A little more tidying. Better notes around how the absolute maximum threshold was arrived at.

test/gamepadutils.c

@@ -236,7 +236,7 @@ void DrawGyroDebugAxes(SDL_Renderer *renderer, const Quaternion *orientation, co
     SDL_RenderLine(renderer, origin_screen.x, origin_screen.y, up_screen.x, up_screen.y);
     SDL_SetRenderDrawColor(renderer, GYRO_COLOR_BLUE);
     SDL_RenderLine(renderer, origin_screen.x, origin_screen.y, back_screen.x, back_screen.y);
-    
+
     /* Restore current color */
     SDL_SetRenderDrawColor(renderer, r, g, b, a);
 }
@@ -1053,7 +1053,7 @@ GyroDisplay *CreateGyroDisplay(SDL_Renderer *renderer)
         ctx->next_reported_sensor_time = 0;
         ctx->current_calibration_phase = GYRO_CALIBRATION_PHASE_OFF;
         ctx->calibration_phase_progress_fraction = 0.0f; /* [0..1] */
-        ctx->accelerometer_noise_sq = 0.0f;              
+        ctx->accelerometer_noise_sq = 0.0f;
         ctx->accelerometer_noise_tolerance_sq = ACCELEROMETER_NOISE_THRESHOLD; /* Will be overwritten but this avoids divide by zero. */
         ctx->reset_gyro_button = CreateGamepadButton(renderer, "Reset View");
         ctx->calibrate_gyro_button = CreateGamepadButton(renderer, "Recalibrate Drift");
@@ -1678,7 +1678,6 @@ void RenderGamepadDisplay(GamepadDisplay *ctx, SDL_Gamepad *gamepad)
                 SDLTest_DrawString(ctx->renderer, x + center - SDL_strlen(text) * FONT_CHARACTER_SIZE, y, text);
                 SDL_snprintf(text, sizeof(text), "[%.2f,%.2f,%.2f]%s/s", ctx->gyro_data[0] * RAD_TO_DEG, ctx->gyro_data[1] * RAD_TO_DEG, ctx->gyro_data[2] * RAD_TO_DEG, DEGREE_UTF8);
                 SDLTest_DrawString(ctx->renderer, x + center + 2.0f, y, text);
-           
 
                 /* Display the testcontroller tool's evaluation of drift. This is also useful to get an average rate of turn in calibrated turntable tests. */
                 if (ctx->gyro_drift_correction_data[0] != 0.0f && ctx->gyro_drift_correction_data[2] != 0.0f && ctx->gyro_drift_correction_data[2] != 0.0f )
@@ -1758,7 +1757,6 @@ void RenderGyroDriftCalibrationButton(GyroDisplay *ctx, GamepadDisplay *gamepad_
     const float new_line_height = gamepad_display->button_height + 2.0f;
     GamepadButton *start_calibration_button = GetGyroCalibrateButton(ctx);
 
-
     /* Show the recalibration progress bar. */
     float recalibrate_button_width = GetGamepadButtonLabelWidth(start_calibration_button) + 2 * BUTTON_PADDING;
     SDL_FRect recalibrate_button_area;
@@ -1784,14 +1782,12 @@ void RenderGyroDriftCalibrationButton(GyroDisplay *ctx, GamepadDisplay *gamepad_
 
     SetGamepadButtonLabel(start_calibration_button, label_text);
     SetGamepadButtonArea(start_calibration_button, &recalibrate_button_area);
-    RenderGamepadButton(start_calibration_button);  
+    RenderGamepadButton(start_calibration_button);
 
     bool bExtremeNoise = ctx->accelerometer_noise_sq > ACCELEROMETER_MAX_NOISE_G_SQ;
     /* Explicit warning message if we detect too much movement */
     if (ctx->current_calibration_phase == GYRO_CALIBRATION_PHASE_OFF) {
-        
-        if (bExtremeNoise)
-        {
+        if (bExtremeNoise) {
             SDL_strlcpy(label_text, "GamePad Must Be Still", sizeof(label_text));
             SDLTest_DrawString(ctx->renderer, recalibrate_button_area.x, recalibrate_button_area.y + recalibrate_button_area.h + new_line_height, label_text);
             SDL_strlcpy(label_text, "Place GamePad On Table", sizeof(label_text));
@@ -1799,12 +1795,14 @@ void RenderGyroDriftCalibrationButton(GyroDisplay *ctx, GamepadDisplay *gamepad_
         }
     }
 
