calculate constraint softness dynamically

src/app.c

@@ -335,9 +335,8 @@ void app_entry_point(struct string args_str)
     struct mixer_startup_receipt mixer_sr = mixer_startup();
     struct sound_startup_receipt sound_sr = sound_startup(&work_sr, &asset_cache_sr, &resource_sr);
     struct draw_startup_receipt draw_sr = draw_startup(&renderer_sr, &font_sr);
-    struct phys_startup_receipt phys_sr = phys_startup();
     struct sim_startup_receipt sim_sr = sim_startup();
-    struct user_startup_receipt user_sr = user_startup(&work_sr, &renderer_sr, &font_sr, &sprite_sr, &draw_sr, &asset_cache_sr, &sound_sr, &mixer_sr, &phys_sr, &host_sr, &sim_sr, connect_address, &window);
+    struct user_startup_receipt user_sr = user_startup(&work_sr, &renderer_sr, &font_sr, &sprite_sr, &draw_sr, &asset_cache_sr, &sound_sr, &mixer_sr, &host_sr, &sim_sr, connect_address, &window);
     struct playback_startup_receipt playback_sr = playback_startup(&mixer_sr);
 
     (UNUSED)user_sr;

src/config.h

@@ -57,8 +57,13 @@
 #define SIM_SPAWN_TESTENT 0
 #define SIM_PLAYER_AIM 1
 
+#if 0
 # define SIM_MAX_LINEAR_VELOCITY 500
 # define SIM_MAX_ANGULAR_VELOCITY (TAU * 20)
+#else
+# define SIM_MAX_LINEAR_VELOCITY F32_INFINITY
+# define SIM_MAX_ANGULAR_VELOCITY F32_INFINITY
+#endif
 
 #define COLLIDER_DEBUG 0
 #define COLLIDER_DEBUG_DETAILED 1

src/phys.c

@@ -6,36 +6,6 @@
 #include "space.h"
 #include "uid.h"
 
-GLOBAL struct {
-    /* Constants */
-    struct math_spring_result contact_softness;
-    struct math_spring_result mouse_joint_linear_softness;
-    struct math_spring_result mouse_joint_angular_softness;
-} G = ZI, DEBUG_ALIAS(G, G_phys);
-
-/* ========================== *
- * Startup
- * ========================== */
-
-struct phys_startup_receipt phys_startup(void)
-{
-    /* Initialize constants */
-    const f32 substep_dt = (1.f / ((f32)SIM_TICKS_PER_SECOND * (f32)SIM_PHYSICS_SUBSTEPS));
-
-    const f32 contact_frequency = (1.f / substep_dt) / 8.f;
-    const f32 contact_damping_ratio = 10;
-    G.contact_softness = math_spring(contact_frequency, contact_damping_ratio, substep_dt);
-
-    const f32 mouse_joint_linear_frequency = 5.0f;
-    const f32 mouse_joint_linear_damping_ratio = 0.7f;
-    const f32 mouse_joint_angular_frequency = 0.5f;
-    const f32 mouse_joint_angular_damping_ratio = 0.1f;
-    G.mouse_joint_linear_softness = math_spring(mouse_joint_linear_frequency, mouse_joint_linear_damping_ratio, substep_dt);
-    G.mouse_joint_angular_softness = math_spring(mouse_joint_angular_frequency, mouse_joint_angular_damping_ratio, substep_dt);
-
-    return (struct phys_startup_receipt) { 0 };
-}
-
 /* ========================== *
  * Contact
  * ========================== */
@@ -173,7 +143,6 @@ void phys_create_and_update_contacts(struct phys_step_ctx *ctx, f32 elapsed_dt,
                         contact = &constraint->points[constraint->num_points++];
                         MEMZERO_STRUCT(contact);
                         contact->id = id;
-                        constraint->softness = G.contact_softness;
                         constraint->pushout_velocity = 3.0f;
                     }
 
@@ -491,7 +460,9 @@ void phys_solve_contacts(struct phys_step_ctx *ctx, f32 dt, b32 apply_bias)
                     velocity_bias = separation / dt;
                 } else if (apply_bias) {
                     /* Soft constraint */
-                    struct math_spring_result softness = constraint->softness;
+                    const f32 spring_hz = 25;
+                    const f32 spring_damp = 10;
+                    struct math_spring_result softness = math_spring(spring_hz, spring_damp, dt);
                     f32 pushout_velocity = constraint->pushout_velocity;
                     mass_scale = softness.mass_scale;
                     impulse_scale = softness.impulse_scale;
@@ -562,6 +533,12 @@ void phys_solve_contacts(struct phys_step_ctx *ctx, f32 dt, b32 apply_bias)
  * Motor joint
  * ========================== */
 
