BizHawk/waterbox/sameboy/sgb.c

1044 lines
23 KiB
C

#include "sgb.h"
#include <stdlib.h>
#include <string.h>
#include <stdio.h>
#include "snes_spc/spc.h"
#include "../emulibc/emulibc.h"
#define utils_log printf
const uint8_t iplrom[64] = {
/*ffc0*/ 0xcd, 0xef, //mov x,#$ef
/*ffc2*/ 0xbd, //mov sp,x
/*ffc3*/ 0xe8, 0x00, //mov a,#$00
/*ffc5*/ 0xc6, //mov (x),a
/*ffc6*/ 0x1d, //dec x
/*ffc7*/ 0xd0, 0xfc, //bne $ffc5
/*ffc9*/ 0x8f, 0xaa, 0xf4, //mov $f4,#$aa
/*ffcc*/ 0x8f, 0xbb, 0xf5, //mov $f5,#$bb
/*ffcf*/ 0x78, 0xcc, 0xf4, //cmp $f4,#$cc
/*ffd2*/ 0xd0, 0xfb, //bne $ffcf
/*ffd4*/ 0x2f, 0x19, //bra $ffef
/*ffd6*/ 0xeb, 0xf4, //mov y,$f4
/*ffd8*/ 0xd0, 0xfc, //bne $ffd6
/*ffda*/ 0x7e, 0xf4, //cmp y,$f4
/*ffdc*/ 0xd0, 0x0b, //bne $ffe9
/*ffde*/ 0xe4, 0xf5, //mov a,$f5
/*ffe0*/ 0xcb, 0xf4, //mov $f4,y
/*ffe2*/ 0xd7, 0x00, //mov ($00)+y,a
/*ffe4*/ 0xfc, //inc y
/*ffe5*/ 0xd0, 0xf3, //bne $ffda
/*ffe7*/ 0xab, 0x01, //inc $01
/*ffe9*/ 0x10, 0xef, //bpl $ffda
/*ffeb*/ 0x7e, 0xf4, //cmp y,$f4
/*ffed*/ 0x10, 0xeb, //bpl $ffda
/*ffef*/ 0xba, 0xf6, //movw ya,$f6
/*fff1*/ 0xda, 0x00, //movw $00,ya
/*fff3*/ 0xba, 0xf4, //movw ya,$f4
/*fff5*/ 0xc4, 0xf4, //mov $f4,a
/*fff7*/ 0xdd, //mov a,y
/*fff8*/ 0x5d, //mov x,a
/*fff9*/ 0xd0, 0xdb, //bne $ffd6
/*fffb*/ 0x1f, 0x00, 0x00, //jmp ($0000+x)
/*fffe*/ 0xc0, 0xff //reset vector location ($ffc0)
};
// the "reference clock" is tied to the GB cpu. 35112 of these should equal one GB LCD frame.
// it is always increasing and never resets/rebases
const int refclocks_per_spc_sample = 67; // ~32055hz
typedef struct
{
// writes to FF00
uint64_t last_write_time; // last write time relative to reference clock
uint8_t last_write_value;
// recv packets
uint8_t read_index; // 0-127, index of the next bit read. if 255, not currently reading
uint8_t packet[16]; // a packet in the process of being formed
uint8_t command[16 * 7]; // a command in the process of being formed
uint8_t expected_packets; // total number of packets expected for a command
uint8_t next_packet; // index of the next packet to be read
// joypad reading
uint8_t joypad_index; // index of currently reading joypad
uint8_t num_joypads; // number of currently selected joypads (MLT_REQ)
uint8_t joypad_data[4]; // data for each joypad
uint8_t joypad_has_been_read; // state for advancing joypad_index. extermely weird; logic lifted from VBA and probably wrong
// palettes
uint32_t palette[8][16];
uint32_t auxpalette[512][4];
// border
uint8_t tiles[256][64]; // tiles stored in packed form
uint16_t tilemap[32 * 32];
// frame data
uint8_t frame[160 * 144]; // the most recent obtained full frame
uint32_t frozenframe[256 * 224]; // the most recent saved full frame (MASK_EN)
uint8_t attr[20 * 18]; // current attr map for the GB screen
uint8_t auxattr[45][20 * 18]; // 45 attr files
// MASK_EN
uint8_t active_mask; // true if mask is currently being used
// audio
SNES_SPC *spc;
uint64_t frame_start; // when the current audio frame started relative to reference clock
uint32_t clock_remainder; // number of reference clocks not sent to the SPC last frame
uint8_t sound_control[4]; // TODO...
