/**********************
height.c
**********************/

#include "addrs.h"
#include "height.h"
#include <stdio.h>
#include <stdlib.h>
#include "arctan.h"

// create a dynamic TMD for a tile/cell.
u_long CreateTileTMD(long h1, long h2, long h3, long h4)
{
	static u_long firstStart=0;
	u_long returnValue;

	// set position of vertices
	TMD_setVERTEX(&currentMap->tile[0].vert[0], -TILE_LENGTH, h1, TILE_WIDTH);
	TMD_setVERTEX(&currentMap->tile[0].vert[1],  TILE_LENGTH, h2, TILE_WIDTH);
	TMD_setVERTEX(&currentMap->tile[0].vert[2],  TILE_LENGTH, h3,-TILE_WIDTH);
	TMD_setVERTEX(&currentMap->tile[0].vert[3], -TILE_LENGTH, h4,-TILE_WIDTH);

	// set colour to be used.
	TMD_setCOLOUR(&currentMap->tile[0].col[0], 255,255,0);
	TMD_setCOLOUR(&currentMap->tile[0].col[1], 255,0,0);
	TMD_setCOLOUR(&currentMap->tile[0].col[2], 0,255,0);
	TMD_setCOLOUR(&currentMap->tile[0].col[3], 0,255,255);

	if(firstStart == 0)
	{
		TMD_prepare(FREE_MEM, &currentMap->tile[0].vert[0], 
					&currentMap->tile[0].col[0],0);
		firstStart = 1;
	}
	else
	{
		TMD_prepare(0, &currentMap->tile[0].vert[0], 
					&currentMap->tile[0].col[0],0);
	}

	//create face (0,1,3,2,0,1,2,3)2,3
	// 1,3,2,1,2,3
	TMD_set3_NS_GP(0,1,2,0,1,3);
	TMD_set3_NS_GP(2,3,0,3,2,0);

	// finish
	returnValue = TMD_finish();
	return(returnValue);
}

// Creates a model for a TMD.
void CreateTileModels()
{
    long index,x=0,z=0;

    for(index = 0; index < currentMap->MapArea; index++)
    {
      InitialiseModel(&currentMap->tileModel[index],x*(TILE_LENGTH<<1),0,
			z*(TILE_WIDTH<<1),currentMap->DYNAMIC_TMD[index]);

      // Use first TMDS co-ordinate system.
      if(index !=0)currentMap->tileModel[index].Object_Coord.super = 
				&currentMap->tileModel[0].Object_Coord;

      if(++x >= currentMap->MapLength){ z++; x=0; }
    }
}

// setup map by creating a TMD and a height field entry
// for each and every tile/cell.
void SetupMap()
{
	long index,x=0,z=0;

	//create TMDs
	for(index=0; index < currentMap->MapArea; index++)
	{
	   currentMap->DYNAMIC_TMD[index] =
			(u_long*) CreateTileTMD(currentMap->heightFields[x][z+1],
						currentMap->heightFields[x+1][z+1],
						currentMap->heightFields[x+1][z],
						currentMap->heightFields[x][z]);
	   if(++x >= currentMap->MapLength){ z++; x=0; }
	}

	// setup models
	CreateTileModels();
}

//Rotate the whole map around cell 0,0.
void RotateMap(long x, long y, long z)
{
	RotateModelMatrix(&currentMap->tileModel[0],x,y,z);
}

// Draw every bit of the height field map.
void DrawMap()
{
	long index;

	// may need to roll out for more speed if possible.
	for(index=0; index < currentMap->MapArea; index++)
	{
		DrawObject(&currentMap->tileModel[index]);
	}
}

// Find a height from world co-ordinates by translating them
// to cell co-ordinates.
long FindHeight(long rx,long rz)
{
   long h1,h2,h3,h4,cellx,cellz;
   long offsetX,offsetZ;
   long height1;
   long height2;
   long heightTotal;

