Files
pikuma_ps1/code/duffle/pad.atom.c
T
2026-08-05 02:00:41 -04:00

185 lines
9.8 KiB
C

#ifdef INTELLISENSE_DIRECTIVES
# include "gen/macs.h"
# include "gen/offsets.h"
# include "mips.h"
# include "dsl.atom.h"
# include "lottes_tape.h"
# include "pad.h"
#endif
ATOM_FILE_DEBUGGER_LINE_MARKER(pad_atom_c);
#pragma region Baked Atoms
/* ----- pad_bios_snapshot -----
* Per-frame snapshot of one BIOS pad buffer into PadState.
* Decoder (branch ladder on raw[0] status + raw[1] id):
* 1. raw[0] == 0xFF -> Disconnected (buttons=0, axes=0x80)
* 2. raw[0]==0 && raw[1]==0 -> Pending (buttons=0, axes=0x80)
* 3. raw[1] == 0x41 -> Digital (buttons normalized; axes=0x80)
* 4. raw[1] == 0x53 -> AnalogStick (buttons normalized; axes from raw[4..7])
* 5. raw[1] in 0x7x -> AnalogPad (buttons normalized; axes from raw[4..7])
* 6. else -> Unsupported (buttons=0, axes=0x80)
*
* Buttons normalization: byte_swap16((~raw_buttons) & 0xFFFF).
* raw_buttons = load_half_u(raw, 2) = raw[2] | (raw[3] << 8).
* byte_swap16(x) = (x >> 8) | (x << 8); nor(x, R_0) = ~x. store_half truncates to 16 bits so the upper-16 mask is implicit in the store.
*
* Register use (atom-local; no wave-context touched):
* R_T0 = raw base (kept throughout; axes loads read raw[4..7] from R_T0)
* R_T1 = state base (kept throughout; all stores go through R_T1)
* R_T2 = raw[0] status (alive across the disc/pending/id dispatch, then dead)
* R_T3 = raw[1] id (alive across the id dispatch, then dead)
* R_T4 = scratch (shifts, compares, immediate loads, store values)
* R_T5 = scratch (parallel lui+ori for the 0x80808080 axes constant + byte-swap target)
*/
enum {
R_PadRaw = R_T0 atom_reg atom_type(U1),
R_PadState = R_T1 atom_reg,
R_RawStatus = R_T2 atom_reg,
R_RawId = R_T3 atom_reg,
};
typedef Struct_(Binds_PadBiosSnapshot) {
PadBiosRaw* raw;
PadState* state;
};
internal MipsAtom_(pad_bios_snapshot) atom_info(atom_bind(Binds_PadBiosSnapshot)
, atom_reads( R_PadRaw, R_PadState, R_RawStatus, R_RawId, R_T4, R_T5, R_TapePtr)
, atom_writes(R_PadRaw, R_PadState, R_RawStatus, R_RawId, R_T4, R_T5, R_TapePtr)
) {
/* === Bind consumption: T0 = raw, T1 = state, advance R_TapePtr by 8. */
load_word(R_PadRaw, R_TapePtr, O_(Binds_PadBiosSnapshot,raw)),
load_word(R_PadState, R_TapePtr, O_(Binds_PadBiosSnapshot,state)),
add_ui_self( R_TapePtr, S_(Binds_PadBiosSnapshot)),
/* === Read raw[0] (status) + raw[1] (id) */
load_byte_u(R_RawStatus, R_PadRaw, 0),
load_byte_u(R_RawId, R_PadRaw, 1),
atom_label(snap_root) /* === Case 1: Disconnected (status == 0xFF). */
add_ui(R_T4, R_0, 0xFF), branch_ne(R_RawStatus, R_T4, atom_offset(snap_root, skip_disconnected)),
/* BD-slot: pre-compute PadStatus_Disconnected. Branch reads R_T4=0xFF in EX before this WB completes.
