ardupilot/libraries/AP_Common/Bitmask.h

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2016-11-17 03:19:05 -04:00
/*
This program is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation, either version 3 of the License, or
(at your option) any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
/*
simple bitmask class
*/
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#pragma once
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class Bitmask {
public:
Bitmask(uint16_t numbits) :
numwords((numbits+31)/32) {
bits = new uint32_t[numwords];
}
~Bitmask(void) {
delete[] bits;
}
// set given bitnumber
void set(uint16_t bit) {
uint16_t word = bit/32;
uint8_t ofs = bit & 0x1f;
bits[word] |= (1U << ofs);
}
// clear given bitnumber
void clear(uint16_t bit) {
uint16_t word = bit/32;
uint8_t ofs = bit & 0x1f;
bits[word] &= ~(1U << ofs);
}
// clear all bits
void clearall(void) {
for (uint16_t i=0; i<numwords; i++) {
bits[i] = 0;
}
}
// return true if given bitnumber is set
bool get(uint16_t bit) {
uint16_t word = bit/32;
uint8_t ofs = bit & 0x1f;
return (bits[word] & (1U << ofs)) != 0;
}
// return true if all bits are clear
bool empty(void) {
for (uint16_t i=0; i<numwords; i++) {
if (bits[i] != 0) {
return false;
}
}
return true;
}
private:
uint16_t numwords;
uint32_t *bits;
};