// transfers
uint32_t waiting_transfer;
#define TRN_NONE 0
#define TRN_SOUND 1
#define TRN_PAL 2
#define TRN_CHR_LOW 3
#define TRN_CHR_HI 4
#define TRN_PCT 5
#define TRN_ATTR 6
int32_t transfer_countdown; // number of frames until transfer. not entirely accurate
} sgb_t;
static sgb_t sgb;
static uint32_t makecol(uint16_t c)
{
return c >> 7 & 0xf8 | c >> 12 & 0x07 | c << 6 & 0xf800 | c << 1 & 0x0700 | c << 19 & 0xf80000 | c << 14 & 0x070000 | 0xff000000;
}
static void cmd_trn(uint32_t which)
{
if ((sgb.command[0] & 7) == 1)
{
if (sgb.waiting_transfer == TRN_NONE)
{
sgb.waiting_transfer = which;
sgb.transfer_countdown = 4;
}
else
{
utils_log("SGB: TRN already queued!\n");
}
}
else
{
utils_log("SGB: cmd_trn bad length\n");
}
}
static void cmd_pal(int a, int b)
{
if ((sgb.command[0] & 7) == 1)
{
uint32_t c[7];
for (int i = 0; i < 7; i++)
c[i] = makecol(sgb.command[i * 2 + 1] | sgb.command[i * 2 + 2] << 8);
sgb.palette[0][0] = c[0];
sgb.palette[1][0] = c[0];
sgb.palette[2][0] = c[0];
sgb.palette[3][0] = c[0];
sgb.palette[a][1] = c[1];
sgb.palette[a][2] = c[2];
sgb.palette[a][3] = c[3];
sgb.palette[b][1] = c[4];
sgb.palette[b][2] = c[5];
sgb.palette[b][3] = c[6];
}
else
{
utils_log("SGB: cmd_pal bad length\n");
}
}
static void cmd_pal_set(void)
{
if ((sgb.command[0] & 7) == 1)
{
int p0 = sgb.command[1] | sgb.command[2] << 8 & 0x100;
for (int i = 0; i < 4; i++)
{
int p = sgb.command[i * 2 + 1] | sgb.command[i * 2 + 2] << 8 & 0x100;
sgb.palette[i][0] = sgb.auxpalette[p0][0];
sgb.palette[i][1] = sgb.auxpalette[p][1];
sgb.palette[i][2] = sgb.auxpalette[p][2];
sgb.palette[i][3] = sgb.auxpalette[p][3];
}
if (sgb.command[9] & 0x80) // change attribute
{
int attr = sgb.command[9] & 0x3f;
if (attr >= 45)
attr = 44;
memcpy(sgb.attr, sgb.auxattr[attr], sizeof(sgb.attr));
}
if (sgb.command[9] & 0x40) // cancel mask
{
sgb.active_mask = 0;
}
}
else
{
utils_log("SGB: cmd_pal bad length\n");
}
}
static void cmd_attr_blk()
{
int nset = sgb.command[1];
if (nset <= 0 || nset >= 19)
{
utils_log("SGB: cmd_attr_blk bad nset\n");
return;
}
int npacket = (nset * 6 + 16) / 16;
if ((sgb.command[0] & 7) != npacket)
{
utils_log("SGB: cmd_attr_blk bad length\n");
return;
}
for (int i = 0; i < nset; i++)
{
int ctrl = sgb.command[i * 6 + 2] & 7;
int pals = sgb.command[i * 6 + 3];
int x1 = sgb.command[i * 6 + 4];
int y1 = sgb.command[i * 6 + 5];
int x2 = sgb.command[i * 6 + 6];
int y2 = sgb.command[i * 6 + 7];
int inside = ctrl & 1;
int line = ctrl & 2;
int outside = ctrl & 4;
int insidepal = pals & 3;
int linepal = pals >> 2 & 3;
int outsidepal = pals >> 4 & 3;
if (ctrl == 1)
{
ctrl = 3;
linepal = insidepal;
}
else if (ctrl == 4)
{
ctrl = 6;
linepal = outsidepal;
}
uint8_t *dst = sgb.attr;
for (int y = 0; y < 18; y++)
{
for (int x = 0; x < 20; x++)
{
if (outside && (x < x1 || x > x2 || y < y1 || y > y2))
*dst = outsidepal;
else if (inside && x > x1 && x < x2 && y > y1 && y < y2)
*dst = insidepal;
else if (line)
