/***************************************************************************
video.c
Functions to emulate the video hardware of the machine.
***************************************************************************/
#include "emu.h"
#include "includes/snk6502.h"
#define TOTAL_COLORS(m,gfxn) ((m).gfx[gfxn]->total_colors * (m).gfx[gfxn]->color_granularity)
#define COLOR(m,gfxn,offs) ((m).config().m_gfxdecodeinfo[gfxn].color_codes_start + offs)
/***************************************************************************
Convert the color PROMs into a more useable format.
Zarzon has a different PROM layout from the others.
***************************************************************************/
PALETTE_INIT( snk6502 )
{
snk6502_state *state = machine.driver_data<snk6502_state>();
int i;
for (i = 0; i < machine.total_colors(); i++)
{
int bit0, bit1, bit2, r, g, b;
/* red component */
bit0 = (*color_prom >> 0) & 0x01;
bit1 = (*color_prom >> 1) & 0x01;
bit2 = (*color_prom >> 2) & 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 = 0;
bit1 = (*color_prom >> 6) & 0x01;
bit2 = (*color_prom >> 7) & 0x01;
b = 0x21 * bit0 + 0x47 * bit1 + 0x97 * bit2;
state->m_palette[i] = MAKE_RGB(r, g, b);
color_prom++;
}
state->m_backcolor = 0; /* background color can be changed by the game */
for (i = 0; i < TOTAL_COLORS(machine,0); i++)
palette_set_color(machine, COLOR(machine, 0, i), state->m_palette[i]);
for (i = 0; i < TOTAL_COLORS(machine,1); i++)
{
if (i % 4 == 0)
palette_set_color(machine, COLOR(machine, 1, i), state->m_palette[4 * state->m_backcolor + 0x20]);
else
palette_set_color(machine, COLOR(machine, 1, i), state->m_palette[i + 0x20]);
}
}
WRITE8_HANDLER( snk6502_videoram_w )
{
snk6502_state *state = space->machine().driver_data<snk6502_state>();
state->m_videoram[offset] = data;
tilemap_mark_tile_dirty(state->m_bg_tilemap, offset);
}
WRITE8_HANDLER( snk6502_videoram2_w )
{
snk6502_state *state = space->machine().driver_data<snk6502_state>();
state->m_videoram2[offset] = data;
tilemap_mark_tile_dirty(state->m_fg_tilemap, offset);
}
WRITE8_HANDLER( snk6502_colorram_w )
{
snk6502_state *state = space->machine().driver_data<snk6502_state>();
state->m_colorram[offset] = data;
tilemap_mark_tile_dirty(state->m_bg_tilemap, offset);
tilemap_mark_tile_dirty(state->m_fg_tilemap, offset);
}
WRITE8_HANDLER( snk6502_charram_w )
{
snk6502_state *state = space->machine().driver_data<snk6502_state>();
if (state->m_charram[offset] != data)
{
state->m_charram[offset] = data;
gfx_element_mark_dirty(space->machine().gfx[0], (offset/8) % 256);
}
}
WRITE8_HANDLER( snk6502_flipscreen_w )
{
snk6502_state *state = space->machine().driver_data<snk6502_state>();
int bank;
/* bits 0-2 select background color */
if (state->m_backcolor != (data & 7))
{
int i;
state->m_backcolor = data & 7;
for (i = 0;i < 32;i += 4)
palette_set_color(space->machine(), COLOR(space->machine(), 1, i), state->m_palette[4 * state->m_backcolor + 0x20]);
}
/* bit 3 selects char bank */
bank = (~data & 0x08) >> 3;
if (state->m_charbank != bank)
{
state->m_charbank = bank;
tilemap_mark_all_tiles_dirty_all(space->machine());
}
/* bit 7 flips screen */
if (flip_screen_get(space->machine()) != (data & 0x80))
{
flip_screen_set(space->machine(), data & 0x80);
tilemap_mark_all_tiles_dirty_all(space->machine());
}
}
WRITE8_HANDLER( snk6502_scrollx_w )
{
snk6502_state *state = space->machine().driver_data<snk6502_state>();
tilemap_set_scrollx(state->m_bg_tilemap, 0, data);
}
WRITE8_HANDLER( snk6502_scrolly_w )
{
snk6502_state *state = space->machine().driver_data<snk6502_state>();
tilemap_set_scrolly(state->m_bg_tilemap, 0, data);
}
static TILE_GET_INFO( get_bg_tile_info )
{
snk6502_state *state = machine.driver_data<snk6502_state>();
int code = state->m_videoram[tile_index] + 256 * state->m_charbank;
int color = (state->m_colorram[tile_index] & 0x38) >> 3;