+struct phys_motor_joint_def phys_motor_joint_def_init(void)
+{
+    struct phys_motor_joint_def def = ZI;
+    return def;
+}
+
 struct phys_motor_joint phys_motor_joint_from_def(struct phys_motor_joint_def def)
 {
     struct phys_motor_joint res = ZI;
@@ -750,14 +727,27 @@ void phys_solve_motor_joints(struct phys_step_ctx *ctx, f32 dt)
  * Mouse joint
  * ========================== */
 
+struct phys_mouse_joint_def phys_mouse_joint_def_init(void)
+{
+    struct phys_mouse_joint_def def = ZI;
+    def.linear_spring_hz = 5.0f;
+    def.linear_spring_damp = 0.7f;
+    def.angular_spring_hz = 5.0f;
+    def.angular_spring_damp = 0.1f;
+    def.max_force = 1000.0f;
+    return def;
+}
+
 struct phys_mouse_joint phys_mouse_joint_from_def(struct phys_mouse_joint_def def)
 {
     struct phys_mouse_joint res = ZI;
     res.target = def.target;
     res.point_local_start = def.point_local_start;
     res.point_local_end = def.point_local_end;
-    res.linear_softness = G.mouse_joint_linear_softness;
+    res.linear_spring_hz = def.linear_spring_hz;
-    res.angular_softness = G.mouse_joint_angular_softness;
+    res.linear_spring_damp = def.linear_spring_damp;
+    res.angular_spring_hz = def.linear_spring_hz;
+    res.angular_spring_damp = def.angular_spring_damp;
     res.max_force = def.max_force;
     return res;
 }
@@ -851,7 +841,7 @@ void phys_solve_mouse_joints(struct phys_step_ctx *ctx, f32 dt)
 
             /* Angular impulse */
             {
-                struct math_spring_result softness = joint->angular_softness;
+                struct math_spring_result softness = math_spring(joint->angular_spring_hz, joint->angular_spring_damp, dt);
                 f32 mass_scale = softness.mass_scale;
                 f32 impulse_scale = softness.impulse_scale;
                 f32 impulse = mass_scale * (-w / inv_i) - impulse_scale * joint->angular_impulse;
@@ -871,7 +861,7 @@ void phys_solve_mouse_joints(struct phys_step_ctx *ctx, f32 dt)
                 struct v2 vcp = v2_sub(point_start, xf.og);
                 struct v2 separation = v2_sub(point_start, point_end);
 
-                struct math_spring_result softness = joint->linear_softness;
+                struct math_spring_result softness = math_spring(joint->linear_spring_hz, joint->linear_spring_damp, dt);
                 struct v2 bias = v2_mul(separation, softness.bias_rate);
                 f32 mass_scale = softness.mass_scale;
                 f32 impulse_scale = softness.impulse_scale;

src/phys.h

@@ -29,13 +29,6 @@ struct phys_step_ctx {
     phys_collision_callback_func *collision_callback;
 };
 
-/* ========================== *
- * Startup
- * ========================== */
-
-struct phys_startup_receipt { i32 _; };
-struct phys_startup_receipt phys_startup(void);
-
 /* ========================== *
  * Contact
  * ========================== */
@@ -76,7 +69,6 @@ struct phys_contact_constraint {
 
     f32 friction;
 
-    struct math_spring_result softness;
     f32 pushout_velocity;
 };
 
@@ -134,6 +126,7 @@ struct phys_motor_joint {
     f32 angular_mass;
 };
 
+struct phys_motor_joint_def phys_motor_joint_def_init(void);
 struct phys_motor_joint phys_motor_joint_from_def(struct phys_motor_joint_def def);
 void phys_prepare_motor_joints(struct phys_step_ctx *ctx);
 void phys_warm_start_motor_joints(struct phys_step_ctx *ctx);
@@ -147,6 +140,10 @@ struct phys_mouse_joint_def {
     struct sim_ent_id target;
     struct v2 point_local_start;
     struct v2 point_local_end;
+    f32 linear_spring_hz;
+    f32 linear_spring_damp;
+    f32 angular_spring_hz;
+    f32 angular_spring_damp;
     f32 max_force;
 };
 
@@ -154,8 +151,10 @@ struct phys_mouse_joint {
     struct sim_ent_id target;
     struct v2 point_local_start;
     struct v2 point_local_end;
-    struct math_spring_result linear_softness;
+    f32 linear_spring_hz;
-    struct math_spring_result angular_softness;
+    f32 linear_spring_damp;
+    f32 angular_spring_hz;
+    f32 angular_spring_damp;
     f32 max_force;
 
     f32 inv_m;
@@ -167,6 +166,7 @@ struct phys_mouse_joint {
     struct xform linear_mass_xf;
 };
 
