// license:BSD-3-Clause
// copyright-holders:Nicola Salmoria
/***************************************************************************
video.c
Functions to emulate the video hardware of the machine.
***************************************************************************/
#include "emu.h"
#include "includes/firetrap.h"
/***************************************************************************
Convert the color PROMs into a more useable format.
Fire Trap has one 256x8 and one 256x4 palette PROMs.
I don't know for sure how the palette PROMs are connected to the RGB
output, but it's probably the usual:
bit 7 -- 220 ohm resistor -- GREEN
-- 470 ohm resistor -- GREEN
-- 1 kohm resistor -- GREEN
-- 2.2kohm resistor -- GREEN
-- 220 ohm resistor -- RED
-- 470 ohm resistor -- RED
-- 1 kohm resistor -- RED
bit 0 -- 2.2kohm resistor -- RED
bit 3 -- 220 ohm resistor -- BLUE
-- 470 ohm resistor -- BLUE
-- 1 kohm resistor -- BLUE
bit 0 -- 2.2kohm resistor -- BLUE
***************************************************************************/
PALETTE_INIT_MEMBER(firetrap_state, firetrap)
{
const uint8_t *color_prom = memregion("proms")->base();
int i;
for (i = 0; i < palette.entries(); i++)
{
int bit0, bit1, bit2, bit3, r, g, b;
bit0 = (color_prom[i] >> 0) & 0x01;
bit1 = (color_prom[i] >> 1) & 0x01;
bit2 = (color_prom[i] >> 2) & 0x01;
bit3 = (color_prom[i] >> 3) & 0x01;
r = 0x0e * bit0 + 0x1f * bit1 + 0x43 * bit2 + 0x8f * bit3;
bit0 = (color_prom[i] >> 4) & 0x01;
bit1 = (color_prom[i] >> 5) & 0x01;
bit2 = (color_prom[i] >> 6) & 0x01;
bit3 = (color_prom[i] >> 7) & 0x01;
g = 0x0e * bit0 + 0x1f * bit1 + 0x43 * bit2 + 0x8f * bit3;
bit0 = (color_prom[i + palette.entries()] >> 0) & 0x01;
bit1 = (color_prom[i + palette.entries()] >> 1) & 0x01;
bit2 = (color_prom[i + palette.entries()] >> 2) & 0x01;
bit3 = (color_prom[i + palette.entries()] >> 3) & 0x01;
b = 0x0e * bit0 + 0x1f * bit1 + 0x43 * bit2 + 0x8f * bit3;
palette.set_pen_color(i, rgb_t(r,g,b));
}
}
/***************************************************************************
Callbacks for the TileMap code
***************************************************************************/
TILEMAP_MAPPER_MEMBER(firetrap_state::get_fg_memory_offset)
{
return (row ^ 0x1f) + (col << 5);
}
TILEMAP_MAPPER_MEMBER(firetrap_state::get_bg_memory_offset)
{
return ((row & 0x0f) ^ 0x0f) | ((col & 0x0f) << 4) |
/* hole at bit 8 */
((row & 0x10) << 5) | ((col & 0x10) << 6);
}
TILE_GET_INFO_MEMBER(firetrap_state::get_fg_tile_info)
{
int code = m_fgvideoram[tile_index];
int color = m_fgvideoram[tile_index + 0x400];
SET_TILE_INFO_MEMBER(0,
code | ((color & 0x01) << 8),
color >> 4,
0);
}
inline void firetrap_state::get_bg_tile_info(tile_data &tileinfo, int tile_index, uint8_t *bgvideoram, int gfx_region)
{
int code = bgvideoram[tile_index];
int color = bgvideoram[tile_index + 0x100];
SET_TILE_INFO_MEMBER(gfx_region,
code + ((color & 0x03) << 8),
(color & 0x30) >> 4,
TILE_FLIPXY((color & 0x0c) >> 2));
}
TILE_GET_INFO_MEMBER(firetrap_state::get_bg1_tile_info)
{
get_bg_tile_info(tileinfo, tile_index, m_bg1videoram, 1);
}
TILE_GET_INFO_MEMBER(firetrap_state::get_bg2_tile_info)
{
get_bg_tile_info(tileinfo, tile_index, m_bg2videoram, 2);
}
/***************************************************************************
Start the video hardware emulation.
