#define FILENAME "box.3ds"
#include <stdio.h>
#include <fstream.h>
#include "3dschunks.h"


void output(char *string)
{
  FILE *fp;
  fp = fopen("fileinfo.txt","a+");
  fprintf(fp,"%s",string);
  fclose(fp);
}

struct stChunk
{
  unsigned short ID;
  unsigned int length;
  unsigned int bytesRead;
};

void ReadChunk(FILE*fp,stChunk *pChunk)
{
  unsigned short ID         = 0;
  unsigned int bytesRead    = 0;
  unsigned int bChunkLength = 0;

  bytesRead  = fread(&ID,1,2,fp);
  bytesRead += fread(&bChunkLength,1,4,fp);

  pChunk->ID        = ID;
  pChunk->length    = bChunkLength;
  pChunk->bytesRead = bytesRead;
}

void SkipChunk(FILE*fp,stChunk *pChunk)
{
  int buffer[50000] = {0};
  fread(buffer,1,pChunk->length - pChunk->bytesRead,fp);
}

void DisplayChunkInfo(stChunk* pChunk)
{
  char buf[1000] = {0};
  sprintf(buf, "Chunk ID: 0x %04x   Size of Chunk: %u\n", pChunk->ID, pChunk->length);
  output(buf);
}

void ReadKEYF3DS(FILE *fp, stChunk* Chunk)
{
  while(Chunk->bytesRead < Chunk -> length){
   stChunk tempChunk = {0};
   ReadChunk(fp, &tempChunk);
   DisplayChunkInfo(&tempChunk);
   
   switch(tempChunk.ID){
   default:
	SkipChunk(fp,&tempChunk);
   }
  Chunk->bytesRead += tempChunk.length;
 }
}
/*
read the actual object stuff
*/
void ReadVerticesMESH_FACES(FILE *fp,stChunk* Chunk)
{
  unsigned int iNumberFaces = 0; //= Chunk->length -6;
  Chunk->bytesRead += fread(&iNumberFaces,1,2,fp);

  char buff[100];
  sprintf(buff, "Number of Faces %u\n", iNumberFaces);
  output(buff);
  struct stFace{unsigned short p1,p2,p3;};
  stFace *pFaces = new stFace[iNumberFaces];

  Chunk->bytesRead += fread(pFaces,1,iNumberFaces* sizeof(stFace),fp);
  for(int i=0; i<iNumberFaces;i++)
  {
    sprintf(buff, "\t Face:  Index1: %d, Index2: %d, Index3 %d\n",pFaces[i].p1, pFaces[i].p2, pFaces[i].p3);
    output(buff);
  }
  delete pFaces;
  SkipChunk(fp,Chunk);
}

void ReadVerticesMESH_VERTICES(FILE *fp,stChunk* Chunk)
{
  unsigned int iNumberVertices = 0;
  Chunk->bytesRead += fread(&iNumberVertices,1,2,fp);

  //xyz
  char buff[300];
  sprintf(buff, "Number of Vertices %d\n", iNumberVertices);
  output(buff);

  struct stVect{float x,y,z;};
  stVect *pVerts = new stVect[iNumberVertices];
  Chunk->bytesRead += fread( (void*)pVerts, 1, iNumberVertices*sizeof(stVect), fp);
  for(int i=0; i<iNumberVertices; i++)
  {
    sprintf(buff, "\t Vertices Point: x: %.2f, \ty: %.2f, \tz: %.2f\n",pVerts[i].x, pVerts[i].y, pVerts[i].z);
    output(buff);
  }
  delete[] pVerts;
  SkipChunk(fp,Chunk);
}

void LoadMeshOBJ_MESH(FILE *fp,stChunk* Chunk)
{
  output("\n");

  while(Chunk->bytesRead < Chunk->length){
   stChunk tempChunk = {0};
   ReadChunk(fp,&tempChunk);
   DisplayChunkInfo(&tempChunk);

    switch(tempChunk.ID){
     case MESH_VERTICES:
	ReadVerticesMESH_VERTICES(fp,&tempChunk);
     break;

     case MESH_FACES:
	ReadVerticesMESH_FACES(fp, &tempChunk);
     break;

     default:
	SkipChunk(fp,&tempChunk);
     }
  Chunk->bytesRead += tempChunk.length;
 }
}
/*
get object data
*/
int GetString(FILE *fp)
{
  int index = 0;
  char buffer[100] = {0};
  fread(buffer,1,1,fp);

