the linked list. If it has moved enough to be out
of place on the list, then this function deletes it from the list and reinserts it where 
it belongs.
*****************************************************************************************/

void	solids::FixPositionOnList (solid_object *target)
{
	/* CASE 1: Object is at start of list */
	if (target == solids_list)
	{
		if ( (((ABS(target->cel->ccb_YPos - target->next->cel->ccb_YPos)) <= FUDGE_FACTOR)
	 	        && (target->cel->ccb_XPos < target->next->cel->ccb_XPos))
		 	  || (target->cel->ccb_YPos + FUDGE_FACTOR < target->next->cel->ccb_YPos) )
					return;

		RemoveFromList(target);
		InsertAtProperPointInList(target);
		return;
	}

	/* CASE 2: Object is at end of list */
	if (target->next == (solid_object *) NULL)
	{
		if ( (((ABS(target->previous->cel->ccb_YPos-target->cel->ccb_YPos)) <= FUDGE_FACTOR)
	 	       && (target->previous->cel->ccb_XPos < target->cel->ccb_XPos))
			  || (target->previous->cel->ccb_YPos + FUDGE_FACTOR < target->cel->ccb_YPos) )
					return;

		RemoveFromList(target);
		InsertAtProperPointInList(target);
		return;
	}

	/* CASE 3: Object is in the middle of the list */
	if ( ( (((ABS(target->cel->ccb_YPos - target->next->cel->ccb_YPos)) <= FUDGE_FACTOR)
 	         && (target->cel->ccb_XPos < target->next->cel->ccb_XPos))
	 	  || (target->cel->ccb_YPos + FUDGE_FACTOR < target->next->cel->ccb_YPos) )
	 && ( (((ABS(target->previous->cel->ccb_YPos - target->cel->ccb_YPos)) <= FUDGE_FACTOR)
	        && (target->previous->cel->ccb_XPos < target->cel->ccb_XPos))
		  || (target->previous->cel->ccb_YPos + FUDGE_FACTOR < target->cel->ccb_YPos) ) )
				return;

	RemoveFromList(target);
	InsertAtProperPointInList(target);
}

/****************************  solids::DetectCollision  *********************************
   This function is a comprehensive collision detection function. It takes as input an 
object to be checked, along with collision detection parameters for that object, and 
returns either NULL, in the event that no collisions were found, or a pointer to the 
closest solid object that it has collided with. Note that the target object need not be
on the solids list.
   This function has been tailored somewhat to meet the specific needs of Icebreaker. If 
the object in question collides with an object of a specific type, namely DEATH_SCENE,
it will report this only if that was the only object that was collided with. If a more 
substantial object was run into, then that object will be reported instead of the 
DEATH_SCENE object.
*****************************************************************************************/

solid_object*	solids::DetectCollision (CCB *target, int32 target_cd_x,int32 target_cd_y,
													 bool exclude_dudemeyer)
{
	register solid_object	*traversal_ptr;
	register int32          object_center_x,object_center_y;
	register int32          target_center_x,target_center_y;
	solid_object				*collision_list[MAX_DETECTABLE_COLLISIONS];
	int32							collisions;
	int32							x_diff[2],y_diff[2];

	target_center_x = FIND_CENTER_X (target);
	target_center_y = FIND_CENTER_Y (target);
	traversal_ptr = solids_list;
	collisions = 0;

	while (traversal_ptr != (solid_object *) NULL)
	{
		if (traversal_ptr->cel != target)
		{
			object_center_x = FIND_CENTER_X (traversal_ptr->cel);
			object_center_y = FIND_CENTER_Y (traversal_ptr->cel);
			if ( ((ABS(object_center_x - target_center_x))
			                         <= traversal_ptr->col_detect_x + target_cd_x)
			  && ((ABS(object_center_y - target_center_y))
			                         <= traversal_ptr->col_detect_y + target_cd_y) )
			{
				collisions++;
				if (collisions > MAX_DETECTABLE_COLLISIONS)
				{
					printf("Warning: trying to exceed MAX_DETECTABLE_COLLISIONS.\n");
					break;
				}
				/* We only register this object as a collision in the following cases: */
				/*   a) it's not a death scene                                         */
				/*   b) the only collision we find is a death scene                    */
				/*   c) it's the dudemeyer and the exclusion flag is not set           */
				if (traversal_ptr->object_type == DEATH_SCENE)
				{
					/* thus, if this is a death scene, we save it if we've got nothing  */
					/* else of note, otherwise we forget we ever saw it.                */
					if (collisions == 1)
						collision_list[collisions - 1] = traversal_ptr;
					else
						collisions--;
				}
				else
				{
					/* and if this isn't a death scene, but we previously had saved a   */
					/* death scene, we now remove the death scene from the list and put */
					/* this down instead.                                               */
					if ((collisions == 2) && (collision_list[0]->object_type==DEATH_SCENE))
						collisions = 1;
					collision_list[collisions - 1] = traversal_ptr;
				}
				if ((traversal_ptr->object_type == DUDEMEYER) && (exclude_dudemeyer))
					collisions--;
			}
		}
		traversal_ptr = traversal_ptr->next;
	}
		
	if (collisions == 0)
		return((solid_object *) NULL);
	