-    if (ctx->current_calibration_phase == GYRO_CALIBRATION_PHASE_NOISE_PROFILING
-        || ctx->current_calibration_phase == GYRO_CALIBRATION_PHASE_DRIFT_PROFILING)
+    if (ctx->current_calibration_phase == GYRO_CALIBRATION_PHASE_NOISE_PROFILING ||
+        ctx->current_calibration_phase == GYRO_CALIBRATION_PHASE_DRIFT_PROFILING)
     {
         float flAbsoluteNoiseFraction = SDL_clamp(ctx->accelerometer_noise_sq / ACCELEROMETER_MAX_NOISE_G_SQ, 0.0f, 1.0f);
         float flAbsoluteToleranceFraction = SDL_clamp(ctx->accelerometer_noise_tolerance_sq / ACCELEROMETER_MAX_NOISE_G_SQ, 0.0f, 1.0f);
-        float flRelativeNoiseFraction = SDL_clamp(ctx->accelerometer_noise_sq / ctx->accelerometer_noise_tolerance_sq, 0.0f, 1.0f);
+
+        float flMaxNoiseForThisPhase = ctx->current_calibration_phase == GYRO_CALIBRATION_PHASE_NOISE_PROFILING ? ACCELEROMETER_MAX_NOISE_G_SQ : ctx->accelerometer_noise_tolerance_sq;
+        float flRelativeNoiseFraction = SDL_clamp(ctx->accelerometer_noise_sq / flMaxNoiseForThisPhase, 0.0f, 1.0f);
 
         float noise_bar_height = gamepad_display->button_height;
         SDL_FRect noise_bar_rect;
@@ -1813,7 +1811,7 @@ void RenderGyroDriftCalibrationButton(GyroDisplay *ctx, GamepadDisplay *gamepad_
         noise_bar_rect.w = recalibrate_button_area.w;
         noise_bar_rect.h = noise_bar_height;
 
-        SDL_snprintf(label_text, sizeof(label_text), "Noise Tolerance: %3.3fG ", SDL_sqrtf(ctx->accelerometer_noise_tolerance_sq) );
+        SDL_snprintf(label_text, sizeof(label_text), "Accelerometer Noise Tolerance: %3.3fG ", SDL_sqrtf(ctx->accelerometer_noise_tolerance_sq) );
         SDLTest_DrawString(ctx->renderer, recalibrate_button_area.x, recalibrate_button_area.y + recalibrate_button_area.h + new_line_height * 2, label_text);
 
         /* Adjust the noise bar rectangle based on the accelerometer noise value */
@@ -1837,7 +1835,7 @@ void RenderGyroDriftCalibrationButton(GyroDisplay *ctx, GamepadDisplay *gamepad_
         tolerance_bar_rect.w = tolerance_bar_fill_width;
         tolerance_bar_rect.h = noise_bar_height;
 
-        SDL_SetRenderDrawColor(ctx->renderer, 128, 128, 0, 255); 
+        SDL_SetRenderDrawColor(ctx->renderer, 128, 128, 0, 255);
         SDL_RenderRect(ctx->renderer, &tolerance_bar_rect);        /* draw the tolerance rectangle */
 
         SDL_SetRenderDrawColor(ctx->renderer, 100, 100, 100, 255); /* gray box */
@@ -1985,7 +1983,6 @@ void RenderGyroDisplay(GyroDisplay *ctx, GamepadDisplay *gamepadElements, SDL_Ga
         float bottom = RenderEulerReadout(ctx, gamepadElements);
         RenderGyroGizmo(ctx, gamepad, bottom);
     }
-
     SDL_SetRenderDrawColor(ctx->renderer, r, g, b, a);
 }
 

test/gamepadutils.h

@@ -143,9 +143,12 @@ extern void DestroyGamepadButton(GamepadButton *ctx);
 
 /* Gyro element Display */
 
-/* This is used as the initial noise tolernace threshold. It's set very close to zero to avoid divide by zero while we're evaluating the noise profile. Each controller may have a very different noise profile.*/
+/* This is used as the initial noise tolerance threshold. It's set very close to zero to avoid divide by zero while we're evaluating the noise profile. Each controller may have a very different noise profile.*/
 #define ACCELEROMETER_NOISE_THRESHOLD 1e-6f
-#define ACCELEROMETER_MAX_NOISE_G_SQ  ( 0.125f * 0.125f )
+/* The value below is based on observation of a Dualshock controller. Of all gamepads observed, the Dualshock (PS4) tends to have one of the noisiest accelerometers. Increase this threshold if a controller is failing to pass the noise profiling stage while stationary on a table. */
+#define ACCELEROMETER_MAX_NOISE_G 0.075f
+#define ACCELEROMETER_MAX_NOISE_G_SQ (ACCELEROMETER_MAX_NOISE_G * ACCELEROMETER_MAX_NOISE_G)
+
 /* Gyro Calibration Phases */
 typedef enum
 {