   // calculate cell position from actual positon here
   // so its not calulated more then once.
   cellx = (rx+TILE_LENGTH) / (TILE_LENGTH<<1);
   cellz = (rz+TILE_WIDTH) / (TILE_WIDTH<<1);

   // derefernce heights to be used.
   h1 = currentMap->heightFields[cellx][cellz];
   h2 = currentMap->heightFields[cellx+1][cellz]; 
   h3 = currentMap->heightFields[cellx][cellz+1];
   h4 = currentMap->heightFields[cellx+1][cellz+1];

   // calculate offset of position (same as cells, done here
   // to reduce calculations).
   offsetX =  (rx+TILE_LENGTH) % (TILE_LENGTH<<1);
   offsetZ =  (rz+TILE_WIDTH) % (TILE_WIDTH<<1);

  // calculate X heights
  height1=(long)((h1*((TILE_LENGTH<<1)-offsetX)) + (h2 * offsetX))/(TILE_LENGTH<<1);
  height2=(long)((h3*((TILE_LENGTH<<1)-offsetX)) + (h4 * offsetX))/(TILE_LENGTH<<1);

  // calculate Z height
  heightTotal=(long)((height1 * ((TILE_WIDTH<<1)-offsetZ)) + (height2 * offsetZ))/(TILE_WIDTH<<1);

  return (heightTotal);	
}


// Rotation between to heights. 

// *****   bugs galore here !!!!! *********

long FindRotation(long height1, long height2, long length)
{
	register int delta, delta2;  

	// If heights the same exit as there is no slope
	if(height1==height2) return(0);

	// If front higher then the back
	if(height1 > height2)
	{
		// first delta is the difference between the heights.
		delta= (height1 - height2);
		//uses advanced atan function which is very fast
		delta2=rinvtan(length, delta);		
		return ((long)(delta2 & 4095)); 	
	
	} // If the front is lower then the back
	else
	{
		delta= (height2 - height1);
		delta2=rinvtan(length, delta);	
		return ((long)4096-(delta2 & 4095));
	}
}

// Sets the current Map pointer.
void SetCurrentMap(MAP *theMap)
{
	currentMap = theMap;
}

// Sets dimensions and creates dynamic arrays
void SetDimensions(MAP *theMap,u_long NuTx,u_long ML, u_long MW)
{
   u_long index;

   // Set Dimensions etc.
   theMap->NuTextures=NuTx;
   theMap->MapLength =ML;
   theMap->MapWidth  =MW;
   theMap->MapArea   =theMap->MapLength * theMap->MapWidth;

   // Dynamically allocated memory for Arrays.
   theMap->DYNAMIC_TMD    =(u_long **)malloc (sizeof(u_long)*theMap->MapArea);
   theMap->tileModel      =(ObjectStruct *)malloc (sizeof(ObjectStruct)*theMap->MapArea);
   theMap->tile	          =(TileStruct *)malloc (sizeof(TileStruct)*theMap->MapArea);
   theMap->TEXTURE_MAPS   =(u_long **)malloc (sizeof(u_long)*theMap->NuTextures);	   
   theMap->heightFields   =(long **)malloc(sizeof(long)*(theMap->MapLength+1));	
   theMap->texturePosition=(long **)malloc(sizeof(long)*theMap->MapLength);

   // Finish allocation for grid arrays		
   for(index = 0; index < theMap->MapLength+1;index++)
   {
	theMap->heightFields[index] =(long *)malloc(sizeof(long)*(theMap->MapWidth+1));
   }
   for(index = 0; index < theMap->MapLength+1;index++)
   {
	theMap->texturePosition[index] =(long *)malloc(sizeof(long)*theMap->MapWidth);
   }
}

// set up world constraints
void SetAttributes(MAP * theMap,long grav,long fric, long wind)
{
	theMap->GRAVITY =  grav;
	theMap->FRICTION = fric;
	theMap->WIND     = wind;
}

