summaryrefslogblamecommitdiffstatshomepage
path: root/src/mame/video/1942.cpp
blob: 2c2acdcb5efac91d299d985347eeabb55bf9b991 (plain) (tree)
1
2
3
4
5
6
7
8
9
10
                       
                                            







                                                                            
                
                          














                                                                              
 
                                                               
 
                                                               
 
                                     
         
                                           
 
                                



                                                             

                                                                                    



                                                             

                                                                                    



                                                             
                                                                                    
 
                                                              
         
 
 
                                                              
 
                                
 
                                                               
                              
                                                                     


                                                    


                                                                              
 


                                                                  
         



                                                                                         

                             
 



                                                                              

 
                                                                
 
                                       
                                               
 
                                                                     
                                       
                                                                           


 
 





                                                                            
                                                   


                        

                                                  
                               




                                                     
                                                   




                                                                        

                                                 
                               
                                                     
                                                                 








                                                                            
                               
 

                                                                                                                                                                           
 
                                             

 
                                
 

                                                                                                                                                                           



                                             






                                                                            
                                              
 

                                                      

 
                                              
 

                                                                                  


 
                                                
 
                                   
         
                                          
                                               


         
                                          
 

                                                                       


 
                                        

                             

                                 
 
                                                              
 
                                                                                               
 
                                     








                                                                            
                                                                               


                 
                                                                  
         
                                              
 




                                                                                      
                        
 
                                  






                                                      
                                                        
                           
                              


                  
                                                                      
                                                     
                                                                    
                                                                 







                                 
                                                                                                           
 
                                                           
                                       
                                                           

                 

 
                                                                                
 
                                                                      
         
                                                                                          
                                                                         
                                                       

 

                                                                                       
 
                        


                                      

                                 




                                      

                                                      
                                                            


                              

                      

                  
                                                                      







                                                                    
 
// license:BSD-3-Clause
// copyright-holders:Paul Leaman, Couriersud
/***************************************************************************

  video.c

  Functions to emulate the video hardware of the machine.

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

#include "emu.h"
#include "includes/1942.h"

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

  Convert the color PROMs into a more useable format.

  1942 has three 256x4 palette PROMs (one per gun) and three 256x4 lookup
  table PROMs (one for characters, one for sprites, one for background tiles).
  The palette PROMs are connected to the RGB output this way:

  bit 3 -- 220 ohm resistor  -- RED/GREEN/BLUE
        -- 470 ohm resistor  -- RED/GREEN/BLUE
        -- 1  kohm resistor  -- RED/GREEN/BLUE
  bit 0 -- 2.2kohm resistor  -- RED/GREEN/BLUE

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

void _1942_state::create_palette(palette_device &palette) const
{
	const uint8_t *color_prom = memregion("proms")->base();

	for (int i = 0; i < 256; i++)
	{
		int bit0, bit1, bit2, bit3;

		// red component
		bit0 = (color_prom[i + 0 * 256] >> 0) & 0x01;
		bit1 = (color_prom[i + 0 * 256] >> 1) & 0x01;
		bit2 = (color_prom[i + 0 * 256] >> 2) & 0x01;
		bit3 = (color_prom[i + 0 * 256] >> 3) & 0x01;
		int const r = 0x0e * bit0 + 0x1f * bit1 + 0x43 * bit2 + 0x8f * bit3;
		// green component
		bit0 = (color_prom[i + 1 * 256] >> 0) & 0x01;
		bit1 = (color_prom[i + 1 * 256] >> 1) & 0x01;
		bit2 = (color_prom[i + 1 * 256] >> 2) & 0x01;
		bit3 = (color_prom[i + 1 * 256] >> 3) & 0x01;
		int const g = 0x0e * bit0 + 0x1f * bit1 + 0x43 * bit2 + 0x8f * bit3;
		// blue component
		bit0 = (color_prom[i + 2 * 256] >> 0) & 0x01;
		bit1 = (color_prom[i + 2 * 256] >> 1) & 0x01;
		bit2 = (color_prom[i + 2 * 256] >> 2) & 0x01;
		bit3 = (color_prom[i + 2 * 256] >> 3) & 0x01;
		int const b = 0x0e * bit0 + 0x1f * bit1 + 0x43 * bit2 + 0x8f * bit3;

		palette.set_indirect_color(i, rgb_t(r, g, b));
	}
}

void _1942_state::_1942_palette(palette_device &palette) const
{
	create_palette(palette);

	const uint8_t *color_prom = memregion("proms")->base();
	color_prom += 3 * 256;
	// color_prom now points to the beginning of the lookup table


