/*
Last Update:28-Jan-1999

POFTFOLIO GRAPHICS LIBRARY V 0.1 ALFA

Biblioteka podstawowych procedur graficznych dla palmtopa atari portfolio
AUTOR: Pawel Wozniczka, e-mail: pwoz@ekonom.ar.wroc.pl

oprocz :
 copy_to_lcd() wzieta z pliku pf4.txt (portfolio newsletter)
 lineto(...)  wzieta z ksiazki:
		      "Procedury Graficzne dla kart EGA,VGA,SVGA"
		      Jaroslaw Skolimowski wyd. Helion
-------------------------------------------------------------------------
polityka dystrybucyjna:

Mozna dowolnie rozpowszechniac, uzywac, dokonywac zmian (o ile sa sensowne)
-------------------------------------------------------------------------
--------------------------------------------------------------------------
AUTOR --NIE!!!!--- PONOSI ZADNEJ ODPOWIEDZIALNOSCI ZA EWENTUALNE SZKODY
WYWOLANE UZYTKOWANIEM TEGO OPROGRAMOWANIA!!!!
-------------------------------------------------------------------------
-------------------------------------------------------------------------
Dostepne funkcje: (jesli dopiszesz jakas funkc. to dopisz ja tutaj)

set_mode(...) - ustawianie trybu graficznego
bios_pixel(...) - wstawia pixel bezposrednio na LCD
set_pixel(...) - ustawia pixel w video-ram
hor_line(..) - rysuje pozioma linie w V-ram'ie
vert_line(...) - rysuje pionowa linie w V-ram'ie
fill_rect(...) - rysuje wypelniony prostakat- uzywa hor_line(..)
inverse_buf() - invertuje zawarotsc V-ram'u
lineto(...) - rysuje dowolna linie w V-ram'ie
clear_buf() - czysci zawartosc V-ram'u
copy_to_lcd() - kopiuje zawartosc V-ram'u do LCD (wyswietla)

*/

#include<dos.h>
#include<mem.h>

unsigned char far *buf;  //wskaznik do V-ram'u


//------------------------------------------------------------------------
//parametry: mode: 1- tryb graficzny, 2- tryb tekstowy
//------------------------------------------------------------------------
void set_mode(unsigned char mode)
{
short int mod;

buf=(unsigned char far*)MK_FP(0xB000,0);

if(mode) mod=0x0A;
else mod=0x07;

asm{
  MOV AX,mod;
  INT 0x10;
}
}
//--------------------------------------------------------------------
void bios_pixel(short int x,short int y,unsigned char c)
{
asm{
 mov cx,x
 mov dx,y
 mov bx,0
 mov ah,12
 mov al,c
 int 0x10
 }
}
//--------------------------------------------------------------------
void set_pixel(unsigned char x,unsigned char y,unsigned char action)
{
unsigned int offset;

offset=y*30+(x>>3);
if(action==1) *(buf+offset)=*(buf+offset) | (128 >> (x%8));
if(action==0) *(buf+offset)=*(buf+offset) & ~(128 >> (x%8));
if(action==2) *(buf+offset)=*(buf+offset) ^ (128 >> (x%8));
}

//-----------------------------------------------------------------------
void hor_line(unsigned char x1,unsigned char x2,unsigned char y,unsigned char col)
{
unsigned char temp,l,deltax,x1m,x2m,byte,al,x1pd;
unsigned int offset;

if(x1>x2) {temp=x1;x1=x2;x2=temp;}
offset=y*30+(x1>>3);

deltax=(x2-x1);

if(deltax<8)
{
x1m=x1%8;

if(x1m==0) byte=255<<(8-deltax);
else {
	x1pd=x1m+deltax;
	if(x1pd<9)
	   {
	   *(buf+offset)=*(buf+offset) | ((255>>x1m) & (255<<(8-x1pd)));
		   return;
	   }
	else {
		*(buf+offset)=*(buf+offset) | (255>>x1m);
	       *(buf+offset+1)=*(buf+offset+1) | (255<<(8-(x1pd-8)));
	       return;
	     }

    }
*(buf+offset)=*(buf+offset) | byte;
return;
}
x1m=x1%8;
if(x1m==0) {*(buf+offset)=255;offset++;deltax-=8;}
else {*(buf+offset)=*(buf+offset) |(255>>x1m);offset++;deltax-=(8-x1m);}
while(deltax)
{
if(deltax>=8) {*(buf+offset)=255;offset++;deltax-=8;}
else
{
x2m=x2%8;
*(buf+offset)=*(buf+offset) | (255<<(8-deltax));
break;
}
}

