/***************************************************************************
video.c
Functions to emulate the video hardware of the machine.
***************************************************************************/
#include "driver.h"
static UINT16 xscroll;
static UINT16 yscroll;
static tilemap *background, *foreground;
static const UINT8 *spritepalettebank;
UINT16 *amazon_videoram;
static
TILE_GET_INFO( get_bg_tile_info )
{
/* xxxx.----.----.----
* ----.xx--.----.----
* ----.--xx.xxxx.xxxx */
unsigned data = amazon_videoram[tile_index];
unsigned color = data>>11;
SET_TILE_INFO( 1,data&0x3ff,color,0 );
}
static
TILE_GET_INFO( get_fg_tile_info )
{
int data = videoram16[tile_index];
SET_TILE_INFO( 0,data&0xff,0,0 );
}
static void draw_sprites(running_machine *machine, mame_bitmap *bitmap, const rectangle *cliprect )
{
const gfx_element *pGfx = machine->gfx[2];
const UINT16 *pSource = spriteram16;
int i;
int transparent_pen;
if( pGfx->total_elements > 0x200 )
{ /* HORE HORE Kid */
transparent_pen = 0xf;
}
else
{
transparent_pen = 0x0;
}
for( i=0; i<0x200; i+=8 )
{
int tile = pSource[1]&0xff;
int attrs = pSource[2];
int flipx = attrs&0x04;
int flipy = attrs&0x08;
int color = (attrs&0xf0)>>4;
int sx = (pSource[3] & 0xff) - 0x80 + 256 * (attrs & 1);
int sy = 240 - (pSource[0] & 0xff);
if( transparent_pen )
{
int bank;
if( attrs&0x02 ) tile |= 0x200;
if( attrs&0x10 ) tile |= 0x100;
bank = (tile&0xfc)>>1;
if( tile&0x200 ) bank |= 0x80;
if( tile&0x100 ) bank |= 0x01;
color &= 0xe;
color += 16*(spritepalettebank[bank]&0xf);
}
else
{
if( attrs&0x02 ) tile|= 0x100;
color += 16 * (spritepalettebank[(tile>>1)&0xff] & 0x0f);
}
if (flip_screen)
{
sx=240-sx;
sy=240-sy;
flipx = !flipx;
flipy = !flipy;
}
drawgfx(
bitmap,pGfx,tile, color,flipx,flipy,sx,sy,cliprect,TRANSPARENCY_PEN,transparent_pen );
pSource += 4;
}
}
PALETTE_INIT( amazon )
{
#define TOTAL_COLORS(gfxn) (machine->gfx[gfxn]->total_colors * machine->gfx[gfxn]->color_granularity)
#define COLOR(gfxn,offs) (colortable[machine->drv->gfxdecodeinfo[gfxn].color_codes_start + offs])
int i;
for( i = 0; i<machine->drv->total_colors; i++)
{
int bit0,bit1,bit2,bit3,r,g,b;
bit0 = (color_prom[0] >> 0) & 0x01;
bit1 = (color_prom[0] >> 1) & 0x01;
bit2 = (color_prom[0] >> 2) & 0x01;
bit3 = (color_prom[0] >> 3) & 0x01;
r = 0x0e * bit0 + 0x1f * bit1 + 0x43 * bit2 + 0x8f * bit3;
bit0 = (color_prom[machine->drv->total_colors] >> 0) & 0x01;
bit1 = (color_prom[machine->drv->total_colors] >> 1) & 0x01;
bit2 = (color_prom[machine->drv->total_colors] >> 2) & 0x01;
bit3 = (color_prom[machine->drv->total_colors] >> 3) & 0x01;
g = 0x0e * bit0 + 0x1f * bit1 + 0x43 * bit2 + 0x8f * bit3;
bit0 = (color_prom[2*machine->drv->total_colors] >> 0) & 0x01;
bit1 = (color_prom[2*machine->drv->total_colors] >> 1) & 0x01;
