비트플래그, 비트마스크

1. 비트플래그

• bitset

#include <iostream>
#include <bitset>

using namespace std;

int main() {
	/*
	bool item1_flag = false;
	bool item2_flag = false;
	bool item3_flag = false;
	bool item4_flag = false;
	*/
	const unsigned char opt0 = 1 << 0;	
	const unsigned char opt1 = 1 << 1;
	const unsigned char opt2 = 1 << 2;
	const unsigned char opt3 = 1 << 3;


	cout << bitset<8>(opt0) << endl;
	cout << bitset<8>(opt1) << endl;
	cout << bitset<8>(opt2) << endl;
	cout << bitset<8>(opt3) << endl;


	unsigned char items_flag = 0;
	cout << "No item " << bitset<8>(items_flag) << endl;

	items_flag |= opt0;
	cout << "Item 0 obtained " << bitset<8>(items_flag) << endl;
	
	items_flag |= opt3;
	cout << "Item 3 obtained " << bitset<8>(items_flag) << endl;

	items_flag &= ~opt3;
	cout << "Item 3 lost " << bitset<8>(items_flag) << endl;

	if (items_flag & opt1) {
		cout << "Has item1" << endl;
	}
	else { cout << "Not have item1" << endl; }

	items_flag |= (opt2 | opt3);
	cout << "Item 2,3 obtained " << bitset<8>(items_flag) << endl;

	if ((items_flag & opt2) && !(items_flag & opt1)) {
		items_flag ^= opt2;
		items_flag ^= opt1;
	}
	return 0;

}

 

2. 비트마스크

#include <iostream>
#include <bitset>

using namespace std;

int main() {
	const unsigned int red_mask = 0xFF0000;
	const unsigned int green_mask = 0x00FF00;
	const unsigned int blue_mask = 0x0000FF;

	unsigned int pixel_color = 0xDAA520;
	
	unsigned char red, green, blue;
	cout << bitset<32>(pixel_color) << endl;

	red = (pixel_color & red_mask)>>16;
	cout << "red " << bitset<8>(red) << " " << int(red) << endl;
	green = (pixel_color & green_mask)>>8;
	cout << "green " << bitset<8>(green) << " " << int(green) << endl;
	blue = pixel_color & blue_mask;
	cout << "blue " << bitset<8>(blue) << " " << int(blue) << endl;

	return 0;
}