Revert "perf(axis): replace int64_t with int32_t in torque pipeline for Cortex-M4 efficiency"

This reverts commit 711739d.

Author: manoukianv

Firmware/FFBoard/Inc/Axis.h

@@ -342,7 +342,7 @@ class Axis : public PersistentStorage, public CommandHandler, public ErrorHandle
 	 * @brief Calculates the FFB torque exponential torque, from the input torque and apply expo and scaler
 	 * @return The calculated exponential torque.
 	 */
-	int64_t calculateFFBTorque();
+	int32_t calculateFFBTorque();
 
 	/**
 	 * @brief Starts a force fade-in.
@@ -412,7 +412,7 @@ class Axis : public PersistentStorage, public CommandHandler, public ErrorHandle
 	 */
 	void setExpo(int val);
 
-	int32_t calculateExpoTorque(int32_t torque);
+	float calculateExpoTorque(float torque);
 	/**
 	 * @brief Applies the speed limiter PI controller to the torque.
 	 * @param torque A reference to the torque value to be modified.

Firmware/FFBoard/Src/Axis.cpp

@@ -694,35 +694,32 @@ uint16_t Axis::getPower(){
 /**
  * Calculates an exponential torque correction curve and scale for FFBEffect
  */
-int32_t Axis::calculateExpoTorque(int32_t torque){
-	float torquef = (float)torque / (float)0x7fff; // This down and upscaling may introduce float artifacts. Do this before scaling down.
-	if(torquef < 0){
-		return -powf(-torquef,expo) * 0x7fff;
-	}else{
-		return powf(torquef,expo) * 0x7fff;
-	}
+float Axis::calculateExpoTorque(float torque){
+	float torqueSign = torque > 0 ? 1.0f : -1.0f;
+	torque = powf(fabsf(torque), expo) * torqueSign;
+	return torque;
 }
 
-int64_t Axis::calculateFFBTorque() {
+int32_t Axis::calculateFFBTorque(){
 
-	int64_t torque = this->ffbEffectTorque;
+	// 1. Initial conversion and normalization
+	// Convert to float and move to [-1.0, 1.0] range immediately.
+	float torque = (float)this->ffbEffectTorque * (1.0f / 32767.0f);
 
-	// 1. Game Clipping detection
-	// If the game sends more than the theoretical maximum (+/- 32767), the signal is clipped at the source.
-	if(abs(torque) >= 0x7fff){
+	// 2. Game Clipping detection
+	// Performed on normalized value for consistency.
+	if(fabsf(torque) >= 1.0f){
 		pulseClipLed(); // Visual alert: game signal is clipping
 	}
 
-	// 2. Apply Expo (Linearization or sensation curve)
-	if(expo != 1){
+	// 3. Apply Expo (Linearization or sensation curve)
+	if(expo != 1.0f){
 		torque = calculateExpoTorque(torque);
 	}
 
-	// 3. Game specific gain (effectRatioScaler)
-	// Scale the FFB from game only (allows lowering game effects without lowering endstops)
-	torque = (int64_t)((float)torque * effectRatioScaler);
-
-	return torque;
+	// 4. Final scaling and single conversion back to integer
+	// Apply both the FFB range and the effect ratio in one final step.
+	return (int32_t)(torque * 32767.0f * effectRatioScaler);
 }
 
 int32_t Axis::getTorque() { return metric.current.torque; } // Fix: move from previous to current
@@ -821,8 +818,8 @@ void Axis::applyTorqueSlewRateLimiter(int32_t& torque)
 {
 	// Limits the rate of change of the torque (slew rate), to smooths out sudden changes in torque.
 	// Essential for a natural feel and to prevent "clanking" noises.
-	if(maxTorqueRateMS == 0) {
-		return; // Limiter is disabled
+	if (maxTorqueRateMS <= 0) {
+		return;
 	}
 
 	// This prevents sudden torque jumps, resulting in a smoother feel.