*dst = linepal;
dst++;
}
}
}
}
static void cmd_attr_lin()
{
int nset = sgb.command[1];
if (nset <= 0 || nset >= 111)
{
utils_log("SGB: cmd_attr_lin bad nset\n");
return;
}
int npacket = (nset + 17) / 16;
if ((sgb.command[0] & 7) != npacket)
{
utils_log("SGB: cmd_attr_lin bad length\n");
return;
}
for (int i = 0; i < nset; i++)
{
uint8_t v = sgb.command[i + 2];
int line = v & 31;
int a = v >> 5 & 3;
if (v & 0x80) // horizontal
{
if (line > 17)
line = 17;
memset(sgb.attr + line * 20, a, 20);
}
else // vertical
{
if (line > 19)
line = 19;
uint8_t *dst = sgb.attr + line;
for (int i = 0; i < 18; i++, dst += 20)
dst[0] = a;
}
}
}
static void cmd_attr_div()
{
if ((sgb.command[0] & 7) == 1)
{
uint8_t v = sgb.command[1];
int c = v & 3;
int a = v >> 2 & 3;
int b = v >> 4 & 3;
int pos = sgb.command[2];
uint8_t *dst = sgb.attr;
if (v & 0x40) // horizontal
{
if (pos > 17)
pos = 17;
int i;
for (i = 0; i < pos; i++, dst += 20)
memset(dst, a, 20);
memset(dst, b, 20);
i++, dst += 20;
for (; i < 18; i++, dst += 20)
memset(dst, c, 20);
}
else // vertical
{
if (pos > 19)
pos = 19;
for (int j = 0; j < 18; j++)
{
int i;
for (i = 0; i < pos; i++)
*dst++ = a;
*dst++ = b;
i++;
for (; i < 20; i++)
*dst++ = c;
}
}
}
else
{
utils_log("SGB: cmd_attr_div bad length\n");
}
}
static void cmd_attr_chr()
{
int x = sgb.command[1];
int y = sgb.command[2];
int n = sgb.command[3] | sgb.command[4] << 8;
if (n > 360)
{
utils_log("SGB: cmd_attr_chr bad n\n");
return;
}
int npacket = (n + 87) / 64;
if ((sgb.command[0] & 7) < npacket)
{
utils_log("SGB: cmd_attr_chr bad length\n");
return;
}
uint8_t *dst = sgb.attr;
if (x > 19)
x = 19;
if (y > 17)
y = 17;
int vertical = sgb.command[5];
for (int i = 0; i < n; i++)
{
uint8_t v = sgb.command[i / 4 + 6];
int a = v >> (2 * (3 - (i & 3))) & 3;
dst[y * 20 + x] = a;
if (vertical)
{
y++;
if (y == 18)
{
y = 0;
x++;
if (x == 20)
return;
}
}
else
{
x++;
if (x == 20)
{
x = 0;
y++;
if (y == 18)
return;
}
}
}
}
static void cmd_attr_set()
{
if ((sgb.command[0] & 7) == 1)
{
int attr = sgb.command[1] & 0x3f;
if (attr >= 45)
attr = 44;
memcpy(sgb.attr, sgb.auxattr[attr], sizeof(sgb.attr));
if (sgb.command[1] & 0x40)
{
sgb.active_mask = 0;
}
}
else
{
utils_log("SGB: cmd_attr_set bad length\n");
}
}
static void cmd_mlt_req(void)
{
if ((sgb.command[0] & 7) == 1)
{
switch (sgb.command[1] & 3)
{
case 0:
case 2:
sgb.num_joypads = 1;
sgb.joypad_index = 0;
break;
case 1:
sgb.num_joypads = 2;
sgb.joypad_index = 1;
break;
case 3:
sgb.num_joypads = 4;
sgb.joypad_index = 1;
break;
}
utils_log("SGB: %u joypads\n", sgb.num_joypads);
}
else
{
utils_log("SGB: cmd_mlt_req bad length\n");
}
}
static void cmd_mask(void)
{
if ((sgb.command[0] & 7) == 1)
{
switch (sgb.command[1] & 3)
{
case 0:
sgb.active_mask = 0;
break;
case 1:
sgb.active_mask = 1;
break;
case 2:
case 3:
sgb.active_mask = 1;
for (int i = 0; i < 256 * 224; i++)
sgb.frozenframe[i] = sgb.palette[0][0];
break;
}
}
else
{
utils_log("SGB: cmd_mask bad length\n");