bit2 = (color_prom[2*machine->drv->total_colors] >> 2) & 0x01;
bit3 = (color_prom[2*machine->drv->total_colors] >> 3) & 0x01;
b = 0x0e * bit0 + 0x1f * bit1 + 0x43 * bit2 + 0x8f * bit3;
palette_set_color(machine,i,MAKE_RGB(r,g,b));
color_prom++;
}
color_prom += 2*machine->drv->total_colors;
/* color_prom now points to the beginning of the lookup table */
/* characters use colors 0-15 */
for (i = 0;i < TOTAL_COLORS(0);i++)
COLOR(0,i) = i;
/* background tiles use colors 192-255 in four banks */
/* the bottom two bits of the color code select the palette bank for */
/* pens 0-7; the top two bits for pens 8-15. */
for (i = 0;i < TOTAL_COLORS(1);i++)
{
if (i & 8) COLOR(1,i) = 192 + (i & 0x0f) + ((i & 0xc0) >> 2);
else COLOR(1,i) = 192 + (i & 0x0f) + ((i & 0x30) >> 0);
}
/* sprites use colors 128-191 in four banks */
/* The lookup table tells which colors to pick from the selected bank */
/* the bank is selected by another PROM and depends on the top 8 bits of */
/* the sprite code. The PROM selects the bank *separately* for pens 0-7 and */
/* 8-15 (like for tiles). */
for (i = 0;i < TOTAL_COLORS(2)/16;i++)
{
int j;
for (j = 0;j < 16;j++)
{
if (i & 8)
COLOR(2,i + j * (TOTAL_COLORS(2)/16)) = 128 + ((j & 0x0c) << 2) + (*color_prom & 0x0f);
else
COLOR(2,i + j * (TOTAL_COLORS(2)/16)) = 128 + ((j & 0x03) << 4) + (*color_prom & 0x0f);
}
color_prom++;
}
/* color_prom now points to the beginning of the sprite palette bank table */
spritepalettebank = color_prom; /* we'll need it at run time */
}
WRITE16_HANDLER( amazon_background_w )
{
COMBINE_DATA( &amazon_videoram[offset] );
tilemap_mark_tile_dirty( background, offset );
}
WRITE16_HANDLER( amazon_foreground_w )
{
COMBINE_DATA( &videoram16[offset] );
tilemap_mark_tile_dirty( foreground, offset );
}
WRITE16_HANDLER( amazon_flipscreen_w )
{
if( ACCESSING_LSB )
{
coin_counter_w( 0, data&0x01 );
coin_counter_w( 1, (data&0x02)>>1 );
flip_screen_set(data&0x04);
}
}
WRITE16_HANDLER( amazon_scrolly_w )
{
COMBINE_DATA(&yscroll);
tilemap_set_scrolly(background,0,yscroll);
}
WRITE16_HANDLER( amazon_scrollx_w )
{
COMBINE_DATA(&xscroll);
tilemap_set_scrollx(background,0,xscroll);
}
VIDEO_START( amazon )
{
background = tilemap_create(get_bg_tile_info,tilemap_scan_cols,TILEMAP_TYPE_PEN,16,16,64,32);
foreground = tilemap_create(get_fg_tile_info,tilemap_scan_cols,TILEMAP_TYPE_PEN,8,8,64,32);
tilemap_set_transparent_pen(foreground,0xf);
/* register for saving */
state_save_register_global(xscroll);
state_save_register_global(yscroll);
}
VIDEO_UPDATE( amazon )
{
if( xscroll&0x2000 )
{
fillbitmap( bitmap,get_black_pen(machine),cliprect );
}
else
{
tilemap_draw( bitmap,cliprect, background, 0, 0 );
}
draw_sprites( machine, bitmap,cliprect );
tilemap_draw( bitmap,cliprect, foreground, 0, 0 );
return 0;
}