create ground friction joint dynamically

src/config.h

@@ -37,11 +37,8 @@
 #define GAME_PHYSICS_ENABLE_RELAXATION 1
 
 #define USER_DRAW_MENKOWSKI 0
-#define GAME_PHYSICS_ENABLE_GROUND_FRICTION 1
 #define GAME_PHYSICS_ENABLE_COLLISION 1
-#define GAME_SPAWN_LOTS 0
 #define GAME_SPAWN_TESTENT 0
-#define GAME_SPAWN_BOX 0
 #define GAME_PLAYER_AIM 1
 
 //#define GAME_MAX_LINEAR_VELOCITY 500

src/entity.h

@@ -282,6 +282,7 @@ struct entity {
     f32 mass_unscaled;      /* Mass of entity in kg before any transformations */
     f32 inertia_unscaled;   /* Inertia of entity in kg*m^2 before any transformations */
 
+    struct entity_handle ground_friction_joint;
     f32 linear_ground_friction;
     f32 angular_ground_friction;
 

src/game.c

@@ -296,18 +296,12 @@ INTERNAL void reset_world(void)
 
 /* TODO: Remove this */
 
-INTERNAL void spawn_test_entities(f32 offset)
+INTERNAL void spawn_test_entities(void)
 {
     struct entity *root = entity_from_handle(G.tick.entity_store, G.tick.entity_store->root);
     root->mass_unscaled = F32_INFINITY;
     root->inertia_unscaled = F32_INFINITY;
 
-    //const f32 offset_all = -20000;
-    //const f32 offset_all = -5000;
-    const f32 offset_all = 0;
-    (UNUSED)offset;
-    (UNUSED)offset_all;
-
     /* Player */
     struct entity *player_ent = entity_nil();
     //if (!G.extra_spawn) {
@@ -317,9 +311,6 @@ INTERNAL void spawn_test_entities(f32 offset)
 
         struct v2 pos = V2(1, -1);
 
-        pos = v2_add(pos, V2(0, offset));
-        pos = v2_add(pos, V2(0, offset_all));
-
         //struct v2 size = V2(0.5, 0.5);
         //struct v2 size = V2(0.5, 0.25);
         struct v2 size = V2(1.0, 1.0);
@@ -350,13 +341,13 @@ INTERNAL void spawn_test_entities(f32 offset)
         //e->sprite_span_name = STR("idle.one_handed");
         e->sprite_span_name = STR("idle.two_handed");
 
-
         struct xform xf = XFORM_TRS(.t = pos, .r = r, .s = size);
         //xf.bx.y = -1.f;
 
         entity_set_xform(e, xf);
 
-        e->linear_ground_friction = 250;e->angular_ground_friction = 200;
+        e->linear_ground_friction = 250;
+        e->angular_ground_friction = 200;
 
         //e->control_force = 500;
         e->control_force = 500;
@@ -367,99 +358,11 @@ INTERNAL void spawn_test_entities(f32 offset)
         entity_enable_prop(e, ENTITY_PROP_PHYSICAL);
 
         player_ent = e;
-
-#if 1
-        {
-            struct entity *joint_ent = entity_alloc(root);
-            entity_enable_prop(joint_ent, ENTITY_PROP_PHYSICAL);
-            entity_enable_prop(joint_ent, ENTITY_PROP_MOTOR_JOINT);
-            entity_enable_prop(joint_ent, ENTITY_PROP_ACTIVE);
-
-            struct motor_joint_def def = ZI;
-            def.e0 = root->handle;
-            def.e1 = e->handle;
-            def.correction_rate = 0;
-            def.max_force = e->linear_ground_friction;
-            def.max_torque = e->angular_ground_friction;
-            joint_ent->motor_joint_data = motor_joint_from_def(def);
-        }
-#endif
-
-
-
-
-
-
-
     }
 
