// license:BSD-3-Clause
// copyright-holders:David Haywood, Pierpaolo Prazzoli
#include "emu.h"
#include "includes/scotrsht.h"
/* Similar as Iron Horse */
PALETTE_INIT_MEMBER(scotrsht_state, scotrsht)
{
const uint8_t *color_prom = memregion("proms")->base();
int i;
/* create a lookup table for the palette */
for (i = 0; i < 0x100; i++)
{
int r = pal4bit(color_prom[i + 0x000]);
int g = pal4bit(color_prom[i + 0x100]);
int b = pal4bit(color_prom[i + 0x200]);
palette.set_indirect_color(i, rgb_t(r, g, b));
}
/* color_prom now points to the beginning of the lookup table */
color_prom += 0x300;
/* characters use colors 0x80-0xff, sprites use colors 0-0x7f */
for (i = 0; i < 0x200; i++)
{
int j;
for (j = 0; j < 8; j++)
{
uint8_t ctabentry = ((~i & 0x100) >> 1) | (j << 4) | (color_prom[i] & 0x0f);
palette.set_pen_indirect(((i & 0x100) << 3) | (j << 8) | (i & 0xff), ctabentry);
}
}
}
WRITE8_MEMBER(scotrsht_state::videoram_w)
{
m_videoram[offset] = data;
m_bg_tilemap->mark_tile_dirty(offset);
}
WRITE8_MEMBER(scotrsht_state::colorram_w)
{
m_colorram[offset] = data;
m_bg_tilemap->mark_tile_dirty(offset);
}
WRITE8_MEMBER(scotrsht_state::charbank_w)
{
if (m_charbank != (data & 0x01))
{
m_charbank = data & 0x01;
m_bg_tilemap->mark_all_dirty();
}
/* other bits unknown */
}
WRITE8_MEMBER(scotrsht_state::palettebank_w)
{
if (m_palette_bank != ((data & 0x70) >> 4))
{
m_palette_bank = ((data & 0x70) >> 4);
m_bg_tilemap->mark_all_dirty();
}
machine().bookkeeping().coin_counter_w(0, data & 1);
machine().bookkeeping().coin_counter_w(1, data & 2);
// data & 4 unknown
}
TILE_GET_INFO_MEMBER(scotrsht_state::get_bg_tile_info)
{
int attr = m_colorram[tile_index];
int code = m_videoram[tile_index] + (m_charbank << 9) + ((attr & 0x40) << 2);
int color = (attr & 0x0f) + m_palette_bank * 16;
int flag = 0;
if(attr & 0x10) flag |= TILE_FLIPX;
if(attr & 0x20) flag |= TILE_FLIPY;
// data & 0x80 -> tile priority?
SET_TILE_INFO_MEMBER(0, code, color, flag);
}
/* Same as Jailbreak + palette bank */
void scotrsht_state::draw_sprites(bitmap_ind16 &bitmap, const rectangle &cliprect )
{
for (int i = 0; i < m_spriteram.bytes(); i += 4)
{
int attr = m_spriteram[i + 1]; // attributes = ?tyxcccc
int code = m_spriteram[i] + ((attr & 0x40) << 2);
int color = (attr & 0x0f) + m_palette_bank * 16;
int flipx = attr & 0x10;
int flipy = attr & 0x20;
int sx = m_spriteram[i + 2] - ((attr & 0x80) << 1);
int sy = m_spriteram[i + 3];
if (flip_screen())
{
sx = 240 - sx;
sy = 240 - sy;
flipx = !flipx;
flipy = !flipy;
}
m_gfxdecode->gfx(1)->transmask(bitmap,cliprect, code, color, flipx, flipy,
sx, sy,
m_palette->transpen_mask(*m_gfxdecode->gfx(1), color, m_palette_bank * 16));
}
}
void scotrsht_state::video_start()
{
m_bg_tilemap = &machine().tilemap().create(*m_gfxdecode, tilemap_get_info_delegate(FUNC(scotrsht_state::get_bg_tile_info),this), TILEMAP_SCAN_ROWS, 8, 8, 64, 32);
m_bg_tilemap->set_scroll_cols(64);
save_item(NAME(m_irq_enable));
save_item(NAME(m_charbank));
save_item(NAME(m_palette_bank));
}
uint32_t scotrsht_state::screen_update(screen_device &screen, bitmap_ind16 &bitmap, const rectangle &cliprect)
{
for (int col = 0; col < 32; col++)
m_bg_tilemap->set_scrolly(col, m_scroll[col]);
m_bg_tilemap->draw(screen, bitmap, cliprect, 0, 0);
draw_sprites(bitmap, cliprect);
return 0;
}