	/* if more than one object was collided with, then the one to be reported is the  */
	/* one closest to the target object.                                              */
	traversal_ptr = collision_list[0];
	for (int32 i = 1; i < collisions; i++)
	{
		x_diff[0] = (ABS(FIND_CENTER_X(traversal_ptr->cel) - target_center_x));
		y_diff[0] = (ABS(FIND_CENTER_Y(traversal_ptr->cel) - target_center_y));
		x_diff[1] = (ABS(FIND_CENTER_X(collision_list[i]->cel) - target_center_x));
		y_diff[1] = (ABS(FIND_CENTER_Y(collision_list[i]->cel) - target_center_y));
		if ((x_diff[0] > x_diff[1]) || (y_diff[0] > y_diff[1]))
			traversal_ptr = collision_list[i];
	}
	return(traversal_ptr);
}

/****************************  solids::DetectCollision  *********************************
   This is an alternate version of the DetectCollision function which has been optimized
for use when checking to see if an object that IS stored on the solids list has collided
with another object on the solids list. It only checks as much of the solids list as
needed to determine if any collisions occurred.
*****************************************************************************************/

solid_object*	solids::DetectCollision (solid_object *target, bool ignore_rocks)
{
	register solid_object	*traversal_ptr;
	register int32          object_center_x,object_center_y;
	register int32          target_center_x,target_center_y;
	solid_object				*collision_list[MAX_DETECTABLE_COLLISIONS];
	int32							collisions;
	int32							x_diff[2],y_diff[2];

	target_center_x = FIND_CENTER_X (target->cel);
	target_center_y = FIND_CENTER_Y (target->cel);
	collisions = 0;

	/* we start by checking against all objects upstream of the target object, stopping */
	/* when we get to an object that is out of range along both axes.                   */
	traversal_ptr = target->previous;
	while (traversal_ptr != (solid_object *) NULL)
	{
		object_center_x = FIND_CENTER_X (traversal_ptr->cel);
		object_center_y = FIND_CENTER_Y (traversal_ptr->cel);

		/* once we find an object that is up and to the left of us and farther away    */
		/* than the maximum size an object can be, then we stop looking further.       */
		if ((traversal_ptr->cel->ccb_XPos + (TILE_WIDTH << 16)  < target->cel->ccb_XPos)
		 && (traversal_ptr->cel->ccb_YPos + (TILE_HEIGHT << 16) < target->cel->ccb_YPos))
			break;

		if ( ((ABS(object_center_x - target_center_x))
		                         <= traversal_ptr->col_detect_x + target->col_detect_x)
		  && ((ABS(object_center_y - target_center_y))
		                         <= traversal_ptr->col_detect_y + target->col_detect_y) )
		{
			collisions++;
			if (collisions > MAX_DETECTABLE_COLLISIONS)
			{
				printf("Warning: trying to exceed MAX_DETECTABLE_COLLISIONS (upstream).\n");
				collisions = MAX_DETECTABLE_COLLISIONS;
				break;
			}
			/* We only register this object as a collision in the following cases: */
			/*   a) it's not a death scene                                         */
			/*   b) the only collision we find is a death scene                    */
			/*   c) it's a rock and ignore_rocks is not set                        */

			if ((ignore_rocks)
			 && (traversal_ptr->object_type >= FIRST_BOULDER)
			 && (traversal_ptr->object_type <= LAST_BOULDER))
				collisions--;
			else
			{
				if (traversal_ptr->object_type == DEATH_SCENE)
				{
					/* thus, if this is a death scene, we save it if we've got nothing  */
					/* else of note, otherwise we forget we ever saw it.                */
					if (collisions == 1)
						collision_list[collisions - 1] = traversal_ptr;
					else
						collisions--;
				}
				else
				{
					/* and if this isn't a death scene, but we previously had saved a   */
					/* death scene, we now remove the death scene from the list and put */
					/* this down instead.                                               */
					if ((collisions == 2) && (collision_list[0]->object_type==DEATH_SCENE))
						collisions = 1;
					collision_list[collisions - 1] = traversal_ptr;
				}
			}
		}
		traversal_ptr = traversal_ptr->previous;
	}

	/* now we check all of the downstream objects that are within range on either axis. */
	traversal_ptr = target->next;
	while (traversal_ptr != (solid_object *) NULL)
	{
		object_center_x = FIND_CENTER_X (traversal_ptr->cel);
		object_center_y = FIND_CENTER_Y (traversal_ptr->cel);
		
		/* once we find an object that is down and to the right of us and farther away */
		/* than the maximum size an object can be, then we stop looking further.       */
		if ((traversal_ptr->cel->ccb_XPos > target->cel->ccb_XPos + (TILE_WIDTH << 16))
		 && (traversal_ptr->cel->ccb_YPos > target->cel->ccb_YPos + (TILE_HEIGHT << 16)))
			break;

		if ( ((ABS(object_center_x - target_center_x))
		                         <= traversal_ptr->col_detect_x + target->col_detect_x)
		  && ((ABS(object_center_y - target_center_y))
		                         <= traversal_ptr->col_detect_y + target->col_detect_y) )
		{
			collisions++;
			if (collisions > MAX_DETECTABLE_COLLISIONS)
			{
				printf("Warning: trying to exceed MAX_DETECTABLE_COLLISIONS (downstream).\n");
				collisions = MAX_DETECTABLE_COLLISIONS;
				break;
			}
			/* We only register this object as a collision in the following cases: */
			/*   a) it's not a death scene                                         */
			/*   b) the only collision we find is a death scene                    */
			/*   c) it's a rock and ignore_rocks is not set                        */