-#if GAME_SPAWN_TESTENT
+    /* Player weapon */
-    {
-        struct entity *e = entity_alloc(root);
-
-#if 0
-        //struct v2 pos = V2(0.25, -10);
-        //struct v2 pos = V2(0.25, -7);
-        //struct v2 pos = V2(0.25, -5.27);
-        struct v2 pos = V2(0.5, -1);
-
-        pos = v2_add(pos, V2(0, offset));
-        pos = v2_add(pos, V2(0, offset_all));
-
-        //struct v2 size = V2(1, 1);
-        struct v2 size = V2(0.5, 0.5);
-        //struct v2 size = V2(1.0, 0.5);
-        //f32 r = PI;
-        //f32 r = PI / 4;
-        //f32 r = PI / 3;
-        //f32 r = 0.05;
-        //f32 r = PI / 2;
-        f32 r = 0;
-
-        struct xform xf = XFORM_TRS(.t = pos, .r = r, .s = size);
-#else
-        struct xform xf = { .bx = {-0.108915359, -0.488007843}, .by = {0.488007843, -0.108915359}, .og = {1.62569654, -0.750172377}, };
-#endif
-
-
-        entity_set_xform(e, xf);
-
-        //e->sprite = sprite_tag_from_path(STR("res/graphics/tim.ase"));
-        e->sprite = sprite_tag_from_path(STR("res/graphics/box.ase"));
-        //e->sprite_span_name = STR("idle.unarmed");
-        //e->sprite_span_name = STR("idle.one_handed");
-        e->sprite_span_name = STR("idle.two_handed");
-
-        //entity_enable_prop(e, ENTITY_PROP_PLAYER_CONTROLLED);
-        //e->control_force = 4500;
-        //e->control_force = 1200;
-        e->control_force = 250;
-        e->control_torque = 10;
-        e->control.focus = V2(0, -1);
-
-        entity_enable_prop(e, ENTITY_PROP_PHYSICAL);
-        e->mass_unscaled = 100;
-        //e->inertia_unscaled = F32_INFINITY;
-        e->inertia_unscaled = 25;
-        e->linear_ground_friction = 1000;
-        e->angular_ground_friction = 100;
-
-        entity_enable_prop(e, ENTITY_PROP_TEST);
-    }
-#endif
-
-    /* Weapon */
-#if 1
     if (player_ent->valid) {
-#if 0
-        struct v2 pos = V2(1, 0);
-        struct v2 size = V2(1, 1);
-        f32 r = PI / 4;
-        struct entity *e = entity_alloc(root);
-#else
         struct entity *e = entity_alloc(player_ent);
-#endif
-
         e->sprite = sprite_tag_from_path(STR("res/graphics/gun.ase"));
 
         entity_enable_prop(e, ENTITY_PROP_ATTACHED);
@@ -470,44 +373,6 @@ INTERNAL void spawn_test_entities(f32 offset)
 
         player_ent->equipped = e->handle;
     }
-#endif
-
-    /* Box */
-#if GAME_SPAWN_BOX
-    if (!G.extra_spawn) {
-        struct v2 pos = V2(0.5, 0);
-        //struct v2 pos = V2(0.5, 29);
-        //struct v2 pos = V2(0.5, 24);
-        //struct v2 pos = V2(1, -1);
-#if 0
-        struct v2 size = V2(1, 1);
-#else
-        //struct v2 size = V2(5000, 1);
-        struct v2 size = V2(50, 1);
-        //struct v2 size = V2(1, 1);
-#endif
-        //f32 rot = PI / 4;
-        f32 rot = 0;
-        struct entity *e = entity_alloc(root);
-
-        pos = v2_add(pos, V2(0, offset_all));
-
-        e->sprite = sprite_tag_from_path(STR("res/graphics/box.ase"));
-
-        entity_enable_prop(e, ENTITY_PROP_PHYSICAL);
-#if 0
-        e->mass_unscaled = 500;
-        e->inertia_unscaled = 500;
-#else
-        e->mass_unscaled = F32_INFINITY;
-        e->inertia_unscaled = F32_INFINITY;
-#endif
-        e->linear_ground_friction = 10000;
-        e->angular_ground_friction = 10000;
-
-        entity_set_xform(e, XFORM_TRS(.t = pos, .s = size, .r = rot));
-    }
-#endif
 
     /* Camera */
     if (!G.extra_spawn && player_ent->valid) {
@@ -1202,6 +1067,7 @@ INTERNAL void create_mouse_joints(struct game_cmd_array game_cmds)
             entity_enable_prop(joint_ent, ENTITY_PROP_MOUSE_JOINT);
             entity_enable_prop(joint_ent, ENTITY_PROP_ACTIVE);
         }
+
         struct mouse_joint *joint = &joint_ent->mouse_joint_data;
 
         struct xform xf = entity_get_xform(target_ent);
@@ -1534,7 +1400,7 @@ INTERNAL void game_update(struct game_cmd_array game_cmds)
         static b32 run = 0;
         if (!run) {
             run = 1;
-            spawn_test_entities(0);
+            spawn_test_entities();
         }
     }
 
@@ -1562,14 +1428,7 @@ INTERNAL void game_update(struct game_cmd_array game_cmds)
             case GAME_CMD_KIND_SPAWN_TEST:
             {
                 logf_info("Spawning (test)");
-#if GAME_SPAWN_LOTS
+                spawn_test_entities();
-//#if 0
-                for (u32 i = 0; i < 50; ++i) {
-                    spawn_test_entities(-(f32)i);
-                }
-#else
-                spawn_test_entities(0);
-#endif
             } break;
             default: break;
         };
@@ -1892,7 +1751,8 @@ INTERNAL void game_update(struct game_cmd_array game_cmds)
                 bullet->bullet_src = ent->handle;
                 bullet->bullet_src_pos = rel_pos;
                 bullet->bullet_src_dir = rel_dir;
-                bullet->bullet_impulse = 0.25f;
+                bullet->bullet_impulse = 0.1f;
+                //bullet->bullet_impulse = 0.25f;
                 //bullet->bullet_impulse = 1.f;
                 bullet->mass_unscaled = 0.04f;
                 bullet->inertia_unscaled = 0.00001f;
@@ -2042,76 +1902,30 @@ INTERNAL void game_update(struct game_cmd_array game_cmds)
      * Create ground friction force (gravity)
      * ========================== */
 
