// license:BSD-3-Clause
// copyright-holders:Ernesto Corvi, Brad Oliver, Fabio Priuli
/******************************************************************************
Nintendo 2C0x PPU emulation.
Written by Ernesto Corvi.
This code is heavily based on Brad Oliver's MESS implementation.
2009-04: Changed NES PPU to be a device (Nathan Woods)
2009-07: Changed NES PPU to use a device memory map (Robert Bohms)
Current known bugs
General:
* PPU timing is imprecise for updates that happen mid-scanline. Some games
may demand more precision.
NES-specific:
* Micro Machines has minor rendering glitches (needs better timing).
* Mach Rider has minor road rendering glitches (needs better timing).
* Rad Racer demonstrates road glitches: it changes horizontal scrolling mid-line.
******************************************************************************/
#include "emu.h"
#include "video/ppu2c0x.h"
#include "screen.h"
/***************************************************************************
CONSTANTS
***************************************************************************/
/* constant definitions */
#define VISIBLE_SCREEN_WIDTH (32*8) /* Visible screen width */
#define VISIBLE_SCREEN_HEIGHT (30*8) /* Visible screen height */
#define VIDEOMEM_SIZE 0x1000 /* videomem size */
#define VIDEOMEM_PAGE_SIZE 0x400 /* videomem page size */
#define SPRITERAM_SIZE 0x100 /* spriteram size */
#define SPRITERAM_MASK (0x100-1) /* spriteram size */
#define CHARGEN_NUM_CHARS 512 /* max number of characters handled by the chargen */
/* default monochromatic colortable */
static const pen_t default_colortable_mono[] =
{
0,1,2,3,
0,1,2,3,
0,1,2,3,
0,1,2,3,
0,1,2,3,
0,1,2,3,
0,1,2,3,
0,1,2,3,
};
/* default colortable */
static const pen_t default_colortable[] =
{
0,1,2,3,
0,5,6,7,
0,9,10,11,
0,13,14,15,
0,17,18,19,
0,21,22,23,
0,25,26,27,
0,29,30,31,
};
//**************************************************************************
// GLOBAL VARIABLES
//**************************************************************************
// devices
DEFINE_DEVICE_TYPE(PPU_2C02, ppu2c02_device, "ppu2c02", "2C02 PPU")
DEFINE_DEVICE_TYPE(PPU_2C03B, ppu2c03b_device, "ppu2c03b", "2C03B PPC")
DEFINE_DEVICE_TYPE(PPU_2C04, ppu2c04_device, "ppu2c04", "2C04 PPU")
DEFINE_DEVICE_TYPE(PPU_2C07, ppu2c07_device, "ppu2c07", "2C07 PPU")
DEFINE_DEVICE_TYPE(PPU_PALC, ppupalc_device, "ppupalc", "Generic PAL Clone PPU")
DEFINE_DEVICE_TYPE(PPU_2C05_01, ppu2c05_01_device, "ppu2c05_01", "2C05_01 PPU")
DEFINE_DEVICE_TYPE(PPU_2C05_02, ppu2c05_02_device, "ppu2c05_02", "2C05_02 PPU")
DEFINE_DEVICE_TYPE(PPU_2C05_03, ppu2c05_03_device, "ppu2c05_03", "2C05_03 PPU")
DEFINE_DEVICE_TYPE(PPU_2C05_04, ppu2c05_04_device, "ppu2c05_04", "2C05_04 PPU")
// default address map
void ppu2c0x_device::ppu2c0x(address_map &map)
{
if (!has_configured_map(0))
{
map(0x0000, 0x3eff).ram();
map(0x3f00, 0x3fff).rw(FUNC(ppu2c0x_device::palette_read), FUNC(ppu2c0x_device::palette_write));
// map(0x0000, 0x3fff).ram();
}
}
//-------------------------------------------------
// memory_space_config - return a description of
// any address spaces owned by this device
//-------------------------------------------------
device_memory_interface::space_config_vector ppu2c0x_device::memory_space_config() const
{
return space_config_vector {
std::make_pair(0, &m_space_config)
};
}
//-------------------------------------------------
// ppu2c0x_device - constructor
//-------------------------------------------------
void ppu2c0x_device::device_config_complete()
{
/* reset the callbacks */
m_scanline_callback_proc.set(nullptr);
m_hblank_callback_proc.set(nullptr);
m_vidaccess_callback_proc.set(nullptr);
m_latch.set(nullptr);
}
ppu2c0x_device::ppu2c0x_device(const machine_config &mconfig, device_type type, const char *tag, device_t *owner, uint32_t clock)
: device_t(mconfig, type, tag, owner, clock)
, device_memory_interface(mconfig, *this)
, device_video_interface(mconfig, *this)
, device_palette_interface(mconfig, *this)
, m_space_config("videoram", ENDIANNESS_LITTLE, 8, 17, 0, address_map_constructor(FUNC(ppu2c0x_device::ppu2c0x), this))
, m_cpu(*this, finder_base::DUMMY_TAG)
, m_scanline(0) // reset the scanline count
, m_scanline_callback_proc(*this)
, m_hblank_callback_proc(*this)
, m_vidaccess_callback_proc(*this)
, m_int_callback(*this)
, m_refresh_data(0)
, m_refresh_latch(0)
, m_x_fine(0)
, m_toggle(0)
, m_add(1)
, m_videomem_addr(0)
, m_data_latch(0)
, m_buffered_data(0)
, m_tile_page(0)
, m_sprite_page(0)
, m_back_color(0)
, m_scan_scale(1) // set the scan scale (this is for dual monitor vertical setups)
, m_tilecount(0)
, m_draw_phase(0)
, m_latch(*this)
, m_use_sprite_write_limitation(true)
{
for (auto & elem : m_regs)
elem = 0;
memset(m_palette_ram, 0, ARRAY_LENGTH(m_palette_ram));
m_scanlines_per_frame = NTSC_SCANLINES_PER_FRAME;
m_vblank_first_scanline = VBLANK_FIRST_SCANLINE;
/* usually, no security value... */
