/*
 *  Copyright (C) 2002-2003  The DOSBox Team
 *
 *  This program is free software; you can redistribute it and/or modify
 *  it under the terms of the GNU General Public License as published by
 *  the Free Software Foundation; either version 2 of the License, or
 *  (at your option) any later version.
 *
 *  This program is distributed in the hope that it will be useful,
 *  but WITHOUT ANY WARRANTY; without even the implied warranty of
 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *  GNU Library General Public License for more details.
 *
 *  You should have received a copy of the GNU General Public License
 *  along with this program; if not, write to the Free Software
 *  Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
 */

/* $Id: int10_char.cpp,v 1.19 2003/09/24 19:33:26 qbix79 Exp $ */

/* Character displaying moving functions */

#include "dosbox.h"
#include "bios.h"
#include "mem.h"
#include "inout.h"
#include "int10.h"

static INLINE void CGA_CopyRow(Bit8u cleft,Bit8u cright,Bit8u rold,Bit8u rnew,PhysPt base) {
	Bit8u cheight = real_readb(BIOSMEM_SEG,BIOSMEM_CHAR_HEIGHT);
	PhysPt dest=base+((CurMode->twidth*rnew)*(cheight/2)+cleft)*2;
	PhysPt src=base+((CurMode->twidth*rold)*(cheight/2)+cleft)*2;	
	Bitu copy=(cright-cleft)*2;Bitu nextline=CurMode->twidth*2;
	for (Bitu i=0;i<cheight/2;i++) {
		MEM_BlockCopy(dest,src,copy);
		MEM_BlockCopy(dest+8*1024,src+8*1024,copy);
		dest+=nextline;src+=nextline;
	}
}

static INLINE void EGA16_CopyRow(Bit8u cleft,Bit8u cright,Bit8u rold,Bit8u rnew,PhysPt base) {
	PhysPt src,dest;Bitu copy;
	Bit8u cheight = real_readb(BIOSMEM_SEG,BIOSMEM_CHAR_HEIGHT);
	dest=base+(CurMode->twidth*rnew)*cheight+cleft;	
	src=base+(CurMode->twidth*rold)*cheight+cleft;	
	Bitu nextline=CurMode->twidth;
	/* Setup registers correctly */
	IO_Write(0x3ce,5);IO_Write(0x3cf,1);		/* Memory transfer mode */
	IO_Write(0x3c4,2);IO_Write(0x3c5,0xf);		/* Enable all Write planes */
	/* Do some copying */
	Bitu rowsize=(cright-cleft);
	copy=cheight;
	for (;copy>0;copy--) {
		for (Bitu x=0;x<rowsize;x++) mem_writeb(dest+x,mem_readb(src+x));
		dest+=nextline;src+=nextline;
	}
	/* Restore registers */
	IO_Write(0x3ce,5);IO_Write(0x3cf,0);		/* Normal transfer mode */
}


static INLINE void TEXT_CopyRow(Bit8u cleft,Bit8u cright,Bit8u rold,Bit8u rnew,PhysPt base) {
	PhysPt src,dest;
	src=base+(rold*CurMode->twidth+cleft)*2;
	dest=base+(rnew*CurMode->twidth+cleft)*2;
	MEM_BlockCopy(dest,src,(cright-cleft)*2);
}

static INLINE void CGA_FillRow(Bit8u cleft,Bit8u cright,Bit8u row,PhysPt base,Bit8u attr) {
	Bit8u cheight = real_readb(BIOSMEM_SEG,BIOSMEM_CHAR_HEIGHT);
	PhysPt dest=base+((CurMode->twidth*row)*(cheight/2)+cleft)*2;
	Bitu copy=(cright-cleft)*2;Bitu nextline=CurMode->twidth*2;
	for (Bitu i=0;i<cheight/2;i++) {
		for (Bitu x=0;x<copy;x++) {
			mem_writeb(dest+x,attr);
			mem_writeb(dest+8*1024+x,attr);
		}
		dest+=nextline;
	}
}

static INLINE void EGA16_FillRow(Bit8u cleft,Bit8u cright,Bit8u row,PhysPt base,Bit8u attr) {
	/* Set Bitmask / Color / Full Set Reset */
	IO_Write(0x3ce,0x8);IO_Write(0x3cf,0xff);
	IO_Write(0x3ce,0x0);IO_Write(0x3cf,attr);
	IO_Write(0x3ce,0x1);IO_Write(0x3cf,0xf);
	/* Write some bytes */
	PhysPt dest;
	Bit8u cheight = real_readb(BIOSMEM_SEG,BIOSMEM_CHAR_HEIGHT);
	dest=base+(CurMode->twidth*row)*cheight+cleft;	
	Bitu nextline=CurMode->twidth;
	Bitu copy = cheight;	Bitu rowsize=(cright-cleft);
	for (;copy>0;copy--) {
		for (Bitu x=0;x<rowsize;x++) mem_writeb(dest+x,0xff);
		dest+=nextline;
	}
	IO_Write(0x3cf,0);

