// license:BSD-3-Clause
// copyright-holders:Phil Stroffolino
// thanks-to:Enrique Sanchez
/***************************************************************************
video.c
Functions to emulate the video hardware of the machine.
***************************************************************************/
#include "emu.h"
#include "includes/yiear.h"
/***************************************************************************
Convert the color PROMs into a more useable format.
Yie Ar Kung-Fu has one 32x8 palette PROM, connected to the RGB output this
way:
bit 7 -- 220 ohm resistor -- BLUE
-- 470 ohm resistor -- BLUE
-- 220 ohm resistor -- GREEN
-- 470 ohm resistor -- GREEN
-- 1 kohm resistor -- GREEN
-- 220 ohm resistor -- RED
-- 470 ohm resistor -- RED
bit 0 -- 1 kohm resistor -- RED
***************************************************************************/
void yiear_state::yiear_palette(palette_device &palette) const
{
uint8_t const *color_prom = memregion("proms")->base();
for (int i = 0; i < palette.entries(); i++)
{
int bit0, bit1, bit2;
// red component
bit0 = BIT(*color_prom, 0);
bit1 = BIT(*color_prom, 1);
bit2 = BIT(*color_prom, 2);
int const r = 0x21 * bit0 + 0x47 * bit1 + 0x97 * bit2;
// green component
bit0 = BIT(*color_prom, 3);
bit1 = BIT(*color_prom, 4);
bit2 = BIT(*color_prom, 5);
int const g = 0x21 * bit0 + 0x47 * bit1 + 0x97 * bit2;
// blue component
bit0 = 0;
bit1 = BIT(*color_prom, 6);
bit2 = BIT(*color_prom, 7);
int const b = 0x21 * bit0 + 0x47 * bit1 + 0x97 * bit2;
palette.set_pen_color(i, rgb_t(r,g,b));
color_prom++;
}
}
WRITE8_MEMBER(yiear_state::yiear_videoram_w)
{
m_videoram[offset] = data;
m_bg_tilemap->mark_tile_dirty(offset / 2);
}
WRITE8_MEMBER(yiear_state::yiear_control_w)
{
/* bit 0 flips screen */
if (flip_screen() != (data & 0x01))
{
flip_screen_set(data & 0x01);
machine().tilemap().mark_all_dirty();
}
/* bit 1 is NMI enable */
m_yiear_nmi_enable = data & 0x02;
/* bit 2 is IRQ enable */
m_yiear_irq_enable = data & 0x04;
/* bits 3 and 4 are coin counters */
machine().bookkeeping().coin_counter_w(0, data & 0x08);
machine().bookkeeping().coin_counter_w(1, data & 0x10);
}
TILE_GET_INFO_MEMBER(yiear_state::get_bg_tile_info)
{
int offs = tile_index * 2;
int attr = m_videoram[offs];
int code = m_videoram[offs + 1] | ((attr & 0x10) << 4);
// int color = (attr & 0xf0) >> 4;
int flags = ((attr & 0x80) ? TILE_FLIPX : 0) | ((attr & 0x40) ? TILE_FLIPY : 0);
SET_TILE_INFO_MEMBER(0, code, 0, flags);
}
void yiear_state::video_start()
{
m_bg_tilemap = &machine().tilemap().create(*m_gfxdecode, tilemap_get_info_delegate(*this, FUNC(yiear_state::get_bg_tile_info)), TILEMAP_SCAN_ROWS, 8, 8, 32, 32);
}
void yiear_state::draw_sprites( bitmap_ind16 &bitmap, const rectangle &cliprect )
{
uint8_t *spriteram = m_spriteram;
uint8_t *spriteram_2 = m_spriteram2;
int offs;
for (offs = m_spriteram.bytes() - 2; offs >= 0; offs -= 2)
{
int attr = spriteram[offs];
int code = spriteram_2[offs + 1] + 256 * (attr & 0x01);
int color = 0;
int flipx = ~attr & 0x40;
int flipy = attr & 0x80;
int sy = 240 - spriteram[offs + 1];
int sx = spriteram_2[offs];
if (flip_screen())
{
sy = 240 - sy;
flipy = !flipy;
}
if (offs < 0x26)
{
sy++; /* fix title screen & garbage at the bottom of the screen */
}
m_gfxdecode->gfx(1)->transpen(bitmap,cliprect,
code, color,
flipx, flipy,
sx, sy, 0);
}
}
uint32_t yiear_state::screen_update_yiear(screen_device &screen, bitmap_ind16 &bitmap, const rectangle &cliprect)
{
m_bg_tilemap->draw(screen, bitmap, cliprect, 0, 0);
draw_sprites(bitmap, cliprect);
return 0;
}