/************************************
      Seta custom ST-0016 chip
    driver by Tomasz Slanina
************************************/

#include "driver.h"
#include "vidhrdw/generic.h"
#include "machine/random.h"
#include "state.h"

UINT8 *st0016_charram,*st0016_spriteram,*st0016_paletteram;

#define ISMACS (st0016_game&0x80)

#define ST0016_MAX_SPR_BANK   0x10
#define ST0016_MAX_CHAR_BANK  0x10000
#define ST0016_MAX_PAL_BANK   4

#define ST0016_SPR_BANK_SIZE  0x1000
#define ST0016_CHAR_BANK_SIZE 0x20
#define ST0016_PAL_BANK_SIZE  0x200

#define UNUSED_PEN 1024

#define ST0016_SPR_BANK_MASK  (ST0016_MAX_SPR_BANK-1)
#define ST0016_CHAR_BANK_MASK (ST0016_MAX_CHAR_BANK-1)
#define ST0016_PAL_BANK_MASK  (ST0016_MAX_PAL_BANK-1)

static int st0016_spr_bank,st0016_spr2_bank,st0016_pal_bank,st0016_char_bank;
static int spr_dx,spr_dy;

int st0016_game;
static UINT8 st0016_vregs[0xc0];
static int st0016_ramgfx;

static gfx_layout charlayout =
{
	8,8,
	0x10000,
	4,
	{ 0, 1, 2, 3 },
	{ 1*4, 0*4, 3*4, 2*4, 5*4, 4*4, 7*4, 6*4 },
	{ 0*32, 1*32, 2*32, 3*32, 4*32, 5*32, 6*32, 7*32 },
	8*8*4
};

WRITE8_HANDLER(st0016_sprite_bank_w)
{
/*
    76543210
        xxxx - spriteram  bank1
    xxxx     - spriteram  bank2
*/
	st0016_spr_bank=data&ST0016_SPR_BANK_MASK;
	st0016_spr2_bank=(data>>4)&ST0016_SPR_BANK_MASK;
}

WRITE8_HANDLER(st0016_palette_bank_w)
{
/*
    76543210
          xx - palram  bank
    xxxxxx   - unknown/unused
*/
	st0016_pal_bank=data&ST0016_PAL_BANK_MASK;
}

WRITE8_HANDLER(st0016_character_bank_w)
{
/*
    fedcba9876543210
    xxxxxxxxxxxxxxxx - character (bank )
*/

	if(offset&1)
		st0016_char_bank=(st0016_char_bank&0xff)|(data<<8);
	else
		st0016_char_bank=(st0016_char_bank&0xff00)|data;

	st0016_char_bank&=ST0016_CHAR_BANK_MASK;
}


READ8_HANDLER (st0016_sprite_ram_r)
{
	return st0016_spriteram[ST0016_SPR_BANK_SIZE*st0016_spr_bank+offset];
}

WRITE8_HANDLER (st0016_sprite_ram_w)
{

	st0016_spriteram[ST0016_SPR_BANK_SIZE*st0016_spr_bank+offset]=data;
}

READ8_HANDLER (st0016_sprite2_ram_r)
{
	return st0016_spriteram[ST0016_SPR_BANK_SIZE*st0016_spr2_bank+offset];
}

WRITE8_HANDLER (st0016_sprite2_ram_w)
{
	st0016_spriteram[ST0016_SPR_BANK_SIZE*st0016_spr2_bank+offset]=data;
}

READ8_HANDLER (st0016_palette_ram_r)
{
	return st0016_paletteram[ST0016_PAL_BANK_SIZE*st0016_pal_bank+offset];
}

WRITE8_HANDLER (st0016_palette_ram_w)
{
	int color=(ST0016_PAL_BANK_SIZE*st0016_pal_bank+offset)/2;
	int r,g,b,val;
	st0016_paletteram[ST0016_PAL_BANK_SIZE*st0016_pal_bank+offset]=data;
	val=st0016_paletteram[color*2]+(st0016_paletteram[color*2+1]<<8);
	r=(val&31)<<3;
	val>>=5;
	g=(val&31)<<3;
	val>>=5;
	b=(val&31)<<3;
	if(!color)
		palette_set_color(UNUSED_PEN,r,g,b); /* same as color 0 - bg ? */
	palette_set_color(color,r,g,b);
}

