io_scroll.c

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/* console scrolling for when VIEW is used */

#include "../fb.h"
#include "fb_private_console.h"
#include <dpmi.h>
#include <go32.h>

static void hFillRect( int x1, int y1, int x2, int y2 )
{
        int cols, rows;
        fb_ConsoleGetSize( &cols, &rows );

        int chars = (x2 - x1 + 1) * (y2 - y1 + 1);

        unsigned long physAddr = fb_hGetPageAddr( __fb_con.active, cols, rows );
        if( physAddr == 0 )
        {
        /* change the cursor pos (faster than using LOCATE) */
        unsigned short oldPos = fb_hSetCursorPos( x1, y1 );

                __dpmi_regs regs;
                regs.x.ax = 0x0920;
                regs.h.bh = __fb_con.active;
                regs.h.bl = fb_ConsoleGetColorAtt();
                regs.x.cx = chars;
                __dpmi_int(0x10, &regs);

                /* restore old pos */
                fb_hSetCursorPos( oldPos, -1 );
        }
        else
        {
        unsigned short attr = fb_ConsoleGetColorAtt() << 8;
        if( (x2 - x1 + 1) == cols )
        {
                unsigned short *buffer = alloca( chars * sizeof( short ) );
                int i;
                for( i = 0, buffer += chars; i < chars; ++i )
                        *--buffer = attr | 0x20;

                _movedataw( _my_ds(), (int)buffer,
                                _dos_ds, physAddr + (cols << 1) * y1,
                                chars );
                }
                else
                {
                chars = x2 - x1 + 1;
                unsigned short *buffer = alloca( chars * sizeof( short ) );
                int i;
                for( i = 0, buffer += chars; i < chars; ++i )
                        *--buffer = attr | 0x20;

                for( i = y1; i < y2; i++ )
                        _movedataw( _my_ds(), (int)buffer,
                                        _dos_ds, physAddr + (cols << 1) * i + (x1 << 1),
                                        chars );
                }
    }
}

static void hMoveRect( int x1, int y1, int x2, int y2, int nrows )
{
        int cols, rows;
        fb_ConsoleGetSize( &cols, &rows );

        int chars = (x2 - x1 + 1) * (y2 - y1 + 1 - nrows);

        unsigned long physAddr = fb_hGetPageAddr( __fb_con.active, cols, rows );
        if( physAddr == 0 )
        {
                /* !!!WRITEME!!!*/
        }
        else
        {
        if( (x2 - x1 + 1) == cols )
        {
                _movedataw( _dos_ds, physAddr + (cols << 1) * (y1+nrows),
                                _dos_ds, physAddr + (cols << 1) * y1,
                                chars );
                }
                else
                {
                chars = x2 - x1 + 1;
                int i;
                for( i = y1; i < y2 - nrows; i++ )
                        _movedataw( _dos_ds, physAddr + (cols << 1) * (i+1) + (x1 << 1),
                                        _dos_ds, physAddr + (cols << 1) * i + (x1 << 1),
                                        chars );
        }
        }

}

void fb_ConsoleScroll_BIOS( int x1, int y1, int x2, int y2, int nrows )
{
    __dpmi_regs regs;

    /* stupid BIOS can't scroll a specific page */
        if( __fb_con.active != __fb_con.visible )
        {
                if( nrows == 0 )
                {
                        hFillRect( x1, y1, x2, y2 );
                }
                else
                {
                        hMoveRect( x1, y1, x2, y2, nrows );
                        hFillRect( x1, y2-(nrows-1), x2, y2 );
                }

                return;
        }

    regs.h.bl = 0;
    regs.h.bh = (unsigned char) fb_ConsoleGetColorAtt();
    regs.h.cl = (unsigned char) x1;
    regs.h.ch = (unsigned char) y1;
    regs.h.dl = (unsigned char) x2;
    regs.h.dh = (unsigned char) y2;

    if( nrows >= 0 ) {
        regs.x.ax = (unsigned short) (0x0600 + nrows);
    } else {
        regs.x.ax = (unsigned short) (0x0700 + -nrows);
    }
    __dpmi_int(0x10, &regs);
}

void fb_ConsoleScrollEx( int x1, int y1, int x2, int y2, int nrows )
{
    int rows;

        if( nrows == 0 )
        return;

        fb_ConsoleGetSize( NULL, &rows );

    if( nrows <= -rows || nrows >= rows )
        nrows = 0;

    fb_ConsoleScroll_BIOS( x1-1, y1-1, x2-1, y2-1, nrows );

#if 0
    if( nrows > 0 ) {
        fb_ConsoleLocate_BIOS( y2 - 1 - nrows, x1, -1 );
    } else if( nrows < 0 ) {
        fb_ConsoleLocate_BIOS( y1 - 1 - nrows, x1, -1 );
    } else {
        fb_ConsoleLocate_BIOS( y1 - 1, x1 - 1, -1 );
    }
#endif
}

void fb_ConsoleScroll( int nrows )
{
        int toprow, botrow;
    int cols;

        if( nrows == 0 )
        return;

        fb_ConsoleGetSize( &cols, NULL );
    fb_ConsoleGetView( &toprow, &botrow );

    return fb_ConsoleScrollEx( 1, toprow, cols, botrow, nrows );
}