libpng.h

 
#ifndef _PNG_H
#define _PNG_H
 
#ifdef __cplusplus
extern "C" {
#endif
 
#include <stdint.h>
 
typedef union {
  uint8_t p[4];
  struct { uint8_t r, g, b, a; };
  struct { uint8_t red, green, blue, alpha; };
} pixel_t;
 
typedef struct {
  uint32_t height, width;
  pixel_t *rgba;
} image_t;
 
 
 
image_t *load_image(const char *filename);
 
void save_image(image_t *img, const char *filename);
 
image_t *new_image(uint32_t width, uint32_t height);
 
void free_image(image_t *img);
 
 
#ifdef __cplusplus
} // end extern "C"
#endif
 
 
 
#ifdef __cplusplus
class Image {
  public:
    Image(uint32_t width, uint32_t height) : data(new_image(width, height)) {}
    Image(const char *filename) : data(load_image(filename)) { }
    
    Image() : data(nullptr) {}
    ~Image() { if(!data) free_image(data);}
    
    pixel_t* operator[](uint32_t y) { return &(data->rgba[data->width * y]); }
    
    void save(const char *filename) const {
      save_image(data, filename);
    }
    
    uint32_t width() const { return data->width; }
 
    uint32_t height() const { return data->height; }
 
    bool empty() const {return data == nullptr;}
  private:
    image_t* data;
};
#else
#define pixel_xy(img,x,y) (img)->rgba[(x) + (y)*(img)->width]
#endif
 
#endif