// Accessor functions, Oh er object orientty
long getWind()     {return currentMap->WIND;}
long getFriction() {return currentMap->FRICTION;}
long getGravity()  {return currentMap->GRAVITY;}

void DestroyMap(MAP *theMap)
{
	long index;
	
	free(theMap->tileModel);
	free(theMap->tile);
	free(theMap->DYNAMIC_TMD);
	free(theMap->TEXTURE_MAPS);

	// Just to be on the safe side	
	for(index = 0; index < theMap->MapLength+1; index++)
		free(theMap->heightFields[index]);
	free(theMap->heightFields);

	for(index = 0; index < theMap->MapLength; index++)
		free(theMap->texturePosition[index]);
	free(theMap->texturePosition);
}

// This is used as a demo. Just sets a load of heights up in the heightfield array.
// nothing special here.
void SetDemoMap()
{
   SetDimensions(&map1,2,10,10);
   SetAttributes(&map1,40,2,40);

   //Set Heights
   map1.heightFields[0][0] = 0;
   map1.heightFields[0][1] = 0;
   map1.heightFields[0][2] = 0;
   map1.heightFields[0][3] = -1000;
   map1.heightFields[0][4] = 0;
   map1.heightFields[0][5] = 0;
   map1.heightFields[0][6] = 0;
   map1.heightFields[0][7] = 0;
   map1.heightFields[0][8] = 0;
   map1.heightFields[0][9] = 0;
   map1.heightFields[0][10]= 0;
   map1.heightFields[1][0] = 0;
   map1.heightFields[1][1] = 0;
   map1.heightFields[1][2] = -1000;
   map1.heightFields[1][3] = 0;
   map1.heightFields[1][4] = 0;
   map1.heightFields[1][5] = 0;
   map1.heightFields[1][6] = -1000;
   map1.heightFields[1][7] = 0;
   map1.heightFields[1][8] = 0;
   map1.heightFields[1][9] = 0;
   map1.heightFields[1][10]= 1000;
   map1.heightFields[2][0] = 0;
   map1.heightFields[2][1] = 0;
   map1.heightFields[2][2] = -1000;
   map1.heightFields[2][3] = 0;
   map1.heightFields[2][4] = 0;
   map1.heightFields[2][5] = 0;
   map1.heightFields[2][6] = -1000;
   map1.heightFields[2][7] = -1000;
   map1.heightFields[2][8] = -1000;
   map1.heightFields[2][9] = -1000;
   map1.heightFields[2][10]= -1000;
   map1.heightFields[3][0] = 0;
   map1.heightFields[3][1] = 0;
   map1.heightFields[3][2] = -1000;
   map1.heightFields[3][3] = 0;
   map1.heightFields[3][4] = 0;
   map1.heightFields[3][5] = 0;
   map1.heightFields[3][6] = -1000;
   map1.heightFields[3][7] = -2000;
   map1.heightFields[3][8] = -2000;
   map1.heightFields[3][9] = -2000;
   map1.heightFields[3][10]= 0;
   map1.heightFields[4][0] = 0;
   map1.heightFields[4][1] = 0;
   map1.heightFields[4][2] = -1000;
   map1.heightFields[4][3] = 0;