READ8_HANDLER(st0016_character_ram_r)
{
	return st0016_charram[ST0016_CHAR_BANK_SIZE*st0016_char_bank+offset];
}

WRITE8_HANDLER(st0016_character_ram_w)
{
	st0016_charram[ST0016_CHAR_BANK_SIZE*st0016_char_bank+offset]=data;
	decodechar(Machine->gfx[st0016_ramgfx], st0016_char_bank,(UINT8 *) st0016_charram,  &charlayout);
}

READ8_HANDLER(st0016_vregs_r)
{
/*
        $0, $1 = max scanline(including vblank)/timer? ($3e7)

        $8-$40 = bg tilemaps  (8 bytes each) :
                   0 - ? = usually 0/20/ba*
                   1 - 0 = disabled , !zero = address of tilemap in spriteram /$1000  (for example: 3 -> tilemap at $3000 )
                   2 - ? = usually ff/1f/af*
                   3 - priority ? = 0 - under sprites , $ff - over sprites \
                   4 - ? = $7f/$ff
                   5 - ? = $29/$20 (29 when tilemap must be drawn over sprites . maybe this is real priority ?)
                   6 - ? = 0
                   7 - ? =$20/$10/$12*


        $40-$60 = scroll registers , X.w, Y.w

*/

	switch (offset)
	{
		case 0:
		case 1:
			return mame_rand();
	}

	return st0016_vregs[offset];
}

READ8_HANDLER(st0016_dma_r)
{
	/* bits 0 and 1 = 0 -> DMA transfer complete */
	if(ISMACS)
		return 0;
	else
		return 0;
}


WRITE8_HANDLER(st0016_vregs_w)
{
	/*

       I/O ports:

        $a0 \
        $a1 - source address >> 1
        $a2 /

        $a3 \
        $a4 - destination address >> 1  (inside character ram)
        $a5 /

        $a6 \
        &a7 - (length inbytes - 1 ) >> 1

        $a8 - 76543210
              ??faaaaa

              a - most sign. bits of length
              f - DMA start latch

    */

	st0016_vregs[offset]=data;
	if(offset==0xa8 && (data&0x20))
	{
		UINT32 srcadr=(st0016_vregs[0xa0]|(st0016_vregs[0xa1]<<8)|(st0016_vregs[0xa2]<<16))<<1;
		UINT32 dstadr=(st0016_vregs[0xa3]|(st0016_vregs[0xa4]<<8)|(st0016_vregs[0xa5]<<16))<<1;
		UINT32 length=((st0016_vregs[0xa6]|(st0016_vregs[0xa7]<<8)|((st0016_vregs[0xa8]&0x1f)<<16))+1)<<1;
		while(length>0)
		{
			if( srcadr < (memory_region_length(REGION_CPU1)-0x10000) && (dstadr < ST0016_MAX_CHAR_BANK*ST0016_CHAR_BANK_SIZE))
			{
				st0016_char_bank=dstadr>>5;
				st0016_character_ram_w(dstadr&0x1f,memory_region(REGION_CPU1)[0x10000+srcadr]);
				srcadr++;
				dstadr++;
				length--;
			}
			else
			{
				/* samples ? sound dma ? */
				logerror("unknown DMA copy : src - %X, dst - %X, len - %X, PC - %X\n",srcadr,dstadr,length,activecpu_get_previouspc());
				break;
			}
		}
	}
}

static void drawsprites( mame_bitmap *bitmap, const rectangle *cliprect)
{
	/*
    object ram :

     each entry is 8 bytes:

       76543210 (bit)
     0 llllllll
     1 ---1SSSl
     2 oooooooo
     3 fooooooo
     4 xxxxxxxx
     5 ------xx
     6 yyyyyyyy
     7 ------yy

       1 - always(?) set
       S - scroll index ? (ports $40-$60, X(word),Y(word) )
       l - sublist length (8 byte entries -1)
       o - sublist offset (*8 to get real offset)
       f - end of list  flag
       x,y - sprite coords

     sublist format (8 bytes/entry):

