Programmer 7500/MAX_PROGRAMMERS.iso/INFO/PROGJRN/PJ_7_3A.ARC/DISPLAY.CPP

C/C++ Source or Header | 1989-02-22 | 4.7 KB | 255 lines

// display.cpp    the Display class methods
//
// (c) Aspen Scientific 1989. All Rights Reserved.
// Author: Vaughn Vernon

#include "display.cls"

// for Microsoft C, not Zortech
#ifndef __ZTC__
# include <memory.h>
# include <conio.h>
#else
static void movedata(unsigned, unsigned, unsigned, unsigned, unsigned);
#endif

// ***************************************************************
// ** the Display methods in this file are implemented for MS-DOS
// ** in a text display (non-graphics) environment.  it uses
// ** 8086 interrupts and the Microsoft C int86() function, as
// ** well as far pointers to the video memory map segment.
// ***************************************************************

#include <dos.h>

static union REGS vRegs;
static union REGS videoSaveMode;
static const unsigned monoSeg  = 0xb000;
static const unsigned colorSeg = 0xb800;

#if defined(M_I86SM) || defined(M_I86MM)
static unsigned ds;
#endif

static unsigned map[80];

Display::Display(const Mouse * mou) : cursor(0,0)
{
    if (init == 1)
        return;

    mouse = mou;

    // for small and medium models (small data), need data seg
    struct SREGS segs;
    segread(&segs);
    ds = segs.ds;

    // find out the current video mode, save
    // it, then set the new mode if necessary.

    vRegs.h.ah = 0x0f;
    int86(0x10, &vRegs, &vRegs);
    videoSaveMode = vRegs;

    // return of 7 in AL register is mono
    if (vRegs.h.al == 7) {
        videoSeg = monoSeg;
        color = 0;
        snow  = 0;
    }
    else {

        videoSeg = colorSeg;
        color = 1;

        if (vRegs.h.al != 3) {
            vRegs.h.ah = 0;
            vRegs.h.al = 3;
            int86(0x10, &vRegs, &vRegs);
        }

        // check for a snowing display; an EGA
        // or VGA is automatic no-snow.

        unsigned EGAMemory, EGAMode;

        vRegs.h.ah = 0x12;
        vRegs.h.bl = 0x10;
        int86(0x10, &vRegs, &vRegs);

        EGAMemory = vRegs.h.bl;
        EGAMode   = vRegs.h.bh;

        // if the returned memory is out of range, or
        // the ega/vga card is not attached to the color
        // display (EGAMode != 0), assume snow.

        if (EGAMemory < 0 || EGAMemory > 3 || EGAMode != 0)
            snow = 1;
        else
            snow = 0;
    }

    // set the Display size
    origin(Point(0,0));
    corner(Point(24,79));

    clear();

    draw();

    init=1;
}

Display::~Display()
{
    clear();
    cursor(0,0);
    draw();
    vRegs = videoSaveMode;
    int86(0x10, &vRegs, &vRegs);
}

void
Display::clear()
{
    Point size = extent();

    mouse->hide();

    vRegs.h.dh = size.x() + 1;
    vRegs.h.dl = size.y() + 1;
    vRegs.h.bh = defAttr.get() >> 8;
    vRegs.x.cx = 0;
    vRegs.h.al = 0;
    vRegs.h.ah = 6;
    int86(0x10, &vRegs, &vRegs);

    mouse->show();
}

void
Display::operator()(unsigned row, unsigned col)
{
    Point top, bot;

    top = origin();
    bot = corner();

    if (row < top.x() || row > bot.x() ||
        col < top.y() || col > bot.y())
        return;

    // move cursor
    cursor(int(row), int(col));
    draw();
}

void
Display::cursorOff()
{
    vRegs.x.cx = 0x2000;
    vRegs.h.ah = 1;
    int86(0x10, &vRegs, &vRegs);
}

void
Display::cursorOn()
{
    if (hasColor())
        vRegs.x.cx = 0x0607;
    else
        vRegs.x.cx = 0x0b0c;

    vRegs.h.ah = 1;
    int86(0x10, &vRegs, &vRegs);
}

void
Display::putString(Point & p, const unsigned char * s, DisplayAttr & a)
{
    cursor = p;

    register unsigned c = cursor.y();
    register unsigned len=0;
    unsigned *mp = map;
    for ( ; c <= width() && *s; ++c, ++len)
        *mp++ = (unsigned)*s++ | a.get();

    mouse->hide();

    // protect against flicker
    if (snow)
        while ((inp(0x03da) & 8) == 0)
            ;

#if defined(M_I86SM) || defined(M_I86MM)
    movedata(ds, (unsigned)map,
#else
    movedata(FP_SEG(map), FP_OFF(map),
#endif
        videoSeg, cursor.x() * 160 + cursor.y() * 2, len * 2);

    mouse->show();

    cursor(cursor.x(), c);
}

void
Display::putChar(Point & p, unsigned char c, DisplayAttr & a)
{
    cursor = p;

    *map = c | a.get();

    mouse->hide();

    // protect against flicker
    if (snow)
        while ((inp(0x03da) & 8) == 0)
            ;

#if defined(M_I86SM) || defined(M_I86MM)
    movedata(ds, (unsigned)map,
#else
    movedata(FP_SEG(map), FP_OFF(map),
#endif
        videoSeg, cursor.x() * 160 + cursor.y() * 2, 2);

    mouse->show();

    if (cursor.y() != width())
        cursor(cursor.x(), cursor.y() + 1);
}

// just update cursor
void
Display::draw()
{
    vRegs.h.dh = cursor.x();
    vRegs.h.dl = cursor.y();
    vRegs.h.bh = 0;
    vRegs.h.ah = 2;
    int86(0x10, &vRegs, &vRegs);
}

#ifdef __ZTC__

static void
movedata(unsigned sSeg, unsigned sOff, unsigned dSeg, unsigned dOff, unsigned n)
{
    unsigned far *src, far *dest;

    src  = MK_FP(sSeg, sOff);
    dest = MK_FP(dSeg, dOff);

    // divide by 2
    n >>= 1;

    for (register int i=0; i < n; ++i)
        *dest++ = *src++;
}

#endif