* If branch NOT taken (fall through to pending/id_dispatch), R_T4 is overwritten by the next case body's add_ui — harmless. */
atom_label(disconnected) /* === Disconnected body. */
/* R_T4 = PadStatus_Disconnected from snap_root BD-slot. */
store_word(R_T4, R_PadState, O_(PadState,status)),
store_half(R_0, R_PadState, O_(PadState,buttons)),
/* axes = 0x80808080 (centered) — single sw writes the 4-byte axes block at offset 8 (left_x, left_y, right_x, right_y). */
load_upper_i(R_T4, 0x8080), or_i_self(R_T4, 0x8080),
store_word( R_T4, R_PadState, O_(PadState,left_x)),
store_byte( R_RawId, R_PadState, O_(PadState,id)),
jump_rel(atom_offset(disconnected, snap_end)),
/* BD-slot: load next atom's entry point (replaces the nop).
* The unconditional branch always jumps to snap_end, where mac_yield_tail()
* transfers control to R_AtomJmp without re-loading it. */
mac_yield_load(),
atom_label(skip_disconnected)
/* === Case 2: Pending (status == 0 && id == 0)
* Combined check: if (status | id) != 0 then skip to id_dispatch.
* Falls through to the Pending case only when both are zero. */
or_u_self(R_RawStatus, R_RawId), branch_ne(R_RawStatus, R_0, atom_offset(case_2, id_dispatch)),
/* BD-slot: pre-compute PadStatus_Pending. Branch reads R_RawStatus in EX before this WB completes.
* If branch NOT taken (fall through to id_dispatch), R_T4 is overwritten by the digital/analog body add_ui — harmless. */
atom_label(pending) /* === Pending body */
/* R_T4 = PadStatus_Pending from case_2 BD-slot. */
store_word(R_T4, R_PadState, O_(PadState,status)),
store_half(R_0, R_PadState, O_(PadState,buttons)),
/* axes = 0x80808080 (centered) — single sw writes the 4-byte axes block at offset 8 (left_x, left_y, right_x, right_y). */
load_upper_i(R_T4, 0x8080), or_i_self(R_T4, 0x8080),
store_word( R_T4, R_PadState, O_(PadState,left_x)),
store_byte( R_RawId, R_PadState, O_(PadState,id)),
jump_rel(atom_offset(pending, snap_end)),
mac_yield_load(),
atom_label(id_dispatch) /* === Case 3-6: ID dispatch */
add_ui(R_T4, R_0, 0x41), branch_ne(R_RawId, R_T4, atom_offset(id_dispatch, try_analog_stick)),
/* BD-slot: pre-compute PadStatus_Digital. Branch reads R_RawId in EX before this WB completes.
* If branch NOT taken (fall through to try_analog_stick), R_T4 is overwritten by the analog body add_ui. */
/* === Digital body (status, buttons normalize, axes=0x80, id, branch. */
/* R_T4 = PadStatus_Digital from id_dispatch BD-slot. */
store_word( R_T4, R_PadState, O_(PadState,status)),
load_half_u(R_T4, R_PadRaw, 2 * S_(U1)),
/* Fill R_T4's load-delay slot with the 0x80808080 axes constant into R_T5
* (R_T5 is dead on this path; it's only consumed at the analog_pad range check). */
load_upper_i(R_T5, 0x8080), or_i_self(R_T5, 0x8080),
nor_u( R_T4, R_T4, R_0), /* raw_buttons is already in host bit order; no swap needed */
store_half( R_T4, R_PadState, O_(PadState,buttons)),
/* axes = 0x80808080 (centered) — single sw writes the 4-byte axes block at offset 8 (left_x, left_y, right_x, right_y). */
store_word( R_T5, R_PadState, O_(PadState,left_x)),
add_ui( R_T4, R_0, 0x41),
store_byte( R_T4, R_PadState, O_(PadState,id)),
jump_rel(atom_offset(id_dispatch, snap_end)),
mac_yield_load(),
atom_label(try_analog_stick) /* === Case 4: AnalogStick (id == 0x53)*/
add_ui(R_T4, R_0, 0x53), branch_ne(R_RawId, R_T4, atom_offset(try_analog_stick, try_analog_pad)),
/* BD-slot: pre-compute PadStatus_AnalogStick. Branch reads R_RawId in EX before this WB completes.
* If branch NOT taken (fall through to try_analog_pad), R_T4 is overwritten by the analog_pad body add_ui. */
atom_label(analog_stick) /* === AnalogStick body
* Axes are loaded as two halfwords: raw[6..7] → left_xy (sh at offset 8), raw[4..5] → right_xy (sh at offset 10).