m_security_value = 0;
}
ppu2c0x_rgb_device::ppu2c0x_rgb_device(const machine_config &mconfig, device_type type, const char *tag, device_t *owner, uint32_t clock) : ppu2c0x_device(mconfig, type, tag, owner, clock)
, m_palette_data(*this, "palette", 0xc0)
{
}
// NTSC NES
ppu2c02_device::ppu2c02_device(const machine_config &mconfig, const char *tag, device_t *owner, uint32_t clock) : ppu2c0x_device(mconfig, PPU_2C02, tag, owner, clock)
{
}
// Playchoice 10
ppu2c03b_device::ppu2c03b_device(const machine_config &mconfig, const char *tag, device_t *owner, uint32_t clock) : ppu2c0x_rgb_device(mconfig, PPU_2C03B, tag, owner, clock)
{
}
// Vs. Unisystem
ppu2c04_device::ppu2c04_device(const machine_config &mconfig, const char *tag, device_t *owner, uint32_t clock) : ppu2c0x_rgb_device(mconfig, PPU_2C04, tag, owner, clock)
{
}
// PAL NES
ppu2c07_device::ppu2c07_device(const machine_config &mconfig, const char *tag, device_t *owner, uint32_t clock) : ppu2c0x_device(mconfig, PPU_2C07, tag, owner, clock)
{
m_scanlines_per_frame = PAL_SCANLINES_PER_FRAME;
}
// PAL clones
ppupalc_device::ppupalc_device(const machine_config &mconfig, const char *tag, device_t *owner, uint32_t clock) : ppu2c0x_device(mconfig, PPU_PALC, tag, owner, clock)
{
m_scanlines_per_frame = PAL_SCANLINES_PER_FRAME;
m_vblank_first_scanline = VBLANK_FIRST_SCANLINE_PALC;
}
// The PPU_2C05 variants have different protection value, set at device start, but otherwise are all the same...
// Vs. Unisystem (Ninja Jajamaru Kun)
ppu2c05_01_device::ppu2c05_01_device(const machine_config &mconfig, const char *tag, device_t *owner, uint32_t clock) : ppu2c0x_rgb_device(mconfig, PPU_2C05_01, tag, owner, clock)
{
m_security_value = 0x1b; // game (jajamaru) doesn't seem to ever actually check it
}
// Vs. Unisystem (Mighty Bomb Jack)
ppu2c05_02_device::ppu2c05_02_device(const machine_config &mconfig, const char *tag, device_t *owner, uint32_t clock) : ppu2c0x_rgb_device(mconfig, PPU_2C05_02, tag, owner, clock)
{
m_security_value = 0x3d;
}
// Vs. Unisystem (Gumshoe)
ppu2c05_03_device::ppu2c05_03_device(const machine_config &mconfig, const char *tag, device_t *owner, uint32_t clock) : ppu2c0x_rgb_device(mconfig, PPU_2C05_03, tag, owner, clock)
{
m_security_value = 0x1c;
}
// Vs. Unisystem (Top Gun)
ppu2c05_04_device::ppu2c05_04_device(const machine_config &mconfig, const char *tag, device_t *owner, uint32_t clock) : ppu2c0x_rgb_device(mconfig, PPU_2C05_04, tag, owner, clock)
{
m_security_value = 0x1b;
}
//-------------------------------------------------
// device_start - device-specific startup
//-------------------------------------------------
void ppu2c0x_device::device_start()
{
// bind our handler
m_int_callback.resolve_safe();
// allocate timers
m_hblank_timer = timer_alloc(TIMER_HBLANK);
m_nmi_timer = timer_alloc(TIMER_NMI);
m_scanline_timer = timer_alloc(TIMER_SCANLINE);
/* initialize the scanline handling portion */
m_scanline_timer->adjust(screen().time_until_pos(1));
m_hblank_timer->adjust(m_cpu->cycles_to_attotime(260) / 3); // ??? FIXME - hardcoding NTSC, need better calculation
m_nmi_timer->adjust(attotime::never);
/* allocate a screen bitmap, videomem and spriteram, a dirtychar array and the monochromatic colortable */
m_bitmap = std::make_unique<bitmap_rgb32>(VISIBLE_SCREEN_WIDTH, VISIBLE_SCREEN_HEIGHT);
m_spriteram = make_unique_clear<uint8_t[]>(SPRITERAM_SIZE);
m_colortable = std::make_unique<pen_t[]>(ARRAY_LENGTH(default_colortable));
m_colortable_mono = std::make_unique<pen_t[]>(ARRAY_LENGTH(default_colortable_mono));
/* initialize the color tables */
for (int i = 0; i < ARRAY_LENGTH(default_colortable_mono); i++)
{
/* monochromatic table */
m_colortable_mono[i] = default_colortable_mono[i];
/* color table */
m_colortable[i] = default_colortable[i];
}
init_palette();
// register for state saving
save_item(NAME(m_scanline));
save_item(NAME(m_refresh_data));
save_item(NAME(m_refresh_latch));
save_item(NAME(m_x_fine));
save_item(NAME(m_toggle));
save_item(NAME(m_add));
save_item(NAME(m_videomem_addr));
save_item(NAME(m_data_latch));
save_item(NAME(m_buffered_data));
save_item(NAME(m_tile_page));
save_item(NAME(m_sprite_page));
save_item(NAME(m_back_color));
save_item(NAME(m_scan_scale));
save_item(NAME(m_scanlines_per_frame));
save_item(NAME(m_vblank_first_scanline));
save_item(NAME(m_regs));
save_item(NAME(m_palette_ram));
save_item(NAME(m_draw_phase));
save_item(NAME(m_tilecount));
save_pointer(NAME(m_spriteram), SPRITERAM_SIZE);
save_pointer(NAME(m_colortable), ARRAY_LENGTH(default_colortable));
save_pointer(NAME(m_colortable_mono), ARRAY_LENGTH(default_colortable_mono));
save_item(NAME(*m_bitmap));
}
//**************************************************************************
// INLINE HELPERS
//**************************************************************************
//-------------------------------------------------