       76543210
     0 cccccccc
     1 cccccccc
     2 --kkkkkk
     3 QW------
     4 xxxxxxxx
     5 -B---XXx
     6 yyyyyyyy
     7 -----YYy

      c - character code
      k - palette
      QW - flips
      x,y - coords
      XX,YY - size (1<<size)
      B - merge pixel data with prevoius one (8bpp mode - neratte: seta logo and title screen)

    */

	int i,j,lx,ly,x,y,code,offset,length,sx,sy,color,flipx,flipy,scrollx,scrolly;


	for(i=0;i<ST0016_SPR_BANK_SIZE*ST0016_MAX_SPR_BANK;i+=8)
	{
		x=st0016_spriteram[i+4]+((st0016_spriteram[i+5]&3)<<8);
  	y=st0016_spriteram[i+6]+((st0016_spriteram[i+7]&3)<<8);

  	scrollx=(st0016_vregs[(((st0016_spriteram[i+1]&0x0f)>>1)<<2)+0x40]+256*st0016_vregs[(((st0016_spriteram[i+1]&0x0f)>>1)<<2)+1+0x40])&0x3ff;
  	scrolly=(st0016_vregs[(((st0016_spriteram[i+1]&0x0f)>>1)<<2)+2+0x40]+256*st0016_vregs[(((st0016_spriteram[i+1]&0x0f)>>1)<<2)+3+0x40])&0x3ff;

		if(!ISMACS)
		{
	  	if (x & 0x200) x-= 0x400; /*sign */
  		if (y & 0x200) y-= 0x400;

  		if (scrollx & 0x200) scrollx-= 0x400; /*sign */
  		if (scrolly & 0x200) scrolly-= 0x400;
  	}

  	x+=scrollx;
  	y+=scrolly;

  	if(ISMACS)
  		y+=0x20;

		if( st0016_spriteram[i+3]&0x80) /* end of list */
			break;

		offset=st0016_spriteram[i+2]+256*(st0016_spriteram[i+3]);
		offset<<=3;

		length=st0016_spriteram[i+0]+1+256*(st0016_spriteram[i+1]&1);

		if(offset<ST0016_SPR_BANK_SIZE*ST0016_MAX_SPR_BANK)
		{
			for(j=0;j<length;j++)
			{
				code=st0016_spriteram[offset]+256*st0016_spriteram[offset+1];
				sx=st0016_spriteram[offset+4]+((st0016_spriteram[offset+5]&1)<<8);
				sy=st0016_spriteram[offset+6]+((st0016_spriteram[offset+7]&1)<<8);

				if(ISMACS)
					sy=0xe0-sy;

				sx+=x;
				sy+=y;
				color=st0016_spriteram[offset+2]&0x3f;
				lx=(st0016_spriteram[offset+5]>>2)&3;
				ly=(st0016_spriteram[offset+7]>>2)&3;
				flipx=st0016_spriteram[offset+3]&0x80;
				flipy=st0016_spriteram[offset+3]&0x40;

				if(ISMACS)
					sy-=(1<<ly)*8;

				{
					int x0,y0,i0=0;
					for(x0=(flipx?((1<<lx)-1):0);x0!=(flipx?-1:(1<<lx));x0+=(flipx?-1:1))
						for(y0=(flipy?((1<<ly)-1):0);y0!=(flipy?-1:(1<<ly));y0+=(flipy?-1:1))
					 	{
							/* custom draw */
							UINT16 *destline;
							int yloop,xloop;
							int ypos, xpos;
							int tileno;
							const gfx_element *gfx = Machine->gfx[0];
							UINT8 *srcgfx;
							int gfxoffs;
							ypos = sy+y0*8+spr_dy;
							xpos = sx+x0*8+spr_dx;
							tileno = code+i0++;
							gfxoffs = 0;
							srcgfx= gfx->gfxdata+(64*tileno);

							for (yloop=0; yloop<8; yloop++)
							{
								UINT16 drawypos;

								if (!flipy) {drawypos = ypos+yloop;} else {drawypos = (ypos+8-1)-yloop;}
								destline = (UINT16 *)(bitmap->line[drawypos]);