			if ((ignore_rocks)
			 && (traversal_ptr->object_type >= FIRST_BOULDER)
			 && (traversal_ptr->object_type <= LAST_BOULDER))
				collisions--;
			else
			{
				if (traversal_ptr->object_type == DEATH_SCENE)
				{
					/* thus, if this is a death scene, we save it if we've got nothing  */
					/* else of note, otherwise we forget we ever saw it.                */
					if (collisions == 1)
						collision_list[collisions - 1] = traversal_ptr;
					else
						collisions--;
				}
				else
				{
					/* and if this isn't a death scene, but we previously had saved a   */
					/* death scene, we now remove the death scene from the list and put */
					/* this down instead.                                               */
					if ((collisions == 2) && (collision_list[0]->object_type==DEATH_SCENE))
						collisions = 1;
					collision_list[collisions - 1] = traversal_ptr;
				}
			}
		}
		traversal_ptr = traversal_ptr->next;
	}

	if (collisions == 0)
		return((solid_object *) NULL);
	
	/* if more than one object was collided with, then the one to be reported is the  */
	/* one closest to the target object.                                              */
	traversal_ptr = collision_list[0];
	for (int32 i = 1; i < collisions; i++)
	{
		x_diff[0] = (ABS(FIND_CENTER_X(traversal_ptr->cel) - target_center_x));
		y_diff[0] = (ABS(FIND_CENTER_Y(traversal_ptr->cel) - target_center_y));
		x_diff[1] = (ABS(FIND_CENTER_X(collision_list[i]->cel) - target_center_x));
		y_diff[1] = (ABS(FIND_CENTER_Y(collision_list[i]->cel) - target_center_y));
		if ((x_diff[0] > x_diff[1]) || (y_diff[0] > y_diff[1]))
			traversal_ptr = collision_list[i];
	}
	return(traversal_ptr);
}

/**************************  solids::CompareForCollisions  ******************************
   This function takes as input pointers to a pair of solid objects, and returns TRUE if 
they have collided. If either object no longer exists, or if there is no collision, then 
FALSE is returned. This function is meant as a time saver for cases in which one object 
expects to be collide repeatedly with another specific object. In these cases, there is
no need to traverse the entire solids list looking for collisions where you know one is 
likely to occur with one particular object.
*****************************************************************************************/

bool  solids::CompareForCollisions(solid_object *thing1, solid_object *thing2)
{
	if ((thing1 == (solid_object *) NULL) || (thing2 == (solid_object *) NULL))
		return(FALSE);

	if ((thing1->cel == (CCB *) NULL) || (thing2->cel == (CCB *) NULL))
		return(FALSE);

	return ( ((ABS((FIND_CENTER_X (thing1->cel)) - (FIND_CENTER_X (thing2->cel))))
                                        <= thing1->col_detect_x + thing2->col_detect_x)
         && ((ABS((FIND_CENTER_Y (thing1->cel)) - (FIND_CENTER_Y (thing2->cel))))
                                        <= thing1->col_detect_y + thing2->col_detect_y) );
}

/*****************************  solids::MoveWorld  **************************************
   This function shifts all of the objects on the solids list a given distance in either 
or both directions as specified by the values of x_change and y_change. These parameters
can have either positive or negative values depending on which direction you wish to 
move the objects.
*****************************************************************************************/

void  solids::MoveWorld (int32 x_change, int32 y_change)
{
	register solid_object	*traversal_ptr;

	traversal_ptr = solids_list;
	while (traversal_ptr != (solid_object *) NULL)
	{
		traversal_ptr->cel->ccb_XPos += x_change;
		traversal_ptr->cel->ccb_YPos += y_change;
		traversal_ptr = traversal_ptr->next;
	}
}

/*******************************  solids::ChangeArt  ************************************
   Changing the artwork a CCB considers its own is very easy: you just change the 
values of two pointers within its structure so that they reference a difference CCB's art 
information. However, which CCB should we go to in order to get our new art pointers?
This routine decides that, too.
*****************************************************************************************/

void  solids::ChangeArt(CCB *target_cel, int32 solid_id)
{
	CCB	*source_cel;
	int32	x,y;

