Created
          October 3, 2022 22:05 
        
      - 
      
- 
        Save carlfriess/93d79163e001940f9699f8455befd3e8 to your computer and use it in GitHub Desktop. 
    Simple bitmap data structure
  
        
  
    
      This file contains hidden or bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
      Learn more about bidirectional Unicode characters
    
  
  
    
  | #ifndef BITMAP_H | |
| #define BITMAP_H | |
| #include <stdint.h> | |
| #include <stdbool.h> | |
| #include <stdlib.h> | |
| #include <string.h> | |
| typedef uint32_t bitmap_t; | |
| static inline bitmap_t *bitmap_alloc(size_t n) { | |
| return calloc((n >> 5) + (n & 0x1f ? 1 : 0), sizeof(bitmap_t)); | |
| } | |
| static inline void bitmap_clear(bitmap_t *bitmap, size_t n) { | |
| memset(bitmap, 0, ((n >> 5) + (n & 0x1f ? 1 : 0)) * sizeof(bitmap_t)); | |
| } | |
| static inline bool bitmap_is_bit_set(const bitmap_t *bitmap, size_t bit) { | |
| bitmap_t cell = bitmap[bit >> 5]; | |
| return (cell >> (bit & 0x1f)) & 1; | |
| } | |
| static inline void bitmap_set_bit(bitmap_t *bitmap, size_t bit) { | |
| bitmap[bit >> 5] |= 1UL << (bit & 0x1f); | |
| } | |
| static inline void bitmap_clear_bit(bitmap_t *bitmap, size_t bit) { | |
| bitmap[bit >> 5] &= ~(1UL << (bit & 0x1f)); | |
| } | |
| #endif //BITMAP_H | 
  
    Sign up for free
    to join this conversation on GitHub.
    Already have an account?
    Sign in to comment