***************************************************************************/
void firetrap_state::video_start()
{
m_fg_tilemap = &machine().tilemap().create(*m_gfxdecode, tilemap_get_info_delegate(FUNC(firetrap_state::get_fg_tile_info),this), tilemap_mapper_delegate(FUNC(firetrap_state::get_fg_memory_offset),this), 8, 8, 32, 32);
m_bg1_tilemap = &machine().tilemap().create(*m_gfxdecode, tilemap_get_info_delegate(FUNC(firetrap_state::get_bg1_tile_info),this), tilemap_mapper_delegate(FUNC(firetrap_state::get_bg_memory_offset),this), 16, 16, 32, 32);
m_bg2_tilemap = &machine().tilemap().create(*m_gfxdecode, tilemap_get_info_delegate(FUNC(firetrap_state::get_bg2_tile_info),this), tilemap_mapper_delegate(FUNC(firetrap_state::get_bg_memory_offset),this), 16, 16, 32, 32);
m_fg_tilemap->set_transparent_pen(0);
m_bg1_tilemap->set_transparent_pen(0);
}
/***************************************************************************
Memory handlers
***************************************************************************/
WRITE8_MEMBER(firetrap_state::firetrap_fgvideoram_w)
{
m_fgvideoram[offset] = data;
m_fg_tilemap->mark_tile_dirty(offset & 0x3ff);
}
WRITE8_MEMBER(firetrap_state::firetrap_bg1videoram_w)
{
m_bg1videoram[offset] = data;
m_bg1_tilemap->mark_tile_dirty(offset & 0x6ff);
}
WRITE8_MEMBER(firetrap_state::firetrap_bg2videoram_w)
{
m_bg2videoram[offset] = data;
m_bg2_tilemap->mark_tile_dirty(offset & 0x6ff);
}
WRITE8_MEMBER(firetrap_state::firetrap_bg1_scrollx_w)
{
m_scroll1_x[offset] = data;
m_bg1_tilemap->set_scrollx(0, m_scroll1_x[0] | (m_scroll1_x[1] << 8));
}
WRITE8_MEMBER(firetrap_state::firetrap_bg1_scrolly_w)
{
m_scroll1_y[offset] = data;
m_bg1_tilemap->set_scrolly(0, -(m_scroll1_y[0] | (m_scroll1_y[1] << 8)));
}
WRITE8_MEMBER(firetrap_state::firetrap_bg2_scrollx_w)
{
m_scroll2_x[offset] = data;
m_bg2_tilemap->set_scrollx(0, m_scroll2_x[0] | (m_scroll2_x[1] << 8));
}
WRITE8_MEMBER(firetrap_state::firetrap_bg2_scrolly_w)
{
m_scroll2_y[offset] = data;
m_bg2_tilemap->set_scrolly(0, -(m_scroll2_y[0] | (m_scroll2_y[1] << 8)));
}
/***************************************************************************
Display refresh
***************************************************************************/
void firetrap_state::draw_sprites( bitmap_ind16 &bitmap, const rectangle &cliprect )
{
int offs;
for (offs = 0; offs < m_spriteram.bytes(); offs += 4)
{
int sx, sy, flipx, flipy, code, color;
/* the meaning of bit 3 of [offs] is unknown */
sy = m_spriteram[offs];
sx = m_spriteram[offs + 2];
code = m_spriteram[offs + 3] + 4 * (m_spriteram[offs + 1] & 0xc0);
color = ((m_spriteram[offs + 1] & 0x08) >> 2) | (m_spriteram[offs + 1] & 0x01);
flipx = m_spriteram[offs + 1] & 0x04;
flipy = m_spriteram[offs + 1] & 0x02;
if (flip_screen())
{
sx = 240 - sx;
sy = 240 - sy;
flipx = !flipx;
flipy = !flipy;
}
if (m_spriteram[offs + 1] & 0x10) /* double width */
{
if (flip_screen()) sy -= 16;
m_gfxdecode->gfx(3)->transpen(bitmap,cliprect,
code & ~1,
color,
flipx,flipy,
sx,flipy ? sy : sy + 16,0);
m_gfxdecode->gfx(3)->transpen(bitmap,cliprect,
code | 1,
color,
flipx,flipy,
sx,flipy ? sy + 16 : sy,0);
/* redraw with wraparound */
m_gfxdecode->gfx(3)->transpen(bitmap,cliprect,
code & ~1,
color,
flipx,flipy,
sx - 256,flipy ? sy : sy + 16,0);
m_gfxdecode->gfx(3)->transpen(bitmap,cliprect,
code | 1,
color,
flipx,flipy,
sx - 256,flipy ? sy + 16 : sy,0);
}
else
{
m_gfxdecode->gfx(3)->transpen(bitmap,cliprect,
code,
color,
flipx,flipy,
sx,sy,0);
/* redraw with wraparound */
m_gfxdecode->gfx(3)->transpen(bitmap,cliprect,
code,
color,
flipx,flipy,
sx - 256,sy,0);
}
}
}
uint32_t firetrap_state::screen_update_firetrap(screen_device &screen, bitmap_ind16 &bitmap, const rectangle &cliprect)
{
m_bg2_tilemap->draw(screen, bitmap, cliprect, 0, 0);
m_bg1_tilemap->draw(screen, bitmap, cliprect, 0, 0);
draw_sprites(bitmap, cliprect);
m_fg_tilemap->draw(screen, bitmap, cliprect, 0, 0);
return 0;
}