saturn-examples/scsp/sound_cpu__midi.cpp

387 lines
10 KiB
C++

#include <cstdint>
#include <optional>
#include "vdp2.h"
#include "smpc.h"
#include "scu.h"
#include "sh2.h"
#include "scsp.h"
#include "../common/copy.hpp"
#include "../common/intback.hpp"
#include "../common/vdp2_func.hpp"
#include "../common/string.hpp"
extern void * _m68k_start __asm("_binary_m68k_midi_bin_start");
extern void * _m68k_size __asm("_binary_m68k_midi_bin_size");
extern void * _nec_bitmap_start __asm("_binary_res_nec_bitmap_bin_start");
constexpr inline uint16_t rgb15(int32_t r, int32_t g, int32_t b)
{
return ((b & 31) << 10) | ((g & 31) << 5) | ((r & 31) << 0);
}
void palette_data()
{
vdp2.cram.u16[1 + 0 ] = rgb15( 0, 0, 0);
vdp2.cram.u16[2 + 0 ] = rgb15(31, 31, 31);
vdp2.cram.u16[1 + 16] = rgb15(31, 31, 31);
vdp2.cram.u16[2 + 16] = rgb15( 0, 0, 0);
vdp2.cram.u16[1 + 32] = rgb15(10, 10, 10);
vdp2.cram.u16[2 + 32] = rgb15(31, 31, 31);
}
namespace pix_fmt_4bpp
{
constexpr inline uint32_t
bit(uint8_t n, int32_t i)
{
i &= 7;
auto b = (n >> (7 - i)) & 1;
return ((b + 1) << ((7 - i) * 4));
}
constexpr inline uint32_t
bits(uint8_t n)
{
return
bit(n, 0) | bit(n, 1) | bit(n, 2) | bit(n, 3)
| bit(n, 4) | bit(n, 5) | bit(n, 6) | bit(n, 7);
}
static_assert(bits(0b1100'1110) == 0x2211'2221);
static_assert(bits(0b1010'0101) == 0x2121'1212);
static_assert(bits(0b1000'0000) == 0x2111'1111);
}
void cell_data()
{
const uint8_t * normal = reinterpret_cast<uint8_t*>(&_nec_bitmap_start);
for (int ix = 0; ix <= (0x7f - 0x20); ix++) {
for (int y = 0; y < 8; y++) {
const uint8_t row_n = normal[ix * 8 + y];
vdp2.vram.u32[ 0 + (ix * 8) + y] = pix_fmt_4bpp::bits(row_n);
}
}
}
struct count_flop {
s8 count;
u8 flop;
u8 das;
u8 repeat;
};
struct input {
count_flop right;
count_flop left;
count_flop down;
count_flop up;
count_flop start;
count_flop a;
count_flop b;
count_flop c;
count_flop r;
count_flop x;
count_flop y;
count_flop z;
count_flop l;
};
constexpr int input_arr = 10;
constexpr int input_das = 20;
constexpr int input_debounce = 2;
static inline void
input_count(count_flop& button, uint32_t input, uint32_t mask)
{
if ((input & mask) == 0) {
if (button.count < input_debounce)
button.count += 1;
else
button.das += 1;
} else {
if (button.count == 0) {
button.flop = 0;
button.das = 0;
button.repeat = 0;
}
else if (button.count > 0)
button.count -= 1;
}
}
static inline int32_t
input_flopped(count_flop& button)
{
if (button.count == input_debounce && button.flop == 0) {
button.flop = 1;
return 1;
} else if (button.flop == 1 && button.das == input_das && button.repeat == 0) {
button.repeat = 1;
button.das = 0;
return 2;
} else if (button.repeat == 1 && (button.das == input_arr)) {
button.das = 0;
return 2;
} else {
return 0;
}
}
struct state {
struct input input;
};
static struct state state = { 0 };
void digital_callback(uint8_t fsm_state, uint8_t data)
{
switch (fsm_state) {
case intback::DATA1:
input_count(state.input.right, data, DIGITAL__1__RIGHT);
input_count(state.input.left, data, DIGITAL__1__LEFT);
input_count(state.input.down, data, DIGITAL__1__DOWN);
input_count(state.input.up, data, DIGITAL__1__UP);
input_count(state.input.start, data, DIGITAL__1__START);
input_count(state.input.a, data, DIGITAL__1__A);
input_count(state.input.c, data, DIGITAL__1__C);
input_count(state.input.b, data, DIGITAL__1__B);
break;
case intback::DATA2:
input_count(state.input.r, data, DIGITAL__2__R);
