Taking screenshot using bmp file in c? - c

Question

I'm trying to create a 3D Game using c.
when adding the flag '--save'
The game takes a screenshot and saves it.
so to do this (taking a screenshot from the game).
I have to use BMP file, so I have to make it using c.
The code:
#include "../includes/cub3d.h"
t_screenshot *ft_init_shot(t_mlx *mlx)
{
t_screenshot *takeshot;
takeshot = malloc(1 * sizeof(t_screenshot));
takeshot->width = w;
takeshot->height = h;
takeshot->bitcount = 24;
takeshot->width_in_bytes = ((takeshot->width * takeshot->bitcount + 31) / 32) * 4;
takeshot->imagesize = takeshot->width_in_bytes * takeshot->height;
takeshot->filesize = 54 + takeshot->imagesize;
return (takeshot);
}
unsigned char *ft_bitheader(t_mlx *mlx)
{
unsigned char *header;
uint32_t bisize;
uint32_t bfoffbits;
uint16_t biplanes;
header =(unsigned char *)malloc(54 * sizeof(char));
bisize = 40;
bfoffbits = 54;
biplanes = 1;
memcpy(header, "BM", 2);
memcpy(header + 2 , &mlx->shot->filesize, 4);
memcpy(header + 10, &bfoffbits, 4);
memcpy(header + 14, &bisize, 4);
memcpy(header + 18, &mlx->shot->width, 4);
memcpy(header + 22, &mlx->shot->height, 4);
memcpy(header + 26, &biplanes, 2);
memcpy(header + 28, &mlx->shot->bitcount, 2);
memcpy(header + 34, &mlx->shot->imagesize, 4);
return (header);
}
void screen_shot(t_mlx *mlx)
{
ft_move(mlx);
ft_update(mlx, YES);
mlx->shot = ft_init_shot(mlx);
mlx->shot->header = ft_bitheader(mlx);
screno(mlx);
}
void screno(t_mlx *mlx)
{
int x ;
int y ;
int row;
int col;
x = 0;
y = 0;
row = mlx->shot->height - 1;
col = 0;
unsigned char* buf = malloc(mlx->shot->imagesize);
while (row >= 0)
{
y = 0;
col = 0;
while (col < mlx->shot->width)
{
int red = (mlx->tex.img_data[x * w + y] >> 16) & 0xFF;
int green = (mlx->tex.img_data[x * w + y] >> 8) & 0xFF;
int blue = mlx->tex.img_data[x * w + y] & 0xFF;
buf[row * mlx->shot->width_in_bytes + col * 3 + 0] = blue;
buf[row * mlx->shot->width_in_bytes + col * 3 + 1] = green;
buf[row * mlx->shot->width_in_bytes + col * 3 + 2] = red;
col++;
y++;
}
row--;
x++;
}
ft_printf("Taking ScreenShoot....\n");
FILE *image = fopen("screenshot.bmp", "wb");
ft_printf("ScreenShot Has been saved under The name 'screenshot.bmp']\n");
fwrite(mlx->shot->header, 1, 54, image);
fwrite((char*)buf, 1, mlx->shot->imagesize, image);
fclose(image);
free(buf);
}
The problem is when I compiling This code the image appear some time and some time give me this error:
Thank You for Your help.