   map1.heightFields[4][4] = 0;
   map1.heightFields[4][5] = 0;
   map1.heightFields[4][6] = -3000;
   map1.heightFields[4][7] = -3000;
   map1.heightFields[4][8] = -3000;
   map1.heightFields[4][9] = -3000;
   map1.heightFields[4][10]= 0;
   map1.heightFields[5][0] = 0;
   map1.heightFields[5][1] = 0;
   map1.heightFields[5][2] = -1000;
   map1.heightFields[5][3] = 0;
   map1.heightFields[5][4] = 0;
   map1.heightFields[5][5] = 0;
   map1.heightFields[5][6] = -2000;
   map1.heightFields[5][7] = -2000;
   map1.heightFields[5][8] = -2000;
   map1.heightFields[5][9] = -2000;
   map1.heightFields[5][10]= 0;
   map1.heightFields[6][0] = 0;
   map1.heightFields[6][1] = 0;
   map1.heightFields[6][2] = -1000;
   map1.heightFields[6][3] = 0;
   map1.heightFields[6][4] = 0;
   map1.heightFields[6][5] = 0;
   map1.heightFields[6][6] = -1000;
   map1.heightFields[6][7] = -1000;
   map1.heightFields[6][8] = -1000;
   map1.heightFields[6][9] = -1000;
   map1.heightFields[6][10]= 0;
   map1.heightFields[7][0] = 0;
   map1.heightFields[7][1] = 0;
   map1.heightFields[7][2] = -1000;
   map1.heightFields[7][3] = 0;
   map1.heightFields[7][4] = 0;
   map1.heightFields[7][5] = 0;
   map1.heightFields[7][6] = -1000;
   map1.heightFields[7][7] = 0;
   map1.heightFields[7][8] = 0;
   map1.heightFields[7][9] = 0;
   map1.heightFields[7][10]= 0;
   map1.heightFields[8][0] = 0;
   map1.heightFields[8][1] = 0;
   map1.heightFields[8][2] = -1000;
   map1.heightFields[8][3] = 0;
   map1.heightFields[8][4] = 1000;
   map1.heightFields[8][5] = 1000;
   map1.heightFields[8][6] = 1000;
   map1.heightFields[8][7] = 1000;
   map1.heightFields[8][8] = 0;
   map1.heightFields[8][9] = 0;
   map1.heightFields[8][10]= 0;
   map1.heightFields[9][0] = 0;
   map1.heightFields[9][1] = 0;
   map1.heightFields[9][2] = -1000;
   map1.heightFields[9][3] = 0;
   map1.heightFields[9][4] = 0;
   map1.heightFields[9][5] = 0;
   map1.heightFields[9][6] = -1000;
   map1.heightFields[9][7] = 0;
   map1.heightFields[9][8] = 0;
   map1.heightFields[9][9] = 0;
   map1.heightFields[9][10]= 0;
   map1.heightFields[10][0] = 0;
   map1.heightFields[10][1] = 0;
   map1.heightFields[10][2] = -1000;
   map1.heightFields[10][3] = 0;
   map1.heightFields[10][4] = 0;
   map1.heightFields[10][5] = 0;
   map1.heightFields[10][6] = -1000;
   map1.heightFields[10][7] = 0;
   map1.heightFields[10][8] = 0;
   map1.heightFields[10][9] = 0;
   map1.heightFields[10][10]= 0;