								for (xloop=0; xloop<8; xloop++)
								{
									UINT16 drawxpos;
									int pixdata;
									pixdata = srcgfx[gfxoffs];

									if (!flipx) { drawxpos = xpos+xloop; } else { drawxpos = (xpos+8-1)-xloop; }

									if ((drawxpos >= cliprect->min_x) && (drawxpos <= cliprect->max_x) && (drawypos >= cliprect->min_y) && (drawypos <= cliprect->max_y) )
									{
										/*Quick and dirty kludge to get past the booting tests in yuka*/
										#if 0
										if(st0016_spriteram[offset+5]&0x20)
										{
											#ifdef MAME_DEBUG
											ui_popup("sprite bit activated");
											#endif
											break;
										}
										#endif

										if(st0016_spriteram[offset+5]&0x40)
											destline[drawxpos] |= pixdata<<4;
										else
											if(pixdata || destline[drawxpos]==UNUSED_PEN)
												destline[drawxpos] = pixdata + (color*16);
									}

									gfxoffs++;
								}
							}
					 	}
				}
				offset+=8;
				if(offset>=ST0016_SPR_BANK_SIZE*ST0016_MAX_SPR_BANK)
					break;
			}
		}
	}
}

WRITE8_HANDLER(st0016_rom_bank_w);
extern int st0016_rom_bank;

static void st0016_postload(void)
{
	int i;
	st0016_rom_bank_w(0,st0016_rom_bank);
	for(i=0;i<ST0016_MAX_CHAR_BANK;i++)
		decodechar(Machine->gfx[st0016_ramgfx], i,(UINT8 *) st0016_charram,  &charlayout);
}


void st0016_save_init(void)
{
	state_save_register_int("st0016", 0, "sprbank",&st0016_spr_bank);
	state_save_register_int("st0016", 0, "sprbank2",&st0016_spr2_bank);
	state_save_register_int("st0016", 0, "palbank",&st0016_pal_bank);
	state_save_register_int("st0016", 0, "charbank",&st0016_char_bank);
	state_save_register_int("st0016", 0, "rombank",&st0016_rom_bank);
	state_save_register_UINT8("st0016", 0, "vregs",&st0016_vregs[0], 0xc0);
	state_save_register_UINT8("st0016", 0, "charram",st0016_charram, ST0016_MAX_CHAR_BANK*ST0016_CHAR_BANK_SIZE);
	state_save_register_UINT8("st0016", 0, "palram",(UINT8*)st0016_paletteram, ST0016_MAX_PAL_BANK*ST0016_PAL_BANK_SIZE);
	state_save_register_UINT8("st0016", 0, "sprram",(UINT8*)st0016_spriteram, ST0016_MAX_SPR_BANK*ST0016_SPR_BANK_SIZE);
	state_save_register_func_postload(st0016_postload);
}

VIDEO_START( st0016 )
{
	int gfx_index=0;

	st0016_charram=auto_malloc(ST0016_MAX_CHAR_BANK*ST0016_CHAR_BANK_SIZE);
	st0016_spriteram=auto_malloc(ST0016_MAX_SPR_BANK*ST0016_SPR_BANK_SIZE);
	st0016_paletteram=auto_malloc(ST0016_MAX_PAL_BANK*ST0016_PAL_BANK_SIZE);

	/* find first empty slot to decode gfx */
	for (gfx_index = 0; gfx_index < MAX_GFX_ELEMENTS; gfx_index++)
		if (Machine->gfx[gfx_index] == 0)
			break;

	if (gfx_index == MAX_GFX_ELEMENTS)
		return 1;

	/* create the char set (gfx will then be updated dynamically from RAM) */
	Machine->gfx[gfx_index] = decodegfx((UINT8 *)st0016_charram,&charlayout);
	if (!Machine->gfx[gfx_index])
		return 1;

