Camera: Improve arm inertia

diff --git a/src/camera.cpp b/src/camera.cpp
index 2de76da193e49871d6977418d9f54917da24eed3..40fd6276739f4731a8cca4ebde6d63243ef1c4a7 100644 (file)
--- a/src/camera.cpp
+++ b/src/camera.cpp
@@ -195,39 +195,51 @@ void Camera::step(f32 dtime)
        }
 }
 
-void Camera::addArmInertia(f32 player_yaw, f32 frametime)
+static inline v2f dir(const v2f &pos_dist)
 {
-       if (m_timer.X == 0.0f) {
-               // In the limit case where timer is 0 set a static velocity (generic case divide by zero)
-               m_cam_vel.X = 1.0001f;
+       f32 x = pos_dist.X - 55.0f;
+       f32 y = pos_dist.Y + 35.0f;
+
+       f32 x_abs = std::fabs(x);
+       f32 y_abs = std::fabs(y);
+
+       if (x_abs >= y_abs) {
+               y *= (1.0f / x_abs);
+               x /= x_abs;
        }
-       else
-               m_cam_vel.X = std::fabs((m_last_cam_pos.X - player_yaw) / m_timer.X) * 0.01f;
 
-       if (m_timer.Y == 0.0f) {
-               // In the limit case where timer is 0 set a static velocity (generic case divide by zero)
-               m_cam_vel.Y = 1.0001f;
+       if (y_abs >= x_abs) {
+               x *= (1.0f / y_abs);
+               y /= y_abs;
        }
-       else
-               m_cam_vel.Y = std::fabs((m_last_cam_pos.Y - m_camera_direction.Y) / m_timer.Y);
+
+       return v2f(std::fabs(x), std::fabs(y));
+}
+
+void Camera::addArmInertia(f32 player_yaw, f32 frametime)
+{
+       m_cam_vel.X = std::fabs((m_last_cam_pos.X - player_yaw) / frametime) * 0.01f;
+       m_cam_vel.Y = std::fabs((m_last_cam_pos.Y - m_camera_direction.Y) / frametime);
 
        if (m_cam_vel.X > 1.0f || m_cam_vel.Y > 1.0f) {
                /*
-                  the arm moves when the camera moves fast enough.
+                   The arm moves relative to the camera speed,
+                   with an acceleration factor.
                */
 
                if (m_cam_vel.X > 1.0f) {
-                       m_timer.X = frametime;
-
                        if (m_cam_vel.X > m_cam_vel_old.X)
                                m_cam_vel_old.X = m_cam_vel.X;
 
-                       if (m_last_cam_pos.X > player_yaw)
+                       if (m_last_cam_pos.X > player_yaw) {
                                // right
+                               m_cam_vel.X -= std::fabs(55.0f - m_wieldmesh_offset.X) * 0.1f;
                                m_wieldmesh_offset.X -= (0.1f + frametime) * m_cam_vel.X;
-                       else
+                       } else {
                                // left
+                               m_cam_vel.X += std::fabs(55.0f - m_wieldmesh_offset.X) * 0.1f;
                                m_wieldmesh_offset.X += (0.1f + frametime) * m_cam_vel.X;
+                       }
 
                        if (m_last_cam_pos.X != player_yaw)
                                m_last_cam_pos.X = player_yaw;
@@ -236,47 +248,54 @@ void Camera::addArmInertia(f32 player_yaw, f32 frametime)
                }
 
                if (m_cam_vel.Y > 1.0f) {
-                       m_timer.Y = frametime;
-
                        if (m_cam_vel.Y > m_cam_vel_old.Y)
                                m_cam_vel_old.Y = m_cam_vel.Y;
 
-                       if (m_last_cam_pos.Y > m_camera_direction.Y)
+                       if (m_last_cam_pos.Y > m_camera_direction.Y) {
                                // down
+                               m_cam_vel.Y -= std::fabs(-35.0f - m_wieldmesh_offset.Y) * 0.1f;
                                m_wieldmesh_offset.Y += (0.1f + frametime) * m_cam_vel.Y;
-                       else
+                       } else {
                                // up
+                               m_cam_vel.Y += std::fabs(-35.0f - m_wieldmesh_offset.Y) * 0.1f;
                                m_wieldmesh_offset.Y -= (0.1f + frametime) * m_cam_vel.Y;
+                       }
 