input_count(state.input.x, data, DIGITAL__2__X);
input_count(state.input.y, data, DIGITAL__2__Y);
input_count(state.input.z, data, DIGITAL__2__Z);
input_count(state.input.l, data, DIGITAL__2__L);
break;
default: break;
}
}
extern "C"
void smpc_int(void) __attribute__ ((interrupt_handler));
void smpc_int(void)
{
scu.reg.IST &= ~(IST__SMPC);
scu.reg.IMS = ~(IMS__SMPC | IMS__V_BLANK_IN);
intback::fsm(digital_callback, nullptr);
}
constexpr int32_t plane_a = 2;
constexpr inline int32_t plane_offset(int32_t n) { return n * 0x2000; }
constexpr int32_t page_size = 64 * 64 * 2; // N0PNB__1WORD (16-bit)
constexpr int32_t plane_size = page_size * 1;
constexpr int32_t cell_size = (8 * 8) / 2; // N0CHCN__16_COLOR (4-bit)
constexpr int32_t character_size = cell_size * (1 * 1); // N0CHSZ__1x1_CELL
constexpr int32_t page_width = 64;
static int plane_ix = 0;
inline void
set_char(int32_t x, int32_t y, uint8_t palette, uint8_t c)
{
const auto ix = (plane_offset(plane_a + plane_ix) / 2) + (y * page_width) + x;
vdp2.vram.u16[ix] =
PATTERN_NAME_TABLE_1WORD__PALETTE(palette)
| PATTERN_NAME_TABLE_1WORD__CHARACTER((c - 0x20));
}
static int render_state = 0;
void render()
{
if (++render_state < 1)
return;
render_state = 0;
// 012345678901234
static uint8_t label[] = "midi";
for (uint32_t i = 0; label[i] != 0; i++) {
set_char(0 + i, 1, 0, label[i]);
}
uint32_t i;
uint8_t buf[8];
static uint8_t l1[] = "evnt";
string::hex(buf, 8, scsp.ram.u32[0]);
for (i = 0; i < 4; i++) set_char(0 + i, 3, 0, l1[i]);
for (i = 0; i < 8; i++) set_char(5 + i, 3, 0, buf[i]);
static uint8_t l2[] = "s_dt";
string::hex(buf, 8, scsp.ram.u32[1]);
for (i = 0; i < 4; i++) set_char(0 + i, 4, 0, l2[i]);
for (i = 0; i < 8; i++) set_char(5 + i, 4, 0, buf[i]);
static uint8_t l3[] = "e_dt";
string::hex(buf, 8, scsp.ram.u32[2]);
for (i = 0; i < 4; i++) set_char(0 + i, 5, 0, l3[i]);
for (i = 0; i < 8; i++) set_char(5 + i, 5, 0, buf[i]);
static uint8_t l4[] = "note";
string::hex(buf, 8, scsp.ram.u32[3]);
for (i = 0; i < 4; i++) set_char(0 + i, 6, 0, l4[i]);
for (i = 0; i < 8; i++) set_char(5 + i, 6, 0, buf[i]);
}
void update()
{
}
extern "C"
void v_blank_in_int(void) __attribute__ ((interrupt_handler));
void v_blank_in_int()
{
scu.reg.IST &= ~(IST__V_BLANK_IN);
scu.reg.IMS = ~(IMS__SMPC | IMS__V_BLANK_IN);
// flip planes;
vdp2.reg.MPCDN0 = MPCDN0__N0MPB(0) | MPCDN0__N0MPA(plane_a + plane_ix);
//plane_ix = !plane_ix;
// wait at least 300us, as specified in the SMPC manual.
// It appears reading FRC.H is mandatory and *must* occur before FRC.L on real
// hardware.
while ((sh2.reg.FTCSR & FTCSR__OVF) == 0 && sh2.reg.FRC.H == 0 && sh2.reg.FRC.L < 63);
if ((vdp2.reg.TVSTAT & TVSTAT__VBLANK) != 0) {
// on real hardware, SF contains uninitialized garbage bits other than the
// lsb.
while ((smpc.reg.SF & 1) != 0);
smpc.reg.SF = 0;
smpc.reg.IREG[0].val = INTBACK__IREG0__STATUS_DISABLE;
smpc.reg.IREG[1].val = ( INTBACK__IREG1__PERIPHERAL_DATA_ENABLE
| INTBACK__IREG1__PORT2_15BYTE
| INTBACK__IREG1__PORT1_15BYTE
);
smpc.reg.IREG[2].val = INTBACK__IREG2__MAGIC;
smpc.reg.COMREG = COMREG__INTBACK;
}
update();
render();
}
void init_snd_cpu()
{
/*
The Saturn BIOS does not (un)initialize the DSP. Without zeroizing the DSP
program, the SCSP DSP appears to have a program that continuously writes to
0x30000 through 0x3ffff in sound RAM, which has the effect of destroying any
samples stored there.