test/testcontroller.c

@@ -211,7 +211,7 @@ void ResetGyroOrientation(IMUState *imustate)
 }
 
 /* More time = more accurate drift correction*/
-#define SDL_GAMEPAD_IMU_NOISE_SETTLING_PERIOD_NS            (1 * SDL_NS_PER_SECOND)
+#define SDL_GAMEPAD_IMU_NOISE_SETTLING_PERIOD_NS            ( SDL_NS_PER_SECOND / 2)
 #define SDL_GAMEPAD_IMU_NOISE_EVALUATION_PERIOD_NS            (4 * SDL_NS_PER_SECOND)
 #define SDL_GAMEPAD_IMU_NOISE_PROFILING_PHASE_DURATION_NS   (SDL_GAMEPAD_IMU_NOISE_SETTLING_PERIOD_NS + SDL_GAMEPAD_IMU_NOISE_EVALUATION_PERIOD_NS)
 #define SDL_GAMEPAD_IMU_CALIBRATION_PHASE_DURATION_NS       (5 * SDL_NS_PER_SECOND)
@@ -222,12 +222,11 @@ void ResetGyroOrientation(IMUState *imustate)
 void CalibrationPhase_NoiseProfiling(IMUState *imustate)
 {
     /* If we have really large movement (i.e. greater than a fraction of G), then we want to start noise evaluation over. The frontend will warn the user to put down the controller. */
-    const float flAbsoluteMaxAccelerationG = 0.125f;
-    if (imustate->accelerometer_length_squared > (flAbsoluteMaxAccelerationG * flAbsoluteMaxAccelerationG) ) {
+    if (imustate->accelerometer_length_squared > ACCELEROMETER_MAX_NOISE_G_SQ) {
         BeginNoiseCalibrationPhase(imustate);
         return;
     }
-    
+
     Uint64 now = SDL_GetTicksNS();
     Uint64 delta_ns = now - imustate->calibration_phase_start_time_ticks_ns;
 
@@ -1433,7 +1432,7 @@ static void HandleGamepadGyroEvent(SDL_Event *event)
 /* Two strategies for evaluating polling rate - one based on a fixed packet count, and one using a fixed time window.
  * Smaller values in either will give you a more responsive polling rate estimate, but this may fluctuate more.
  * Larger values in either will give you a more stable average but they will require more time to evaluate.
- * Generally, wired connections tend to give much more stable 
+ * Generally, wired connections tend to give much more stable
  */
 /* #define SDL_USE_FIXED_PACKET_COUNT_FOR_ESTIMATION */
 #define SDL_GAMEPAD_IMU_MIN_POLLING_RATE_ESTIMATION_COUNT 2048
@@ -1479,7 +1478,7 @@ static void UpdateGamepadOrientation( Uint64 delta_time_ns )
 static void HandleGamepadSensorEvent( SDL_Event* event )
 {
     if (!controller)
-        return;   
+        return;
 
     if (controller->id != event->gsensor.which)
         return;
@@ -1504,7 +1503,7 @@ static void HandleGamepadSensorEvent( SDL_Event* event )
 
         /* Show how far we are through the current phase. When off, just default to zero progress */
         Uint64 now = SDL_GetTicksNS();
-        float duration = 0.0f;
+        Uint64 duration = 0;
         if (controller->imu_state->calibration_phase == GYRO_CALIBRATION_PHASE_NOISE_PROFILING) {
             duration = SDL_GAMEPAD_IMU_NOISE_PROFILING_PHASE_DURATION_NS;
         } else if (controller->imu_state->calibration_phase == GYRO_CALIBRATION_PHASE_DRIFT_PROFILING) {
@@ -1512,7 +1511,7 @@ static void HandleGamepadSensorEvent( SDL_Event* event )
         }
 
         Uint64 delta_ns = now - controller->imu_state->calibration_phase_start_time_ticks_ns;
-        float drift_calibration_progress_frac = duration > 0.0f ? ((float)delta_ns / (float)duration) : 0.0f;
+        float drift_calibration_progress_fraction = duration > 0.0f ? ((float)delta_ns / (float)duration) : 0.0f;
 
         int reported_polling_rate_hz = sensorTimeStampDelta_ns > 0 ? (int)(SDL_NS_PER_SECOND / sensorTimeStampDelta_ns) : 0;
 
@@ -1524,10 +1523,9 @@ static void HandleGamepadSensorEvent( SDL_Event* event )
             reported_polling_rate_hz,
             controller->imu_state->imu_estimated_sensor_rate,
             controller->imu_state->calibration_phase,
-            drift_calibration_progress_frac,
+            drift_calibration_progress_fraction,
             controller->imu_state->accelerometer_length_squared,
             controller->imu_state->accelerometer_tolerance_squared
-
         );
 
         /* Also show the gyro correction next to the gyro speed - this is useful in turntable tests as you can use a turntable to calibrate for drift, and that drift correction is functionally the same as the turn table speed (ignoring drift) */