	/* characters use palette entries 128-143 */
	int colorbase = 0;
	for (int i = 0; i < 64 * 4; i++)
		palette.set_pen_indirect(colorbase + i, 0x80 | *color_prom++);

	// background tiles use palette entries 0-63 in four banks
	colorbase += 64 * 4;
	for (int i = 0; i < 32 * 8; i++)
	{
		palette.set_pen_indirect(colorbase + 0 * 32 * 8 + i, 0x00 | *color_prom);
		palette.set_pen_indirect(colorbase + 1 * 32 * 8 + i, 0x10 | *color_prom);
		palette.set_pen_indirect(colorbase + 2 * 32 * 8 + i, 0x20 | *color_prom);
		palette.set_pen_indirect(colorbase + 3 * 32 * 8 + i, 0x30 | *color_prom);
		color_prom++;
	}

	// sprites use palette entries 64-79
	colorbase += 4 * 32 * 8;
	for (int i = 0; i < 16 * 16; i++)
		palette.set_pen_indirect(colorbase + i, 0x40 | *color_prom++);
}

void _1942p_state::_1942p_palette(palette_device &palette) const
{
	for (int i = 0; i < 0x400; i++)
		palette.set_pen_indirect(i, i);

	uint8_t const *const color_prom = memregion("proms")->base();
	for (int i = 0; i < 0x100; i++)
		palette.set_pen_indirect(i + 0x400, color_prom[i] | 0x240);
}



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

  Callbacks for the TileMap code

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

TILE_GET_INFO_MEMBER(_1942_state::get_fg_tile_info)
{
	int code, color;

	code = m_fg_videoram[tile_index];
	color = m_fg_videoram[tile_index + 0x400];
	SET_TILE_INFO_MEMBER(0,
			code + ((color & 0x80) << 1),
			color & 0x3f,
			0);
}

TILE_GET_INFO_MEMBER(_1942_state::get_bg_tile_info)
{
	int code, color;

	tile_index = (tile_index & 0x0f) | ((tile_index & 0x01f0) << 1);

	code = m_bg_videoram[tile_index];
	color = m_bg_videoram[tile_index + 0x10];
	SET_TILE_INFO_MEMBER(1,
			code + ((color & 0x80) << 1),
			(color & 0x1f) + (0x20 * m_palette_bank),
			TILE_FLIPYX((color & 0x60) >> 5));
}


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

  Start the video hardware emulation.

***************************************************************************/
void _1942_state::video_start()
{
	m_fg_tilemap = &machine().tilemap().create(*m_gfxdecode, tilemap_get_info_delegate(*this, FUNC(_1942_state::get_fg_tile_info)), TILEMAP_SCAN_ROWS, 8, 8, 32, 32);
	m_bg_tilemap = &machine().tilemap().create(*m_gfxdecode, tilemap_get_info_delegate(*this, FUNC(_1942_state::get_bg_tile_info)), TILEMAP_SCAN_COLS, 16, 16, 32, 16);

	m_fg_tilemap->set_transparent_pen(0);
}

void _1942p_state::video_start()
{
	m_fg_tilemap = &machine().tilemap().create(*m_gfxdecode, tilemap_get_info_delegate(*this, FUNC(_1942_state::get_fg_tile_info)), TILEMAP_SCAN_ROWS, 8, 8, 32, 32);
	m_bg_tilemap = &machine().tilemap().create(*m_gfxdecode, tilemap_get_info_delegate(*this, FUNC(_1942_state::get_bg_tile_info)), TILEMAP_SCAN_COLS, 16, 16, 32, 16);

	m_fg_tilemap->set_transparent_pen(3);
}


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

  Memory handlers

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

WRITE8_MEMBER(_1942_state::_1942_fgvideoram_w)
{
	m_fg_videoram[offset] = data;
	m_fg_tilemap->mark_tile_dirty(offset & 0x3ff);
}

