Improved emulation of SGB multiplayer, fixes #405

This commit is contained in:
Lior Halphon 2021-10-09 14:52:28 +03:00
parent 164a870189
commit 191f7cee02
4 changed files with 16 additions and 15 deletions

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@ -12,7 +12,7 @@ void GB_update_joyp(GB_gameboy_t *gb)
previous_state = gb->io_registers[GB_IO_JOYP] & 0xF; previous_state = gb->io_registers[GB_IO_JOYP] & 0xF;
key_selection = (gb->io_registers[GB_IO_JOYP] >> 4) & 3; key_selection = (gb->io_registers[GB_IO_JOYP] >> 4) & 3;
gb->io_registers[GB_IO_JOYP] &= 0xF0; gb->io_registers[GB_IO_JOYP] &= 0xF0;
uint8_t current_player = gb->sgb? (gb->sgb->current_player & (gb->sgb->player_count - 1) & 3) : 0; uint8_t current_player = gb->sgb? gb->sgb->current_player : 0;
switch (key_selection) { switch (key_selection) {
case 3: case 3:
if (gb->sgb && gb->sgb->player_count > 1) { if (gb->sgb && gb->sgb->player_count > 1) {

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@ -355,6 +355,12 @@ static void sanitize_state(GB_gameboy_t *gb)
if (gb->object_priority == GB_OBJECT_PRIORITY_UNDEFINED) { if (gb->object_priority == GB_OBJECT_PRIORITY_UNDEFINED) {
gb->object_priority = gb->cgb_mode? GB_OBJECT_PRIORITY_INDEX : GB_OBJECT_PRIORITY_X; gb->object_priority = gb->cgb_mode? GB_OBJECT_PRIORITY_INDEX : GB_OBJECT_PRIORITY_X;
} }
if (gb->sgb) {
if (gb->sgb->player_count != 1 && gb->sgb->player_count != 2 && gb->sgb->player_count != 4) {
gb->sgb->player_count = 1;
}
gb->sgb->current_player &= gb->sgb->player_count - 1;
}
if (gb->sgb && !gb->sgb->v14_3) { if (gb->sgb && !gb->sgb->v14_3) {
#ifdef GB_BIG_ENDIAN #ifdef GB_BIG_ENDIAN
for (unsigned i = 0; i < sizeof(gb->sgb->border.raw_data) / 2; i++) { for (unsigned i = 0; i < sizeof(gb->sgb->border.raw_data) / 2; i++) {
@ -719,7 +725,7 @@ static int save_state_internal(GB_gameboy_t *gb, virtual_file_t *file, bool appe
bess_sgb.attribute_files = (BESS_buffer_t){LE32(sizeof(gb->sgb->attribute_files)), bess_sgb.attribute_files = (BESS_buffer_t){LE32(sizeof(gb->sgb->attribute_files)),
LE32(sgb_offset + offsetof(GB_sgb_t, attribute_files))}; LE32(sgb_offset + offsetof(GB_sgb_t, attribute_files))};
bess_sgb.multiplayer_state = (gb->sgb->player_count << 4) | (gb->sgb->current_player & (gb->sgb->player_count - 1)); bess_sgb.multiplayer_state = (gb->sgb->player_count << 4) | gb->sgb->current_player;
if (file->write(file, &bess_sgb, sizeof(bess_sgb)) != sizeof(bess_sgb)) { if (file->write(file, &bess_sgb, sizeof(bess_sgb)) != sizeof(bess_sgb)) {
goto error; goto error;
} }

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@ -382,15 +382,12 @@ static void command_ready(GB_gameboy_t *gb)
// Not supported, but used by almost all SGB games for hot patching, so let's mute the warning for this // Not supported, but used by almost all SGB games for hot patching, so let's mute the warning for this
break; break;
case MLT_REQ: case MLT_REQ:
if (gb->sgb->player_count == 1) {
gb->sgb->current_player = 0;
}
gb->sgb->player_count = (gb->sgb->command[1] & 3) + 1; /* Todo: When breaking save state comaptibility, gb->sgb->player_count = (gb->sgb->command[1] & 3) + 1; /* Todo: When breaking save state comaptibility,
fix this to be 0 based. */ fix this to be 0 based. */
if (gb->sgb->player_count == 3) { if (gb->sgb->player_count == 3) {
gb->sgb->current_player++; gb->sgb->player_count++;
} }
gb->sgb->mlt_lock = true; gb->sgb->current_player &= (gb->sgb->player_count - 1);
break; break;
case CHR_TRN: case CHR_TRN:
gb->sgb->vram_transfer_countdown = 2; gb->sgb->vram_transfer_countdown = 2;
@ -446,18 +443,16 @@ void GB_sgb_write(GB_gameboy_t *gb, uint8_t value)
command_size = SGB_PACKET_SIZE * 8; command_size = SGB_PACKET_SIZE * 8;
} }
if ((value & 0x20) == 0 && (gb->io_registers[GB_IO_JOYP] & 0x20) != 0) { if ((value & 0x20) != 0 && (gb->io_registers[GB_IO_JOYP] & 0x20) == 0) {
gb->sgb->mlt_lock ^= true; if ((gb->sgb->player_count & 1) == 0) {
gb->sgb->current_player++;
gb->sgb->current_player &= (gb->sgb->player_count - 1);
}
} }
switch ((value >> 4) & 3) { switch ((value >> 4) & 3) {
case 3: case 3:
gb->sgb->ready_for_pulse = true; gb->sgb->ready_for_pulse = true;
if ((gb->sgb->player_count & 1) == 0 && !gb->sgb->mlt_lock) {
gb->sgb->current_player++;
gb->sgb->current_player &= 3;
gb->sgb->mlt_lock = true;
}
break; break;
case 2: // Zero case 2: // Zero

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@ -61,7 +61,7 @@ struct GB_sgb_s {
uint8_t received_header[0x54]; uint8_t received_header[0x54];
/* Multiplayer (cont) */ /* Multiplayer (cont) */
bool mlt_lock; GB_PADDING(bool, mlt_lock);
bool v14_3; // True on save states created on 0.14.3 or newer; Remove when breaking save state compatibility! bool v14_3; // True on save states created on 0.14.3 or newer; Remove when breaking save state compatibility!
}; };