// readbyte - read a byte at the given address
//-------------------------------------------------
inline uint8_t ppu2c0x_device::readbyte(offs_t address)
{
return space().read_byte(address);
}
//-------------------------------------------------
// writebyte - write a byte at the given address
//-------------------------------------------------
inline void ppu2c0x_device::writebyte(offs_t address, uint8_t data)
{
space().write_byte(address, data);
}
/***************************************************************************
IMPLEMENTATION
***************************************************************************/
/*************************************
*
* PPU Palette Initialization
*
*************************************/
void ppu2c0x_device::init_palette()
{
init_palette(false);
}
void ppu2c0x_device::init_palette(bool indirect)
{
/* This routine builds a palette using a transformation from */
/* the YUV (Y, B-Y, R-Y) to the RGB color space */
/* The NES has a 64 color palette */
/* 16 colors, with 4 luminance levels for each color */
/* The 16 colors circle around the YUV color space, */
const double tint = 0.22; /* adjust to taste */
const double hue = 287.0;
const double Kr = 0.2989;
const double Kb = 0.1145;
const double Ku = 2.029;
const double Kv = 1.140;
static const double brightness[3][4] =
{
{ 0.50, 0.75, 1.0, 1.0 },
{ 0.29, 0.45, 0.73, 0.9 },
{ 0, 0.24, 0.47, 0.77 }
};
int entry = 0;
/* Loop through the emphasis modes (8 total) */
for (int color_emphasis = 0; color_emphasis < 8; color_emphasis++)
{
/*
double r_mod = 0.0;
double g_mod = 0.0;
double b_mod = 0.0;
switch (color_emphasis)
{
case 0: r_mod = 1.0; g_mod = 1.0; b_mod = 1.0; break;
case 1: r_mod = 1.24; g_mod = .915; b_mod = .743; break;
case 2: r_mod = .794; g_mod = 1.09; b_mod = .882; break;
case 3: r_mod = .905; g_mod = 1.03; b_mod = 1.28; break;
case 4: r_mod = .741; g_mod = .987; b_mod = 1.0; break;
case 5: r_mod = 1.02; g_mod = .908; b_mod = .979; break;
case 6: r_mod = 1.02; g_mod = .98; b_mod = .653; break;
case 7: r_mod = .75; g_mod = .75; b_mod = .75; break;
}
*/
/* loop through the 4 intensities */
for (int color_intensity = 0; color_intensity < 4; color_intensity++)
{
/* loop through the 16 colors */
for (int color_num = 0; color_num < 16; color_num++)
{
double sat;
double y, u, v;
double rad;
switch (color_num)
{
case 0:
sat = 0; rad = 0;
y = brightness[0][color_intensity];
break;
case 13:
sat = 0; rad = 0;
y = brightness[2][color_intensity];
break;
case 14:
case 15:
sat = 0; rad = 0; y = 0;
break;
default:
sat = tint;
rad = M_PI * ((color_num * 30 + hue) / 180.0);
y = brightness[1][color_intensity];
break;
}
u = sat * cos(rad);
v = sat * sin(rad);
/* Transform to RGB */
double R = (y + Kv * v) * 255.0;
double G = (y - (Kb * Ku * u + Kr * Kv * v) / (1 - Kb - Kr)) * 255.0;
double B = (y + Ku * u) * 255.0;
/* Clipping, in case of saturation */
if (R < 0)
R = 0;
if (R > 255)
R = 255;
if (G < 0)
G = 0;
if (G > 255)
G = 255;
if (B < 0)
B = 0;
if (B > 255)
B = 255;
/* Round, and set the value */
if (indirect)
set_indirect_color(entry++, rgb_t(floor(R + .5), floor(G + .5), floor(B + .5)));
else
set_pen_color(entry++, floor(R + .5), floor(G + .5), floor(B + .5));
}
}
}
/* color tables are modified at run-time, and are initialized on 'ppu2c0x_reset' */
}
void ppu2c0x_rgb_device::init_palette()
{
/* Loop through the emphasis modes (8 total) */
int entry = 0;
for (int color_emphasis = 0; color_emphasis < 8; color_emphasis++)
{
for (int color_num = 0; color_num < 64; color_num++)
{
int R = ((color_emphasis & 1) ? 7 : m_palette_data[color_num * 3]);
int G = ((color_emphasis & 2) ? 7 : m_palette_data[color_num * 3 + 1]);
int B = ((color_emphasis & 4) ? 7 : m_palette_data[color_num * 3 + 2]);
set_pen_color(entry++, pal3bit(R), pal3bit(G), pal3bit(B));
}
}
/* color tables are modified at run-time, and are initialized on 'ppu2c0x_reset' */
}
#if 0
/* the charlayout we use for the chargen */
static const gfx_layout ppu_charlayout =
{
8, 8, /* 8*8 characters */
0,
2, /* 2 bits per pixel */
{ 8*8, 0 }, /* the two bitplanes are separated */
{ 0, 1, 2, 3, 4, 5, 6, 7 },
{ 0*8, 1*8, 2*8, 3*8, 4*8, 5*8, 6*8, 7*8 },
16*8 /* every char takes 16 consecutive bytes */
};
#endif
/*************************************
*
* PPU Initialization and Disposal
*
*************************************/
//-------------------------------------------------
// device_timer - handle timer events
//-------------------------------------------------
void ppu2c0x_device::device_timer(emu_timer &timer, device_timer_id id, int param, void *ptr)
{
int blanked, vblank;
switch (id)
{
case TIMER_HBLANK:
blanked = (m_regs[PPU_CONTROL1] & (PPU_CONTROL1_BACKGROUND | PPU_CONTROL1_SPRITES)) == 0;
vblank = ((m_scanline >= m_vblank_first_scanline - 1) && (m_scanline < m_scanlines_per_frame - 1)) ? 1 : 0;
//update_scanline();
if (!m_hblank_callback_proc.isnull())
m_hblank_callback_proc(m_scanline, vblank, blanked);