WRITE8_MEMBER(_1942_state::_1942_bgvideoram_w)
{
	m_bg_videoram[offset] = data;
	m_bg_tilemap->mark_tile_dirty((offset & 0x0f) | ((offset >> 1) & 0x01f0));
}


WRITE8_MEMBER(_1942_state::_1942_palette_bank_w)
{
	if (m_palette_bank != data)
	{
		m_palette_bank = data & 3;
		m_bg_tilemap->mark_all_dirty();
	}
}

WRITE8_MEMBER(_1942_state::_1942_scroll_w)
{
	m_scroll[offset] = data;
	m_bg_tilemap->set_scrollx(0, m_scroll[0] | (m_scroll[1] << 8));
}


WRITE8_MEMBER(_1942_state::_1942_c804_w)
{
	/* bit 7: flip screen
	   bit 4: cpu B reset
	   bit 0: coin counter */

	machine().bookkeeping().coin_counter_w(0,data & 0x01);

	m_audiocpu->set_input_line(INPUT_LINE_RESET, (data & 0x10) ? ASSERT_LINE : CLEAR_LINE);

	flip_screen_set(data & 0x80);
}


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

  Display refresh

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

void _1942_state::draw_sprites(bitmap_ind16 &bitmap, const rectangle &cliprect)
{
	int offs;

	for (offs = m_spriteram.bytes() - 4; offs >= 0; offs -= 4)
	{
		int i, code, col, sx, sy, dir;

		code = (m_spriteram[offs] & 0x7f) + 4 * (m_spriteram[offs + 1] & 0x20)
				+ 2 * (m_spriteram[offs] & 0x80);
		col = m_spriteram[offs + 1] & 0x0f;
		sx = m_spriteram[offs + 3] - 0x10 * (m_spriteram[offs + 1] & 0x10);
		sy = m_spriteram[offs + 2];
		dir = 1;

		if (flip_screen())
		{
			sx = 240 - sx;
			sy = 240 - sy;
			dir = -1;
		}

		/* handle double / quadruple height */
		i = (m_spriteram[offs + 1] & 0xc0) >> 6;
		if (i == 2)
			i = 3;

		do
		{
			m_gfxdecode->gfx(2)->transpen(bitmap,cliprect,
					code + i,col,
					flip_screen(),flip_screen(),
					sx,sy + 16 * i * dir,15);

			i--;
		} while (i >= 0);
	}


}

uint32_t _1942_state::screen_update(screen_device &screen, bitmap_ind16 &bitmap, const rectangle &cliprect)
{
	m_bg_tilemap->draw(screen, bitmap, cliprect, 0, 0);
	draw_sprites(bitmap, cliprect);
	m_fg_tilemap->draw(screen, bitmap, cliprect, 0, 0);
	return 0;
}


void _1942p_state::draw_sprites(bitmap_ind16 &bitmap, const rectangle &cliprect)
{
	for (int offs = m_spriteram.bytes() - 4; offs >= 0; offs -= 4)
	{
		int code = (m_spriteram[offs] & 0x7f) + 4 * (m_spriteram[offs + 3] & 0x20)
					+ 2 * (m_spriteram[offs] & 0x80);
		int col = m_spriteram[offs + 3] & 0x0f;


		int sx = m_spriteram[offs + 2] - 0x10 * (m_spriteram[offs + 3] & 0x10);
		int sy = m_spriteram[offs + 1];

		int dir;
		if (flip_screen())
		{
			sx = 240 - sx;
			dir = -1;
		}
		else
		{
			sy = 240 - sy;
			dir = 1;
		}

		/* handle double / quadruple height */
		int i = (m_spriteram[offs + 3] & 0xc0) >> 6;
		if (i == 2)
			i = 3;

		i = 0;

		do
		{
			m_gfxdecode->gfx(2)->transpen(bitmap,cliprect,
					code + i,col,
					flip_screen(),flip_screen(),
					sx,sy + 16 * i * dir,15);

			i--;
		} while (i >= 0);
	}

}