}

static INLINE void TEXT_FillRow(Bit8u cleft,Bit8u cright,Bit8u row,PhysPt base,Bit8u attr) {
	/* Do some filing */
	PhysPt dest;
	dest=base+(row*CurMode->twidth+cleft)*2;
	Bit16u fill=(attr<<8)+' ';
	for (Bit8u x=0;x<(cright-cleft);x++) {
		mem_writew(dest,fill);
		dest+=2;
	}
}


void INT10_ScrollWindow(Bit8u rul,Bit8u cul,Bit8u rlr,Bit8u clr,Bit8s nlines,Bit8u attr,Bit8u page) {
/* Do some range checking */
	if (CurMode->type!=M_TEXT16) page=0xff;
	BIOS_NCOLS;BIOS_NROWS;
	if(rul>rlr) return;
	if(cul>clr) return;
	if(rlr>=nrows) rlr=(Bit8u)nrows-1;
	if(clr>=ncols) clr=(Bit8u)ncols-1;
	clr++;

	/* Get the correct page */
	if(page==0xFF) page=real_readb(BIOSMEM_SEG,BIOSMEM_CURRENT_PAGE);
	PhysPt base=CurMode->pstart+page*real_readw(BIOSMEM_SEG,BIOSMEM_PAGE_SIZE);

	/* See how much lines need to be copied */
	Bit8u start,end;Bits next;
	/* Copy some lines */
	if (nlines>0) {
		start=rlr-nlines+1;
		end=rul;
		next=-1;
	} else if (nlines<0) {
		start=rul-nlines-1;
		end=rlr;
		next=1;
	} else {
		nlines=rlr-rul+1;
		goto filling;
	}
	while (start!=end) {
		start+=next;
		switch (CurMode->type) {
		case M_TEXT16:
			TEXT_CopyRow(cul,clr,start,start+nlines,base);break;
		case M_CGA2:
		case M_CGA4:
			CGA_CopyRow(cul,clr,start,start+nlines,base);break;
		case M_EGA16:		
			EGA16_CopyRow(cul,clr,start,start+nlines,base);break;
		default:
			LOG(LOG_INT10,LOG_ERROR)("Unhandled mode %d for scroll",CurMode->type);
		}	
	} 
	/* Fill some lines */
filling:
	if (nlines>0) {
		start=rul;
	} else {
		nlines=-nlines;
		start=rlr-nlines+1;
	}
	for (;nlines>0;nlines--) {
		switch (CurMode->type) {
		case M_TEXT16:
			TEXT_FillRow(cul,clr,start,base,attr);break;
		case M_CGA2:
		case M_CGA4:
			CGA_FillRow(cul,clr,start,base,attr);break;
		case M_EGA16:		
			EGA16_FillRow(cul,clr,start,base,attr);break;
		default:
			LOG(LOG_INT10,LOG_ERROR)("Unhandled mode %d for scroll",CurMode->type);
		}	
		start++;
	} 
}

void INT10_SetActivePage(Bit8u page) {

	Bit16u mem_address;
	
	if (page>7) return;
	mem_address=page*real_readw(BIOSMEM_SEG,BIOSMEM_PAGE_SIZE);
	/* Write the new page start */
	real_writew(BIOSMEM_SEG,BIOSMEM_CURRENT_START,mem_address);
	if (CurMode->mode<0x8) mem_address>>=1;
	/* Write the new start address in vgahardware */
	IO_Write(real_readw(BIOSMEM_SEG,BIOSMEM_CRTC_ADDRESS),0x0c);
	IO_Write(real_readw(BIOSMEM_SEG,BIOSMEM_CRTC_ADDRESS)+1,(Bit8u)(mem_address>>8));
	IO_Write(real_readw(BIOSMEM_SEG,BIOSMEM_CRTC_ADDRESS),0x0d);
	IO_Write(real_readw(BIOSMEM_SEG,BIOSMEM_CRTC_ADDRESS)+1,(Bit8u)mem_address);

