OpenPuck/OpenPuck/gamepad_util.h

// gamepad_util.h -- shared helpers for building host USB gamepad reports from g_in.
//
// These are reused across the DualSense / DS4 / Switch personalities: analog-stick rescaling, Steam-trackpad
// -> absolute-touch mapping, and the PlayStation-layout button/hat/face/shoulder packers. Per-target button
// code maps (codeToXB / codeToSwitch / codeToJc) live with their own controllers; only the cross-mode pieces
// are here.
#pragma once
#include <stdint.h>
#include "triton.h"

// int16 stick (center 0) -> uint8 (center 0x80), optional axis invert (HID Y is down-positive).
uint8_t swStick(int16_t v, bool invert);

// Write a signed 16-bit value little-endian.
static inline void le16(uint8_t *p, int16_t v)
{
	p[0] = (uint8_t)(v & 0xFF);
	p[1] = (uint8_t)((v >> 8) & 0xFF);
}

// Fill a DS4/DualSense motion-calibration feature report PAYLOAD. The TinyUSB GET_REPORT path already wrote the
// report id and hands us the buffer PAST it, so our offsets = the kernel's buf[] index minus one (bias at 0..5,
// stays zero from the caller's memset). Zero bias + symmetric non-zero ranges so hid-playstation's/hid-sony's
// divisor (|plus-bias|+|minus-bias|, and gyro speed_plus+speed_minus) is never zero. Shared by report 0x02 (DS4)
// and 0x05 (DualSense) -- identical layout; the caller returns size-1 and leaves trailing bytes zero.
void psNeutralCalib(uint8_t *buf);

// Steam trackpad s16 coords -> absolute touch surface. TOUCH_PAD_W is split into left/right halves so both
// pads can co-exist as two contacts on a single DualSense/DS4 touchpad.
#define TOUCH_PAD_W 1920u
uint16_t padNormU16(int16_t v, uint16_t maxv);
uint16_t touchHalfX(int16_t v, bool rightHalf);
uint16_t touchYInv(int16_t v, uint16_t height);
void touchPackPoint(uint8_t *base, int finger, bool touch, uint16_t x,
		    uint16_t y);
// DualSense / DS4: many hosts only honor contact slot 0 -- put a lone pad in slot 0, both pads in 0+1.
void touchPackPads(uint8_t *pts, bool lTouch, bool rTouch, uint16_t lx,
		   uint16_t ly, uint16_t rx, uint16_t ry);
void steamPadsToTouch(uint32_t b, uint16_t touchH, int16_t lpx, int16_t lpy,
		      int16_t rpx, int16_t rpy, uint16_t *lx, uint16_t *ly,
		      uint16_t *rx, uint16_t *ry);

// Trackpad -> analog stick blend (WebUI "map trackpad to joystick", g_padStick). A pad mapped to a stick
// BLENDS with it rather than replacing it: while the pad is touched each axis reports whichever of the two
// sources is deflected further from center (signed), so pad and stick stay usable at the same time. An
// untouched pad contributes nothing and the physical stick passes through unchanged -- which also means a
// release can never leave a stale pad value stuck on the axis. b = raw TB_* buttons (touch bits); the
// sticks are updated in place.
void padStickBlend(uint32_t b, int16_t lpx, int16_t lpy, int16_t rpx,
		   int16_t rpy, int16_t *lx, int16_t *ly, int16_t *rx,
		   int16_t *ry);

// g_in[slot] sticks with padStickBlend applied -- what every emulated mode should send to the host.
void slotSticks(uint8_t slot, int16_t *lx, int16_t *ly, int16_t *rx,
		int16_t *ry);

// Convert configurable button code -> TB_* flag (shared across modes).
static inline uint32_t tritonFromCode(uint8_t c)
{
	switch (c) {
	case 1:
		return TB_A;
	case 2:
		return TB_B;
	case 3:
		return TB_X;
	case 4:
		return TB_Y;
	case 5:
		return TB_LB;
	case 6:
		return TB_RB;
	case 7:
		return TB_L3;
	case 8:
		return TB_R3;
	case 9:
		return TB_VIEW;
	case 10:
		return TB_QAM;
	case 11:
		return TB_STEAM;
	case 12:
		return TB_DUP;
	case 13:
		return TB_DDN;
	case 14:
		return TB_DLF;
	case 15:
		return TB_DRT;
	case 16:
		return TB_TOUCH;
	case 17:
		return TB_MUTE;
	case 19:
		return TB_L2; // left trigger (LT / L2 / ZL)
	case 20:
		return TB_R2; // right trigger (RT / R2 / ZR)
	default:
		return 0;
	}
}

// PlayStation-layout button packing (shared by mode_ps5 + mode_hidgyro).
uint32_t psButtonsFromSteam(
	uint32_t raw); // apply back-paddle + chord-guard + QAM remapping
// L1..R3 + Create/Options byte. lt/rt are the per-slot analog trigger values so the digital ZL/ZR trip
// doesn't leak across slots when several slots are active.
uint8_t psShouldersByte(uint32_t b, uint8_t lt, uint8_t rt);
uint8_t psHatNibble(uint32_t b); // d-pad -> 8-way hat (8 = neutral)
uint8_t psFaceNibble(uint32_t b); // face buttons (with A/B + X/Y swap)