pr0b1tscpp

bitshift_example.cc

#include <iostream>
#include <iomanip> // Manipulate IO

using namespace std;

void print_hex(unsigned int* number)
{
	cout << "0x" << setfill('0') << setw(8) << hex << *number << endl;
}

int main()
{
	// 0xFF123456
	unsigned char alpha = 0xFF;
	unsigned char red	= 0x12;
	unsigned char green = 0x34;	
	unsigned char blue  = 0x56;

	unsigned int color = 0;

	// SLOW
	print_hex(&color);
	color += alpha;
	print_hex(&color);
	color <<= 8;
	print_hex(&color);
	color += red;
	print_hex(&color);
	color <<= 8;
	print_hex(&color);
	color += green;
	print_hex(&color);
	color <<= 8;
	print_hex(&color);
	color += blue;
	print_hex(&color);
	// C00L
	color = 0;
	print_hex(&color);
	color = alpha << 24 | red << 16 | green << 8 | blue;
	print_hex(&color);

	return 0;
}