/*******************************************************************
* FileName:        triangles.c
* Processor:       PIC18F4520
* Compiler:        MPLAB C18 v.3.06 
*
* This file uses functions to calculate triangle parameters
*  and determines the top of the triangle
*                                                                     
*
* Creation and Revisions:
*      Author               Date			Comments
*   (Your name here)    
********************************************************************/

/** Header Files ***************************************************/     
#include <p18f4520.h> 
#include <stdio.h>
#include <math.h>

/** Configuration Bits *********************************************/     
#pragma config OSC = EC  // EC = External 4MHz Crystal for PICDEM board only
#pragma config WDT = OFF
#pragma config LVP = OFF
#pragma config BOREN = OFF

/** Define Constants Here ******************************************/

/** Local Function Prototypes **************************************/
int distance(int x1, int y1, int x2, int y2);
int perimeter(int triangle[]);
int centerX(int triangle[]);
int middle(int triangle[]);

/** Global Variables ***********************************************/
// There will be NO global variables
	
/*******************************************************************
* Function:        void main(void)
********************************************************************/
#pragma code
void main (void)
{
	int triangle[] = {0, 0 , 4, 4 , 12, 0};
	int sampleDistance, resultPerimeter, resultCenterX, resultMiddle;
	
	sampleDistance = distance(0, 0, 5, 12);
	printf("The sampleDistance (as int) = %d\n", sampleDistance);
	
	resultPerimeter = perimeter(triangle);
	printf("The perimeter (as int) = %d\n", resultPerimeter);
	
	resultCenterX = centerX(triangle);
	printf("The x center of the triangle (as int) = %d\n", resultCenterX);
	
	resultMiddle = middle(triangle);
	printf("The middle x-coordinate of the triangle is %d\n", resultMiddle);

	while (1)
    {
		// This area loops forever
    }
}

/*******************************************************************
* Additional Helper Functions
********************************************************************/

/*******************************************************************
* Function:			distance
* Input Variables:	x1 - Point 1 x value
					y1 - Point 1 y value
					x2 - Point 2 y value
					y2 - Point 2 y value					
* Output Return:	The distance between the points (truncated to an int)
* Overview:			Determines the distance between Point 1 and Point 2
********************************************************************/
int distance(int x1, int y1, int x2, int y2)
{
	float resultFloat, deltaXFloat, deltaYFloat;
	int result, deltaX, deltaY;
	deltaX = x2 - x1;
	deltaY = y2 - y1;
	deltaXFloat = (float) deltaX;
	deltaYFloat = (float) deltaY;
	resultFloat = sqrt(deltaXFloat*deltaXFloat + deltaYFloat*deltaYFloat);
	result = (int) (resultFloat+.000001);
	return result;
}	

/*******************************************************************
* Function:			perimeter
* Input Variables:	triangle
					 An array of 6 int variables [x1,y1,x2,y2,x3,y3]
					 Example: int x1_element = triangle[0];
* Output Return:	The perimeter of the triangle (truncated to an int)
* Overview:			Determines the perimeter of the triangle by adding up the lenth of each side
********************************************************************/
int perimeter(int triangle[])
{
	int a, b, c;
	a = distance(triangle[0], triangle[1], triangle[2], triangle[3]);
	b = distance(triangle[0], triangle[1], triangle[4], triangle[5]);
	c = distance(triangle[2], triangle[3], triangle[4], triangle[5]);
	return a + b + c;
}
	
/*******************************************************************
* Function:			centerX
* Input Variables:	triangle
					 An array of 6 int variables [x1,y1,x2,y2,x3,y3]
					 Example: int x1_element = triangle[0];
* Output Return:	The average of the x values of the triangle (truncated as an int)
* Overview:			Determines the x value of the centroid of the triangle, 
                     which is an average of the x values
********************************************************************/
int centerX(int triangle[])
{
	// Note: You MUST use a for loop when accumulating the total for full credit	
	int i, total = 0;
	for (i = 0; i <= 4; i+=2) { // x's are every other 
		total += triangle[i];
	}
	return total/3;
}
	
/*******************************************************************
* Function:			middle
* Input Variables:	triangle
					 An array of 6 int variables [x1,y1,x2,y2,x3,y3]
					 Example: int x1_element = triangle[0];
* Output Return:	The middle x value of the triangle
* Overview:			Compares the x values of the triangle and returns the value
                     of the one between the others
********************************************************************/
int middle(int triangle[])
{
	int x1 = triangle[0];
	int x2 = triangle[2];
	int x3 = triangle[4];
	
	// Two ways for x2 to be middle (so use OR)
	if (x1 <= x2 && x2 <= x3 || x1 >= x2 && x2 >= x3) return x2;
	// Same for x1 and x3...
	if (x2 <= x1 && x1 <= x3 || x2 >= x1 && x1 >= x3) return x1;
	if (x1 <= x3 && x3 <= x2 || x1 >= x3 && x3 >= x2) return x3;
}