	source_cel = green_piece_cel;
	switch (solid_id)
	{
		case BLUE_PYRAMID:      if (blue_piece_cel == NULL)
											LoadArtwork(BLUE_PYRAMID);
			       					source_cel = blue_piece_cel;
										break;
		case RED_PYRAMID:       if (red_piece_cel == NULL)
											LoadArtwork(RED_PYRAMID);
			       					source_cel = red_piece_cel;
										break;
		case GREEN_PYRAMID:     if (green_piece_cel == NULL)
											LoadArtwork(GREEN_PYRAMID);
			       					source_cel = green_piece_cel;
										break;
		case PURPLE_PYRAMID:    if (purple_piece_cel == NULL)
											LoadArtwork(PURPLE_PYRAMID);
			       					source_cel = purple_piece_cel;
										break;
		case BOULDER0:      		if (boulder0_cel == NULL)
											LoadArtwork(BOULDER0);
			       					source_cel = boulder0_cel;  
										break;
		case BOULDER1:      		if (boulder1_cel == NULL)
											LoadArtwork(BOULDER1);
			       					source_cel = boulder1_cel;  
										break;
		case BOULDER2:      		if (boulder2_cel == NULL)
											LoadArtwork(BOULDER2);
			       					source_cel = boulder2_cel;
										break;
		case BOULDER3:      		if (boulder3_cel == NULL)
											LoadArtwork(BOULDER3);
			       					source_cel = boulder3_cel; 
										break;
		case BOULDER4:      		if (boulder4_cel == NULL)
											LoadArtwork(BOULDER4);
			       					source_cel = boulder4_cel; 
										break;
		case BOULDER5:      		if (boulder5_cel == NULL)
											LoadArtwork(BOULDER5);
			       					source_cel = boulder5_cel; 
										break;
		case BOULDER6:      		if (boulder6_cel == NULL)
											LoadArtwork(BOULDER6);
			       					source_cel = boulder6_cel; 
										break;
		case BOULDER7:      		if (boulder7_cel == NULL)
											LoadArtwork(BOULDER7);
			       					source_cel = boulder7_cel; 
										break;
		case BOULDER8:      		if (boulder8_cel == NULL)
											LoadArtwork(BOULDER8);
			       					source_cel = boulder8_cel;  
										break;
		case BOULDER9:      		if (boulder9_cel == NULL)
											LoadArtwork(BOULDER9);
			       					source_cel = boulder9_cel;  
										break;
		case BOULDERA:      		if (boulderA_cel == NULL)
											LoadArtwork(BOULDERA);
			       					source_cel = boulderA_cel;  
										break;
		case BOULDERD:      		if (boulderD_cel == NULL)
											LoadArtwork(BOULDERD);
			       					source_cel = boulderD_cel;  
										break;
		case YELLOW_PYRAMID:    source_cel = enemies.yellow_piece_cel;  	break;
		case LTBLUE_PYRAMID:    source_cel = enemies.ltblue_piece_cel;		break;
		case PINK_PYRAMID:      source_cel = enemies.pink_piece_cel;		break;
		case LIME_PYRAMID:      source_cel = enemies.lime_piece_cel;		break;
		case LURKER_PYRAMID:    source_cel = enemies.lurker_piece_cel;		break;
	}	
	if (source_cel == NULL)
	{
		printf("Whoa! solids::ChangeArt got a null pointer! Object type: %ld!\n",solid_id);
		exit(0);
	}
	x = target_cel->ccb_XPos;
	y = target_cel->ccb_YPos;
	memcpy(target_cel,source_cel,sizeof(CCB));
	target_cel->ccb_XPos = x;
	target_cel->ccb_YPos = y;
}

/***************************  solids::TransformSolid  ***********************************
   This function is pretty specific to Icebreaker. It randomly selects an object from
the inanimates database and then, if the object still exists, it alters it in some way.
Once this function has succeeded in altering an object somewhere on the list, it waits
a little while before changing something else.
*****************************************************************************************/

bool  solids::TransformSolid(void)
{
	register solid_object    *traversal_ptr;
	static   struct timeval  old_time;
	int32	                   solid_to_transform;
	int32							 index_into_solids_list;

	/* if less than a second has elapsed since the last time we did one, do nothing. */
	DoIO(timer_request_item,&timer_request_info);
	if (!(  ((old_time.tv_sec + PYRAMID_POP_DELAY <= current_time.tv_sec)
	      && (old_time.tv_usec <= current_time.tv_usec))
	  || (old_time.tv_sec + PYRAMID_POP_DELAY + 1 <= current_time.tv_sec)))
		return(FALSE);
	
	/* Now, pick a number between 1 and the total supply of static pyramids. Then work */
	/* through the list, counting only static pyramids, until we get to the Xth one.   */
	solid_to_transform = RandomNumber(1,196);
	if (solid_to_transform > g_total_pyramids)
		return(FALSE);
	index_into_solids_list = 1;
	traversal_ptr = solids_list;
	while (traversal_ptr != (solid_object *) NULL)
	{		
		if ((traversal_ptr->object_type >= FIRST_STATIC_PYRAMID)
		 && (traversal_ptr->object_type <= LAST_STATIC_PYRAMID))
		{
			if (index_into_solids_list == solid_to_transform)
				break;
			index_into_solids_list++;
		}
		traversal_ptr = traversal_ptr->next;
	}
	
	/* If the traversal pointer is NULL at this point, then it means we got to the end  */
	/* of the list without finding the Xth object, which in turn means that no more     */
	/* static pyramids remain or that our calcuations were incorrect.                   */
	if (traversal_ptr == (solid_object *) NULL)
		return(FALSE);

	if (traversal_ptr->object_type == RED_PYRAMID)
	{
		traversal_ptr->object_type = BLUE_PYRAMID;
		ChangeArt(traversal_ptr->cel, BLUE_PYRAMID);
		old_time.tv_sec  = current_time.tv_sec;
		old_time.tv_usec = current_time.tv_usec;
		return(TRUE);
	}
	else if (traversal_ptr->object_type == GREEN_PYRAMID)
	{
		traversal_ptr->object_type = RED_PYRAMID;
		ChangeArt(traversal_ptr->cel, RED_PYRAMID);
		old_time.tv_sec  = current_time.tv_sec;
		old_time.tv_usec = current_time.tv_usec;
		return(TRUE);
	}
	else if (traversal_ptr->object_type == BLUE_PYRAMID)
	{
		traversal_ptr->object_type = GREEN_PYRAMID;
		ChangeArt(traversal_ptr->cel, GREEN_PYRAMID);
		old_time.tv_sec  = current_time.tv_sec;
		old_time.tv_usec = current_time.tv_usec;
		return(TRUE);
	}

	/* if we get here, then the Xth object wasn't one of the 3 that we can transform. */
	return(FALSE);
}