* R_T5 holds left_xy / id-value in turn (it's dead on this path — only consumed at the analog_pad range check). */
/* R_T4 = PadStatus_AnalogStick from try_analog_stick BD-slot. */
store_word( R_T4, R_PadState, O_(PadState,status)),
load_half_u( R_T4, R_PadRaw, 2 * S_(U1)), /* R_T4 = raw_buttons */
load_half_u( R_T5, R_PadRaw, 6 * S_(U1)), /* R_T5 = left_xy; fills R_T4's load-delay slot (doesn't read R_T4) */
nor_u( R_T4, R_T4, R_0), /* R_T4 = ~raw_buttons */
store_half( R_T4, R_PadState, O_(PadState,buttons)),
load_half_u( R_T4, R_PadRaw, 4 * S_(U1)), /* R_T4 = right_xy; fills R_T5's load-delay slot */
store_half( R_T5, R_PadState, O_(PadState,left_x)), /* R_T5 settled, store left_xy */
store_half( R_T4, R_PadState, O_(PadState,right_x)),
add_ui( R_T5, R_0, 0x53), /* R_T5 = id value (clobbers left_xy, already stored) */
store_byte( R_T5, R_PadState, O_(PadState,id)),
jump_rel(atom_offset(analog_stick, snap_end)),
mac_yield_load(),
atom_label(try_analog_pad) /* === Case 5-6: AnalogPad (id & 0xF0 == 0x70) */
and_i( R_T4, R_RawId, 0xF0),
add_ui( R_T5, R_0, 0x70),
branch_ne(R_T4, R_T5, atom_offset(try_analog_pad, try_unsupported)),
/* BD-slot: pre-compute PadStatus_AnalogPad. Branch reads R_T4 in EX before this WB completes.
* If branch NOT taken (fall through to try_unsupported), R_T4 is overwritten by the unsupported body add_ui. */
atom_label(analog_pad) /* === AnalogPad body
* Same shape as AnalogStick with AnalogPad status. R_T5 holds left_xy (it's dead on this path). */
/* R_T4 = PadStatus_AnalogPad from try_analog_pad BD-slot. */
store_word( R_T4, R_PadState, O_(PadState,status)),
load_half_u(R_T4, R_PadRaw, 2 * S_(U1)), /* R_T4 = raw_buttons */
load_half_u(R_T5, R_PadRaw, 6 * S_(U1)), /* R_T5 = left_xy; fills R_T4's load-delay slot */
nor_u( R_T4, R_T4, R_0), /* R_T4 = ~raw_buttons */
store_half( R_T4, R_PadState, O_(PadState,buttons)),
load_half_u(R_T4, R_PadRaw, 4 * S_(U1)), /* R_T4 = right_xy; fills R_T5's load-delay slot */
store_half( R_T5, R_PadState, O_(PadState,left_x)), /* R_T5 settled, store left_xy */
store_half( R_T4, R_PadState, O_(PadState,right_x)),
store_byte( R_RawId, R_PadState, O_(PadState,id)),
jump_rel(atom_offset(analog_pad, snap_end)),
mac_yield_load(),
atom_label(try_unsupported) /* === Case 7: Unsupported — fall through from the AnalogPad range-check miss. */
add_ui( R_T4, R_0, PadStatus_Unsupported),
store_word(R_T4, R_PadState, O_(PadState,status)),
store_half(R_0, R_PadState, O_(PadState,buttons)),
/* axes = 0x80808080 (centered) — single sw writes the 4-byte axes block at offset 8 (left_x, left_y, right_x, right_y). */
load_upper_i(R_T4, 0x8080), or_i_self(R_T4, 0x8080),
store_word( R_T4, R_PadState, O_(PadState,left_x)),
add_ui( R_T4, R_0, 0xFF), /* 0xFF sentinel: "unknown id" */
store_byte( R_T4, R_PadState, O_(PadState,id)),
/* Fall through to snap_end. */
atom_label(no_jump_fallthrough)
mac_yield_load(),
atom_label(snap_end)
/* NOT mac_yield() — R_AtomJmp was already loaded in the BD-slot of the case-exit branch. */
mac_yield_tail(),
};
#pragma endregion Baked Atoms