// license:BSD-3-Clause
// copyright-holders:Mirko Buffoni
/***************************************************************************
video.c
Functions to emulate the video hardware of the machine.
***************************************************************************/
#include "emu.h"
#include "includes/citycon.h"
/***************************************************************************
Callbacks for the TileMap code
***************************************************************************/
TILEMAP_MAPPER_MEMBER(citycon_state::citycon_scan)
{
/* logical (col,row) -> memory offset */
return (col & 0x1f) + ((row & 0x1f) << 5) + ((col & 0x60) << 5);
}
TILE_GET_INFO_MEMBER(citycon_state::get_fg_tile_info)
{
SET_TILE_INFO_MEMBER(0,
m_videoram[tile_index],
(tile_index & 0x03e0) >> 5, /* color depends on scanline only */
0);
}
TILE_GET_INFO_MEMBER(citycon_state::get_bg_tile_info)
{
uint8_t *rom = memregion("gfx4")->base();
int code = rom[0x1000 * m_bg_image + tile_index];
SET_TILE_INFO_MEMBER(3 + m_bg_image,
code,
rom[0xc000 + 0x100 * m_bg_image + code],
0);
}
/***************************************************************************
Start the video hardware emulation.
***************************************************************************/
void citycon_state::video_start()
{
m_fg_tilemap = &machine().tilemap().create(*m_gfxdecode, tilemap_get_info_delegate(FUNC(citycon_state::get_fg_tile_info),this), tilemap_mapper_delegate(FUNC(citycon_state::citycon_scan),this), 8, 8, 128, 32);
m_bg_tilemap = &machine().tilemap().create(*m_gfxdecode, tilemap_get_info_delegate(FUNC(citycon_state::get_bg_tile_info),this), tilemap_mapper_delegate(FUNC(citycon_state::citycon_scan),this), 8, 8, 128, 32);
m_fg_tilemap->set_transparent_pen(0);
m_fg_tilemap->set_scroll_rows(32);
}
/***************************************************************************
Memory handlers
***************************************************************************/
WRITE8_MEMBER(citycon_state::citycon_videoram_w)
{
m_videoram[offset] = data;
m_fg_tilemap->mark_tile_dirty(offset);
}
WRITE8_MEMBER(citycon_state::citycon_linecolor_w)
{
m_linecolor[offset] = data;
}
WRITE8_MEMBER(citycon_state::citycon_background_w)
{
/* bits 4-7 control the background image */
if (m_bg_image != (data >> 4))
{
m_bg_image = (data >> 4);
m_bg_tilemap->mark_all_dirty();
}
/* bit 0 flips screen */
/* it is also used to multiplex player 1 and player 2 controls */
flip_screen_set(data & 0x01);
/* bits 1-3 are unknown */
// if ((data & 0x0e) != 0) logerror("background register = %02x\n", data);
}
void citycon_state::draw_sprites( bitmap_ind16 &bitmap, const rectangle &cliprect )
{
int offs;
for (offs = m_spriteram.bytes() - 4; offs >= 0; offs -= 4)
{
int sx, sy, flipx;
sx = m_spriteram[offs + 3];
sy = 239 - m_spriteram[offs];
flipx = ~m_spriteram[offs + 2] & 0x10;
if (flip_screen())
{
sx = 240 - sx;
sy = 238 - sy;
flipx = !flipx;
}
m_gfxdecode->gfx(m_spriteram[offs + 1] & 0x80 ? 2 : 1)->transpen(bitmap,cliprect,
m_spriteram[offs + 1] & 0x7f,
m_spriteram[offs + 2] & 0x0f,
flipx,flip_screen(),
sx, sy, 0);
}
}
inline void citycon_state::changecolor_RRRRGGGGBBBBxxxx( int color, int indx )
{
int data = m_palette->basemem().read8(2 * indx | 1) | (m_palette->basemem().read8(2 * indx) << 8);
m_palette->set_pen_color(color, pal4bit(data >> 12), pal4bit(data >> 8), pal4bit(data >> 4));
}
uint32_t citycon_state::screen_update_citycon(screen_device &screen, bitmap_ind16 &bitmap, const rectangle &cliprect)
{
int offs, scroll;
/* Update the virtual palette to support text color code changing on every scanline. */
for (offs = 0; offs < 256; offs++)
{
int indx = m_linecolor[offs];
int i;
for (i = 0; i < 4; i++)
changecolor_RRRRGGGGBBBBxxxx(640 + 4 * offs + i, 512 + 4 * indx + i);
}
scroll = m_scroll[0] * 256 + m_scroll[1];
m_bg_tilemap->set_scrollx(0, scroll >> 1);
for (offs = 6; offs < 32; offs++)
m_fg_tilemap->set_scrollx(offs, scroll);
m_bg_tilemap->draw(screen, bitmap, cliprect, 0, 0);
m_fg_tilemap->draw(screen, bitmap, cliprect, 0, 0);
draw_sprites(bitmap, cliprect);
return 0;
}