/*****************************  solids::DumpList  ***************************************
   This function is used solely for testing and debug purposes. It dumps out a list of
solids (it can be either the solids list or the trash can).
*****************************************************************************************/

void  solids::DumpList(solid_object	*list_to_be_dumped)
{
	solid_object	*traversal_ptr;

	traversal_ptr = list_to_be_dumped;
	while (traversal_ptr != (solid_object *) NULL)
	{
		switch(traversal_ptr->object_type)
		{
			case YELLOW_PYRAMID:		printf("yellow ");  	break;
			case LTBLUE_PYRAMID:		printf("ltblue ");  	break;
			case PINK_PYRAMID:		printf("pink ");  	break;
			case LIME_PYRAMID: 		printf("lime ");  	break;
			case YELLOW_SEEKER:     printf("YELLOW\n");  break;
			case LTBLUE_SEEKER:    	printf("LTBLUE\n");  break;
			case PINK_SEEKER:    	printf("PINK\n");  	break;
			case LIME_SEEKER:    	printf("LIME\n");  	break;
			case DORMANT_CHAMELEON:	printf("DCHAM\n");  	break;
			case WAKING_CHAMELEON:	printf("WCHAM\n");  	break;
			case ACTIVE_CHAMELEON:	printf("ACHAM\n");  	break;
			case ZOMBIE:				printf("ZOMBIE\n");  break;
			case LURKER:				printf("LURKER\n");  break;
			case MEANY:					printf("MEANY\n");  	break;
			case NASTY:					printf("NASTY\n");  	break;
			case GRUMPY:				printf("GRUMPY\n");  break;
			case PHANTOM_BOULDER:	printf("~ ");  		break;
			case BOULDER0:				printf("0 ");  		break;
			case BOULDER1:				printf("1 ");  		break;
			case BOULDER2:				printf("2 ");  		break;
			case BOULDER3:				printf("3 ");  		break;
			case BOULDER4:				printf("4 ");  		break;
			case BOULDER5:				printf("5 ");  		break;
			case BOULDER6:				printf("6 ");  		break;
			case BOULDER7:				printf("7 ");  		break;
			case BOULDER8:				printf("8 ");  		break;
			case BOULDER9:				printf("9 ");  		break;
			case BOULDERA:				printf("A ");  		break;
			case BOULDERD:				printf("D ");  		break;
			case DUDEMEYER:			printf("DM\n");  		break;
			case NOTHING:				printf("-\n");  		break;
			case BLUE_PYRAMID:		printf("B ");   		break;
			case RED_PYRAMID:   		printf("R ");   		break;
			case GREEN_PYRAMID:  	printf("G ");   		break;
			case RAINBOW_PYRAMID:  	printf("T ");   		break;
			case CONCRETE_PYRAMID:  printf("C ");   		break;
			case PURPLE_PYRAMID: 	printf("P ");   		break;
			case BIRTH_SCENE:    	printf("BIRTH\n");  	break;
			case DEATH_SCENE:    	printf("DEATH\n");  	break;
			case SPLIT_SCENE:    	printf("SPLIT\n");  	break;
			default:             	printf("???????\n");	break;
		}
		traversal_ptr = traversal_ptr->next;
	}
	printf("\n");
	printf("==========================================================================\n");
}

/**************************  solids::CreateAnimatedSolid  ********************************
	Since animated solids require constant maintenance in order to keep up their ever 
changing appearance, we maintain a list of the animated solids in the population so as to 
avoid wasting time searching through the entire list of solid objects just to find out 
which ones have animations.
	This function adds a new object to the list of animated solids and initializes the 
solid by linking the data structure to the master copy of the solid's animation, as 
provided in the parameters list.
*****************************************************************************************/

void  solids::CreateAnimatedSolid (anim_source *original, int32 frame_rate,
											  solid_object *solids_entry, bool endless_value)
{
	int32 i,j;
	anisolid  *new_anisolid;

	new_anisolid = new(anisolid);
	new_anisolid->solid_anim.InitializeAnim (original, frame_rate);		
	new_anisolid->endless = endless_value;
	new_anisolid->solids_entry = solids_entry;
	new_anisolid->solid_anim.Restart();
	new_anisolid->next = anisolid_list;
	anisolid_list = new_anisolid;

	if (solids_entry->object_type == RAINBOW_PYRAMID)
	{
		j = RandomNumber(1,18);
		for (i = 0; i <= j; i++)
			new_anisolid->solid_anim.AdvanceFrame();
	}

	if (solids_entry->object_type == CONCRETE_PYRAMID)
		new_anisolid->solid_anim.AdvanceFrame();

	i = solids_entry->cel->ccb_XPos;
	j = solids_entry->cel->ccb_YPos;
	memcpy(solids_entry->cel,new_anisolid->solid_anim.current_frame_ccb,sizeof(CCB));
	solids_entry->cel->ccb_XPos = i;
	solids_entry->cel->ccb_YPos = j;
}

/************************  solids::EliminateAnimatedObject  ******************************
   There are two versions of the EliminateAnimatedObject function. One deletes an animated 
solid from the animated solids list, based on a pointer into that list, and the other 
deletes the solid based only on a pointer to the solid object itself. The second function 
simply finds the animated solid's entry on the anisolids list and passes it along to the 
first function.
	This is the first of these functions.
*****************************************************************************************/

void  solids::EliminateAnimatedObject(anisolid  *target)
{
	anisolid  *traversal_ptr;

	/* if object is at head of list, adjust master list pointer */
	if (target == anisolid_list)
		anisolid_list = target->next;
	else
	{
		/* look through the list until we find the target, then cut it out of the list */
		traversal_ptr = anisolid_list;
		while (traversal_ptr->next != target)
			traversal_ptr = traversal_ptr->next;
		traversal_ptr->next = traversal_ptr->next->next;
	}

