// license:BSD-3-Clause
// copyright-holders:Brad Oliver
/***************************************************************************
video.c
Functions to emulate the video hardware of the machine.
***************************************************************************/
#include "emu.h"
#include "includes/espial.h"
/***************************************************************************
Convert the color PROMs into a more useable format.
Espial has two 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 3 -- 220 ohm resistor -- BLUE
-- 470 ohm resistor -- BLUE
-- 220 ohm resistor -- GREEN
bit 0 -- 470 ohm resistor -- GREEN
bit 3 -- 1 kohm resistor -- GREEN
-- 220 ohm resistor -- RED
-- 470 ohm resistor -- RED
bit 0 -- 1 kohm resistor -- RED
***************************************************************************/
void espial_state::espial_palette(palette_device &palette) const
{
uint8_t const *const color_prom = memregion("proms")->base();
for (int i = 0; i < palette.entries(); i++)
{
int bit0, bit1, bit2;
// red component
bit0 = BIT(color_prom[i], 0);
bit1 = BIT(color_prom[i], 1);
bit2 = BIT(color_prom[i], 2);
int const r = 0x21 * bit0 + 0x47 * bit1 + 0x97 * bit2;
// green component
bit0 = BIT(color_prom[i], 3);
bit1 = BIT(color_prom[i + palette.entries()], 0);
bit2 = BIT(color_prom[i + palette.entries()], 1);
int const g = 0x21 * bit0 + 0x47 * bit1 + 0x97 * bit2;
// blue component
bit0 = 0;
bit1 = BIT(color_prom[i + palette.entries()], 2);
bit2 = BIT(color_prom[i + palette.entries()], 3);
int const b = 0x21 * bit0 + 0x47 * bit1 + 0x97 * bit2;
palette.set_pen_color(i, rgb_t(r, g, b));
}
}
/***************************************************************************
Callbacks for the TileMap code
***************************************************************************/
TILE_GET_INFO_MEMBER(espial_state::get_tile_info)
{
uint8_t code = m_videoram[tile_index];
uint8_t col = m_colorram[tile_index];
uint8_t attr = m_attributeram[tile_index];
SET_TILE_INFO_MEMBER(0,
code | ((attr & 0x03) << 8),
col & 0x3f,
TILE_FLIPYX(attr >> 2));
}
/*************************************
*
* Video system start
*
*************************************/
void espial_state::video_start()
{
m_bg_tilemap = &machine().tilemap().create(*m_gfxdecode, tilemap_get_info_delegate(*this, FUNC(espial_state::get_tile_info)), TILEMAP_SCAN_ROWS, 8, 8, 32, 32);
m_bg_tilemap->set_scroll_cols(32);
save_item(NAME(m_flipscreen));
}
VIDEO_START_MEMBER(espial_state,netwars)
{
/* Net Wars has a tile map that's twice as big as Espial's */
m_bg_tilemap = &machine().tilemap().create(*m_gfxdecode, tilemap_get_info_delegate(*this, FUNC(espial_state::get_tile_info)), TILEMAP_SCAN_ROWS, 8, 8, 32, 64);
m_bg_tilemap->set_scroll_cols(32);
m_bg_tilemap->set_scrolldy(0, 0x100);
save_item(NAME(m_flipscreen));
}
/*************************************
*
* Memory handlers
*
*************************************/
WRITE8_MEMBER(espial_state::espial_videoram_w)
{
m_videoram[offset] = data;
m_bg_tilemap->mark_tile_dirty(offset);
}
WRITE8_MEMBER(espial_state::espial_colorram_w)
{
m_colorram[offset] = data;
m_bg_tilemap->mark_tile_dirty(offset);
}
WRITE8_MEMBER(espial_state::espial_attributeram_w)
{
m_attributeram[offset] = data;
m_bg_tilemap->mark_tile_dirty(offset);
}
WRITE8_MEMBER(espial_state::espial_scrollram_w)
{
m_scrollram[offset] = data;
m_bg_tilemap->set_scrolly(offset, data);
}
WRITE8_MEMBER(espial_state::espial_flipscreen_w)
{
m_flipscreen = data;
m_bg_tilemap->set_flip(m_flipscreen ? TILEMAP_FLIPX | TILEMAP_FLIPY : 0);
}
/*************************************
*
* Video update
*
*************************************/
void espial_state::draw_sprites( bitmap_ind16 &bitmap, const rectangle &cliprect )
{
int offs;
/* Note that it is important to draw them exactly in this */
/* order, to have the correct priorities. */
for (offs = 0; offs < 16; offs++)
{
int sx, sy, code, color, flipx, flipy;
sx = m_spriteram_1[offs + 16];
sy = m_spriteram_2[offs];
code = m_spriteram_1[offs] >> 1;
color = m_spriteram_2[offs + 16];
flipx = m_spriteram_3[offs] & 0x04;
flipy = m_spriteram_3[offs] & 0x08;
if (m_flipscreen)
{
flipx = !flipx;
flipy = !flipy;
}
else
{
sy = 240 - sy;
}
if (m_spriteram_1[offs] & 1) /* double height */
{
if (m_flipscreen)
{
m_gfxdecode->gfx(1)->transpen(bitmap,cliprect,
code,color,
flipx,flipy,
sx,sy + 16,0);
m_gfxdecode->gfx(1)->transpen(bitmap,cliprect,
code + 1,
color,
flipx,flipy,
sx,sy,0);
}
else
{
m_gfxdecode->gfx(1)->transpen(bitmap,cliprect,
code,color,
flipx,flipy,
sx,sy - 16,0);
m_gfxdecode->gfx(1)->transpen(bitmap,cliprect,
code + 1,color,
flipx,flipy,
sx,sy,0);
}
}
else
{
m_gfxdecode->gfx(1)->transpen(bitmap,cliprect,
code,color,
flipx,flipy,
sx,sy,0);
}
}
}
uint32_t espial_state::screen_update_espial(screen_device &screen, bitmap_ind16 &bitmap, const rectangle &cliprect)
{
m_bg_tilemap->draw(screen, bitmap, cliprect, 0, 0);
draw_sprites(bitmap, cliprect);
return 0;
}