screen.cpp

串行通信编程源码

// ******************************************************************** //
//                                                                      //
//      SCREEN.CPP                                                      //
//      Copyright (c) 1993, Michael Holmes and Bob Flanders             //
//      C++ Communication Utilities                                     //
//                                                                      //
//      This file contains the routines for moving to and from          //
//      the window buffers for saving and restoring the screen.         //
//                                                                      //
// ******************************************************************** //


char    huge *vid_seg =                     // video adapter address
            (char huge *) MK_FP(0xb800, 0);



/* ******************************************************************** *
 *
 *  screen_move() -- move between the video adapter and work buffer
 *
 * ******************************************************************** */

void    screen_move(int  left,  int top,    // left and top corner
                    int  right, int bottom, // right and bottom corner
                    char *buffer,           // work buffer
                    int  dir)               // direction (0=to screen)
{
char    huge *p1, huge *p2;                 // work pointers
int     y,                                  // loop variable
        p1size, p2size, size;               // bytes per line


size = (right - left + 1) * 2;              // length of window line
y = ((top - 1) * 160) + ((left - 1) * 2);   // offset into video buffer

if (dir)                                    // q. moving to buffer?
    {
    p1 = buffer;                            // a. yes .. dest is buffer
    p1size = size;                          // ..and line length
    p2 = &vid_seg[y];                       // source is video ram
    p2size = 160;                           // ..and length is 80 * 2
    }
 else
    {
    p1 = &vid_seg[y];                       // else .. source is video ram
    p1size = 160;                           // ..and length is 80 * 2
    p2 = buffer;                            // destination is buffer
    p2size = size;                          // ..and line length
    }

for (y = bottom - top + 1; y--;             // loop thru for whole
           p1 += p1size, p2 += p2size)      // ..screen window moving
    memcpy((void *) p1, (void *) p2, size); // ..from one to the other

}



/* ******************************************************************** *
 *
 *  gettext() -- get text data from the video memory
 *
 * ******************************************************************** */

void    gettext(int  left, int top,         // left and top corner
                int  right, int bottom,     // right and bottom corner
                char *buffer)               // work buffer
{

screen_move(left, top, right, bottom,       // set up common call
        buffer, 1);                         // ..to screen move routine

}



/* ******************************************************************** *
 *
 *  puttext() -- put text data from a work buffer into the video memory
 *
 * ******************************************************************** */

void    puttext(int  left, int top,         // left and top corner
                int  right, int bottom,     // right and bottom corner
                char *buffer)               // work buffer
{

screen_move(left, top, right, bottom,       // set up common call
        buffer, 0);                         // ..to screen move routine

}