SET_TILE_INFO(1, code, color, 0);
}
static TILE_GET_INFO( get_fg_tile_info )
{
snk6502_state *state = machine.driver_data<snk6502_state>();
int code = state->m_videoram2[tile_index];
int color = state->m_colorram[tile_index] & 0x07;
SET_TILE_INFO(0, code, color, 0);
}
VIDEO_START( snk6502 )
{
snk6502_state *state = machine.driver_data<snk6502_state>();
state->m_bg_tilemap = tilemap_create(machine, get_bg_tile_info, tilemap_scan_rows, 8, 8, 32, 32);
state->m_fg_tilemap = tilemap_create(machine, get_fg_tile_info, tilemap_scan_rows, 8, 8, 32, 32);
tilemap_set_transparent_pen(state->m_fg_tilemap, 0);
gfx_element_set_source(machine.gfx[0], state->m_charram);
}
VIDEO_START( pballoon )
{
snk6502_state *state = machine.driver_data<snk6502_state>();
VIDEO_START_CALL( snk6502 );
tilemap_set_scrolldy(state->m_bg_tilemap, -24, 0);
tilemap_set_scrolldy(state->m_fg_tilemap, -24, 0);
}
SCREEN_UPDATE( snk6502 )
{
snk6502_state *state = screen->machine().driver_data<snk6502_state>();
tilemap_draw(bitmap, cliprect, state->m_bg_tilemap, 0, 0);
tilemap_draw(bitmap, cliprect, state->m_fg_tilemap, 0, 0);
return 0;
}
/* Satan of Saturn */
PALETTE_INIT( satansat )
{
snk6502_state *state = machine.driver_data<snk6502_state>();
int i;
for (i = 0; i < machine.total_colors(); i++)
{
int bit0, bit1, bit2, r, g, b;
/* red component */
bit0 = (*color_prom >> 0) & 0x01;
bit1 = (*color_prom >> 1) & 0x01;
bit2 = (*color_prom >> 2) & 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 = 0;
bit1 = (*color_prom >> 6) & 0x01;
bit2 = (*color_prom >> 7) & 0x01;
b = 0x21 * bit0 + 0x47 * bit1 + 0x97 * bit2;
state->m_palette[i] = MAKE_RGB(r, g, b);
color_prom++;
}
state->m_backcolor = 0; /* background color can be changed by the game */
for (i = 0; i < TOTAL_COLORS(machine,0); i++)
palette_set_color(machine, COLOR(machine, 0, i), state->m_palette[4 * (i % 4) + (i / 4)]);
for (i = 0; i < TOTAL_COLORS(machine,1); i++)
{
if (i % 4 == 0)
palette_set_color(machine, COLOR(machine, 1, i), state->m_palette[state->m_backcolor + 0x10]);
else
palette_set_color(machine, COLOR(machine, 1, i), state->m_palette[4 * (i % 4) + (i / 4) + 0x10]);
}
}
WRITE8_HANDLER( satansat_b002_w )
{
/* bit 0 flips screen */
if (flip_screen_get(space->machine()) != (data & 0x01))
{
flip_screen_set(space->machine(), data & 0x01);
tilemap_mark_all_tiles_dirty_all(space->machine());
}
/* bit 1 enables interrups */
/* it controls only IRQs, not NMIs. Here I am affecting both, which */
/* is wrong. */
interrupt_enable_w(space,0,data & 0x02);
/* other bits unused */
}
WRITE8_HANDLER( satansat_backcolor_w )
{
snk6502_state *state = space->machine().driver_data<snk6502_state>();
/* bits 0-1 select background color. Other bits unused. */
if (state->m_backcolor != (data & 0x03))
{
int i;
state->m_backcolor = data & 0x03;
for (i = 0; i < 16; i += 4)
palette_set_color(space->machine(), COLOR(space->machine(), 1, i), state->m_palette[state->m_backcolor + 0x10]);
}
}
static TILE_GET_INFO( satansat_get_bg_tile_info )
{
snk6502_state *state = machine.driver_data<snk6502_state>();
int code = state->m_videoram[tile_index];
int color = (state->m_colorram[tile_index] & 0x0c) >> 2;
SET_TILE_INFO(1, code, color, 0);
}
static TILE_GET_INFO( satansat_get_fg_tile_info )
{
snk6502_state *state = machine.driver_data<snk6502_state>();
int code = state->m_videoram2[tile_index];
int color = state->m_colorram[tile_index] & 0x03;
SET_TILE_INFO(0, code, color, 0);
}
VIDEO_START( satansat )
{
snk6502_state *state = machine.driver_data<snk6502_state>();
state->m_bg_tilemap = tilemap_create(machine, satansat_get_bg_tile_info, tilemap_scan_rows, 8, 8, 32, 32);
state->m_fg_tilemap = tilemap_create(machine, satansat_get_fg_tile_info, tilemap_scan_rows, 8, 8, 32, 32);
tilemap_set_transparent_pen(state->m_fg_tilemap, 0);
gfx_element_set_source(machine.gfx[0], state->m_charram);
}