/***************************************************************************
video.c
Functions to emulate the video hardware of the machine.
***************************************************************************/
#include "driver.h"
UINT8 *vulgus_fgvideoram,*vulgus_bgvideoram;
UINT8 *vulgus_scroll_low,*vulgus_scroll_high;
static int vulgus_palette_bank;
static tilemap *fg_tilemap, *bg_tilemap;
static colortable *vulgus_colortable;
/***************************************************************************
Convert the color PROMs into a more useable format.
***************************************************************************/
PALETTE_INIT( vulgus )
{
int i;
vulgus_colortable = colortable_alloc(machine, 256);
for (i = 0;i < 256;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[256] >> 0) & 0x01;
bit1 = (color_prom[256] >> 1) & 0x01;
bit2 = (color_prom[256] >> 2) & 0x01;
bit3 = (color_prom[256] >> 3) & 0x01;
g = 0x0e * bit0 + 0x1f * bit1 + 0x43 * bit2 + 0x8f * bit3;
bit0 = (color_prom[2*256] >> 0) & 0x01;
bit1 = (color_prom[2*256] >> 1) & 0x01;
bit2 = (color_prom[2*256] >> 2) & 0x01;
bit3 = (color_prom[2*256] >> 3) & 0x01;
b = 0x0e * bit0 + 0x1f * bit1 + 0x43 * bit2 + 0x8f * bit3;
colortable_palette_set_color(vulgus_colortable,i,MAKE_RGB(r,g,b));
color_prom++;
}
color_prom += 2*256;
/* color_prom now points to the beginning of the lookup table */
/* characters use colors 32-47 (?) */
for (i = 0;i < machine->gfx[0]->total_colors * machine->gfx[0]->color_granularity;i++)
colortable_entry_set_value(vulgus_colortable, machine->gfx[0]->color_base + i, 32 + *color_prom++);
/* sprites use colors 16-31 */
for (i = 0;i < machine->gfx[2]->total_colors * machine->gfx[2]->color_granularity;i++)
colortable_entry_set_value(vulgus_colortable, machine->gfx[2]->color_base + i, 16 + *color_prom++);
/* background tiles use colors 0-15, 64-79, 128-143, 192-207 in four banks */
for (i = 0;i < machine->gfx[1]->total_colors * machine->gfx[1]->color_granularity / 4;i++)
{
colortable_entry_set_value(vulgus_colortable, machine->gfx[1]->color_base + 0*32*8 + i, *color_prom);
colortable_entry_set_value(vulgus_colortable, machine->gfx[1]->color_base + 1*32*8 + i, *color_prom + 64);
colortable_entry_set_value(vulgus_colortable, machine->gfx[1]->color_base + 2*32*8 + i, *color_prom + 128);
colortable_entry_set_value(vulgus_colortable, machine->gfx[1]->color_base + 3*32*8 + i, *color_prom + 192);
color_prom++;
}
}
/***************************************************************************
Callbacks for the TileMap code
***************************************************************************/
static TILE_GET_INFO( get_fg_tile_info )
{
int code, color;
code = vulgus_fgvideoram[tile_index];
color = vulgus_fgvideoram[tile_index + 0x400];
SET_TILE_INFO(
0,
code + ((color & 0x80) << 1),
color & 0x3f,
0);
tileinfo->group = color & 0x3f;
}
static TILE_GET_INFO( get_bg_tile_info )
{
int code, color;
code = vulgus_bgvideoram[tile_index];
color = vulgus_bgvideoram[tile_index + 0x400];
SET_TILE_INFO(
1,
code + ((color & 0x80) << 1),
(color & 0x1f) + (0x20 * vulgus_palette_bank),
TILE_FLIPYX((color & 0x60) >> 5));
}
/***************************************************************************
Start the video hardware emulation.
***************************************************************************/
VIDEO_START( vulgus )
{
fg_tilemap = tilemap_create(get_fg_tile_info,tilemap_scan_rows,TILEMAP_TYPE_PEN, 8, 8,32,32);
bg_tilemap = tilemap_create(get_bg_tile_info,tilemap_scan_cols,TILEMAP_TYPE_PEN,16,16,32,32);
colortable_configure_tilemap_groups(vulgus_colortable, fg_tilemap, machine->gfx[0], 47);
}
/***************************************************************************
Memory handlers
***************************************************************************/
WRITE8_HANDLER( vulgus_fgvideoram_w )
{
vulgus_fgvideoram[offset] = data;
tilemap_mark_tile_dirty(fg_tilemap,offset & 0x3ff);
}
WRITE8_HANDLER( vulgus_bgvideoram_w )
{
vulgus_bgvideoram[offset] = data;
tilemap_mark_tile_dirty(bg_tilemap,offset & 0x3ff);
}
WRITE8_HANDLER( vulgus_c804_w )
{
/* bits 0 and 1 are coin counters */
coin_counter_w(0, data & 0x01);
coin_counter_w(1, data & 0x02);
/* bit 7 flips screen */
flip_screen_set(data & 0x80);
}
WRITE8_HANDLER( vulgus_palette_bank_w )
{
if (vulgus_palette_bank != (data & 3))
{
vulgus_palette_bank = data & 3;
tilemap_mark_all_tiles_dirty(bg_tilemap);
}
}
/***************************************************************************
Display refresh
***************************************************************************/
static void draw_sprites(running_machine *machine, mame_bitmap *bitmap,const rectangle *cliprect)
{
int offs;
for (offs = spriteram_size - 4;offs >= 0;offs -= 4)
{
int code,i,col,sx,sy,dir;
code = spriteram[offs];
col = spriteram[offs + 1] & 0x0f;
sx = spriteram[offs + 3];
sy = spriteram[offs + 2];
dir = 1;
if (flip_screen)
{
sx = 240 - sx;
sy = 240 - sy;
dir = -1;
}
i = (spriteram[offs + 1] & 0xc0) >> 6;
if (i == 2) i = 3;
do
{
drawgfx(bitmap,machine->gfx[2],
code + i,
col,
flip_screen,flip_screen,
sx, sy + 16 * i * dir,
cliprect,TRANSPARENCY_PEN,15);
/* draw again with wraparound */
drawgfx(bitmap,machine->gfx[2],
code + i,
col,
flip_screen,flip_screen,
sx, sy + 16 * i * dir - dir * 256,
cliprect,TRANSPARENCY_PEN,15);
i--;
} while (i >= 0);
}
}
VIDEO_UPDATE( vulgus )
{
tilemap_set_scrollx(bg_tilemap, 0, vulgus_scroll_low[1] + 256 * vulgus_scroll_high[1]);
tilemap_set_scrolly(bg_tilemap, 0, vulgus_scroll_low[0] + 256 * vulgus_scroll_high[0]);
tilemap_draw(bitmap,cliprect,bg_tilemap,0,0);
draw_sprites(machine, bitmap,cliprect);
tilemap_draw(bitmap,cliprect,fg_tilemap,0,0);
return 0;
}