From 49b12139ec00397065dd27b3720aff5ce577f4bc Mon Sep 17 00:00:00 2001
From: Vicki Pfau <vi@endrift.com>
Date: Sat, 20 Mar 2021 22:58:52 -0700
Subject: [PATCH] Libretro: Lazy-load sensors

---
 src/platform/libretro/libretro.c | 25 +++++++++++++++++--------
 1 file changed, 17 insertions(+), 8 deletions(-)

diff --git a/src/platform/libretro/libretro.c b/src/platform/libretro/libretro.c
index 427b5c6fd..f3f03843b 100644
--- a/src/platform/libretro/libretro.c
+++ b/src/platform/libretro/libretro.c
@@ -69,7 +69,8 @@ static int rumbleDown;
 static struct mRumble rumble;
 static struct GBALuminanceSource lux;
 static struct mRotationSource rotation;
-static bool rotationEnabled;
+static bool tiltEnabled;
+static bool gyroEnabled;
 static int luxLevelIndex;
 static uint8_t luxLevel;
 static bool luxSensorEnabled;
@@ -100,9 +101,12 @@ static void _initSensors(void) {
 		sensorStateCallback = sensorInterface.set_sensor_state;
 
 		if (sensorStateCallback && sensorGetCallback) {
-			if (sensorStateCallback(0, RETRO_SENSOR_ACCELEROMETER_ENABLE, EVENT_RATE)
-				&& sensorStateCallback(0, RETRO_SENSOR_GYROSCOPE_ENABLE, EVENT_RATE)) {
-				rotationEnabled = true;
+			if (sensorStateCallback(0, RETRO_SENSOR_ACCELEROMETER_ENABLE, EVENT_RATE)) {
+				tiltEnabled = true;
+			}
+
+			if (sensorStateCallback(0, RETRO_SENSOR_GYROSCOPE_ENABLE, EVENT_RATE)) {
+				gyroEnabled = true;
 			}
 
 			if (sensorStateCallback(0, RETRO_SENSOR_ILLUMINANCE_ENABLE, EVENT_RATE)) {
@@ -318,7 +322,8 @@ void retro_init(void) {
 	sensorGetCallback = 0;
 	sensorStateCallback = 0;
 
-	rotationEnabled = false;
+	tiltEnabled = false;
+	gyroEnabled = false;
 	rotation.sample = _updateRotation;
 	rotation.readTiltX = _readTiltX;
 	rotation.readTiltY = _readTiltY;
@@ -363,7 +368,8 @@ void retro_deinit(void) {
 		sensorStateCallback = NULL;
 	}
 
-	rotationEnabled = false;
+	tiltEnabled = false;
+	gyroEnabled = false;
 	luxSensorEnabled = false;
 	sensorsInitDone = false;
 }
@@ -374,7 +380,6 @@ void retro_run(void) {
 	}
 	uint16_t keys;
 
-	_initSensors();
 	inputPollCallback();
 
 	bool updated = false;
@@ -1023,6 +1028,7 @@ static void _updateLux(struct GBALuminanceSource* lux) {
 	}
 
 	if (luxSensorUsed) {
+		_initSensors();
 		float fLux = luxSensorEnabled ? sensorGetCallback(0, RETRO_SENSOR_ILLUMINANCE) : 0.0f;
 		luxLevel = cbrtf(fLux) * 8;
 	} else {
@@ -1124,9 +1130,12 @@ static void _updateRotation(struct mRotationSource* source) {
 	tiltX = 0;
 	tiltY = 0;
 	gyroZ = 0;
-	if (rotationEnabled) {
+	_initSensors();
+	if (tiltEnabled) {
 		tiltX = sensorGetCallback(0, RETRO_SENSOR_ACCELEROMETER_X) * 3e8f;
 		tiltY = sensorGetCallback(0, RETRO_SENSOR_ACCELEROMETER_Y) * -3e8f;
+	}
+	if (gyroEnabled) {
 		gyroZ = sensorGetCallback(0, RETRO_SENSOR_GYROSCOPE_Z) * -1.1e9f;
 	}
 }