	/* set the color information */
	Machine->gfx[gfx_index]->colortable = Machine->remapped_colortable;
	Machine->gfx[gfx_index]->total_colors = 0x40;
	st0016_ramgfx = gfx_index;

	switch(st0016_game&0x3f)
	{
		case 0: /*renju kizoku */
			set_visible_area(0, 40*8-1, 0, 30*8-1);
			spr_dx=0;
			spr_dy=0;
		break;

		case 1: /*neratte cyuh! */
			set_visible_area(8,41*8-1,0,30*8-1);
			spr_dx=0;
			spr_dy=8;
		break;

		case 4: /*mayjinsen 1&2 */
			set_visible_area(0,32*8-1,0,28*8-1);
		break;

		case 10:
			set_visible_area(0,383,0,255);
		break;

		default:
			spr_dx=0;
			spr_dy=0;
	}
	st0016_save_init();
	return 0;
}


static void drawbgmap(mame_bitmap *bitmap,const rectangle *cliprect, int priority)
{
	int j;
	for(j=8;j<0x40;j+=8)
	{
		if(st0016_vregs[j+1] && ((priority && (st0016_vregs[j+3]==0xff))||((!priority)&&(st0016_vregs[j+3]!=0xff))))
		{
			int x,y,code,color;
			int i=st0016_vregs[j+1]*0x1000;
			for(x=0;x<32;x++)
	 			for(y=0;y<8*4;y++)
	 			{

				 	code=st0016_spriteram[i]+256*st0016_spriteram[i+1];
	 				color=st0016_spriteram[i+2];

				 	if(priority)
				 	{
				 		drawgfx(bitmap,Machine->gfx[0],
										code,
										color,
										0,0,
										x*8+spr_dx,y*8+spr_dy,
										&Machine->visible_area,TRANSPARENCY_PEN,0);
					}
					else
					{
							UINT16 *destline;
							int yloop,xloop;
							int ypos, xpos;
							const gfx_element *gfx = Machine->gfx[0];
							UINT8 *srcgfx;
							int gfxoffs;
							ypos = y*8+spr_dy+((st0016_vregs[j+2]==0xaf)?0x50:0);/*hack for mayjinsen title screen */
							xpos = x*8+spr_dx;
							gfxoffs = 0;
							srcgfx= gfx->gfxdata+(64*code);

							for (yloop=0; yloop<8; yloop++)
							{
								UINT16 drawypos;

								drawypos = ypos+yloop;
								destline = (UINT16 *)(bitmap->line[drawypos]);

								for (xloop=0; xloop<8; xloop++)
								{
									UINT16 drawxpos;
									int pixdata;
									pixdata = srcgfx[gfxoffs];

									drawxpos = xpos+xloop;

									if ((drawxpos >= cliprect->min_x) && (drawxpos <= cliprect->max_x) && (drawypos >= cliprect->min_y) && (drawypos <= cliprect->max_y) )
									{
										if(st0016_vregs[j+7]==0x12)
											destline[drawxpos] |= pixdata<<4;
										else
											if(pixdata || destline[drawxpos]==UNUSED_PEN)
												destline[drawxpos] = pixdata + (color*16);
									}

									gfxoffs++;
								}
							}
						}
	 			i+=4;
	 			}
	 	}
	}
}


VIDEO_UPDATE( st0016 )
{
#ifdef MAME_DEBUG
	if(code_pressed_memory(KEYCODE_Z))
	{
		int h,j;
		FILE *p=fopen("vram.bin","wb");
		fwrite(st0016_spriteram,1,0x1000*ST0016_MAX_SPR_BANK,p);
		fclose(p);

		p=fopen("vram.txt","wt");
		for(h=0;h<0xc0;h++)
			fprintf(p,"VREG %.4x - %.4x\n",h,st0016_vregs[h]);
		for(h=0;h<0x1000*ST0016_MAX_SPR_BANK;h+=8)
		{
		 	fprintf(p,"%.4x - %.4x - ",h,h>>3);
		 	for(j=0;j<8;j++)
		 	 	fprintf(p,"%.2x ",st0016_spriteram[h+j]);
		 	 fprintf(p,"\n");
		}
		fclose(p);
	}
#endif
	fillbitmap(bitmap,Machine->pens[UNUSED_PEN],&Machine->visible_area);
	drawbgmap(bitmap,cliprect,0);
 	drawsprites(bitmap,cliprect);
	drawbgmap(bitmap,cliprect,1);
}