m_hblank_timer->adjust(attotime::never);
break;
case TIMER_NMI:
// Actually fire the VMI
m_int_callback(ASSERT_LINE);
m_int_callback(CLEAR_LINE);
m_nmi_timer->adjust(attotime::never);
break;
case TIMER_SCANLINE:
blanked = (m_regs[PPU_CONTROL1] & (PPU_CONTROL1_BACKGROUND | PPU_CONTROL1_SPRITES)) == 0;
vblank = ((m_scanline >= m_vblank_first_scanline - 1) && (m_scanline < m_scanlines_per_frame - 1)) ? 1 : 0;
int next_scanline;
/* if a callback is available, call it */
if (!m_scanline_callback_proc.isnull())
m_scanline_callback_proc(m_scanline, vblank, blanked);
/* update the scanline that just went by */
update_scanline();
/* increment our scanline count */
m_scanline++;
// logerror("starting scanline %d (MAME %d, beam %d)\n", m_scanline, device->screen().vpos(), device->screen().hpos());
/* Note: this is called at the _end_ of each scanline */
if (m_scanline == m_vblank_first_scanline)
{
// logerror("vblank starting\n");
/* We just entered VBLANK */
m_regs[PPU_STATUS] |= PPU_STATUS_VBLANK;
/* If NMI's are set to be triggered, go for it */
if (m_regs[PPU_CONTROL0] & PPU_CONTROL0_NMI)
{
// We need an ever-so-slight delay between entering vblank and firing an NMI - enough so that
// a game can read the high bit of $2002 before the NMI is called (potentially resetting the bit
// via a read from $2002 in the NMI handler).
// B-Wings is an example game that needs this.
m_nmi_timer->adjust(m_cpu->cycles_to_attotime(4));
}
}
if (m_scanline == m_scanlines_per_frame - 1)
{
// logerror("vblank ending\n");
/* clear the vblank & sprite hit flag */
m_regs[PPU_STATUS] &= ~(PPU_STATUS_VBLANK | PPU_STATUS_SPRITE0_HIT | PPU_STATUS_8SPRITES);
}
/* see if we rolled */
else if (m_scanline == m_scanlines_per_frame)
{
/* if background or sprites are enabled, copy the ppu address latch */
if (!blanked)
m_refresh_data = m_refresh_latch;
/* reset the scanline count */
m_scanline = 0;
//logerror("sprite 0 x: %d y: %d num: %d\n", m_spriteram[3], m_spriteram[0] + 1, m_spriteram[1]);
}
next_scanline = m_scanline + 1;
if (next_scanline == m_scanlines_per_frame)
next_scanline = 0;
// Call us back when the hblank starts for this scanline
m_hblank_timer->adjust(m_cpu->cycles_to_attotime(260) / 3); // ??? FIXME - hardcoding NTSC, need better calculation
// trigger again at the start of the next scanline
m_scanline_timer->adjust(screen().time_until_pos(next_scanline * m_scan_scale));
break;
}
}
void ppu2c0x_device::read_tile_plane_data(int address, int color)
{
m_planebuf[0] = readbyte((address & 0x1fff));
m_planebuf[1] = readbyte((address + 8) & 0x1fff);
}
void ppu2c0x_device::shift_tile_plane_data(uint8_t &pix)
{
pix = ((m_planebuf[0] >> 7) & 1) | (((m_planebuf[1] >> 7) & 1) << 1);
m_planebuf[0] = m_planebuf[0] << 1;
m_planebuf[1] = m_planebuf[1] << 1;
}
void ppu2c0x_device::draw_tile_pixel(uint8_t pix, int color, pen_t back_pen, uint32_t *&dest, const pen_t *color_table)
{
pen_t pen;
if (pix)
{
const pen_t *paldata = &color_table[4 * color];
pen = this->pen(paldata[pix]);
}
else
{
pen = back_pen;
}
*dest = pen;
}
void ppu2c0x_device::draw_tile(uint8_t *line_priority, int color_byte, int color_bits, int address, int start_x, pen_t back_pen, uint32_t *&dest, const pen_t *color_table)
{
int color = (((color_byte >> color_bits) & 0x03));
read_tile_plane_data(address, color);
/* render the pixel */
for (int i = 0; i < 8; i++)
{
uint8_t pix;
shift_tile_plane_data(pix);
if ((start_x + i) >= 0 && (start_x + i) < VISIBLE_SCREEN_WIDTH)
{
draw_tile_pixel(pix, color, back_pen, dest, color_table);
// priority marking
if (pix)
line_priority[start_x + i] |= 0x02;
}
dest++;
}
}
void ppu2c0x_device::draw_background(uint8_t *line_priority)
{
bitmap_rgb32 &bitmap = *m_bitmap;
int start_x = (m_x_fine ^ 0x07) - 7;
uint8_t scroll_x_coarse, scroll_y_coarse, scroll_y_fine, color_mask;
int x, tile_index, i;
const pen_t *color_table;
m_tilecount = 0;
/* setup the color mask and colortable to use */
if (m_regs[PPU_CONTROL1] & PPU_CONTROL1_DISPLAY_MONO)
{
color_mask = 0xf0;
color_table = m_colortable_mono.get();
}
else
{
color_mask = 0xff;
color_table = m_colortable.get();
}
/* cache the background pen */
pen_t back_pen = pen(m_back_color & color_mask);
/* determine where in the nametable to start drawing from */
/* based on the current scanline and scroll regs */
scroll_x_coarse = m_refresh_data & 0x1f;
scroll_y_coarse = (m_refresh_data & 0x3e0) >> 5;
scroll_y_fine = (m_refresh_data & 0x7000) >> 12;
x = scroll_x_coarse;
/* get the tile index */
tile_index = ((m_refresh_data & 0xc00) | 0x2000) + scroll_y_coarse * 32;
/* set up dest */
uint32_t *dest = &bitmap.pix32(m_scanline, start_x);
/* draw the 32 or 33 tiles that make up a line */
while (m_tilecount < 34)
{
int color_byte;
int color_bits;
int pos;
int index1;
int page, page2, address;
index1 = tile_index + x;
// page2 is the output of the nametable read (this section is the FIRST read per tile!)