	/* now free up the memory used by the record */
	target->solid_anim.ShutdownForRestart();
	delete(target);
}

/************************  solids::EliminateAnimatedObject  ******************************
   There are two versions of the EliminateAnimatedObject function. One deletes an animated 
solid from the animated solids list, based on a pointer into that list, and the other 
deletes the solid based only on a pointer to the solid object itself. The second function 
simply finds the animated solid's entry on the anisolids list and passes it along to the 
first function.
	This is the second of these functions.
*****************************************************************************************/

void  solids::EliminateAnimatedObject(solid_object *target)
{
	EliminateAnimatedObject(LocateAnimatedObject(target));
}

/*************************  solids::LocateAnimatedObject  ********************************
	For those cases when someone needs to have a pointer to an animated object's animation,
this function looks through the list until it finds it.
*****************************************************************************************/

anisolid*  solids::LocateAnimatedObject(solid_object *target)
{
	anisolid  *traversal_ptr;

	traversal_ptr = anisolid_list;
	while (traversal_ptr != NULL)
	{
		if (traversal_ptr->solids_entry == target)
			return(traversal_ptr);
		traversal_ptr = traversal_ptr->next;
	}
	printf("Zorak! What have you done with that animated Object????\n");
	return((anisolid *) NULL);
}

/************************  solids::MaintainAnimatedObjects  ******************************
	This function is called just prior to displaying the set of solid objects, and it takes 
care of advancing the frame on all animated solids in the population. In addition, if any 
of the animations are one-timers, such as transformation sequences that play once and end 
with the solid taking on a new appearance, then this function handles the cleanup needed 
when an animation of this type reaches the end. 
*****************************************************************************************/

void  solids::MaintainAnimatedObjects(void)
{
	anisolid  *traversal_ptr,*destroy_me;

	traversal_ptr = anisolid_list;
	while (traversal_ptr != (anisolid *) NULL)
	{		
		if (traversal_ptr->solids_entry->cel == (CCB *) NULL)
		{
			destroy_me = traversal_ptr;
			traversal_ptr = traversal_ptr->next;
			EliminateAnimatedObject(destroy_me);
		}
		else
		{
			if ((traversal_ptr->endless) || (!(traversal_ptr->solid_anim.AnimComplete())))
			{
				/* if the scene goes on forever or it isn't over: advance frame and move on */
				if (traversal_ptr->solids_entry->object_type != CONCRETE_PYRAMID)
					traversal_ptr->solid_anim.AdvanceFrame();
				traversal_ptr->solids_entry->cel->ccb_SourcePtr
				                 = traversal_ptr->solid_anim.current_frame_ccb->ccb_SourcePtr;
				traversal_ptr->solids_entry->cel->ccb_PLUTPtr
				                 = traversal_ptr->solid_anim.current_frame_ccb->ccb_PLUTPtr;
				traversal_ptr = traversal_ptr->next;
			}
			else
			{
				/* if the scene is done and it's a one-timer: get rid of it */
				destroy_me = traversal_ptr;
				traversal_ptr = traversal_ptr->next;
				EliminateAnimatedObject(destroy_me);
			}
		}
	}
}

/****************************  solids::ConcealChameleons  ********************************
	This function is used to randomly scatter Chameleon seekers in amongst the supply of
normal green pyramids on a level. It is used only during intialization.
*****************************************************************************************/

void  solids::ConcealChameleons (int32 how_many)
{
	solid_object	*traversal_ptr;
	int32				green_supply;
	
	green_supply = 0;
	traversal_ptr = solids_list;
	while (traversal_ptr != (solid_object *) NULL)
	{
		if (traversal_ptr->object_type == GREEN_PYRAMID)
			green_supply++;
		traversal_ptr = traversal_ptr->next;
	}
	if (how_many > green_supply)
	{
		printf("Hey! What are you trying to pull?!?! That's too many chameleons!\n");
		how_many = green_supply / 2;
	}

	while (how_many)
	{
		if (traversal_ptr == (solid_object *) NULL)
			traversal_ptr = solids_list;
		if ((traversal_ptr->object_type == GREEN_PYRAMID)
		 && (!(enemies.CheckChameleonProximity(traversal_ptr->cel))))
		{
			if (RandomNumber(1,100) == 1)
			{
				enemies.CreateSeeker(DORMANT_CHAMELEON, traversal_ptr->cel->ccb_XPos,
											traversal_ptr->cel->ccb_YPos, NO_DIRECTION);
				EliminateObject(traversal_ptr);
				traversal_ptr = solids_list;
				how_many--;
				green_supply--;
			}
		}
		traversal_ptr = traversal_ptr->next;
	}
}

