Game: Fix camera spin after set_horizontal_look

builtin/settingtypes.txt

@@ -87,7 +87,8 @@
 
 [*General]
 
-#    Smooths rotation of camera, also called look or mouse smoothing. 0 to disable.
+#    Smooths rotation of camera, also called look or mouse smoothing.
+#    0.99 results in the smoothest transitions. 0 to disable.
 camera_smoothing (Camera smoothing) float 0.0 0.0 0.99
 
 #    Smooths rotation of camera when in cinematic mode, 0 to disable. Enter cinematic mode by using the key set in Change Keys.

src/client/game.cpp

@@ -1295,10 +1295,10 @@ void Game::run()
 		processUserInput(dtime);
 		// Update camera before player movement to avoid camera lag of one frame
 		updateCameraDirection(&cam_view_target, dtime);
-		cam_view.camera_yaw += (cam_view_target.camera_yaw -
-				cam_view.camera_yaw) * m_cache_cam_smoothing;
-		cam_view.camera_pitch += (cam_view_target.camera_pitch -
-				cam_view.camera_pitch) * m_cache_cam_smoothing;
+		// Previously, cam_smoothing likely assumed 60 FPS, thus factor 60.
+		float factor = dtime * 60.0f * m_cache_cam_smoothing;
+		wrappedApproachFactor(cam_view.camera_yaw, cam_view_target.camera_yaw, factor, 360.f);
+		wrappedApproachFactor(cam_view.camera_pitch, cam_view_target.camera_pitch, factor, 360.f);
 		updatePlayerControl(cam_view);
 
 		updatePauseState();
@@ -4399,6 +4399,7 @@ void Game::readSettings()
 	else
 		m_cache_cam_smoothing = 1 - g_settings->getFloat("camera_smoothing");
 
+	// 1: instant update, 0.01: very smooth
 	m_cache_cam_smoothing = rangelim(m_cache_cam_smoothing, 0.01f, 1.0f);
 	m_cache_mouse_sensitivity = rangelim(m_cache_mouse_sensitivity, 0.001, 100.0);
 

src/client/game.h

@@ -39,8 +39,8 @@ struct RunStats {
 };
 
 struct CameraOrientation {
-	f32 camera_yaw;    // "right/left"
-	f32 camera_pitch;  // "up/down"
+	f32 camera_yaw;    // "right/left" in degrees
+	f32 camera_pitch;  // "up/down" in degrees
 };
 
 

src/util/numeric.cpp

@@ -187,6 +187,56 @@ s16 adjustDist(s16 dist, float zoom_fov)
 	return std::round(adjustDist((float)dist, zoom_fov));
 }
 
+void paging(u32 length, u32 page, u32 pagecount, u32 &minindex, u32 &maxindex)
+{
+	if (length < 1 || pagecount < 1 || page < 1 || page > pagecount) {
+		// Special cases or invalid parameters
+		minindex = maxindex = 0;
+	} else if(pagecount <= length) {
+		// Less pages than entries in the list:
+		// Each page contains at least one entry
+		minindex = (length * (page-1) + (pagecount-1)) / pagecount;
+		maxindex = (length * page + (pagecount-1)) / pagecount;
+	} else {
+		// More pages than entries in the list:
+		// Make sure the empty pages are at the end
+		if (page < length) {
+			minindex = page-1;
+			maxindex = page;
+		} else {
+			minindex = 0;
+			maxindex = 0;
+		}
+	}
+}
+
+void wrappedApproachShortest(float &current, float target, float stepsize, float maximum)
+{
+	float delta = target - current;
+	if (delta < 0)
+		delta += maximum;
+
+	if (delta > stepsize && maximum - delta > stepsize) {
+		current += (delta < maximum / 2) ? stepsize : -stepsize;
+		if (current >= maximum)
+			current -= maximum;
+	} else {
+		current = target;
+	}
+}
+
+void wrappedApproachFactor(float &current, float target, float factor, float maximum)
+{
+	float delta = fmod(target - current, maximum); // range ]-max, +max[
+	if (delta < -maximum * 0.5f)
+		delta += maximum; // -340° -> +20°
+	else if (delta > maximum * 0.5f)
+		delta -= maximum; // +340° -> -20°
+
+	current += delta * rangelim(factor, 0.0f, 1.0f);
+}
+
+
 void setPitchYawRollRad(core::matrix4 &m, const v3f &rot)
 {
 	f64 a1 = rot.Z, a2 = rot.X, a3 = rot.Y;

src/util/numeric.h

@@ -384,35 +384,7 @@ class IntervalLimiter
 
 	Ensures 0 <= minindex <= maxindex <= length.
 */
-inline void paging(u32 length, u32 page, u32 pagecount, u32 &minindex, u32 &maxindex)
-{
-	if (length < 1 || pagecount < 1 || page < 1 || page > pagecount) {
-		// Special cases or invalid parameters
-		minindex = maxindex = 0;
-	} else if(pagecount <= length) {
-		// Less pages than entries in the list:
-		// Each page contains at least one entry
-		minindex = (length * (page-1) + (pagecount-1)) / pagecount;
-		maxindex = (length * page + (pagecount-1)) / pagecount;
-	} else {
-		// More pages than entries in the list:
-		// Make sure the empty pages are at the end
-		if (page < length) {
-			minindex = page-1;
-			maxindex = page;
-		} else {
-			minindex = 0;
-			maxindex = 0;
-		}
-	}
-}
-
-inline float cycle_shift(float value, float by = 0, float max = 1)
-{
-    if (value + by < 0)   return value + by + max;
-    if (value + by > max) return value + by - max;
-    return value + by;
-}
+void paging(u32 length, u32 page, u32 pagecount, u32 &minindex, u32 &maxindex);
 
 inline bool is_power_of_two(u32 n)
 {
@@ -431,24 +403,15 @@ inline u32 npot2(u32 orig) {
 	return orig + 1;
 }
 
-// Gradual steps towards the target value in a wrapped (circular) system
-// using the shorter of both ways
-template<typename T>
-inline void wrappedApproachShortest(T &current, const T target, const T stepsize,
-	const T maximum)
-{
-	T delta = target - current;
-	if (delta < 0)
-		delta += maximum;
+/// Linear interpolation of two values in a wrapped range (radians, degrees)
+/// @param stepsize Maximal step size between function calls
+/// @param maximum Usually 360.0f or (2 * M_PI)
+void wrappedApproachShortest(float &current, float target, float stepsize, float maximum);
 
-	if (delta > stepsize && maximum - delta > stepsize) {
-		current += (delta < maximum / 2) ? stepsize : -stepsize;
-		if (current >= maximum)
-			current -= maximum;
-	} else {
-		current = target;
-	}
-}
+/// Exponential interpolation of two values in a wrapped range (radians, degrees)
+/// @param factor Interpolation factor in range [0,1]
+/// @param maximum Usually 360.0f or (2 * M_PI)
+void wrappedApproachFactor(float &current, float target, float factor, float maximum);
 
 void setPitchYawRollRad(core::matrix4 &m, const v3f &rot);