Implement multibody joints and the new solver

1 files changed, 0 insertions, 65 deletions

diff --git a/src/dynamics/joint/spring_model.rs b/src/dynamics/joint/spring_model.rs
deleted file mode 100644
index c2c9ebd..0000000
--- a/src/dynamics/joint/spring_model.rs
+++ /dev/null
@@ -1,65 +0,0 @@
-use crate::math::Real;
-
-/// The spring-like model used for constraints resolution.
-#[derive(Copy, Clone, Debug, PartialEq, Eq)]
-#[cfg_attr(feature = "serde-serialize", derive(Serialize, Deserialize))]
-pub enum SpringModel {
-    /// No equation is solved.
-    Disabled,
-    /// The solved spring-like equation is:
-    /// `delta_velocity(t + dt) = stiffness / dt * (target_pos - pos(t)) + damping * (target_vel - vel(t))`
-    ///
-    /// Here the `stiffness` is the ratio of position error to be solved at each timestep (like
-    /// a velocity-based ERP), and the `damping` is the ratio of velocity error to be solved at
-    /// each timestep.
-    VelocityBased,
-    /// The solved spring-like equation is:
-    /// `acceleration(t + dt) = stiffness * (target_pos - pos(t)) + damping * (target_vel - vel(t))`
-    AccelerationBased,
-    /// The solved spring-like equation is:
-    /// `force(t + dt) = stiffness * (target_pos - pos(t + dt)) + damping * (target_vel - vel(t + dt))`
-    ForceBased,
-}
-
-impl Default for SpringModel {
-    fn default() -> Self {
-        SpringModel::VelocityBased
-    }
-}
-
-impl SpringModel {
-    /// Combines the coefficients used for solving the spring equation.
-    ///
-    /// Returns the new coefficients (stiffness, damping, inv_lhs_scale, keep_inv_lhs)
-    /// coefficients for the equivalent impulse-based equation. These new
-    /// coefficients must be used in the following way:
-    /// - `rhs = (stiffness * pos_err + damping * vel_err) / gamma`.
-    /// - `new_inv_lhs = gamma * if keep_inv_lhs { inv_lhs } else { 1.0 }`.
-    /// Note that the returned `gamma` will be zero if both `stiffness` and `damping` are zero.
-    pub fn combine_coefficients(
-        self,
-        dt: Real,
-        stiffness: Real,
-        damping: Real,
-    ) -> (Real, Real, Real, bool) {
-        match self {
-            SpringModel::VelocityBased => (stiffness * crate::utils::inv(dt), damping, 1.0, true),
-            SpringModel::AccelerationBased => {
-                let effective_stiffness = stiffness * dt;
-                let effective_damping = damping * dt;
-                // TODO: Using gamma behaves very badly for some reasons.
-                // Maybe I got the formulation wrong, so let's keep it to 1.0 for now,
-                // and get back to this later.
-                // let gamma = effective_stiffness * dt + effective_damping;
-                (effective_stiffness, effective_damping, 1.0, true)
-            }
-            SpringModel::ForceBased => {
-                let effective_stiffness = stiffness * dt;
-                let effective_damping = damping * dt;
-                let gamma = effective_stiffness * dt + effective_damping;
-                (effective_stiffness, effective_damping, gamma, false)
-            }
-            SpringModel::Disabled => return (0.0, 0.0, 0.0, false),
-        }
-    }
-}