}
}
static void cmd_sound(void)
{
if ((sgb.command[0] & 7) == 1)
{
sgb.sound_control[1] = sgb.command[1];
sgb.sound_control[2] = sgb.command[2];
sgb.sound_control[3] = sgb.command[3];
sgb.sound_control[0] = sgb.command[4];
}
else
{
utils_log("SGB: cmd_sound bad length\n");
}
}
static void do_command(void)
{
const int command = sgb.command[0] >> 3;
switch (command)
{
default:
utils_log("SGB: Unknown or unimplemented command %02xh\n", command);
break;
case 0x00: // PAL01
utils_log("SGB: PAL01\n");
cmd_pal(0, 1);
break;
case 0x01: // PAL23
utils_log("SGB: PAL23\n");
cmd_pal(2, 3);
break;
case 0x02: // PAL03
utils_log("SGB: PAL03\n");
cmd_pal(0, 3);
break;
case 0x03: // PAL12
utils_log("SGB: PAL12\n");
cmd_pal(1, 2);
break;
case 0x0a: // PAL_SET
utils_log("SGB: PAL_SET\n");
cmd_pal_set();
break;
case 0x04: // ATTR_BLK
utils_log("SGB: ATTR_BLK\n");
cmd_attr_blk();
break;
case 0x05: // ATTR_LIN
utils_log("SGB: ATTR_LIN\n");
cmd_attr_lin();
break;
case 0x06: // ATTR_DIV
utils_log("SGB: ATTR_DIV\n");
cmd_attr_div();
break;
case 0x07: // ATTR_CHR
utils_log("SGB: ATTR_CHR\n");
cmd_attr_chr();
break;
case 0x16: // ATTR_SET
utils_log("SGB: ATTR_SET\n");
cmd_attr_set();
break;
case 0x17: // MASK_EN
utils_log("SGB: MASK_EN\n");
cmd_mask();
break;
// unknown functions
case 0x0c: // ATRC_EN
utils_log("SGB: ATRC_EN??\n");
break;
case 0x0d: // TEST_EN
utils_log("SGB: TEST_EN??\n");
break;
case 0x0e: // ICON_EN
utils_log("SGB: ICON_EN??\n");
break;
case 0x18: // OBJ_TRN
// no game used this
utils_log("SGB: OBJ_TRN??\n");
break;
// unimplementable functions
case 0x0f: // DATA_SND
// TODO: Is it possible for this (and DATA_TRN) to write data to
// memory areas used for the attribute file, etc?
// If so, do games do this?
utils_log("SGB: DATA_SND!! %02x:%02x%02x [%02x]\n", sgb.command[3], sgb.command[2], sgb.command[1], sgb.command[4]);
break;
case 0x10: // DATA_TRN
utils_log("SGB: DATA_TRN!!\n");
break;
case 0x12: // JUMP
utils_log("SGB: JUMP!!\n");
break;
// joypad
case 0x11: // MLT_REQ
utils_log("SGB: MLT_REQ\n");
cmd_mlt_req();
break;
// sound
case 0x08: // SOUND
utils_log("SGB: SOUND %02x %02x %02x %02x\n", sgb.command[1], sgb.command[2], sgb.command[3], sgb.command[4]);
cmd_sound();
break;
// all vram transfers
case 0x09: // SOU_TRN
utils_log("SGB: SOU_TRN\n");
cmd_trn(TRN_SOUND);
break;
case 0x0b: // PAL_TRN
utils_log("SGB: PAL_TRN\n");
cmd_trn(TRN_PAL);
break;
case 0x13: // CHR_TRN
utils_log("SGB: CHR_TRN\n");
cmd_trn(sgb.command[1] & 1 ? TRN_CHR_HI : TRN_CHR_LOW);
break;
case 0x14: // PCT_TRN
utils_log("SGB: PCT_TRN\n");
cmd_trn(TRN_PCT);
break;
case 0x15: // ATTR_TRN
utils_log("SGB: ATTR_TRN\n");
cmd_trn(TRN_ATTR);
break;
}
}
static void do_packet(void)
{
memcpy(sgb.command + sgb.next_packet * 16, sgb.packet, sizeof(sgb.packet));
sgb.next_packet++;
if (sgb.expected_packets == 0) // not in the middle of a command
sgb.expected_packets = sgb.command[0] & 7;
if (sgb.expected_packets == 0) // huh?
