四時讀書樂 ( 冬 )

1. 四時讀書樂 (冬) 木落水盡千崖枯，迥然吾亦見真吾。 坐對韋編燈動壁，高歌夜半雪壓廬。 地爐茶鼎烹活火，四壁圖書中有我。 讀書之樂何處尋？數點梅花天地心。 ~ 元‧翁森

2. NCURSES Library - Functions for Screen Handling

3. rand() #include <iostream> using std::cout; using std::endl; int main() { for (int i=0; i<9; i++) cout << rand() % 6 + 1 << endl; return 0; }

4. Sleep( ) #include <iostream> #include <Windows.h> #include <Winbase.h> using std::cout; using std::endl; int main() { for (int i=0; i<9; i++) { cout << rand() % 6 + 1 << endl; Sleep(2000);// 2000 ms = 2s } return 0; }

5. Screen Handling

6. pdcurses_1.cpp #include <iostream> #include <Windows.h> #include <Winbase.h> #include <curses.h> int main() { int i, j; int a[6] = { 0 }; initscr(); for (i=0; i<6; i++) printw("%d ( )\n", i); for (i=0; i<9; i++) { j = rand() % 6; move(10, i*2); printw("%2d", j); move(j, 3); printw("%2d", ++a[j]); refresh(); Sleep(2000); // 2000 ms = 2s } endwin(); return 0; }

7. Definition of curses on Wikipedia • curses is a terminal control library for Unix-like systems, enabling the construction of text user interface (TUI) applications. • The name is a pun on the term “cursor optimization”. It is a library of functions that manage an application's display on character-cell terminals (e.g., VT100)

8. Basic Functions • move(y,x) • Move cursor to (y,x) in screen • addch(ch) • Add a character to screen • addstr(str) • Add a string to screen by calling addch() • printw(fmt, arg1, arg2, …) • Formatted print to screen by calling addstr() • refresh() • Update screen

9. Initialize and Terminate Curses • initscr() • Initialize curses • endwin() • End curses. • This function should be called when your program is finished. • It will release the space allocated to screen handling in your program. • Remember to #include <curses.h> at the beginning of your program.

10. Use Curses Library in Visual C++ 2010 • Download Public Domain Curses Library • Uncompress it and save the 4 files under a local directory, say L:\PDCurses. • In Visual C++ 2010 Express, • Project – Property (or Alt-F7) • Under Configuration Properties • Debugging – Environment • PATH=L:\PDCurses • C/C++ - Additional Include Directories • L:\PDCurses • Expand Linker, choose Input. In Additional Dependencies, insert “L:\PDCurses\pdcurses.lib;”

11. Exercise • Modify pdcurses_1.cpp so that in addition to the counting number, in the same row you also show a bar (e.g. "******") to show the same number of stars.

12. Homework: 8 Queens • Imagine there are 8 queens attending a race. On your computer screen each queen is represented by a character ‘Q’. On each row there is one queen. • If you think a single character is monotonous, you may modify this program to handle 8 horses ~/-\^ • Use a random number generator to determine which queen will move forward. • You may use the Sleep() function to slow down the program. • Suppose the length of each lane is 50. The first queen who arrives at the destination wins the race.

13. 四時讀書樂 (春) 山光照檻水繞廊，舞雩歸詠春風香。 好鳥枝頭亦朋友，落花水面皆文章。 蹉跎莫遣韶光老，人生惟有讀書好。 讀書之樂樂何如，綠滿窗前草不除。 ~ 元‧翁森

14. 四時讀書樂 (夏) 新竹壓檐桑四圍，小齋幽敞明朱暉。 晝長吟罷蟬鳴樹，夜深燼落螢入帷。 北窗高臥羲皇侶，只因素稔讀書趣。 讀書之樂樂無窮，瑤琴一曲來薰風。 ~ 元‧翁森

15. 四時讀書樂 (秋) 昨夜庭前葉有聲，籬豆花開蟋蟀鳴。 不覺商意滿林薄，蕭然萬籟涵虛清。 近床賴有短檠在，趁此讀書功更倍。 讀書之樂樂陶陶，起弄明月霜天高。 ~ 元‧翁森

16. 四時讀書樂 (冬) 木落水盡千崖枯，迥然吾亦見真吾。 坐對韋編燈動壁，高歌夜半雪壓廬。 地爐茶鼎烹活火，四壁圖書中有我。 讀書之樂何處尋？數點梅花天地心。 ~ 元‧翁森

17. Getting Characters from the Terminal • getch() • Get a character from the terminal • getstr(str) • Get a string from the terminal • scanw(fmt, arg1, arg2, …) • Formatted input from the terminal like scanf().