+struct phys_mouse_joint_def phys_mouse_joint_def_init(void);
 struct phys_mouse_joint phys_mouse_joint_from_def(struct phys_mouse_joint_def def);
 void phys_prepare_mouse_joints(struct phys_step_ctx *ctx);
 void phys_warm_start_mouse_joints(struct phys_step_ctx *ctx);

src/renderer_d3d11.c

@@ -480,6 +480,7 @@ struct renderer_startup_receipt renderer_startup(struct sys_window *window)
             .BufferUsage = DXGI_USAGE_RENDER_TARGET_OUTPUT,
             .BufferCount = 2,
             .Scaling = DXGI_SCALING_NONE,
+            .Flags = 0,
 
             /* More efficient FLIP presentation model.
              * Windows 10 allows to use DXGI_SWAP_EFFECT_FLIP_DISCARD

src/sim_step.c

@@ -250,8 +250,10 @@ INTERNAL void spawn_test_entities2(struct sim_ent *parent, struct v2 pos)
         sim_ent_enable_prop(e, SEPROP_DYNAMIC);
         e->mass_unscaled = 100;
         e->inertia_unscaled = 50;
+#if 0
         e->linear_ground_friction = 100;
         e->angular_ground_friction = 50;
+#endif
     }
 #endif
 
@@ -1058,7 +1060,7 @@ void sim_step(struct sim_step_ctx *ctx)
                 sim_ent_enable_prop(joint_ent, SEPROP_ACTIVE);
                 ent->move_joint = joint_ent->id;
 
-                struct phys_motor_joint_def def = ZI;
+                struct phys_motor_joint_def def = phys_motor_joint_def_init();
                 def.e0 = joint_ent->id;  /* Re-using joint entity as e0 */
                 def.e1 = ent->id;
                 def.correction_rate = 0;
@@ -1099,7 +1101,7 @@ void sim_step(struct sim_step_ctx *ctx)
                 sim_ent_enable_prop(joint_ent, SEPROP_ACTIVE);
                 ent->aim_joint = joint_ent->id;
 
-                struct phys_motor_joint_def def = ZI;
+                struct phys_motor_joint_def def = phys_motor_joint_def_init();
                 def.e0 = joint_ent->id;  /* Re-using joint entity as e0 */
                 def.e1 = ent->id;
                 def.max_force = 0;
@@ -1184,7 +1186,7 @@ void sim_step(struct sim_step_ctx *ctx)
 
         struct sim_ent *joint_ent = sim_ent_from_id(world, ent->ground_friction_joint);
 
-        struct phys_motor_joint_def def = ZI;
+        struct phys_motor_joint_def def = phys_motor_joint_def_init();
         def.e0 = root->id;
         def.e1 = ent->id;
         def.correction_rate = 0;
@@ -1239,7 +1241,7 @@ void sim_step(struct sim_step_ctx *ctx)
                 struct xform xf = sim_ent_get_xform(target_ent);
                 f32 mass = target_ent->mass_unscaled * math_fabs(xform_get_determinant(xf));
 
-                struct phys_mouse_joint_def def = ZI;
+                struct phys_mouse_joint_def def = phys_mouse_joint_def_init();
                 def.target = target_ent->id;
                 if (sim_ent_id_eq(joint_ent->mouse_joint_data.target, target_ent->id)) {
                     def.point_local_start = joint_ent->mouse_joint_data.point_local_start;

src/user.c

@@ -188,7 +188,6 @@ struct user_startup_receipt user_startup(struct work_startup_receipt *work_sr,
                                          struct asset_cache_startup_receipt *asset_cache_sr,
                                          struct sound_startup_receipt *sound_sr,
                                          struct mixer_startup_receipt *mixer_sr,
-                                         struct phys_startup_receipt *phys_sr,
                                          struct host_startup_receipt *host_sr,
                                          struct sim_startup_receipt *sim_sr,
                                          struct string connect_address_str,
@@ -202,7 +201,6 @@ struct user_startup_receipt user_startup(struct work_startup_receipt *work_sr,
     (UNUSED)asset_cache_sr;
     (UNUSED)sound_sr;
     (UNUSED)mixer_sr;
-    (UNUSED)phys_sr;
     (UNUSED)host_sr;
     (UNUSED)sim_sr;
 

src/user.h

@@ -10,7 +10,6 @@ struct draw_startup_receipt;
 struct asset_cache_startup_receipt;
 struct sound_startup_receipt;
 struct mixer_startup_receipt;
-struct phys_startup_receipt;
 struct host_startup_receipt;
 struct sim_startup_receipt;
 
@@ -66,7 +65,6 @@ struct user_startup_receipt user_startup(struct work_startup_receipt *work_sr,
                                          struct asset_cache_startup_receipt *asset_cache_sr,
                                          struct sound_startup_receipt *sound_sr,
                                          struct mixer_startup_receipt *mixer_sr,
-                                         struct phys_startup_receipt *phys_sr,
                                          struct host_startup_receipt *host_sr,
                                          struct sim_startup_receipt *sim_sr,
                                          struct string connect_address_str,