{
utils_log("SGB: zero packet command\n");
sgb.expected_packets = 0;
sgb.next_packet = 0;
}
else if (sgb.next_packet == sgb.expected_packets)
{
do_command();
sgb.expected_packets = 0;
sgb.next_packet = 0;
}
}
int sgb_init(const uint8_t *spc, int length)
{
memset(&sgb, 0, sizeof(sgb));
sgb.read_index = 255;
sgb.num_joypads = 1;
sgb.palette[0][0] = 0xffffffff;
sgb.palette[0][1] = 0xffaaaaaa;
sgb.palette[0][2] = 0xff555555;
sgb.palette[0][3] = 0xff000000;
sgb.spc = spc_new();
spc_init_rom(sgb.spc, iplrom);
spc_reset(sgb.spc);
if (spc_load_spc(sgb.spc, spc, length) != NULL)
{
utils_log("SGB: Failed to load SPC\n");
return 0;
}
// make a scratch buffer in a predictable (not stack) place because spc stores multiple pointers to it
// which is kind of nasty...
int16_t *sound_buffer = alloc_invisible(4096 * sizeof(int16_t));
// the combination of the sameboy bootrom plus the built in SPC file we use means
// that the SPC doesn't finish its init fast enough for donkey kong, which starts poking
// data too early. it's just a combination of various HLE concerns not meshing...
spc_set_output(sgb.spc, sound_buffer, 4096);
for (int i = 0; i < 240; i++)
{
spc_end_frame(sgb.spc, 35104);
}
return 1;
}
void sgb_write_ff00(uint8_t val, uint64_t time)
{
val &= 0x30;
//utils_log("ZZ: %02x, %llu", val, time);
const int p14_fell = (val & 0x10) < (sgb.last_write_value & 0x10);
const int p15_fell = (val & 0x20) < (sgb.last_write_value & 0x20);
const int p14_rose = (val & 0x10) > (sgb.last_write_value & 0x10);
const int p15_rose = (val & 0x20) > (sgb.last_write_value & 0x20);
if (val == 0) // reset command processing
{
sgb.read_index = 0;
memset(sgb.packet, 0, sizeof(sgb.packet));
}
else if (sgb.read_index != 255) // currently reading a packet
{
if (p14_fell || p15_fell)
{
if (sgb.read_index == 128) // end of packet
{
if (p14_fell)
do_packet();
else
utils_log("SGB: Stop bit not present\n");
sgb.read_index = 255;
}
else
{
if (p15_fell)
{
int byte = sgb.read_index >> 3;
int bit = sgb.read_index & 7;
sgb.packet[byte] |= 1 << bit;
}
sgb.read_index++;
}
}
}
else // joypad processing
{
if (val == 0x10)
sgb.joypad_has_been_read |= 2; // reading P15
if (val == 0x20)
sgb.joypad_has_been_read |= 1; // reading P14
if (val == 0x30 && (p14_rose || p15_rose))
{
if (sgb.joypad_has_been_read == 7)
{
sgb.joypad_has_been_read = 0;
sgb.joypad_index++;
sgb.joypad_index &= sgb.num_joypads - 1;
//utils_log("SGB: joypad index to %u", sgb.joypad_index);
}
else
{
sgb.joypad_has_been_read &= 3; // the other line must be asserted and a read must happen before joypad_index inc??
}
}
}
sgb.last_write_value = val;
sgb.last_write_time = time;
}
uint8_t sgb_read_ff00(uint64_t time)
{
uint8_t ret = sgb.last_write_value & 0xf0 | 0xc0;
const int p14 = !(ret & 0x10);
const int p15 = !(ret & 0x20);
const int ji = sgb.joypad_index;
// TODO: is this "reset" correct?