18. pdcurses_3.cpp #include <curses.h> int main() { char text[10]; int i, j, c; initscr(); getstr(text);// input the string "1,2" addstr(text); addch('\n'); scanw("%d,%d", &i, &j);// input the string "1,2" again printw("%d\t%d\n", i, j); c = getch(); endwin(); return 0; }

19. noecho() #include <curses.h> int main() { int c; initscr(); // noecho(); do { c = getch(); printw(" %d\n", c); } while (c != '0'); endwin(); return 0; }

20. pdcurses_4.cpp // pdcurses_4.cpp #include <curses.h> int main() { int y=10, x=10; char c; initscr(); noecho(); do { move(y, x); addch('Q'); c = getch(); move(y, x); addch(' '); switch (c) { case 'h': x--; break; case 'l': x++; break; case 'j': y++; break; case 'k': y--; break; } } while (c != 'q'); endwin(); return 0; }

21. curs_set() • curs_set() alters the appearance of the text cursor. • int curs_set(int visibility); • A value of 0 for visibility makes the cursor disappear; • a value of 1 makes the cursor appear "normal" (usually an underline) • 2 makes the cursor "highly visible" (usually a block).

22. pdcurses_4a.cpp // pdcurses_4.cpp #include <curses.h> int main() { int y=10, x=10; char c; initscr(); noecho(); curs_set(0);// no cursor do { move(y, x); addch('Q'); c = getch(); move(y, x); addch(' '); switch (c) { case 'h': x--; break; case 'l': x++; break; case 'j': y++; break; case 'k': y--; break; } } while (c != 'q'); endwin(); return 0; }

23. Function Keys • Call keypad() to enable the handling of Function keys and arrow keys. • int keypad(WINDOW *win, bool bf); • keypad(stdscr, TRUE); • getch() returns an integer corresponding to the key pressed. • If it is a normal character, the integer value will be equivalent to the ASCII code of the character. • Otherwise it returns a number which can be matched with the constants defined in curses.h. • For example if the user presses F1, the integer returned is 265.

24. Function Keys (cont.) • With keypad() enabled, you can check the returned value of getch() with the constants defined in curses.h • KEY_UP, KEY_DOWN, KEY_LEFT, KEY_RIGHT • KEY_HOME, KEY_END, • KEY_F(n)

25. Key Definitions • #define KEY_IC 0x14b /* insert char or enter ins mode (Insert) */ • #define KEY_DC 0x14a /* delete character (Delete) */ • #define KEY_HOME 0x106 /* home key */ • #define KEY_END 0x166 /* end key */ • #define KEY_PPAGE 0x153 /* previous page (PageUp) */ • #define KEY_NPAGE 0x152 /* next page (PageDown) */ • #define PADENTER 0x1cb /* enter on keypad */ You may check curses.h to see more definitions.

26. Colors • To start using color, you should first call the function start_color(). • To find out whether a terminal has color capabilities or not, you can use has_colors() function, which returns FALSE if the terminal does not support color. • Colors are always used in pairs. • A color-pair consists of a foreground color and a background color. • Initializes a color-pair with the routine init_pair(). After it has been initialized, COLOR_PAIR(n) is used to represent the color attribute.

