#include "emu.h"
#include "includes/scotrsht.h"
/* Similar as Iron Horse */
PALETTE_INIT( scotrsht )
{
int i;
/* allocate the colortable */
machine.colortable = colortable_alloc(machine, 0x100);
/* 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]);
colortable_palette_set_color(machine.colortable, i, MAKE_RGB(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 ctabentry = ((~i & 0x100) >> 1) | (j << 4) | (color_prom[i] & 0x0f);
colortable_entry_set_value(machine.colortable, ((i & 0x100) << 3) | (j << 8) | (i & 0xff), ctabentry);
}
}
}
WRITE8_HANDLER( scotrsht_videoram_w )
{
scotrsht_state *state = space->machine().driver_data<scotrsht_state>();
state->m_videoram[offset] = data;
tilemap_mark_tile_dirty(state->m_bg_tilemap, offset);
}
WRITE8_HANDLER( scotrsht_colorram_w )
{
scotrsht_state *state = space->machine().driver_data<scotrsht_state>();
state->m_colorram[offset] = data;
tilemap_mark_tile_dirty(state->m_bg_tilemap, offset);
}
WRITE8_HANDLER( scotrsht_charbank_w )
{
scotrsht_state *state = space->machine().driver_data<scotrsht_state>();
if (state->m_charbank != (data & 0x01))
{
state->m_charbank = data & 0x01;
tilemap_mark_all_tiles_dirty(state->m_bg_tilemap);
}
/* other bits unknown */
}
WRITE8_HANDLER( scotrsht_palettebank_w )
{
scotrsht_state *state = space->machine().driver_data<scotrsht_state>();
if (state->m_palette_bank != ((data & 0x70) >> 4))
{
state->m_palette_bank = ((data & 0x70) >> 4);
tilemap_mark_all_tiles_dirty(state->m_bg_tilemap);
}
coin_counter_w(space->machine(), 0, data & 1);
coin_counter_w(space->machine(), 1, data & 2);
// data & 4 unknown
}
static TILE_GET_INFO( scotrsht_get_bg_tile_info )
{
scotrsht_state *state = machine.driver_data<scotrsht_state>();
int attr = state->m_colorram[tile_index];
int code = state->m_videoram[tile_index] + (state->m_charbank << 9) + ((attr & 0x40) << 2);
int color = (attr & 0x0f) + state->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(0, code, color, flag);
}
/* Same as Jailbreak + palette bank */
static void draw_sprites(running_machine &machine, bitmap_t *bitmap, const rectangle *cliprect )
{
scotrsht_state *state = machine.driver_data<scotrsht_state>();
UINT8 *spriteram = state->m_spriteram;
int i;
for (i = 0; i < state->m_spriteram_size; i += 4)
{
int attr = spriteram[i + 1]; // attributes = ?tyxcccc
int code = spriteram[i] + ((attr & 0x40) << 2);
int color = (attr & 0x0f) + state->m_palette_bank * 16;
int flipx = attr & 0x10;
int flipy = attr & 0x20;
int sx = spriteram[i + 2] - ((attr & 0x80) << 1);
int sy = spriteram[i + 3];
if (flip_screen_get(machine))
{
sx = 240 - sx;
sy = 240 - sy;
flipx = !flipx;
flipy = !flipy;
}
drawgfx_transmask(bitmap, cliprect, machine.gfx[1], code, color, flipx, flipy,
sx, sy,
colortable_get_transpen_mask(machine.colortable, machine.gfx[1], color, state->m_palette_bank * 16));
}
}
VIDEO_START( scotrsht )
{
scotrsht_state *state = machine.driver_data<scotrsht_state>();
state->m_bg_tilemap = tilemap_create(machine, scotrsht_get_bg_tile_info, tilemap_scan_rows, 8, 8, 64, 32);
tilemap_set_scroll_cols(state->m_bg_tilemap, 64);
}
SCREEN_UPDATE( scotrsht )
{
scotrsht_state *state = screen->machine().driver_data<scotrsht_state>();
int col;
for (col = 0; col < 32; col++)
tilemap_set_scrolly(state->m_bg_tilemap, col, state->m_scroll[col]);
tilemap_draw(bitmap, cliprect, state->m_bg_tilemap, 0, 0);
draw_sprites(screen->machine(), bitmap, cliprect);
return 0;
}