   // setup Textures
   map1.TEXTURE_MAPS[0] = (u_long *)GRASS01_TIM;
   map1.TEXTURE_MAPS[1] = (u_long *)TRACK01_TIM;

   // set Texture locations
   map1.texturePosition[0][0]= 0;
   map1.texturePosition[0][1]= 1;
   map1.texturePosition[0][2]= 1;
   map1.texturePosition[0][3]= 1;
   map1.texturePosition[0][4]= 1;
   map1.texturePosition[0][5]= 1;
   map1.texturePosition[0][6]= 1;
   map1.texturePosition[0][7]= 1;
   map1.texturePosition[0][8]= 1;   
   map1.texturePosition[0][9]= 1;
   map1.texturePosition[1][0]= 1;
   map1.texturePosition[1][1]= 1;
   map1.texturePosition[1][2]= 1;
   map1.texturePosition[1][3]= 1;
   map1.texturePosition[1][4]= 1;
   map1.texturePosition[1][5]= 1;
   map1.texturePosition[1][6]= 1;
   map1.texturePosition[1][7]= 1;
   map1.texturePosition[1][8]= 1;
   map1.texturePosition[1][9]= 1;
   map1.texturePosition[2][0]= 1;
   map1.texturePosition[2][1]= 1;
   map1.texturePosition[2][2]= 1;
   map1.texturePosition[2][3]= 1;
   map1.texturePosition[2][4]= 1;
   map1.texturePosition[2][5]= 0;
   map1.texturePosition[2][6]= 0;
   map1.texturePosition[2][7]= 0;
   map1.texturePosition[2][8]= 0;
   map1.texturePosition[2][9]= 0;
   map1.texturePosition[3][0]= 0;
   map1.texturePosition[3][1]= 0;
   map1.texturePosition[3][2]= 0;
   map1.texturePosition[3][3]= 0;
   map1.texturePosition[3][4]= 0;
   map1.texturePosition[3][5]= 0;
   map1.texturePosition[3][6]= 0;
   map1.texturePosition[3][7]= 0;
   map1.texturePosition[3][8]= 0;
   map1.texturePosition[3][9]= 0;
   map1.texturePosition[4][0]= 0;
   map1.texturePosition[4][1]= 0;
   map1.texturePosition[4][2]= 0;
   map1.texturePosition[4][3]= 0;
   map1.texturePosition[4][4]= 0;
   map1.texturePosition[4][5]= 0;
   map1.texturePosition[4][6]= 0;
   map1.texturePosition[4][7]= 0;
   map1.texturePosition[4][8]= 0;
   map1.texturePosition[4][9]= 0;
   map1.texturePosition[5][0]= 0;
   map1.texturePosition[5][1]= 0;
   map1.texturePosition[5][2]= 0;
   map1.texturePosition[5][3]= 0;
   map1.texturePosition[5][4]= 0;
   map1.texturePosition[5][5]= 0;
   map1.texturePosition[5][6]= 0;
   map1.texturePosition[5][7]= 0;
   map1.texturePosition[5][8]= 0;
   map1.texturePosition[5][9]= 0;
   map1.texturePosition[6][0]= 0;
   map1.texturePosition[6][1]= 0;
   map1.texturePosition[6][2]= 0;
   map1.texturePosition[6][3]= 0;
   map1.texturePosition[6][4]= 0;
   map1.texturePosition[6][5]= 0;
   map1.texturePosition[6][6]= 0;
   map1.texturePosition[6][7]= 0;
   map1.texturePosition[6][8]= 0;
   map1.texturePosition[6][9]= 0;
   map1.texturePosition[7][0]= 0;
   map1.texturePosition[7][1]= 0;
   map1.texturePosition[7][2]= 0;
   map1.texturePosition[7][3]= 0;
   map1.texturePosition[7][4]= 0;
   map1.texturePosition[7][5]= 0;
   map1.texturePosition[7][6]= 0;
   map1.texturePosition[7][7]= 0;
   map1.texturePosition[7][8]= 0;
   map1.texturePosition[7][9]= 0;
   map1.texturePosition[8][0]= 0;
   map1.texturePosition[8][1]= 0;
   map1.texturePosition[8][2]= 0;
   map1.texturePosition[8][3]= 0;
   map1.texturePosition[8][4]= 0;
   map1.texturePosition[8][5]= 0;
   map1.texturePosition[8][6]= 0;
   map1.texturePosition[8][7]= 0; 
   map1.texturePosition[8][8]= 0;
   map1.texturePosition[8][9]= 0;
   map1.texturePosition[9][0]= 0;
   map1.texturePosition[9][1]= 0; 
   map1.texturePosition[9][2]= 0;
   map1.texturePosition[9][3]= 0;
   map1.texturePosition[9][4]= 0;
   map1.texturePosition[9][5]= 0;
   map1.texturePosition[9][6]= 0;
   map1.texturePosition[9][7]= 0;
   map1.texturePosition[9][8]= 0;
   map1.texturePosition[9][9]= 0;
}