	// And change the BIOS page
	real_writeb(BIOSMEM_SEG,BIOSMEM_CURRENT_PAGE,page);
	Bit8u cur_row=CURSOR_POS_ROW(page);
	Bit8u cur_col=CURSOR_POS_COL(page);
	// Display the cursor, now the page is active
	INT10_SetCursorPos(cur_row,cur_col,page);
}

void INT10_SetCursorShape(Bit8u first,Bit8u last) {
	real_writew(BIOSMEM_SEG,BIOSMEM_CURSOR_TYPE,last|(first<<8));
	/* Skip CGA cursor emulation if EGA/VGA system is active */
	if (!(real_readb(BIOSMEM_SEG,BIOSMEM_VIDEO_CTL) & 0x8)) {
		/* Check for CGA type 01, invisible */
		if ((first & 0x60) == 0x20) {
			first=0x1e;
			last=0x00;
			goto dowrite;
		}
		/* Check if we need to convert CGA Bios cursor values */
		if (!(real_readb(BIOSMEM_SEG,BIOSMEM_VIDEO_CTL) & 0x1)) {
			if (CurMode->mode>0x3) goto dowrite;	//Only mode 0-3 are text modes on cga
			if ((first & 0xe0) || (last & 0xe0)) goto dowrite;
			Bit8u cheight=real_readb(BIOSMEM_SEG,BIOSMEM_CHAR_HEIGHT)-1;
			/* Creative routine i based of the original ibmvga bios */
			if (last<first) {
				if (!last) goto dowrite;
				first=last;
				last=cheight;
			/* Test if this might be a cga style cursor set, if not don't do anything */
			} else if (((first | last)>=cheight) || !(last==(cheight-1)) || !(first==cheight) ) {
				if (last<=3) goto dowrite;
				if (first+2<last) {
					if (first>2) {
						first=(cheight+1)/2;
						last=cheight;
					} else {
						last=cheight;
					}
				} else {
					first=(first-last)+cheight;
					last=cheight;
					if (cheight>0xc) {
						first--;
						last--;
					}
				}
			}

		}
	}
dowrite:
	IO_Write(0x3d4,0xa);IO_Write(0x3d5,first);
	IO_Write(0x3d4,0xb);IO_Write(0x3d5,last);
}


void INT10_SetCursorPos(Bit8u row,Bit8u col,Bit8u page) {
	Bit16u address;

	if(page>7) return;
	// Bios cursor pos
	real_writeb(BIOSMEM_SEG,BIOSMEM_CURSOR_POS+page*2,col);
	real_writeb(BIOSMEM_SEG,BIOSMEM_CURSOR_POS+page*2+1,row);
	// Set the hardware cursor
	Bit8u current=real_readb(BIOSMEM_SEG,BIOSMEM_CURRENT_PAGE);
	if(page==current) {
		// Get the dimensions
		BIOS_NCOLS;
		// Calculate the address knowing nbcols nbrows and page num
		address=(ncols*row)+col+real_readw(BIOSMEM_SEG,BIOSMEM_CURRENT_START);
		// CRTC regs 0x0e and 0x0f
		IO_Write(real_readw(BIOSMEM_SEG,BIOSMEM_CRTC_ADDRESS),0x0e);
		IO_Write(real_readw(BIOSMEM_SEG,BIOSMEM_CRTC_ADDRESS)+1,(Bit8u)(address>>8));
		IO_Write(real_readw(BIOSMEM_SEG,BIOSMEM_CRTC_ADDRESS),0x0f);
		IO_Write(real_readw(BIOSMEM_SEG,BIOSMEM_CRTC_ADDRESS)+1,(Bit8u)address);
	}
}


void INT10_ReadCharAttr(Bit16u * result,Bit8u page) {
	if(page==0xFF) page=real_readb(BIOSMEM_SEG,BIOSMEM_CURRENT_PAGE);
	Bit8u cur_row=CURSOR_POS_ROW(page);
	Bit8u cur_col=CURSOR_POS_COL(page);
 
	// Compute the address  
	Bit16u address=page*real_readw(BIOSMEM_SEG,BIOSMEM_PAGE_SIZE);
	address+=(cur_row*real_readw(BIOSMEM_SEG,BIOSMEM_NB_COLS)+cur_col)*2;
	// REad the char 
	PhysPt where = CurMode->pstart+address;
	*result=mem_readw(where);
}


