// MoreComplicated.c
// 
// Jaylen VanOrden
// CSE 351 TA
// 9-27-2012
//
// Gives example code for using bitwise and logical operators
// as well as a function which uses printf and a bit mask to
// print out decimal and binary representations of numbers.

#include <stdio.h>

// This is a function prototype - it lets C know
// what the parameters for the function will be.
// We have to include this before we call the function.
void displayTwice(const char* varName, int toDisp);

int main (int argc, char* argv[]){
  
  // Example variables
  int x = 5;
  int y = 103;

  displayTwice("x",x);
  displayTwice("y",y);

  // Bitwise operators
  int or_op = x | y;
  int and_op = x & y;
  int xor_op = x ^ y;

  displayTwice("x | y", or_op);
  displayTwice("x & y", and_op);
  displayTwice("X ^ y", xor_op);

  // Logical operators
  int logical_or = x || y;
  int logical_and = x && y;

  displayTwice("x || y", logical_or);
  displayTwice("x && y", logical_and);

  printf("\nJust working with x now...\n");

  // Shift operators
  int shift_left = x << 2;
  int shift_right = x >> 1;

  displayTwice("x << 2", shift_left);
  displayTwice("x >> 1", shift_right);

  return 0;
}

/*
 * Prints out the variable name and its value in decimal and binary 
 * form.
 *
 * Ex:
 *   displayTwice("bob",9);
 * Prints:
 *   bob:	9	00001001
 */
void displayTwice(const char* varName, int toDisp){

  // %s means "print this string"
  // %d means "display this as a decimal"
  // \t still means tab
  printf("%s:\t%d\t",varName,toDisp);

  int i;

  // Print each bit of the binary representation out
  // For each step, if the bit is set, print a 1
  // otherwise, print a 0.
  for(i = 0; i < 8; i++){

	// Arithmetic shift here?
	unsigned int mask = 0x80 >> i;

	unsigned int result = toDisp & mask;

	// Debug print:
//	printf("\nLooking at spot %d, got mask 0x%x, got result 0x%x / %u\n", i, mask, result, result);

	if(result > 0){
		printf("1");
	} else {
		printf("0");
	}
  }

  // Print a newline character to keep things clean
  printf("\n");
}