/*************************  solids::ResolveRainbowPyramid  *******************************
	This function randomly determines what type of piece a Rainbow pyramid really is. The
types of pieces it can legitimately become is determined by the g_art_usage table. If a
given type of seeker is not in use on the level, then that type of seeker will be invalid
for a Rainbow piece option.
*****************************************************************************************/

void  solids::ResolveRainbowPyramid (solid_object *target)
{
	int16	seekers_available,decision;
	
	seekers_available = 0;
	
	if (enemies.Loaded(LIME_SEEKER))		seekers_available++;
	if (enemies.Loaded(YELLOW_SEEKER))	seekers_available++;
	if (enemies.Loaded(LTBLUE_SEEKER))	seekers_available++;
	if (enemies.Loaded(PINK_SEEKER))		seekers_available++;
	if (enemies.Loaded(LURKER))			seekers_available++;

	if (seekers_available > 2)
		decision = (int16) RandomNumber(0,3 + seekers_available);
	else
		decision = (int16) RandomNumber(0,5);

	switch(decision)
	{
		case 0:	target->object_type = BLUE_PYRAMID;		return;
		case 1:	target->object_type = RED_PYRAMID;		return;
		case 2:	target->object_type = GREEN_PYRAMID;	return;
		case 3:	target->object_type = PURPLE_PYRAMID;	return;
	}

	if (seekers_available == 0)
	{
		target->object_type = RED_PYRAMID;
		return;
	}
	
	while (target->object_type == RAINBOW_PYRAMID)
	{
		target->object_type = RandomNumber(YELLOW_PYRAMID,LIME_PYRAMID);
		if (((target->object_type == LIME_PYRAMID)   && (!(enemies.Loaded(LIME_SEEKER))))
		 || ((target->object_type == YELLOW_PYRAMID) && (!(enemies.Loaded(YELLOW_SEEKER))))
		 || ((target->object_type == LTBLUE_PYRAMID) && (!(enemies.Loaded(LTBLUE_SEEKER))))
		 || ((target->object_type == PINK_PYRAMID)   && (!(enemies.Loaded(PINK_SEEKER))))
		 || ((target->object_type == LURKER_PYRAMID) && (!(enemies.Loaded(LURKER)))))
			target->object_type = RAINBOW_PYRAMID;
	}
}

/***********************  solids::RegisterRocksWithLandscape  ****************************
   This function is used only during initialization. It traverses the entire solids list
and tells a function within the landscape class about each rock it encounters. This is
done for the benefit of seekers who wish an easy list of rocks which they will regard as
hazards for the purpose of efficient avoidance.
*****************************************************************************************/

void  solids::RegisterRocksWithLandscape (void)
{
	register solid_object	*traversal_ptr;

	traversal_ptr = solids_list;
	while (traversal_ptr != (solid_object *) NULL)
	{
		if ((traversal_ptr->object_type >= FIRST_BOULDER)
		 && (traversal_ptr->object_type <= LAST_BOULDER))
			pavement.RegisterRockyTile(traversal_ptr->cel);
		traversal_ptr = traversal_ptr->next;
	}
}

/*************************  solids::CheckForPotentialPits  ******************************
   This function is used only during initialization. It traverses the entire solids list
and makes sure that for all tiles that have purple or rainbow pieces on them, the correct
pit transformation anim is loaded into memory.
*****************************************************************************************/

void  solids::CheckForPotentialPits (void)
{
	register solid_object	*traversal_ptr;

	traversal_ptr = solids_list;
	while (traversal_ptr != (solid_object *) NULL)
	{
		if ((traversal_ptr->object_type == PURPLE_PYRAMID)
		 || (traversal_ptr->object_type == RAINBOW_PYRAMID))
			pavement.LoadPitFormation(traversal_ptr->cel);
		traversal_ptr = traversal_ptr->next;
	}
}

/*************************  solids::ShutdownForRestart  *********************************
   When a game ends, the player will either wish to quit or play again. In either case,
this function should be called to surrender memory that was dynamically allocated during
the game. Needless to say, it is particularly important that this function be called
whenever a game is to be replayed; otherwise the memory that was allocated will be lost
track of and wasted.
*****************************************************************************************/

void  solids::ShutdownForRestart()
{
	anisolid   		*anisolid_traversal,  *anisolid_vanguard;
	int32 i,j;

	/******  throw away all solids  ******/
	EmptyTrash();
	trash_can = solids_list;
	EmptyTrash();

	/****** deallocate all memory used by solids CCBs ******/
	for (i = 0; i < ROWS_IN_LANDSCAPE; i++)
		for (j = 0; j < COLUMNS_IN_LANDSCAPE; j++)
			delete(inanimates_cel_database[i][j]);

	/***** recover all memory used by animated solids *****/
	anisolid_traversal = anisolid_list;
	while (anisolid_traversal != (anisolid *) NULL)
	{
		anisolid_vanguard = anisolid_traversal->next;
		anisolid_traversal->solid_anim.ShutdownForRestart();
		delete(anisolid_traversal);
		anisolid_traversal = anisolid_vanguard;
	}
}

/**************************  solids::ShutdownForExit  ***********************************
   This function deallocates memory that was reserved for storage of artwork elements
that are used repeatedly over a sequence of many games. This function should be called
only when the program is about to be shutdown for good.
*****************************************************************************************/

void  solids::ShutdownForExit()
{
	if (red_piece_cel != NULL)    UnloadCel(red_piece_cel);
	if (blue_piece_cel != NULL)	UnloadCel(blue_piece_cel);
	if (green_piece_cel != NULL)	UnloadCel(green_piece_cel);
	if (purple_piece_cel != NULL)	UnloadCel(purple_piece_cel);
	if (boulder0_cel != NULL)		UnloadCel(boulder0_cel);
	if (boulder1_cel != NULL)		UnloadCel(boulder1_cel);
	if (boulder2_cel != NULL)		UnloadCel(boulder2_cel);
	if (boulder3_cel != NULL)		UnloadCel(boulder3_cel);
	if (boulder4_cel != NULL)		UnloadCel(boulder4_cel);
	if (boulder5_cel != NULL)		UnloadCel(boulder5_cel);
	if (boulder6_cel != NULL)		UnloadCel(boulder6_cel);
	if (boulder7_cel != NULL)		UnloadCel(boulder7_cel);
	if (boulder8_cel != NULL)		UnloadCel(boulder8_cel);
	if (boulder9_cel != NULL)		UnloadCel(boulder9_cel);
	if (boulderA_cel != NULL)		UnloadCel(boulderA_cel);
	if (boulderD_cel != NULL)		UnloadCel(boulderD_cel);
	rainbow_piece_anim.ShutdownForExit();
	concrete_piece_anim.ShutdownForExit();
	blue_death.ShutdownForExit();
	red_death.ShutdownForExit();
	purple_death.ShutdownForExit();
	green_death.ShutdownForExit();
	concrete_death.ShutdownForExit();
	concrete_puff[0].ShutdownForExit();
	concrete_puff[1].ShutdownForExit();
	concrete_puff[2].ShutdownForExit();
}

