Graphics - basics Vectors image described as a set of basic shapes (lines, circles etc.) accurate description easy transformation limited application Bitmaps image described as a matrix of pixels limited resolution needs much more mem...
Bitmaps Most commonly used today Memory requirements for a standard screen: - 1280*1024*3 bytes = 3 932 160 bytes Processing speed for real-time display: - we need about 15 fps - ...it means: 59 millions of bytes per second - ...and today...
Bsearch The task: check, whether a value is in a sorted array A slow solution: linear search A fast solution: binary search A function from stdlib: bsearch void *bsearch(const void *key, const void *base, size_t nelem, size_t width, int (*fcmp)(const void*, const void*)); ...
creat, close, unlink open is like fopen , except that instead of returning a file pointer, it returns a file descriptor, which is just an int open returns -1 if any error occurs int open(char *name, int flags, int perms); #include int fd; ......
exec* int execl (char *path, char *arg0, ..., NULL); int execle (char *path, char *arg0, ..., NULL, char **env); int execlp (char *path, char *arg0, ...); int execlpe(char *path, char *arg0, ..., NULL, char **env); int execv (char *path, char *argv[]); int execve (char *path, char *argv...
File Descriptors A file descriptor is an integer A file descriptor is analogous to the file pointer used by the standard library All information about an open file is maintained by the system The user program refers to the file only by the file descriptor Three files are open, with file d...
Fork UNIX #include #include pid_t fork(void); Example int fork_return; printf("Process %d about to fork a child.\n", getpid()); fork_return = fork(); if( fork_return ...
It is implemented, use it void qsort(void *base, size_t nelem, size_t width, int (*fcmp)(const void *, const void *)); The programmer provides a function comparing elements Elements should be of the same size, stored in an array They may be e.g. pointers ...
stdlib.h: itoa, ltoa, ultoa itoa converts an integer to a string ltoa converts a long to a string ultoa converts an unsigned long to a string Declarations: char *itoa(int value, char *string, int radix); char *ltoa(long value, char *string, int radix); char *ultoa(unsigned long value, char ...
Open As with fopen , the name argument is a character string containing the filename The second argument, flags , is an int that specifies how the file is to be opened The main values are: - O_RDONLY open for reading only - O_WRONLY open for writing only - O_RDWR open for both reading and wri...