page2 = readbyte(index1);
// this is attribute table stuff! (actually read 2 in PPUspeak)!
/* Figure out which byte in the color table to use */
pos = ((index1 & 0x380) >> 4) | ((index1 & 0x1f) >> 2);
page = (index1 & 0x0c00) >> 10;
address = 0x3c0 + pos;
color_byte = readbyte((((page * 0x400) + address) & 0xfff) + 0x2000);
/* figure out which bits in the color table to use */
color_bits = ((index1 & 0x40) >> 4) + (index1 & 0x02);
// 27/12/2002
if (!m_latch.isnull())
m_latch((m_tile_page << 10) | (page2 << 4));
if (start_x < VISIBLE_SCREEN_WIDTH)
{
// need to read 0x0000 or 0x1000 + 16*nametable data
address = ((m_tile_page) ? 0x1000 : 0) + (page2 * 16);
// plus something that accounts for y
address += scroll_y_fine;
draw_tile(line_priority, color_byte, color_bits, address, start_x, back_pen, dest, color_table);
start_x += 8;
/* move to next tile over and toggle the horizontal name table if necessary */
x++;
if (x > 31)
{
x = 0;
tile_index ^= 0x400;
}
}
m_tilecount++;
}
/* if the left 8 pixels for the background are off, blank 'em */
if (!(m_regs[PPU_CONTROL1] & PPU_CONTROL1_BACKGROUND_L8))
{
dest = &bitmap.pix32(m_scanline);
for (i = 0; i < 8; i++)
{
*(dest++) = back_pen;
line_priority[i] ^= 0x02;
}
}
}
void ppu2c0x_device::read_sprite_plane_data(int address)
{
m_planebuf[0] = readbyte((address + 0) & 0x1fff);
m_planebuf[1] = readbyte((address + 8) & 0x1fff);
}
void ppu2c0x_device::make_sprite_pixel_data(uint8_t &pixel_data, int flipx)
{
if (flipx)
{
pixel_data = (m_planebuf[0] & 1) + ((m_planebuf[1] & 1) << 1);
m_planebuf[0] = m_planebuf[0] >> 1;
m_planebuf[1] = m_planebuf[1] >> 1;
}
else
{
pixel_data = ((m_planebuf[0] >> 7) & 1) | (((m_planebuf[1] >> 7) & 1) << 1);
m_planebuf[0] = m_planebuf[0] << 1;
m_planebuf[1] = m_planebuf[1] << 1;
}
}
void ppu2c0x_device::draw_sprite_pixel(int sprite_xpos, int color, int pixel, uint8_t pixel_data, bitmap_rgb32 &bitmap)
{
const pen_t *paldata = &m_colortable[4 * color];
bitmap.pix32(m_scanline, sprite_xpos + pixel) = pen(paldata[pixel_data]);
}
void ppu2c0x_device::read_extra_sprite_bits(int sprite_index)
{
// needed for some clones
}
void ppu2c0x_device::draw_sprites(uint8_t *line_priority)
{
bitmap_rgb32 &bitmap = *m_bitmap;
int sprite_xpos, sprite_ypos, sprite_index;
int tile, index1;
int pri;
int flipx, flipy, color;
int size;
int sprite_count = 0;
int sprite_line;
int first_pixel;
int pixel;
/* determine if the sprites are 8x8 or 8x16 */
size = (m_regs[PPU_CONTROL0] & PPU_CONTROL0_SPRITE_SIZE) ? 16 : 8;
first_pixel = (m_regs[PPU_CONTROL1] & PPU_CONTROL1_SPRITES_L8)? 0: 8;
for (sprite_index = 0; sprite_index < SPRITERAM_SIZE; sprite_index += 4)
{
sprite_ypos = m_spriteram[sprite_index] + 1;
sprite_xpos = m_spriteram[sprite_index + 3];
// The sprite collision acts funny on the last pixel of a scanline.
// The various scanline latches update while the last few pixels
// are being drawn. Since we don't do cycle-by-cycle PPU emulation,
// we fudge it a bit here so that sprite 0 collisions are detected
// when, e.g., sprite x is 254, sprite y is 29 and we're rendering
// at the end of scanline 28.