/*************************  landscape::ShutdownUnusedArtwork  ****************************
	This function examines all of the art elements used by this class and gets rid of any
that are not currently needed, thus freeing up the memory this art was consuming for more
worthwhile causes. The way in which we know whether or not a piece of art is needed is
by examining the values in the global art usage table (g_art_usage). This table is filled
out by the function LoadLevel as the level parameters are parsed. Anything that isn't
set to TRUE in this table will not be needed during this level and can therefore safely
be discarded.
*****************************************************************************************/

void solids::ShutdownUnusedArtwork(void)
{

	if ((red_piece_cel != NULL) && (g_art_usage[RED_PYRAMID] == FALSE))
	{
		UnloadCel(red_piece_cel);
		red_piece_cel = (CCB *) NULL;
		red_death.ShutdownForExit();
	}
	if ((blue_piece_cel != NULL) && (g_art_usage[BLUE_PYRAMID] == FALSE))
	{
		UnloadCel(blue_piece_cel);
		blue_piece_cel = (CCB *) NULL;
		blue_death.ShutdownForExit();
	}
	if ((green_piece_cel != NULL) && (g_art_usage[GREEN_PYRAMID] == FALSE))
	{
		UnloadCel(green_piece_cel);
		green_piece_cel = (CCB *) NULL;
		green_death.ShutdownForExit();
	}
	if ((purple_piece_cel != NULL) && (g_art_usage[PURPLE_PYRAMID] == FALSE))
	{
		UnloadCel(purple_piece_cel);
		purple_piece_cel = (CCB *) NULL;
		purple_death.ShutdownForExit();
	}
	if ((boulder0_cel != NULL) && (g_art_usage[BOULDER0] == FALSE))
	{
		UnloadCel(boulder0_cel);
		boulder0_cel = (CCB *) NULL;
	}
	if ((boulder1_cel != NULL) && (g_art_usage[BOULDER1] == FALSE))
	{
		UnloadCel(boulder1_cel);
		boulder1_cel = (CCB *) NULL;
	}
	if ((boulder2_cel != NULL) && (g_art_usage[BOULDER2] == FALSE))
	{
		UnloadCel(boulder2_cel);
		boulder2_cel = (CCB *) NULL;
	}
	if ((boulder3_cel != NULL) && (g_art_usage[BOULDER3] == FALSE))
	{
		UnloadCel(boulder3_cel);
		boulder3_cel = (CCB *) NULL;
	}
	if ((boulder4_cel != NULL) && (g_art_usage[BOULDER4] == FALSE))
	{
		UnloadCel(boulder4_cel);
		boulder4_cel = (CCB *) NULL;
	}
	if ((boulder5_cel != NULL) && (g_art_usage[BOULDER5] == FALSE))
	{
		UnloadCel(boulder5_cel);
		boulder5_cel = (CCB *) NULL;
	}
	if ((boulder6_cel != NULL) && (g_art_usage[BOULDER6] == FALSE))
	{
		UnloadCel(boulder6_cel);
		boulder6_cel = (CCB *) NULL;
	}
	if ((boulder7_cel != NULL) && (g_art_usage[BOULDER7] == FALSE))
	{
		UnloadCel(boulder7_cel);
		boulder7_cel = (CCB *) NULL;
	}
	if ((boulder8_cel != NULL) && (g_art_usage[BOULDER8] == FALSE))
	{
		UnloadCel(boulder8_cel);
		boulder8_cel = (CCB *) NULL;
	}
	if ((boulder9_cel != NULL) && (g_art_usage[BOULDER9] == FALSE))
	{
		UnloadCel(boulder9_cel);
		boulder9_cel = (CCB *) NULL;
	}
	if ((boulderA_cel != NULL) && (g_art_usage[BOULDERA] == FALSE))
	{
		UnloadCel(boulderA_cel);
		boulderA_cel = (CCB *) NULL;
	}
	if ((boulderD_cel != NULL) && (g_art_usage[BOULDERD] == FALSE))
	{
		UnloadCel(boulderD_cel);
		boulderD_cel = (CCB *) NULL;
	}
	if (g_art_usage[RAINBOW_PYRAMID] == FALSE)
	{
		rainbow_piece_anim.ShutdownForExit();
	}
	if (g_art_usage[CONCRETE_PYRAMID]==FALSE)
	{
		concrete_piece_anim.ShutdownForExit();
		concrete_death.ShutdownForExit();
		concrete_puff[0].ShutdownForExit();
		concrete_puff[1].ShutdownForExit();
		concrete_puff[2].ShutdownForExit();
	}
	ScavengeMem();
}

/**************************************** EOF *******************************************/