sgb.joypad_has_been_read |= 4; // read occured
sgb.read_index = 255;
sgb.next_packet = 0;
sgb.expected_packets = 0;
if (!p14 && !p15)
{
//utils_log("SGB: SCAN%u", ji);
// scan id
return ret | (15 - ji);
}
else
{
// get data
const uint8_t j = sgb.joypad_data[ji];
if (p14)
ret |= j >> 4;
if (p15)
ret |= j & 0x0f;
//utils_log("SGB: READ%u %02x", ji, ret ^ 0x0f);
return ret ^ 0x0f;
}
}
// for each of 4 joypads:
// 7......0
// DULRSsBA
void sgb_set_controller_data(const uint8_t *buttons)
{
memcpy(sgb.joypad_data, buttons, sizeof(sgb.joypad_data));
}
static void trn_sound(const uint8_t *data)
{
const uint8_t *const dataend = data + 0x10000;
uint8_t *const dst = spc_get_ram(sgb.spc);
while (1)
{
if (data + 4 > dataend)
{
utils_log("TRN_SOUND header overflow\n");
break;
}
int len = data[0] | data[1] << 8;
int addr = data[2] | data[3] << 8;
if (!len)
{
utils_log("TRN_SOUND END %04x\n", addr);
break;
}
data += 4;
if (data + len > dataend)
{
utils_log("TRN_SOUND src overflow\n");
break;
}
if (addr + len >= 0x10000)
{
utils_log("TRN_SOUND dst overflow\n");
return;
}
utils_log("TRN_SOUND addr %04x len %04x\n", addr, len);
memcpy(dst + addr, data, len);
data += len;
}
}
static void trn_pal(const uint8_t *data)
{
const uint16_t *src = (const uint16_t *)data;
uint32_t *dst = sgb.auxpalette[0];
for (int i = 0; i < 2048; i++)
dst[i] = makecol(src[i]);
}
static void trn_attr(const uint8_t *data)
{
uint8_t *dst = sgb.auxattr[0];
for (int n = 0; n < 45 * 90; n++)
{
uint8_t s = *data++;
*dst++ = s >> 6 & 3;
*dst++ = s >> 4 & 3;
*dst++ = s >> 2 & 3;
*dst++ = s >> 0 & 3;
}
}
static void trn_pct(const uint8_t *data)
{
memcpy(sgb.tilemap, data, sizeof(sgb.tilemap));
const uint16_t *palettes = (const uint16_t *)(data + sizeof(sgb.tilemap));
uint32_t *dst = sgb.palette[4];
for (int i = 0; i < 64; i++)
dst[i] = makecol(palettes[i]);
}
static void trn_chr(const uint8_t *data, int bank)
{
uint8_t *dst = sgb.tiles[128 * bank];
for (int n = 0; n < 128; n++)
{
for (int y = 0; y < 8; y++)
{
int a = data[0];
int b = data[1] << 1;
int c = data[16] << 2;
int d = data[17] << 3;
for (int x = 7; x >= 0; x--)
{
dst[x] = a & 1 | b & 2 | c & 4 | d & 8;
a >>= 1;
b >>= 1;
c >>= 1;
d >>= 1;
}
dst += 8;
data += 2;
}
data += 16;
}
}
static void do_vram_transfer(void)
{
uint8_t vram[4096];
for (int tilenum = 0; tilenum < 256; tilenum++)
{
const int ty = tilenum / 20;
const int tx = tilenum % 20;
const uint8_t *src = sgb.frame + ty * 8 * 160 + tx * 8;
uint8_t *dst = vram + 16 * tilenum;
for (int j = 0; j < 8; j++)
{
uint32_t a = 0, b = 0;
a |= (src[7] & 1) << 0;
a |= (src[6] & 1) << 1;
a |= (src[5] & 1) << 2;
a |= (src[4] & 1) << 3;
a |= (src[3] & 1) << 4;
a |= (src[2] & 1) << 5;
a |= (src[1] & 1) << 6;
a |= (src[0] & 1) << 7;
b |= (src[7] & 2) >> 1;
b |= (src[6] & 2) << 0;
b |= (src[5] & 2) << 1;
b |= (src[4] & 2) << 2;
b |= (src[3] & 2) << 3;
b |= (src[2] & 2) << 4;
b |= (src[1] & 2) << 5;
b |= (src[0] & 2) << 6;
*dst++ = a;
*dst++ = b;
src += 160;
}
}
switch (sgb.waiting_transfer)
{
case TRN_SOUND:
trn_sound(vram);
break;
case TRN_PAL:
trn_pal(vram);
break;
case TRN_CHR_LOW:
trn_chr(vram, 0);
break;
case TRN_CHR_HI:
trn_chr(vram, 1);
break;