// Battletoads needs this level of precision to be playable.
if ((sprite_index == 0) && (sprite_xpos == 254))
{
sprite_ypos--;
/* set the "sprite 0 hit" flag if appropriate */
if (line_priority[sprite_xpos] & 0x02)
m_regs[PPU_STATUS] |= PPU_STATUS_SPRITE0_HIT;
}
/* if the sprite isn't visible, skip it */
if ((sprite_ypos + size <= m_scanline) || (sprite_ypos > m_scanline))
continue;
tile = m_spriteram[sprite_index + 1];
color = (m_spriteram[sprite_index + 2] & 0x03) + 4;
pri = m_spriteram[sprite_index + 2] & 0x20;
flipx = m_spriteram[sprite_index + 2] & 0x40;
flipy = m_spriteram[sprite_index + 2] & 0x80;
read_extra_sprite_bits(sprite_index);
if (size == 16)
{
/* if it's 8x16 and odd-numbered, draw the other half instead */
if (tile & 0x01)
{
tile &= ~0x01;
tile |= 0x100;
}
}
if (!m_latch.isnull())
m_latch((m_sprite_page << 10) | ((tile & 0xff) << 4));
/* compute the character's line to draw */
sprite_line = m_scanline - sprite_ypos;
if (flipy)
sprite_line = (size - 1) - sprite_line;
if (size == 16 && sprite_line > 7)
{
tile++;
sprite_line -= 8;
}
index1 = tile * 16;
if (size == 8)
index1 += ((m_sprite_page == 0) ? 0 : 0x1000);
read_sprite_plane_data(index1+sprite_line);
/* if there are more than 8 sprites on this line, set the flag */
if (sprite_count == 8)
{
m_regs[PPU_STATUS] |= PPU_STATUS_8SPRITES;
// logerror ("> 8 sprites, scanline: %d\n", m_scanline);
/* the real NES only draws up to 8 sprites - the rest should be invisible */
break;
}
sprite_count++;
/* abort drawing if sprites aren't rendered */
if (!(m_regs[PPU_CONTROL1] & PPU_CONTROL1_SPRITES))
continue;
if (pri)
{
/* draw the low-priority sprites */
for (pixel = 0; pixel < 8; pixel++)
{
uint8_t pixel_data;
make_sprite_pixel_data(pixel_data, flipx);
/* is this pixel non-transparent? */
if (sprite_xpos + pixel >= first_pixel)
{
if (pixel_data)
{
/* has the background (or another sprite) already been drawn here? */
if ((sprite_xpos + pixel) < VISIBLE_SCREEN_WIDTH)
{
if (!line_priority[sprite_xpos + pixel])
{
/* no, draw */
draw_sprite_pixel(sprite_xpos, color, pixel, pixel_data, bitmap);
}
/* indicate that a sprite was drawn at this location, even if it's not seen */
line_priority[sprite_xpos + pixel] |= 0x01;
}
}
/* set the "sprite 0 hit" flag if appropriate */
if (sprite_index == 0 && (pixel_data & 0x03) && ((sprite_xpos + pixel) < 255) && (line_priority[sprite_xpos + pixel] & 0x02))
m_regs[PPU_STATUS] |= PPU_STATUS_SPRITE0_HIT;
}
}
}
else
{
/* draw the high-priority sprites */
for (pixel = 0; pixel < 8; pixel++)
{
uint8_t pixel_data;
make_sprite_pixel_data(pixel_data, flipx);
/* is this pixel non-transparent? */
if (sprite_xpos + pixel >= first_pixel)
{
if (pixel_data)
{
if ((sprite_xpos + pixel) < VISIBLE_SCREEN_WIDTH)
{
/* has another sprite been drawn here? */
if (!(line_priority[sprite_xpos + pixel] & 0x01))
{
/* no, draw */
draw_sprite_pixel(sprite_xpos, color, pixel, pixel_data, bitmap);
line_priority[sprite_xpos + pixel] |= 0x01;
}
}
}
/* set the "sprite 0 hit" flag if appropriate */
if (sprite_index == 0 && (pixel_data & 0x03) && ((sprite_xpos + pixel) < 255) && (line_priority[sprite_xpos + pixel] & 0x02))
m_regs[PPU_STATUS] |= PPU_STATUS_SPRITE0_HIT;
}
}
}
}
}
/*************************************
*
* Scanline Rendering and Update
*
*************************************/
void ppu2c0x_device::render_scanline()
{
uint8_t line_priority[VISIBLE_SCREEN_WIDTH];
/* lets see how long it takes */
g_profiler.start(PROFILER_USER1);
/* clear the line priority for this scanline */
memset(line_priority, 0, VISIBLE_SCREEN_WIDTH);
m_draw_phase = PPU_DRAW_BG;
/* see if we need to render the background */
if (m_regs[PPU_CONTROL1] & PPU_CONTROL1_BACKGROUND)
draw_background(line_priority);
else
{
bitmap_rgb32 &bitmap = *m_bitmap;
/* setup the color mask and colortable to use */
uint8_t color_mask = (m_regs[PPU_CONTROL1] & PPU_CONTROL1_DISPLAY_MONO) ? 0xf0 : 0xff;
/* cache the background pen */
pen_t back_pen = pen(m_back_color & color_mask);
// Fill this scanline with the background pen.
