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// license:BSD-3-Clause
// copyright-holders:Nicola Salmoria
#include "emu.h"
#include "includes/mjkjidai.h"


/***************************************************************************

  Callbacks for the TileMap code

***************************************************************************/

TILE_GET_INFO_MEMBER(mjkjidai_state::get_tile_info)
{
	int attr = m_videoram[tile_index + 0x800];
	int code = m_videoram[tile_index] + ((attr & 0x1f) << 8);
	int color = m_videoram[tile_index + 0x1000];
	tileinfo.set(0, code, color >> 3, 0);
}



/***************************************************************************

  Start the video hardware emulation.

***************************************************************************/

void mjkjidai_state::video_start()
{
	m_bg_tilemap = &machine().tilemap().create(*m_gfxdecode, tilemap_get_info_delegate(*this, FUNC(mjkjidai_state::get_tile_info)), TILEMAP_SCAN_ROWS, 8, 8, 64, 32);
}



/***************************************************************************

  Memory handlers

***************************************************************************/

void mjkjidai_state::videoram_w(offs_t offset, uint8_t data)
{
	m_videoram[offset] = data;
	m_bg_tilemap->mark_tile_dirty(offset & 0x7ff);
}

void mjkjidai_state::ctrl_w(uint8_t data)
{
//  logerror("%s: port c0 = %02x\n", m_maincpu->pc(), data);

	// bit 0 = NMI enable
	m_nmi_enable = data & 1;
	if (!m_nmi_enable)
		m_maincpu->set_input_line(INPUT_LINE_NMI, CLEAR_LINE);

	// bit 1 = flip screen
	flip_screen_set(data & 0x02);

	// bit 2 = display enable
	m_display_enable = data & 0x04;

	// bit 5 = coin counter
	machine().bookkeeping().coin_counter_w(0, data & 0x20);

	// bits 6-7 select ROM bank
	m_mainbank->set_entry(data >> 6);
}



/***************************************************************************

  Display refresh

***************************************************************************/

void mjkjidai_state::draw_sprites(bitmap_ind16 &bitmap, const rectangle &cliprect)
{
	uint8_t *spriteram = &m_videoram[0];
	uint8_t *spriteram_2 = &m_videoram[0x800];
	uint8_t *spriteram_3 = &m_videoram[0x1000];

	for (int offs = 0x20 - 2; offs >= 0; offs -= 2)
	{
		int code = spriteram[offs] + ((spriteram_2[offs] & 0x1f) << 8);
		int color = (spriteram_3[offs] & 0x78) >> 3;
		int sx = 2 * spriteram_2[offs + 1];
		int sy = 240 - spriteram[offs + 1];
		int flipx = code & 1;
		int flipy = code & 2;

		code >>= 2;

		sx += (spriteram_2[offs] & 0x20) >> 5;  // not sure about this

		if (flip_screen())
		{
			sx = 496 - sx;
			sy = 240 - sy;
			flipx = !flipx;
			flipy = !flipy;
		}

		sx += 16;
		sy += 1;

		m_gfxdecode->gfx(1)->transpen(bitmap, cliprect,
				code,
				color,
				flipx, flipy,
				sx, sy, 0);
	}
}



uint32_t mjkjidai_state::screen_update(screen_device &screen, bitmap_ind16 &bitmap, const rectangle &cliprect)
{
	if (!m_display_enable)
		bitmap.fill(m_palette->black_pen(), cliprect);
	else
	{
		m_bg_tilemap->draw(screen, bitmap, cliprect, 0, 0);
		draw_sprites(bitmap, cliprect);
	}
	return 0;
}