case TRN_PCT:
trn_pct(vram);
break;
case TRN_ATTR:
trn_attr(vram);
break;
}
}
static void sgb_render_frame_gb(uint32_t *vbuff)
{
const uint8_t *attr = sgb.attr;
const uint8_t *src = sgb.frame;
uint32_t *dst = vbuff + ((224 - 144) / 2 * 256 + (256 - 160) / 2);
for (int j = 0; j < 144; j++)
{
const uint8_t *attr_line = attr + j / 8 * 20;
for (int i = 0; i < 160; i++)
{
const int attr_index = i / 8;
*dst++ = sgb.palette[attr_line[attr_index]][*src++];
}
dst += 256 - 160;
}
}
static void draw_tile(uint16_t entry, uint32_t *dest)
{
const uint8_t *tile = sgb.tiles[entry & 0xff];
const uint32_t *palette = sgb.palette[entry >> 10 & 7];
int hflip = entry & 0x4000;
int vflip = entry & 0x8000;
int hinc, vinc;
if (hflip)
{
hinc = -1;
dest += 7;
}
else
{
hinc = 1;
}
if (vflip)
{
vinc = -256;
dest += 7 * 256;
}
else
{
vinc = 256;
}
vinc -= 8 * hinc;
for (int y = 0; y < 8; y++, dest += vinc)
{
for (int x = 0; x < 8; x++, dest += hinc)
{
int c = *tile++;
if (c)
*dest = palette[c];
}
}
}
static void sgb_render_border(uint32_t *vbuff)
{
const uint16_t *tilemap = sgb.tilemap;
for (int n = 0; n < 32 * 28; n++)
{
draw_tile(*tilemap++, vbuff);
vbuff += 8;
if ((n & 31) == 31)
vbuff += 256 * 7;
}
}
// 160x144 32bpp pixel data
// assumed to contain exact pixel values 00, 55, aa, ff
void sgb_take_frame(uint32_t *vbuff)
{
for (int i = 0; i < 160 * 144; i++)
{
sgb.frame[i] = 3 - (vbuff[i] >> 6 & 3); // 0, 1, 2, or 3 for each pixel
}
if (sgb.waiting_transfer != TRN_NONE)
{
if (!--sgb.transfer_countdown)
{
do_vram_transfer();
sgb.waiting_transfer = TRN_NONE;
}
}
if (!sgb.active_mask)
{
// render the frame now
for (int i = 0; i < 256 * 224; i++)
sgb.frozenframe[i] = sgb.palette[0][0];
sgb_render_frame_gb(sgb.frozenframe);
sgb_render_border(sgb.frozenframe);
}
}
void sgb_render_frame(uint32_t *vbuff)
{
memcpy(vbuff, sgb.frozenframe, sizeof(sgb.frozenframe));
}
void sgb_render_audio(uint64_t time, void (*callback)(int16_t l, int16_t r, uint64_t time))
{
int16_t sound_buffer[4096];
uint32_t diff = time - sgb.frame_start + sgb.clock_remainder;
//utils_log("%ul", diff);
uint32_t samples = diff / refclocks_per_spc_sample;
uint32_t new_remainder = diff % refclocks_per_spc_sample;
spc_set_output(sgb.spc, sound_buffer, sizeof(sound_buffer) / sizeof(sound_buffer[0]));
int matched = 1;
for (int p = 0; p < 4; p++)
{
if (spc_read_port(sgb.spc, 0, p) != sgb.sound_control[p])
matched = 0;
}
if (matched) // recived
{
sgb.sound_control[0] = 0;
sgb.sound_control[1] = 0;
sgb.sound_control[2] = 0;
}
else
{
utils_log("SPC: %02x %02x %02x %02x => %02x %02x %02x %02x\n",
spc_read_port(sgb.spc, 0, 0),
spc_read_port(sgb.spc, 0, 1),
spc_read_port(sgb.spc, 0, 2),
spc_read_port(sgb.spc, 0, 3),
sgb.sound_control[0],
sgb.sound_control[1],
sgb.sound_control[2],
sgb.sound_control[3]);
}
for (int p = 0; p < 4; p++)
{
spc_write_port(sgb.spc, 0, p, sgb.sound_control[p]);
}
spc_end_frame(sgb.spc, samples * 32);
uint64_t t = sgb.frame_start + refclocks_per_spc_sample - sgb.clock_remainder;
for (int i = 0; i < samples; i++, t += refclocks_per_spc_sample)
callback(sound_buffer[i * 2], sound_buffer[i * 2] + 1, t);
sgb.frame_start = time;
sgb.clock_remainder = new_remainder;
}