for (int i = 0; i < bitmap.width(); i++)
bitmap.pix32(m_scanline, i) = back_pen;
}
m_draw_phase = PPU_DRAW_OAM;
/* if sprites are on, draw them, but we call always to process them */
draw_sprites(line_priority);
m_draw_phase = PPU_DRAW_BG;
/* done updating, whew */
g_profiler.stop();
}
void ppu2c0x_device::update_scanline()
{
if (m_scanline <= BOTTOM_VISIBLE_SCANLINE)
{
/* Render this scanline if appropriate */
if (m_regs[PPU_CONTROL1] & (PPU_CONTROL1_BACKGROUND | PPU_CONTROL1_SPRITES))
{
if (m_scanline_timer->remaining() == attotime::zero)
{
/* If background or sprites are enabled, copy the ppu address latch */
/* Copy only the scroll x-coarse and the x-overflow bit */
m_refresh_data &= ~0x041f;
m_refresh_data |= (m_refresh_latch & 0x041f);
}
// logerror("updating refresh_data: %04x (scanline: %d)\n", m_refresh_data, m_scanline);
render_scanline();
}
else
{
bitmap_rgb32 &bitmap = *m_bitmap;
pen_t back_pen;
/* setup the color mask and colortable to use */
uint8_t color_mask = (m_regs[PPU_CONTROL1] & PPU_CONTROL1_DISPLAY_MONO) ? 0xf0 : 0xff;
/* cache the background pen */
if (m_videomem_addr >= 0x3f00)
{
// If the PPU's VRAM address happens to point into palette ram space while
// both the sprites and background are disabled, the PPU paints the scanline
// with the palette entry at the VRAM address instead of the usual background
// pen. Micro Machines makes use of this feature.
int pen_num = m_palette_ram[(m_videomem_addr & 0x03) ? (m_videomem_addr & 0x1f) : 0];
back_pen = pen(pen_num);
}
else
back_pen = pen(m_back_color & color_mask);
// Fill this scanline with the background pen.
for (int i = 0; i < bitmap.width(); i++)
bitmap.pix32(m_scanline, i) = back_pen;
}
if (m_scanline_timer->remaining() == attotime::zero)
{
/* increment the fine y-scroll */
m_refresh_data += 0x1000;
/* if it's rolled, increment the coarse y-scroll */
if (m_refresh_data & 0x8000)
{
uint16_t tmp;
tmp = (m_refresh_data & 0x03e0) + 0x20;
m_refresh_data &= 0x7c1f;
/* handle bizarro scrolling rollover at the 30th (not 32nd) vertical tile */
if (tmp == 0x03c0)
m_refresh_data ^= 0x0800;
else
m_refresh_data |= (tmp & 0x03e0);
//logerror("updating refresh_data: %04x\n", m_refresh_data);
}
}
}
}
/*************************************
*
* PPU Memory functions
*
*************************************/
WRITE8_MEMBER( ppu2c0x_device::palette_write )
{
int color_emphasis = (m_regs[PPU_CONTROL1] & PPU_CONTROL1_COLOR_EMPHASIS) * 2;
// palette RAM is only 6 bits wide
data &= 0x3f;
// transparent pens are mirrored!
if (offset & 0x3)
{
m_palette_ram[offset & 0x1f] = data;
m_colortable[offset & 0x1f] = data + color_emphasis;
m_colortable_mono[offset & 0x1f] = (data & 0xf0) + color_emphasis;
}
else
{
int i;
if (0 == (offset & 0xf))
{
m_back_color = data;
for (i = 0; i < 32; i += 4)
{
m_colortable[i] = data + color_emphasis;
m_colortable_mono[i] = (data & 0xf0) + color_emphasis;
}
}
m_palette_ram[offset & 0xf] = m_palette_ram[(offset & 0xf) + 0x10] = data;
}
}
READ8_MEMBER( ppu2c0x_device::palette_read )
{
if (m_regs[PPU_CONTROL1] & PPU_CONTROL1_DISPLAY_MONO)
return (m_palette_ram[offset & 0x1f] & 0x30);
else
return (m_palette_ram[offset & 0x1f]);
}
/*************************************
*
* PPU Registers Read
*
*************************************/
READ8_MEMBER( ppu2c0x_device::read )
{
if (offset >= PPU_MAX_REG)
{
logerror("PPU %s: Attempting to read past the chip: offset %x\n", this->tag(), offset);
offset &= PPU_MAX_REG - 1;
}
// see which register to read
switch (offset & 7)
{
case PPU_STATUS: /* 2 */
// The top 3 bits of the status register are the only ones that report data. The
// remainder contain whatever was last in the PPU data latch, except on the RC2C05 (protection)
if (m_security_value)
m_data_latch = (m_regs[PPU_STATUS] & 0xc0) | m_security_value;
else
m_data_latch = m_regs[PPU_STATUS] | (m_data_latch & 0x1f);
// Reset hi/lo scroll toggle
m_toggle = 0;
// If the vblank bit is set, clear all status bits but the 2 sprite flags
if (m_data_latch & PPU_STATUS_VBLANK)
m_regs[PPU_STATUS] &= 0x60;
break;
case PPU_SPRITE_DATA: /* 4 */
m_data_latch = m_spriteram[m_regs[PPU_SPRITE_ADDRESS]];
break;
case PPU_DATA: /* 7 */
if (!m_latch.isnull())
m_latch( m_videomem_addr & 0x3fff);
if (m_videomem_addr >= 0x3f00)
{
m_data_latch = readbyte(m_videomem_addr);
// buffer the mirrored NT data
m_buffered_data = readbyte(m_videomem_addr & 0x2fff);
}
else
{
m_data_latch = m_buffered_data;
m_buffered_data = readbyte(m_videomem_addr);
}
m_videomem_addr += m_add;
break;
default:
break;
}
return m_data_latch;
}
/*************************************
*
* PPU Registers Write
*