*/
reg32 * dsp_steps = reinterpret_cast<reg32*>(&(scsp.reg.dsp.STEP[0].MPRO[0]));
fill<reg32>(dsp_steps, 0, (sizeof (scsp.reg.dsp.STEP)));
/* SEGA SATURN TECHNICAL BULLETIN # 51
The document suggests that Sound RAM is (somewhat) preserved
during SNDOFF.
*/
scsp.reg.ctrl.MIXER = MIXER__MEM4MB;
while ((smpc.reg.SF & 1) != 0);
smpc.reg.SF = 1;
smpc.reg.COMREG = COMREG__SNDOFF;
while (smpc.reg.OREG[31].val != OREG31__SNDOFF);
uint32_t * m68k_main_start = reinterpret_cast<uint32_t*>(&_m68k_start);
uint32_t m68k_main_size = reinterpret_cast<uint32_t>(&_m68k_size);
copy<uint32_t>(&scsp.ram.u32[0], m68k_main_start, m68k_main_size);
while ((smpc.reg.SF & 1) != 0);
smpc.reg.SF = 1;
smpc.reg.COMREG = COMREG__SNDON;
while (smpc.reg.OREG[31].val != OREG31__SNDON);
for (int i = 0; i < 32; i++) {
break;
scsp_slot& slot = scsp.reg.slot[i];
// start address (bytes)
slot.SA = 0; // kx kb sbctl[1:0] ssctl[1:0] lpctl[1:0] 8b sa[19:0]
slot.LSA = 0; // loop start address (samples)
slot.LEA = 0; // loop end address (samples)
slot.EG = EG__RR(0x1f); // d2r d1r ho ar krs dl rr
slot.FM = 0; // stwinh sdir tl mdl mdxsl mdysl
slot.PITCH = 0; // oct fns
slot.LFO = 0; // lfof plfows
slot.MIXER = 0; // disdl dipan efsdl efpan
}
//scsp.reg.slot[0].LOOP |= LOOP__KYONEX;
scsp.reg.ctrl.MIXER = MIXER__MEM4MB | MIXER__MVOL(0xf);
}
void main()
{
init_snd_cpu();
v_blank_in();
// DISP: Please make sure to change this bit from 0 to 1 during V blank.
vdp2.reg.TVMD = ( TVMD__DISP | TVMD__LSMD__NON_INTERLACE
| TVMD__VRESO__240 | TVMD__HRESO__NORMAL_320);
/* set the color mode to 5bits per channel, 1024 colors */
vdp2.reg.RAMCTL = RAMCTL__CRMD__RGB_5BIT_1024;
/* enable display of NBG0 */
vdp2.reg.BGON = BGON__N0ON;
/* set character format for NBG0 to palettized 16 color
set enable "cell format" for NBG0
set character size for NBG0 to 1x1 cell */
vdp2.reg.CHCTLA = CHCTLA__N0CHCN__16_COLOR
| CHCTLA__N0BMEN__CELL_FORMAT
| CHCTLA__N0CHSZ__1x1_CELL;
/* "Note: In color RAM modes 0 and 2, 2048-color becomes 1024-color" */
/* use 1-word (16-bit) pattern names */
vdp2.reg.PNCN0 = PNCN0__N0PNB__1WORD;
/* plane size */
vdp2.reg.PLSZ = PLSZ__N0PLSZ__1x1;
/* map plane offset
1-word: value of bit 6-0 * 0x2000
2-word: value of bit 5-0 * 0x4000
*/
vdp2.reg.MPOFN = MPOFN__N0MP(0); // bits 8~6
vdp2.reg.MPCDN0 = MPCDN0__N0MPB(0) | MPCDN0__N0MPA(plane_a); // bits 5~0
vdp2.reg.MPCDN0 = MPCDN0__N0MPD(0) | MPCDN0__N0MPC(0); // bits 5~0
// zeroize character/cell data from 0 up to plane_a_offset
fill<uint32_t>(&vdp2.vram.u32[(0 / 4)], 0, plane_offset(plane_a));
// zeroize plane_a; `0` is the ascii 0x20 ("space") which doubles as
// "transparency" character.
fill<uint32_t>(&vdp2.vram.u32[(plane_offset(plane_a) / 4)], 0, plane_size * 2);
palette_data();
cell_data();
// free-running timer
sh2.reg.TCR = TCR__CKS__INTERNAL_DIV128;
sh2.reg.FTCSR = 0;
// initialize smpc
smpc.reg.DDR1 = 0; // INPUT
smpc.reg.DDR2 = 0; // INPUT
smpc.reg.IOSEL = 0; // SMPC control
smpc.reg.EXLE = 0; //
sh2_vec[SCU_VEC__SMPC] = (u32)(&smpc_int);
sh2_vec[SCU_VEC__V_BLANK_IN] = (u32)(&v_blank_in_int);
scu.reg.IST = 0;
scu.reg.IMS = ~(IMS__SMPC | IMS__V_BLANK_IN);
}