27. pdcurses_2.cpp #include <curses.h> int main() { initscr(); start_color(); init_pair( 1, COLOR_WHITE, COLOR_RED ); attron( COLOR_PAIR(1) ); printw("Background red"); attroff( COLOR_PAIR(1) ); refresh(); getch(); endwin(); return 0; }

28. Pre-defined Colors on Unix • COLOR_BLACK = 0 • COLOR_RED = 1 • COLOR_GREEN = 2 • COLOR_YELLOW = 3 • COLOR_BLUE = 4 • COLOR_MAGENTA = 5 • COLOR_CYAN = 6 • COLOR_WHITE = 7

29. Exercise: Arrow Keys • Modify pdcurses_4a.cpp so that users can use arrow keys and HJKL to control the movement of ‘Q’. • Moreover, try to allow users to use both uppercase ‘H’ and lowercase ‘h’ to do the same movement. • Users can also change the color of ‘Q’ by pressing ‘0’…’7’.

30. HW: Tetris

31. int timeout(int delay) • The timeout() function affects the behaviour of getch() when reading a character from stdscr. • If delay is a positive number, then getch() will wait for that many milliseconds before returning • If no character was available, then ERR (-1) will be returned.

32. pdcurses_6.cpp #include <curses.h> int main() { int x=10, old_x; int c; initscr(); noecho(); curs_set(0);// hide the cursor timeout(500); // getch() will only wait 0.5 second for (int y=1; y<15; y++) { move(y, x); addch('Q'); old_x = x; c = getch(); switch(c) { case 'h': x--; break; case 'l': x++; break; } move(y, old_x); addch(' '); } refresh(); endwin(); return 0; }

33. HW: Tetris RotationReplayFalling Down

34. Rotate with respect to a fixed point (x+1,y-1) (x+2,y-1) (x,y) (x+1,y) x y

35. Relative Coordinates (1,-1) (2,-1) (0,0) (1,0) x y

36. Rotate 90 Degrees (-1,-2) (-1,-1) (0,-1) (0,0) x y

37. Rotate 180 Degrees (-1,0) (0,0) (-2,1) (-1,1) x y

38. Rotate 270 Degrees (0,0) (0,1) (1,1) x (1,2) y

39. Observe the x and y (y, -x) (-x, -y) (0,0) x (x, y) y (-y, x)

40. switch(rotate) • case 0: • x = x0 + x; • y = y0 + y; • break; • case 2: • x = x0 - x; • y = y0 - y; • break; • case 1: • x = x0 + y; • y = y0 - x; • break; • case 3: • x = x0 - y; • y = y0 + x; • break;

41. Seven Shapes

42. Represent these objects withstruct struct Shape { Cell c[4]; }; struct Cell { int dx; int dy; }

43. Choose a reference point (0,-1) (1,-1) (-1,0) (0,0)

44. Shape s[7]; void init_shape() { int i, j, x, y; FILE* fp; fp = fopen("X:\\WWW\\Course\\CS101\\shape_xy.txt", "r"); for (i=0; i<7; i++) { for (j=0; j<4; j++) { fscanf(fp, "%d %d", &y, &x); s[i].c[j].dx = x; s[i].c[j].dy = y; } } fclose(fp); // Initialize the bottom line for (i=0; i<12; i++) occupy[11][i] = true; } 0 0 0 1 -1 0 -1 1 0 0 1 0 2 0 -1 0 0 0 0 1 -1 0 -1 -1 0 0 0 1 0 -1 -1 0 0 0 0 1 0 2 -1 0 0 0 0 -1 -1 0 -1 1 0 0 0 -1 0 -2 -1 0

45. plot_shape(shape_id, y0, x0, rotate, character) for (j=0; j<4; j++) { x = x0 + s[id].c[j].dx; y = y0 + s[id].c[j].dy; move(y, x); addch(character); }

46. Consider Rotations

47. test_rotate() • KEY_LEFT • KEY_RIGHT • KEY_UP • tetris-1.cpp

48. history.txt • shape, y, x, r 1 1 1 0 1 2 1 0 1 3 2 0 1 4 3 0 1 5 3 1 1 10 3 1 6 1 2 0 6 2 2 0 6 3 3 0 6 4 4 0 6 5 5 1 6 6 6 2 6 7 7 3 6 8 8 0 6 10 8 0 y=1 implies a new object

49. replay() fopen() while ( fscanf( ) != EOF ) { if not a new object erase the old position plot at the new position } fclose()

50. Falling down • Q: When should an object stop falling down? • A: When there get supported by some cells beneath it.