*************************************/
WRITE8_MEMBER( ppu2c0x_device::write )
{
if (offset >= PPU_MAX_REG)
{
logerror("PPU %s: Attempting to write past the chip: offset %x, data %x\n", this->tag(), offset, data);
offset &= PPU_MAX_REG - 1;
}
#ifdef MAME_DEBUG
if (m_scanline <= BOTTOM_VISIBLE_SCANLINE)
{
logerror("PPU register %d write %02x during non-vblank scanline %d (MAME %d, beam pos: %d)\n", offset, data, m_scanline, screen().vpos(), screen().hpos());
}
#endif
/* on the RC2C05, PPU_CONTROL0 and PPU_CONTROL1 are swapped (protection) */
if ((m_security_value) && !(offset & 6))
offset ^= 1;
switch (offset & 7)
{
case PPU_CONTROL0: /* 0 */
m_regs[PPU_CONTROL0] = data;
/* update the name table number on our refresh latches */
m_refresh_latch &= 0x73ff;
m_refresh_latch |= (data & 3) << 10;
/* the char ram bank points either 0x0000 or 0x1000 (page 0 or page 4) */
m_tile_page = (data & PPU_CONTROL0_CHR_SELECT) >> 2;
m_sprite_page = (data & PPU_CONTROL0_SPR_SELECT) >> 1;
m_add = (data & PPU_CONTROL0_INC) ? 32 : 1;
// logerror("control0 write: %02x (scanline: %d)\n", data, m_scanline);
break;
case PPU_CONTROL1: /* 1 */
/* if color intensity has changed, change all the color tables to reflect them */
if ((data & PPU_CONTROL1_COLOR_EMPHASIS) != (m_regs[PPU_CONTROL1] & PPU_CONTROL1_COLOR_EMPHASIS))
{
int i;
for (i = 0; i <= 0x1f; i++)
{
uint8_t oldColor = m_palette_ram[i];
m_colortable[i] = oldColor + (data & PPU_CONTROL1_COLOR_EMPHASIS) * 2;
}
}
// logerror("control1 write: %02x (scanline: %d)\n", data, m_scanline);
m_regs[PPU_CONTROL1] = data;
break;
case PPU_SPRITE_ADDRESS: /* 3 */
m_regs[PPU_SPRITE_ADDRESS] = data;
break;
case PPU_SPRITE_DATA: /* 4 */
// If the PPU is currently rendering the screen, 0xff is written instead of the desired data.
if (m_use_sprite_write_limitation)
if (m_scanline <= BOTTOM_VISIBLE_SCANLINE)
data = 0xff;
m_spriteram[m_regs[PPU_SPRITE_ADDRESS]] = data;
m_regs[PPU_SPRITE_ADDRESS] = (m_regs[PPU_SPRITE_ADDRESS] + 1) & 0xff;
break;
case PPU_SCROLL: /* 5 */
if (m_toggle)
{
/* second write */
m_refresh_latch &= 0x0c1f;
m_refresh_latch |= (data & 0xf8) << 2;
m_refresh_latch |= (data & 0x07) << 12;
// logerror("scroll write 2: %d, %04x (scanline: %d)\n", data, m_refresh_latch, m_scanline);
}
else
{
/* first write */
m_refresh_latch &= 0x7fe0;
m_refresh_latch |= (data & 0xf8) >> 3;
m_x_fine = data & 7;
// logerror("scroll write 1: %d, %04x (scanline: %d)\n", data, m_refresh_latch, m_scanline);
}
m_toggle ^= 1;
break;
case PPU_ADDRESS: /* 6 */
if (m_toggle)
{
/* second write */
m_refresh_latch &= 0x7f00;
m_refresh_latch |= data;
m_refresh_data = m_refresh_latch;
m_videomem_addr = m_refresh_latch;
// logerror("vram addr write 2: %02x, %04x (scanline: %d)\n", data, m_refresh_latch, m_scanline);
}
else
{
/* first write */
m_refresh_latch &= 0x00ff;
m_refresh_latch |= (data & 0x3f) << 8;
// logerror("vram addr write 1: %02x, %04x (scanline: %d)\n", data, m_refresh_latch, m_scanline);
}
m_toggle ^= 1;
break;
case PPU_DATA: /* 7 */
{
int tempAddr = m_videomem_addr & 0x3fff;
if (!m_latch.isnull())
m_latch(tempAddr);
/* if there's a callback, call it now */
if (!m_vidaccess_callback_proc.isnull())
data = m_vidaccess_callback_proc(tempAddr, data);
/* see if it's on the chargen portion */
if (tempAddr < 0x2000)
{
/* store the data */
writebyte(tempAddr, data);
}
else
{
writebyte(tempAddr, data);
}
/* increment the address */
m_videomem_addr += m_add;
}
break;
default:
/* ignore other registers writes */
break;
}
m_data_latch = data;
}
uint16_t ppu2c0x_device::get_vram_dest() {
return m_videomem_addr;
}
void ppu2c0x_device::set_vram_dest(uint16_t dest) {
m_videomem_addr = dest;
}
/*************************************
*
* Sprite DMA
*
*************************************/
void ppu2c0x_device::spriteram_dma( address_space &space, const uint8_t page )
{
int i;
int address = page << 8;
for (i = 0; i < SPRITERAM_SIZE; i++)
{
uint8_t spriteData = space.read_byte(address + i);
space.write_byte(0x2004, spriteData);
}
// should last 513 CPU cycles.
space.device().execute().adjust_icount(-513);
}
/*************************************
*
* PPU Rendering
*
*************************************/
void ppu2c0x_device::render(bitmap_rgb32 &bitmap, int flipx, int flipy, int sx, int sy, const rectangle &cliprect)
{
if (m_scanline_timer->remaining() != attotime::zero)
{
// Partial line update, need to render first (especially for light gun emulation).
update_scanline();
}
copybitmap(bitmap, *m_bitmap, flipx, flipy, sx, sy, cliprect);
}
uint32_t ppu2c0x_device::screen_update(screen_device &screen, bitmap_rgb32 &bitmap, const rectangle &cliprect)
{
render(bitmap, 0, 0, 0, 0, cliprect);
return 0;
}