  while(*(buffer + index++) != 0){
   fread(buffer+index,1,1,fp);
  }
  output(buffer);
  output("\n");

 return(strlen(buffer)+1);
}

void ReadNAMED_OBJECT(FILE *fp,stChunk* Chunk)
{
  output("\n");
  unsigned int characterlen = GetString(fp);
  Chunk->bytesRead += characterlen;

  while(Chunk->bytesRead < Chunk->length){
   stChunk tempChunk = {0};
   ReadChunk(fp,&tempChunk);
   DisplayChunkInfo(&tempChunk);

   switch(tempChunk.ID)
   {
    case OBJ_MESH:
	LoadMeshOBJ_MESH(fp,&tempChunk);
    break;
    default:
	SkipChunk(fp,&tempChunk);
    }
   Chunk->bytesRead += tempChunk.length;
  }
}

void ReadEDIT3DS(FILE *fp, stChunk* Chunk)
{
  output("\n");
  while(Chunk->bytesRead < Chunk->length){
  stChunk tempChunk = {0};
  ReadChunk(fp, &tempChunk);
  DisplayChunkInfo(&tempChunk);
  
  switch(tempChunk.ID){
  case NAMED_OBJECT:
	ReadNAMED_OBJECT(fp, &tempChunk);
  break;
  default:
	SkipChunk(fp,&tempChunk);
  }

  Chunk-> bytesRead += tempChunk.length;
  }
}
/*
read 3ds file
*/
void read3ds()
{
  FILE* pFile;
  pFile = fopen(FILENAME,"rb");
  stChunk Chunk = {0};
  ReadChunk(pFile,&Chunk);
  DisplayChunkInfo(&Chunk);

  while(Chunk.bytesRead< Chunk.length)
  {
   stChunk tempChunk = {0};
   ReadChunk(pFile, &tempChunk);
   DisplayChunkInfo(&tempChunk);

   unsigned int bytesRead=0;

   switch(tempChunk.ID){
    case EDIT3DS:
	ReadEDIT3DS(pFile,&tempChunk);
	bytesRead = tempChunk.length;
    break;

    case KEYF3DS:
	ReadKEYF3DS(pFile,&tempChunk);
	bytesRead = tempChunk.length;
    break;

    default:
	SkipChunk(pFile,&tempChunk);
	bytesRead = tempChunk.length;
    }
   Chunk.bytesRead += bytesRead;
  }
 fclose(pFile);
}



//
OUTPUT!
//

Chunk ID: 0x 4d4d   Size of Chunk: 355
Chunk ID: 0x 0002   Size of Chunk: 10
Chunk ID: 0x 3d3d   Size of Chunk: 339

Chunk ID: 0x afff   Size of Chunk: 66
Chunk ID: 0x 4000   Size of Chunk: 267

0Cube
Chunk ID: 0x 4100   Size of Chunk: 255

Chunk ID: 0x 4110   Size of Chunk: 104
Number of Vertices 8
	 Vertices Point: x: 1.00, 	y: 1.00, 	z: 0.18
	 Vertices Point: x: 1.00, 	y: -1.00, 	z: 0.18
	 Vertices Point: x: -1.00, 	y: -1.00, 	z: 0.18
	 Vertices Point: x: -1.00, 	y: 1.00, 	z: 0.18
	 Vertices Point: x: 1.00, 	y: 1.00, 	z: 2.18
	 Vertices Point: x: 1.00, 	y: -1.00, 	z: 2.18
	 Vertices Point: x: -1.00, 	y: -1.00, 	z: 2.18
	 Vertices Point: x: -1.00, 	y: 1.00, 	z: 2.18
Chunk ID: 0x 4120   Size of Chunk: 145
Number of Faces 12
	 Face:  Index1: 0, Index2: 1, Index3 2
	 Face:  Index1: 0, Index2: 0, Index3 2
	 Face:  Index1: 3, Index2: 0, Index3 4
	 Face:  Index1: 7, Index2: 6, Index3 0
	 Face:  Index1: 4, Index2: 6, Index3 5
	 Face:  Index1: 0, Index2: 0, Index3 4
	 Face:  Index1: 5, Index2: 0, Index3 0
	 Face:  Index1: 5, Index2: 1, Index3 0
	 Face:  Index1: 1, Index2: 5, Index3 6
	 Face:  Index1: 0, Index2: 1, Index3 6
	 Face:  Index1: 2, Index2: 0, Index3 2
	 Face:  Index1: 6, Index2: 7, Index3 0