/****************************************************************************
Irem M57 hardware
****************************************************************************/
#include "emu.h"
#include "includes/m57.h"
/***************************************************************************
Convert the color PROMs into a more useable format.
Tropical Angel has two 256x4 character palette PROMs, one 32x8 sprite
palette PROM, and one 256x4 sprite color lookup table PROM.
I don't know for sure how the palette PROMs are connected to the RGB
output, but it's probably something like this; note that RED and BLUE
are swapped wrt the usual configuration.
bit 7 -- 220 ohm resistor -- RED
-- 470 ohm resistor -- RED
-- 220 ohm resistor -- GREEN
-- 470 ohm resistor -- GREEN
-- 1 kohm resistor -- GREEN
-- 220 ohm resistor -- BLUE
-- 470 ohm resistor -- BLUE
bit 0 -- 1 kohm resistor -- BLUE
***************************************************************************/
PALETTE_INIT( m57 )
{
int i;
machine.colortable = colortable_alloc(machine, 32 * 8 + 16);
/* character palette */
for (i = 0; i < 256; i++)
{
int bit0, bit1, bit2, r, g, b;
/* red component */
bit0 = 0;
bit1 = (color_prom[256] >> 2) & 0x01;
bit2 = (color_prom[256] >> 3) & 0x01;
r = 0x21 * bit0 + 0x47 * bit1 + 0x97 * bit2;
/* green component */
bit0 = (color_prom[0] >> 3) & 0x01;
bit1 = (color_prom[256] >> 0) & 0x01;
bit2 = (color_prom[256] >> 1) & 0x01;
g = 0x21 * bit0 + 0x47 * bit1 + 0x97 * bit2;
/* blue component */
bit0 = (color_prom[0] >> 0) & 0x01;
bit1 = (color_prom[0] >> 1) & 0x01;
bit2 = (color_prom[0] >> 2) & 0x01;
b = 0x21 * bit0 + 0x47 * bit1 + 0x97 * bit2;
colortable_palette_set_color(machine.colortable, i, MAKE_RGB(r,g,b));
colortable_entry_set_value(machine.colortable, i, i);
color_prom++;
}
color_prom += 256;
/* color_prom now points to the beginning of the sprite palette */
/* sprite palette */
for (i = 0; i < 16; i++)
{
int bit0, bit1, bit2, r, g, b;
/* red component */
bit0 = 0;
bit1 = (*color_prom >> 6) & 0x01;
bit2 = (*color_prom >> 7) & 0x01;
r = 0x21 * bit0 + 0x47 * bit1 + 0x97 * bit2;
/* green component */
bit0 = (*color_prom >> 3) & 0x01;
bit1 = (*color_prom >> 4) & 0x01;
bit2 = (*color_prom >> 5) & 0x01;
g = 0x21 * bit0 + 0x47 * bit1 + 0x97 * bit2;
/* blue component */
bit0 = (*color_prom >> 0) & 0x01;
bit1 = (*color_prom >> 1) & 0x01;
bit2 = (*color_prom >> 2) & 0x01;
b = 0x21 * bit0 + 0x47 * bit1 + 0x97 * bit2;
colortable_palette_set_color(machine.colortable, i + 256, MAKE_RGB(r,g,b));
color_prom++;
}
color_prom += 16;
/* color_prom now points to the beginning of the sprite lookup table */
/* sprite lookup table */
for (i = 0; i < 32 * 8; i++)
{
colortable_entry_set_value(machine.colortable, i + 32 * 8, 256 + (~*color_prom & 0x0f));
color_prom++;
}
}
/*************************************
*
* Tilemap info callback
*
*************************************/
static TILE_GET_INFO( get_tile_info )
{
m57_state *state = machine.driver_data<m57_state>();
UINT8 attr = state->m_videoram[tile_index * 2 + 0];
UINT16 code = state->m_videoram[tile_index * 2 + 1] | ((attr & 0xc0) << 2);
SET_TILE_INFO(0, code, attr & 0x0f, TILE_FLIPXY(attr >> 4));
}
/*************************************
*
* Video RAM access
*
*************************************/
WRITE8_HANDLER( m57_videoram_w )
{
m57_state *state = space->machine().driver_data<m57_state>();