-#if 0
-#if GAME_PHYSICS_ENABLE_GROUND_FRICTION
-#if 0
-     /* TODO: Do this globally rather than creating entities for constant forces */
-    for (u64 entity_index = 0; entity_index < store->reserved; ++entity_index) {
-        struct entity *ent = &store->entities[entity_index];
-        if (!entity_is_valid_and_active(ent)) continue;
-        if (!entity_has_prop(ent, ENTITY_PROP_PHYSICAL)) continue;
-        if (ent->linear_ground_friction != 0) {
-            /* Linear velocity */
-            {
-                struct v2 linear_velocity = ent->linear_velocity;
-                if (!v2_is_zero(linear_velocity)) {
-                    /* FIXME: Incorrect behavior at low FPS & low entity density */
-                    const f32 clamp_epsilon = 0.01;
-                    f32 linear_velocity_len = v2_len(linear_velocity);
-                    if (linear_velocity_len >= clamp_epsilon) {
-                        f32 force_len = -linear_velocity_len * ent->linear_ground_friction;
-                        struct v2 force = v2_mul(v2_norm(linear_velocity), force_len);
-                        entity_apply_force_to_center(ent, force);
-                    } else {
-                        /* If linear_velocity is below clamp_epsilon, stop entity movement. */
-                        struct xform xf = entity_get_xform(ent);
-                        f32 mass = ent->mass_unscaled * math_fabs(xform_get_determinant(xf));
-                        struct v2 impulse = v2_mul(v2_neg(linear_velocity), mass);
-                        entity_apply_linear_impulse_to_center(ent, impulse);
-                    }
-                }
-            }
-        }
-        if (ent->angular_ground_friction != 0) {
-            /* Angular velocity */
-            {
-                f32 angular_velocity = ent->angular_velocity;
-                if (angular_velocity != 0) {
-                    /* FIXME: Incorrect (just testing) */
-                    const f32 clamp_epsilon = 0.001;
-                    if (math_fabs(angular_velocity) >= clamp_epsilon) {
-                        f32 torque = -angular_velocity * ent->angular_ground_friction;
-                        entity_apply_torque(ent, torque);
-                    } else {
-                        /* If angular_velocity is below clamp_epsilon, stop entity movement. */
-                        struct xform xf = entity_get_xform(ent);
-                        f32 inertia = ent->inertia_unscaled * math_fabs(xform_get_determinant(xf));
-                        f32 impulse = -angular_velocity * inertia;
-                        entity_apply_angular_impulse(ent, impulse);
-                    }
-                }
-            }
-        }
-    }
-#else
-     /* TODO: Do this globally rather than creating entities for constant forces */
     for (u64 entity_index = 0; entity_index < store->reserved; ++entity_index) {
         struct entity *ent = &store->entities[entity_index];
         if (!entity_is_valid_and_active(ent)) continue;
         if (!entity_has_prop(ent, ENTITY_PROP_PHYSICAL)) continue;
 
+        struct entity *joint_ent = entity_from_handle(store, ent->ground_friction_joint);
 
-        const f32 bla = 0.75f;
+        struct motor_joint_def def = ZI;
-        if (ent->linear_ground_friction != 0) {
+        def.e0 = root->handle;
-            ent->linear_velocity = v2_mul(ent->linear_velocity, bla);
+        def.e1 = ent->handle;
-        }
+        def.correction_rate = 0;
-        if (ent->angular_ground_friction != 0) {
+        def.max_force = ent->linear_ground_friction;
-            ent->angular_velocity *= bla;
+        def.max_torque = ent->angular_ground_friction;
+        if (joint_ent->motor_joint_data.max_force != def.max_force || joint_ent->motor_joint_data.max_torque != def.max_torque) {
+            if (!entity_is_valid_and_active(joint_ent)) {
+                joint_ent = entity_alloc(root);
+                entity_enable_prop(joint_ent, ENTITY_PROP_PHYSICAL);
+                entity_enable_prop(joint_ent, ENTITY_PROP_MOTOR_JOINT);
+                entity_enable_prop(joint_ent, ENTITY_PROP_ACTIVE);
+                joint_ent->motor_joint_data = motor_joint_from_def(def);
+                ent->ground_friction_joint = joint_ent->handle;
+            }
         }
     }
-#endif
-#endif
-#endif
 
     /* ========================== *
      * Physics