}
//---------------------------------------------------------------------
void vert_line(unsigned char x,unsigned char y1,unsigned char y2)
{
unsigned char l;
unsigned int offset;

offset=y1*30+(x>>3);

for(l=0;l<=(y2-y1);l++)
{
*(buf+offset)=*(buf+offset) | (128>>x%8);
offset+=30;
}
}

//----------------------------------------------------------------------
void fill_rect(unsigned char x1,unsigned char y1,unsigned char x2,unsigned char y2,unsigned char action)
{
unsigned char sx,sy,l;

for(l=y1;l<=y2;l++) hor_line(x1,x2,l,action);

}
//-------------------------------------------------------------------------
void inverse_buf(void)
{
unsigned int offset;
for(offset=0;offset<1920;offset++) *(buf+offset)=~*(buf+offset);
}
//------------------------------------------------------------------------
void clear_buf(void)
{
_fmemset(buf,0,1920);
}

//-------------------------------------------------------------------------
void lineto(int startx,int starty,int endx,int endy,int act)



    {
    int count, deltax, deltay, error, t;


    if (endx < startx)
	{
	t = startx;             /* fold quadrants 2, 3 to 1, 4  */
	startx = endx;
	endx = t;
        t = starty;
	starty = endy;
	endy = t;
	}
    deltax = endx - startx;
    deltay = endy - starty;
    if (deltay < 0)
	{
	if (-deltay > deltax)   /* octant 7             */
	    {
	    count = -deltay;
	    error = deltay / 2;
	    do
		{
		set_pixel(startx, starty, act);

		starty--;
		if ((error += deltax) >= 0)
		    {
                    startx++;
                    error += deltay;
		    }
                }
            while (--count >= 0);
            }
	else                    /* octant 8             */
	    {
	    count = deltax;
            error = -deltax / 2;
            do
                {

	       set_pixel(startx, starty, act);

		startx++;
		if ((error -= deltay) >= 0)
		    {
		    starty--;
		    error -= deltax;
		    }
		}
	    while (--count >= 0);
	    }
	}
    else if (deltay > deltax)       /* octant 2         */
	{
	count = deltay;
	error = -deltay / 2;
	do
	    {
		set_pixel(startx, starty, act);

	    starty++;
	    if ((error += deltax) >= 0)
		{
		startx++;
		error -= deltay;
		}
	    }
	while (--count >= 0);
	}
    else                        /* octant 1             */
	{
	count = deltax;
	error = -deltax/2;
	do
	    {

		set_pixel(startx, starty, act);

	    startx++;
	    if ((error += deltay) >= 0)
		{
		starty++;
		error -= deltax;
		}
	    }
	while (--count >= 0);
	}
    }



//--------------------------------------------------------------------------
void copy_to_lcd(void)
{
asm cld
asm push ax
asm push cx
asm push dx
asm push bx
asm push si
asm push di
asm push ds

refresh_hop:
asm mov  si,0;
asm mov  ax,0xb000;
asm mov  ds,ax;
asm mov  di,64;

REFRESH2:

asm mov  cx,30;
asm mov  bx,si;
asm mov  al,0x0a;
asm mov  dx,0x8011;
asm cli;
asm out  dx,al;
asm mov  al,bl;
asm mov  dx,0x8010;
asm out  dx,al;
asm sti;
asm mov  al,0x0b;
asm mov  dx,0x8011;
asm cli;
asm out  dx,al;
asm mov  dx,0x8010;
asm mov  al,bh;
asm and  al,7;
asm out  dx,al;
asm sti;

REFRESH1:

asm lodsb;
asm ror  al,1;
asm mov  ah,al;
asm and  ah,136;
asm ror  al,1;
asm ror  al,1;
asm mov  bl,al;
asm and  bl,68;
asm or   ah,bl;
asm ror  al,1;
asm ror  al,1;
asm mov  bl,al;
asm and  bl,34;
asm or   ah,bl;
asm ror  al,1;
asm ror  al,1;
asm and  al,17;
asm or   al,ah;

asm mov  ah,al;
asm inc  dx;
asm mov  al,0x0c;
asm cli;
asm out  dx,al;
asm mov  al,ah;
asm mov  dx,0x8010;
asm out  dx,al;
asm sti;
asm loop REFRESH1
asm dec  di;
asm jnz  REFRESH2

asm pop  ds
asm pop  di
asm pop  si
asm pop  bx
asm pop  dx
asm pop  cx
asm pop  ax

 }