state->m_videoram[offset] = data;
tilemap_mark_tile_dirty(state->m_bg_tilemap, offset / 2);
}
/*************************************
*
* Video startup
*
*************************************/
VIDEO_START( m57 )
{
m57_state *state = machine.driver_data<m57_state>();
state->m_bg_tilemap = tilemap_create(machine, get_tile_info, tilemap_scan_rows, 8, 8, 32, 32);
tilemap_set_scroll_rows(state->m_bg_tilemap, 256);
state->save_item(NAME(state->m_flipscreen));
}
/*************************************
*
* Outputs
*
*************************************/
WRITE8_HANDLER( m57_flipscreen_w )
{
m57_state *state = space->machine().driver_data<m57_state>();
/* screen flip is handled both by software and hardware */
state->m_flipscreen = (data & 0x01) ^ (~input_port_read(space->machine(), "DSW2") & 0x01);
tilemap_set_flip(state->m_bg_tilemap, state->m_flipscreen ? (TILEMAP_FLIPY | TILEMAP_FLIPX) : 0);
coin_counter_w(space->machine(), 0,data & 0x02);
coin_counter_w(space->machine(), 1,data & 0x20);
}
/*************************************
*
* Background rendering
*
*************************************/
static void draw_background(running_machine &machine, bitmap_t *bitmap, const rectangle *cliprect)
{
m57_state *state = machine.driver_data<m57_state>();
int y,x;
INT16 scrolly;
// from 64 to 127: not wrapped
for (y = 64; y < 128; y++)
tilemap_set_scrollx(state->m_bg_tilemap, y, state->m_scrollram[0x40]);
tilemap_draw(bitmap, cliprect, state->m_bg_tilemap, 0, 0);
// from 128 to 255: wrapped
for (y = 128; y <= cliprect->max_y; y++)
{
scrolly = state->m_scrollram[y] + (state->m_scrollram[y + 0x100] << 8);
if (scrolly >= 0)
{
for (x = cliprect->min_x; x <= cliprect->max_x; x++)
{
if ((x + scrolly) <= cliprect->max_x)
*BITMAP_ADDR16(bitmap, y, x) = *BITMAP_ADDR16(bitmap, y, x + scrolly);
else
*BITMAP_ADDR16(bitmap, y, x) = *BITMAP_ADDR16(bitmap, y, cliprect->max_x);
}
} else {
for (x = cliprect->max_x; x >= cliprect->min_x; x--)
{
if ((x + scrolly) >= cliprect->min_x)
*BITMAP_ADDR16(bitmap, y, x) = *BITMAP_ADDR16(bitmap, y, x + scrolly);
else
*BITMAP_ADDR16(bitmap, y, x) = *BITMAP_ADDR16(bitmap, y, cliprect->min_x);
}
}
}
}
/*************************************
*
* Sprite rendering
*
*************************************/
static void draw_sprites(running_machine &machine, bitmap_t *bitmap, const rectangle *cliprect)
{
m57_state *state = machine.driver_data<m57_state>();
int offs;
for (offs = state->m_spriteram_size - 4; offs >= 0; offs -= 4)
{
UINT8 attributes = state->m_spriteram[offs + 1];
int sx = state->m_spriteram[offs + 3];
int sy = ((224 - state->m_spriteram[offs + 0] - 32) & 0xff) + 32;
int code = state->m_spriteram[offs + 2];
int color = attributes & 0x1f;
int flipy = attributes & 0x80;
int flipx = attributes & 0x40;
int tile_number = code & 0x3f;
int bank = 0;
if (code & 0x80) bank += 1;
if (attributes & 0x20) bank += 2;
if (state->m_flipscreen)
{
sx = 240 - sx;
sy = 224 - sy;
flipx = !flipx;
flipy = !flipy;
}
drawgfx_transmask(bitmap, cliprect, machine.gfx[1 + bank],
tile_number,
color,
flipx, flipy,
sx, sy,
colortable_get_transpen_mask(machine.colortable, machine.gfx[1], color, 256 + 15));
}
}
/*************************************
*
* Video update
*
*************************************/
SCREEN_UPDATE( m57 )
{
draw_background(screen->machine(), bitmap, cliprect);
draw_sprites(screen->machine(), bitmap, cliprect);
return 0;
}