//----------------------------------------------------------------------------
// File: UP3D.h
// Version: 2.0
// Class: Universal Pipeline 3D
// Type: 3D Object
// Author: Ken Anderson
// Date: 3/19/04
// OS dependant: NA
// Desc: The universal pipeline 3d is a link list that acts like a pipeline supplying
//       either 3d renderer with vertices, matricies, render states, lighting
//		 objects and so forth.
//
// Notes: A class was not used here to keep the overhead down as much as 
//		  possible.  In addition, multiple pipelines are not required, thus
//		  one set of global static variables are needed rather than defining
//		  a class for multiple pipelines.
//
// IMPORTANT WARNING:
//	 -Note: Always initialize the pipeline before using it as well as cleaning
//			it up once the 3d management system has completed using it.  Failure
//			to initialize this system will return an error code.  See below.
//			Failure to clean up will leave memory hanging in the system.
//  
//   -NOTE2: The pipeline uses what is referred to as a reverse pipeline, please
//			 see notes in the R-Pipelin.txt file.
//
// Version 2.0 -- Updated 10/11/04 to protect against a tail & head bug that would
//				  leave these special pointers invalid and not set them null.
//
// Required headers: <Headers that are required in numerical order and why>
//	1) C3DTypes.h -- Contains structures, and enumations the class relies on.
//
//----------------------------------------------------------------------------

//Prevent redefinition
#ifndef __UP3D__
#define __UP3D__

#include "C3DTypes.h"

///////////////////////////////////
//        ENUMS                  //
///////////////////////////////////
//Types used for the universal packets being sent throught
//the rendering pipeline.
typedef enum UNIVERSAL_PACKET_TYPE
{
	UPT_UNKNOWN,
	UPT_VERTEX,
	UPT_RENDERSTATE,
	UPT_TSS,
	UPT_MATRIX,
	UPT_LIGHT,
	UPT_MATERIAL,
	UPT_TEXTURE
} UPT;

/////////////////////////////////////////////////////////////////////////
//								UNIVERSAL PACKET					   //
/////////////////////////////////////////////////////////////////////////
//The special packet is used to hold an array of void pointers with a 
//field that specifies the amount of pointers.
typedef struct SPECIAL_BUFFER_PACKET
{
	void** vhBuffers;
	Dword  dwBufferNum;
} SPECIALBP, *PSPECIALBP;

//The universal packet is designed to be the main element used in the 
//rendering pipeline allowing blocks & packets to be used by the renderer
//in the order specified by the programmer.
typedef struct UNIVERSAL_PACKET
{
	void*     pPacket;
	void*     pHead;
	void*	  pTail;
	UPT		  type;
	UNIVERSAL_PACKET* Next;
	UNIVERSAL_PACKET* Prev;
} SC3DUniversal, *PSC3DUniversal, **HSC3DUniversal;

//Pipeline pointers.
static PSC3DUniversal UP3Dm_pPHead, UP3Dm_pPTail, UP3Dm_pPCurr;
static bool UP3Dm_bInited = false;
static bool UP3Dm_bEmpty;

///////////////////////////////////
//          FUNCTIONS            //
///////////////////////////////////
//Init.
void UP3D_Init();
void UP3D_Cleanup();
//void UP3D_DeleteTypes(SC3DUniversal* pDel);
C3DERR UP3D_EmptyPipe();
C3DERR UP3D_InitChk();

//Create New Element
PSC3DUniversal UP3D_CreateTopUniversalElement(void* pPacket=NULL, UPT type=UPT_UNKNOWN);
PSC3DUniversal UP3D_CreateCurrentUniversalElement(void* pPacket=NULL, UPT type=UPT_UNKNOWN);
PSC3DUniversal UP3D_CreateUniversalElement(void* pPacket, UPT type, HSC3DUniversal pLoc);

//Delete element.
C3DERR UP3D_DeleteTopUniversalElement();
C3DERR UP3D_DeleteCurrentUniversalElement();
C3DERR UP3D_DeleteUniversalElement(PSC3DUniversal pLoc);

//Set the details.
C3DERR UP3D_SetCurrentPacket(void* pPacket, UPT type);
C3DERR UP3D_SetCurrentHead(void* pHead);
C3DERR UP3D_SetCurrentTail(void* pTail);

//Current pointer settings.
C3DERR UP3D_SetCurrentToHead();
C3DERR UP3D_SetCurrentToTail();
C3DERR UP3D_SetCurrent(PSC3DUniversal pCurr);

//Set details of specified packet
C3DERR UP3D_SetPacket(PSC3DUniversal pCurr, void* pPacket, UPT type);
C3DERR UP3D_SetPacketOnly(PSC3DUniversal pCurr, void* pPacket);
C3DERR UP3D_SetHead(PSC3DUniversal pCurr, void* pHead);
C3DERR UP3D_SetTail(PSC3DUniversal pCurr, void* pTail);

//Return Current details.
void* UP3D_ReturnCurrentPacket();
UPT UP3D_ReturnCurrentType();
void* UP3D_ReturnCurrentHead();
void* UP3D_ReturnCurrentTail();

PSC3DUniversal UP3D_ReturnPipelineHead();
PSC3DUniversal UP3D_ReturnPipelineTail();
PSC3DUniversal UP3D_ReturnPipelineCurr();

#endif