static void WriteChar(Bit16u col,Bit16u row,Bit8u page,Bit8u chr,Bit8u attr,bool useattr) {
	PhysPt fontdata;
	Bitu x,y;
	Bit8u cheight = real_readb(BIOSMEM_SEG,BIOSMEM_CHAR_HEIGHT);
	switch (CurMode->type) {
	case M_TEXT16:
		{	
			// Compute the address  
			Bit16u address=page*real_readw(BIOSMEM_SEG,BIOSMEM_PAGE_SIZE);
			address+=(row*real_readw(BIOSMEM_SEG,BIOSMEM_NB_COLS)+col)*2;
			// Write the char 
			PhysPt where = CurMode->pstart+address;
			mem_writeb(where,chr);
			if (useattr) {
				mem_writeb(where+1,attr);
			}
		}
		return;
	case M_CGA4:
	case M_CGA2:
		if (chr<128) fontdata=Real2Phys(RealGetVec(0x43))+chr*cheight; //was plain 8
		else {
			chr-=128;
			fontdata=Real2Phys(RealGetVec(0x1F))+(chr)*cheight; //was plain 8
		}
		break;
	default:
		fontdata=Real2Phys(RealGetVec(0x43))+chr*cheight;
		break;
	}
	x=8*col;
	y=cheight*row;
	//TODO Check for out of bounds
	for (Bit8u h=0;h<cheight;h++) {
		Bit8u bitsel=128;
		Bit8u bitline=mem_readb(fontdata++); //added ++ for at least the CGA modes.
		Bit16u tx=x;
		while (bitsel) {
			if (bitline&bitsel) INT10_PutPixel(tx,y,page,attr);
			else INT10_PutPixel(tx,y,page,attr & 0x80);
			tx++;
			bitsel>>=1;
		}
		y++;
	}

}

void INT10_WriteChar(Bit8u chr,Bit8u attr,Bit8u page,Bit16u count,bool showattr) {
	//TODO Check if this page thing is correct
	if (CurMode->type!=M_TEXT16) page=0xff;
	if(page==0xFF) page=real_readb(BIOSMEM_SEG,BIOSMEM_CURRENT_PAGE);
	Bit8u cur_row=CURSOR_POS_ROW(page);
	Bit8u cur_col=CURSOR_POS_COL(page);
	BIOS_NCOLS;BIOS_NROWS;
	while (count>0) {
		WriteChar(cur_col,cur_row,page,chr,attr,showattr);
		count--;
		cur_col++;
		if(cur_col==ncols) {
			cur_col=0;
			cur_row++;
		}
	}
}


void INT10_TeletypeOutput(Bit8u chr,Bit8u attr,bool showattr) {
	//TODO Check if this page thing is correct
	Bit8u page=real_readb(BIOSMEM_SEG,BIOSMEM_CURRENT_PAGE);
	BIOS_NCOLS;BIOS_NROWS;
	Bit8u cur_row=CURSOR_POS_ROW(page);
	Bit8u cur_col=CURSOR_POS_COL(page);

	switch (chr) {
	case 7:
	//TODO BEEP
	break;
	case 8:
		if(cur_col>0) cur_col--;
		break;
	case '\r':
		cur_col=0;
		break;
	case '\n':
		cur_col=0;
		cur_row++;
		break;
	case '\t':
		do {
			INT10_TeletypeOutput(' ',attr,showattr);
			cur_row=CURSOR_POS_ROW(page);
			cur_col=CURSOR_POS_COL(page);
		} while(cur_col%8);
		break;
	default:
		/* Draw the actual Character */
		WriteChar(cur_col,cur_row,page,chr,attr,showattr);
		cur_col++;
	}
	if(cur_col==ncols) {
		cur_col=0;
		cur_row++;
	}
	// Do we need to scroll ?
	if(cur_row==nrows) {
		INT10_ScrollWindow(0,0,nrows-1,ncols-1,-1,0x07,page);
		cur_row--;
	}
 	// Set the cursor for the page
	INT10_SetCursorPos(cur_row,cur_col,page);
}

void INT10_WriteString(Bit8u row,Bit8u col,Bit8u flag,Bit8u attr,PhysPt string,Bit16u count,Bit8u page) {
	//TODO Check if this page thing is correct
	if (CurMode->type!=M_TEXT16) page=0xff;

	if(page==0xFF) page=real_readb(BIOSMEM_SEG,BIOSMEM_CURRENT_PAGE);
	BIOS_NCOLS;BIOS_NROWS;
	Bit8u cur_row=CURSOR_POS_ROW(page);
	Bit8u cur_col=CURSOR_POS_COL(page);
	
	// if row=0xff special case : use current cursor position
	if (row==0xff) {
		row=cur_row;
		col=cur_col;
	}

	INT10_SetCursorPos(row,col,page);
	while (count>0) {
		Bit8u chr=mem_readb(string);
		string++;
		if (flag&2) {
			attr=mem_readb(string);
			string++;
		}
		INT10_TeletypeOutput(chr,attr,true);
		count--;
	}
	if (flag & 1) {
		INT10_SetCursorPos(cur_row,cur_col,page);
	}
}