root/test/manual/etags/cp-src/screen.cpp

DEFINITIONS

1. goto_xy
2. hide_cursor
3. cursor_position
4. clear_screen
5. write_xyc

     1 /* ======================================================================= */
     2 /*                                SCREEN.CPP                               */
     3 /* ======================================================================= */
     4 
     5 #include "stdio.h"
     6 #include "stdlib.h"
     7 #include "dos.h"
     8 
     9 #include "screen.h"
    10 
    11 /* ----------------------------------------------------------------------- */
    12 /*              Cursor Position and Screen Buffering Functions             */
    13 /* ----------------------------------------------------------------------- */
    14 
    15 unsigned char cursor_x, cursor_y;
    16 static union REGS regs;
    17 
    18 void goto_xy(unsigned char x, unsigned char y)
    19     {
    20     regs.h.ah = 2;
    21     regs.h.bh = 0;
    22     regs.h.dh = y;
    23     regs.h.dl = x;
    24     int86(0x10, &regs, &regs);
    25     }
    26 
    27 void hide_cursor(void)
    28     {
    29     goto_xy(0, NUM_ROWS);
    30     }
    31 
    32 void cursor_position(void)
    33     {
    34     regs.h.ah = 3;
    35     regs.h.bh = 0;
    36     int86(0x10, &regs, &regs);
    37     cursor_x = regs.h.dl;
    38     cursor_y = regs.h.dh;
    39     }
    40 
    41 void clear_screen(void)
    42     {
    43     unsigned int i, j;
    44     char far *p;
    45 
    46     p = SCREEN_START;
    47     for (i = 0; i < NUM_ROWS; i++)
    48         for (j = 0; j < 80; j++)
    49             {
    50             *p++ = ' ';
    51             *p++ = LIGHTGRAY;
    52             }
    53     }
    54 
    55 void write_xyc(int x, int y, char c)
    56     {
    57     char far *p;
    58 
    59     p = SCREEN_FP(x, y);
    60     *p++ = c;
    61     *p = LIGHTGRAY;
    62     }