cgascr.cc.svn-base

德国Erlangen大学教学操作系统源码。

/* $Id: cgascr.cc,v 1.4 2002/10/15 11:42:22 gal Exp $ */

/*****************************************************************************/
/* Betriebssysteme                                                           */
/*---------------------------------------------------------------------------*/
/*                                                                           */
/*                             C G A _ S C R E E N                           */
/*                                                                           */
/*---------------------------------------------------------------------------*/
/* Mit Hilfe dieser Klasse kann man auf den Bildschirm des PCs zugreifen.    */
/* Der Zugriff erfolgt direkt auf der Hardwareebene, d.h. ueber den Bild-    */
/* schirmspeicher bzw. die I/O-Ports der Grafikkarte.                        */
/*****************************************************************************/

#include "machine/cgascr.h"
#include "machine/io_port.h"
#include "object/o_stream.h"

CGA_Screen::CGA_Screen()
	: m_screen((char*)0xb8000), m_index(0x3d4), m_data(0x3d5), m_curX(0), m_curY(0),
	  m_color(CGA_Screen::CGA_Attrib::fg_white | CGA_Screen::CGA_Attrib::bg_black | CGA_Screen::CGA_Attrib::noblink)
{
}
	
CGA_Screen::CGA_Screen(CGA_Screen &scr)
	: m_screen((char*)0xb8000), m_index(0x3d4), m_data(0x3d5), m_curX(scr.m_curX), m_curY(scr.m_curY), m_color(scr.m_color)
{
}

CGA_Screen::~CGA_Screen()
{
}

void CGA_Screen::show (int x, int y, char c, unsigned char attrib)
{
	int idx = offset(x, y);
	if(idx < 0)
		return;
		
	m_screen[idx] = c;
	m_screen[idx+1] = attrib;
}

void CGA_Screen::setpos (int x, int y)
{
	int pos = offset(x, y);
	if(pos < 0)
		return;
	pos /= 2;
	
	m_index.outb(14);
	m_data.outb((pos >> 8) & 0xFF );
	m_index.outb(15);
	m_data.outb(pos & 0xFF);
	m_curX = x;
	m_curY = y;
}

void CGA_Screen::getpos (int &x, int &y)
{
	unsigned int offset = 0;
	m_index.outb(14);
	offset |= ( (m_data.inb() & 0xFF) << 8 );
	m_index.outb(15);
	offset |= ( m_data.inb() & 0xFF );
	x = m_curX = offset % CGA_Attrib::screen_width;
	y = m_curY = offset / CGA_Attrib::screen_width;
}

void CGA_Screen::print (char* text, int length, unsigned char attrib)
{
	unsigned int len = (unsigned int)length;
	for(unsigned int i = 0; i < len; i++)
		print(text[i], attrib);
}

void CGA_Screen::print (char c, unsigned char attrib)
{
	if(c != '\n') {
		show(m_curX, m_curY, c, attrib);
		incpos();
	} else {
		println();
	}
}

void CGA_Screen::println ()
{
	m_curX = CGA_Attrib::screen_width - 1;
	incpos();
}

void CGA_Screen::incpos()
{
	m_curX++;
	if(m_curX >= CGA_Attrib::screen_width) {
		m_curX = 0;
		m_curY++;
		if(m_curY >= CGA_Attrib::screen_height) {
			scroll(m_curY + 1 - CGA_Attrib::screen_height);
			m_curY = CGA_Attrib::screen_height - 1;
		}
	}
	setpos(m_curX, m_curY);
}

void CGA_Screen::decpos()
{
	m_curX--;
	if(m_curX < 0) {
		m_curX = 0;
		m_curY--;
		if(m_curY < 0)
			m_curY = 0;
	}
	setpos(m_curX, m_curY);
}

void CGA_Screen::scroll(int line)
{
	int totalOffset = CGA_Attrib::screen_width * CGA_Attrib::screen_height * 2 * sizeof(char);
	if(line <= 0) {
		return;
		
	} else if(line >= CGA_Attrib::screen_height) {
		for(unsigned int head = 0; (int)head < totalOffset; head++)
			m_screen[head] = 0;
			
	} else {
		for(unsigned int head = 0, tail = offset(0, line); (int)tail < totalOffset; head++, tail++)
			m_screen[head] = m_screen[tail];
		
		for(unsigned int tail = offset(0, CGA_Attrib::screen_height - line); (int)tail < totalOffset; tail++)
			m_screen[tail] = 0;
	}
}

int CGA_Screen::offset (int x, int y) const
{
	if (x < 0 || y < 0 || x >= CGA_Attrib::screen_width || y >= CGA_Attrib::screen_height)
		return -1;
	else
		return (y * CGA_Attrib::screen_width + x) * 2 * sizeof(char);
}


void CGA_Screen::clear()
{
	scroll(CGA_Attrib::screen_height);
	setpos(0, 0);
}


void CGA_Screen::goto_head()
{
	m_curX = 0;
	setpos(m_curX, m_curY);
}

void CGA_Screen::goto_end()
{
	m_curX = CGA_Screen::CGA_Attrib::screen_width - 1;
	setpos(m_curX, m_curY);
}

void CGA_Screen::set_fg_color(int color)
{
	m_color = (m_color & ~0xf) | (color & 0xf);
}

void CGA_Screen::set_bg_color(int color)
{
	m_color = (m_color & ~0x70) | (color & 0x70);
}

void CGA_Screen::set_blink(bool on)
{
	m_color = on ? (m_color | 0x80) : (m_color & ~0x80);
}

void CGA_Screen::set_color(int color)
{
	m_color = color & 0xff;
}


int CGA_Screen::get_fg_color()
{
	return m_color & 0xf;
}

int CGA_Screen::get_bg_color()
{
	return m_color & 0x70;
}

bool CGA_Screen::is_blink()
{
	return m_color & 0x80;
}

int CGA_Screen::get_color()
{
	return m_color & 0xff;
}