                        if (m_last_cam_pos.Y != m_camera_direction.Y)
                                m_last_cam_pos.Y = m_camera_direction.Y;
 
                        m_wieldmesh_offset.Y = rangelim(m_wieldmesh_offset.Y, -45.0f, -30.0f);
                }
+
+               m_arm_dir = dir(m_wieldmesh_offset);
        } else {
                /*
-                  the arm now gets back to its default position when the camera stops.
+                   Now the arm gets back to its default position when the camera stops,
+                   following a vector, with a smooth deceleration factor.
                */
 
-               if (floor(m_wieldmesh_offset.X) == 55.0f) {
+               f32 acc_X = (m_cam_vel_old.X * (1.0f + (1.0f - m_arm_dir.X))) /
+                       (20.0f / std::fabs(55.0f - m_wieldmesh_offset.X));
+               f32 acc_Y = (m_cam_vel_old.Y * (1.0f + (1.0f - m_arm_dir.Y))) /
+                       (15.0f / std::fabs(-35.0f - m_wieldmesh_offset.Y));
+
+               if (std::fabs(55.0f - m_wieldmesh_offset.X) < 0.1f)
                        m_cam_vel_old.X = 0.0f;
-                       m_wieldmesh_offset.X = 55.0f;
-               }
 
                if (m_wieldmesh_offset.X > 55.0f)
-                       m_wieldmesh_offset.X -= (0.05f + frametime) * m_cam_vel_old.X;
+                       m_wieldmesh_offset.X -= (0.2f + frametime) * acc_X;
+
                if (m_wieldmesh_offset.X < 55.0f)
-                       m_wieldmesh_offset.X += (0.05f + frametime) * m_cam_vel_old.X;
+                       m_wieldmesh_offset.X += (0.2f + frametime) * acc_X;
 
-               if (floor(m_wieldmesh_offset.Y) == -35.0f) {
+               if (std::fabs(-35.0f - m_wieldmesh_offset.Y) < 0.1f)
                        m_cam_vel_old.Y = 0.0f;
-                       m_wieldmesh_offset.Y = -35.0f;
-               }
 
                if (m_wieldmesh_offset.Y > -35.0f)
-                       m_wieldmesh_offset.Y -= (0.05f + frametime) * m_cam_vel_old.Y;
+                       m_wieldmesh_offset.Y -= (0.1f + frametime) * acc_Y;
+
                if (m_wieldmesh_offset.Y < -35.0f)
-                       m_wieldmesh_offset.Y += (0.05f + frametime) * m_cam_vel_old.Y;
+                       m_wieldmesh_offset.Y += (0.1f + frametime) * acc_Y;
        }
 }
 
@@ -468,7 +487,7 @@ void Camera::update(LocalPlayer* player, f32 frametime, f32 busytime,
        m_cameranode->setAspectRatio(m_aspect);
        m_cameranode->setFOV(m_fov_y);
 
-       if (m_arm_inertia)
+       if (m_arm_inertia && frametime > 0.0f)
                addArmInertia(player->getYaw(), frametime);
 
        // Position the wielded item

diff --git a/src/camera.h b/src/camera.h
index 4b2d9d45ece7ec211501c2e2f928832b1afc3d61..f88f1cc94b97d36cce167f897e05ebd60a42a84e 100644 (file)
--- a/src/camera.h
+++ b/src/camera.h
@@ -191,7 +191,7 @@ private:
        v3s16 m_camera_offset;
 
        v2f m_wieldmesh_offset = v2f(55.0f, -35.0f);
-       v2f m_timer;
+       v2f m_arm_dir;
        v2f m_cam_vel;
        v2f m_cam_vel_old;
        v2f m_last_cam_pos;