// license:BSD-3-Clause
// copyright-holders:David Haywood, Farfetch'd
/* Speed Spin video, see driver file for notes */
#include "emu.h"
#include "includes/speedspn.h"
TILE_GET_INFO_MEMBER(speedspn_state::get_tile_info)
{
int code = m_vidram[tile_index*2+1] | (m_vidram[tile_index*2] << 8);
int attr = m_attram[tile_index^0x400];
SET_TILE_INFO_MEMBER(0,code,attr & 0x3f,(attr & 0x80) ? TILE_FLIPX : 0);
}
void speedspn_state::video_start()
{
m_display_disable = false;
m_bank_vidram = 0;
m_vidram.resize(0x1000 * 2);
memset(&m_vidram[0], 0, 0x1000*2);
m_tilemap = &machine().tilemap().create(*m_gfxdecode, tilemap_get_info_delegate(FUNC(speedspn_state::get_tile_info),this),TILEMAP_SCAN_COLS, 8, 8,64,32);
save_item(NAME(m_display_disable));
save_item(NAME(m_bank_vidram));
save_item(NAME(m_vidram));
}
WRITE8_MEMBER(speedspn_state::vidram_w)
{
m_vidram[offset + m_bank_vidram] = data;
if (m_bank_vidram == 0)
m_tilemap->mark_tile_dirty(offset/2);
}
WRITE8_MEMBER(speedspn_state::attram_w)
{
m_attram[offset] = data;
m_tilemap->mark_tile_dirty(offset^0x400);
}
READ8_MEMBER(speedspn_state::vidram_r)
{
return m_vidram[offset + m_bank_vidram];
}
WRITE8_MEMBER(speedspn_state::vidram_bank_w)
{
// logerror("VidRam Bank: %04x\n", data);
m_bank_vidram = data & 1;
m_bank_vidram *= 0x1000;
}
WRITE8_MEMBER(speedspn_state::display_disable_w)
{
// logerror("Global display: %u\n", data);
m_display_disable = data & 1;
}
void speedspn_state::draw_sprites(bitmap_ind16 &bitmap, const rectangle &cliprect )
{
gfx_element *gfx = m_gfxdecode->gfx(1);
uint8_t *source = &m_vidram[0x1000];
uint8_t *finish = source + 0x1000;
while( source<finish )
{
int xpos = source[0];
int tileno = source[1];
int attr = source[2];
int ypos = source[3];
int color;
if (!attr && xpos) break; // end of sprite list marker?
if (attr&0x10) xpos +=0x100;
xpos = 0x1f8-xpos;
tileno += ((attr & 0xe0) >> 5) * 0x100;
color = attr & 0x0f;
gfx->transpen(bitmap,cliprect,
tileno,
color,
0,0,
xpos,ypos,15);
source +=4;
}
}
uint32_t speedspn_state::screen_update(screen_device &screen, bitmap_ind16 &bitmap, const rectangle &cliprect)
{
if (m_display_disable)
{
bitmap.fill(m_palette->black_pen(), cliprect);
return 0;
}
#if 0
{
FILE* f;
f = fopen("vidram.bin","wb");
fwrite(m_vidram, 1, 0x1000 * 2, f);
fclose(f);
}
#endif
m_tilemap->set_scrollx(0, 0x100); // verify
m_tilemap->draw(screen, bitmap, cliprect, 0,0);
draw_sprites(bitmap,cliprect);
return 0;
}