Rename filter() arguments to "input" and "output".

Rename delta, noise, and output state attributes to last_* for consistency.

1 files changed, 10 insertions, 12 deletions

diff --git a/ftnoir_filter_ewma2/ftnoir_filter_ewma2.cpp b/ftnoir_filter_ewma2/ftnoir_filter_ewma2.cpp
index 8520eb71..cdf18263 100644
--- a/ftnoir_filter_ewma2/ftnoir_filter_ewma2.cpp
+++ b/ftnoir_filter_ewma2/ftnoir_filter_ewma2.cpp
@@ -37,16 +37,15 @@ void FTNoIR_Filter::reset()
     timer.invalidate();
 }
 
-void FTNoIR_Filter::filter(const double *target_camera_position,
-                           double *new_camera_position)
+void FTNoIR_Filter::filter(const double *input, double *output)
 {
     // Start the timer and initialise filter state if it's not running.
     if (!timer.isValid()) {
         timer.start();
         for (int i=0;i<6;i++) {
-            output[i] = target_camera_position[i];
-            delta[i] = 0.0;
-            noise[i] = 0.0;
+            last_output[i] = input[i];
+            last_delta[i] = 0.0;
+            last_noise[i] = 0.0;
         }
     }
     // Get the time in seconds since last run and restart the timer.
@@ -57,13 +56,13 @@ void FTNoIR_Filter::filter(const double *target_camera_position,
     // Calculate the new camera position.
     for (int i=0;i<6;i++) {
         // Calculate the current and smoothed delta.
-        double new_delta = target_camera_position[i]-output[i];
-        delta[i] = delta_alpha*new_delta + (1.0-delta_alpha)*delta[i];
+        double delta = input[i] - last_output[i];
+        last_delta[i] = delta_alpha*delta + (1.0-delta_alpha)*last_delta[i];
         // Calculate the current and smoothed noise variance.
-        double new_noise = delta[i]*delta[i];
-        noise[i] = noise_alpha*new_noise + (1.0-noise_alpha)*noise[i];
+        double noise = last_delta[i]*last_delta[i];
+        last_noise[i] = noise_alpha*noise + (1.0-noise_alpha)*last_noise[i];
         // Normalise the noise between 0->1 for 0->9 variances (0->3 stddevs).
-        double norm_noise = std::min<double>(new_noise/(9.0*noise[i]), 1.0);
+        double norm_noise = std::min<double>(noise/(9.0*last_noise[i]), 1.0);
         // Calculate the smoothing 0.0->1.0 from the normalized noise.
         // TODO(abo): change kSmoothingScaleCurve to a float where 1.0 is sqrt(norm_noise).
         double smoothing = 1.0 - pow(norm_noise, s.kSmoothingScaleCurve/20.0);
@@ -73,8 +72,7 @@ void FTNoIR_Filter::filter(const double *target_camera_position,
         // Calculate the dynamic alpha.
         double alpha = dt/(dt + RC);
         // Calculate the new output position.
-        output[i] = alpha*target_camera_position[i] + (1.0-alpha)*output[i];
-        new_camera_position[i] = output[i];
+        output[i] = last_output[i] = alpha*input[i] + (1.0-alpha)*last_output[i];
     }
 }