// license:BSD-3-Clause
// copyright-holders:Nicola Salmoria
#include "emu.h"
#include "includes/cbasebal.h"
/***************************************************************************
Callbacks for the TileMap code
***************************************************************************/
TILE_GET_INFO_MEMBER(cbasebal_state::get_bg_tile_info)
{
uint8_t attr = m_scrollram[2 * tile_index + 1];
SET_TILE_INFO_MEMBER(1,
m_scrollram[2 * tile_index] + ((attr & 0x07) << 8) + 0x800 * m_tilebank,
(attr & 0xf0) >> 4,
(attr & 0x08) ? TILE_FLIPX : 0);
}
TILE_GET_INFO_MEMBER(cbasebal_state::get_fg_tile_info)
{
uint8_t attr = m_textram[tile_index + 0x800];
SET_TILE_INFO_MEMBER(0,
m_textram[tile_index] + ((attr & 0xf0) << 4),
attr & 0x07,
(attr & 0x08) ? TILE_FLIPX : 0);
}
/***************************************************************************
Start the video hardware emulation.
***************************************************************************/
void cbasebal_state::video_start()
{
m_textram = std::make_unique<uint8_t[]>(0x1000);
m_scrollram = std::make_unique<uint8_t[]>(0x1000);
m_bg_tilemap = &machine().tilemap().create(*m_gfxdecode, tilemap_get_info_delegate(*this, FUNC(cbasebal_state::get_bg_tile_info)), TILEMAP_SCAN_ROWS, 16, 16, 64, 32);
m_fg_tilemap = &machine().tilemap().create(*m_gfxdecode, tilemap_get_info_delegate(*this, FUNC(cbasebal_state::get_fg_tile_info)), TILEMAP_SCAN_ROWS, 8, 8, 64, 32);
m_fg_tilemap->set_transparent_pen(3);
save_pointer(NAME(m_textram), 0x1000);
save_pointer(NAME(m_scrollram), 0x1000);
}
/***************************************************************************
Memory handlers
***************************************************************************/
WRITE8_MEMBER(cbasebal_state::cbasebal_textram_w)
{
m_textram[offset] = data;
m_fg_tilemap->mark_tile_dirty(offset & 0x7ff);
}
READ8_MEMBER(cbasebal_state::cbasebal_textram_r)
{
return m_textram[offset];
}
WRITE8_MEMBER(cbasebal_state::cbasebal_scrollram_w)
{
m_scrollram[offset] = data;
m_bg_tilemap->mark_tile_dirty(offset / 2);
}
READ8_MEMBER(cbasebal_state::cbasebal_scrollram_r)
{
return m_scrollram[offset];
}
WRITE8_MEMBER(cbasebal_state::cbasebal_gfxctrl_w)
{
/* bit 0 is unknown - toggles continuously */
/* bit 1 is flip screen */
m_flipscreen = data & 0x02;
machine().tilemap().set_flip_all(m_flipscreen ? (TILEMAP_FLIPY | TILEMAP_FLIPX) : 0);
/* bit 2 is unknown - unused? */
/* bit 3 is tile bank */
if (m_tilebank != ((data & 0x08) >> 3))
{
m_tilebank = (data & 0x08) >> 3;
m_bg_tilemap->mark_all_dirty();
}
/* bit 4 is sprite bank */
m_spritebank = (data & 0x10) >> 4;
/* bits 5 is text enable */
m_text_on = ~data & 0x20;
/* bits 6-7 are bg/sprite enable (don't know which is which) */
m_bg_on = ~data & 0x40;
m_obj_on = ~data & 0x80;
/* other bits unknown, but used */
}
WRITE8_MEMBER(cbasebal_state::cbasebal_scrollx_w)
{
m_scroll_x[offset] = data;
m_bg_tilemap->set_scrollx(0, m_scroll_x[0] + 256 * m_scroll_x[1]);
}
WRITE8_MEMBER(cbasebal_state::cbasebal_scrolly_w)
{
m_scroll_y[offset] = data;
m_bg_tilemap->set_scrolly(0, m_scroll_y[0] + 256 * m_scroll_y[1]);
}
/***************************************************************************
Display refresh
***************************************************************************/
void cbasebal_state::draw_sprites( bitmap_ind16 &bitmap, const rectangle &cliprect )
{
uint8_t *spriteram = m_spriteram;
int offs, sx, sy;
/* the last entry is not a sprite, we skip it otherwise spang shows a bubble */
/* moving diagonally across the screen */
for (offs = m_spriteram.bytes() - 8; offs >= 0; offs -= 4)
{
int code = spriteram[offs];
int attr = spriteram[offs + 1];
int color = attr & 0x07;
int flipx = attr & 0x08;
sx = spriteram[offs + 3] + ((attr & 0x10) << 4);
sy = ((spriteram[offs + 2] + 8) & 0xff) - 8;
code += (attr & 0xe0) << 3;
code += m_spritebank * 0x800;
if (m_flipscreen)
{
sx = 496 - sx;
sy = 240 - sy;
flipx = !flipx;
}
m_gfxdecode->gfx(2)->transpen(bitmap,cliprect,
code,
color,
flipx,m_flipscreen,
sx,sy,15);
}
}
uint32_t cbasebal_state::screen_update_cbasebal(screen_device &screen, bitmap_ind16 &bitmap, const rectangle &cliprect)
{
if (m_bg_on)
m_bg_tilemap->draw(screen, bitmap, cliprect, 0, 0);
else
bitmap.fill(768, cliprect);
if (m_obj_on)
draw_sprites(bitmap, cliprect);
if (m_text_on)
m_fg_tilemap->draw(screen, bitmap, cliprect, 0, 0);
return 0;
}