code: improve vehicle physics

code/game/src/vehicle.c

@@ -10,7 +10,7 @@ uint64_t vehicle_spawn(void) {
     
     Vehicle *veh = ecs_get_mut(world_ecs(), e, Vehicle, NULL);
     zpl_zero_item(veh);
-    veh->wheel_base = 60.0f;
+    veh->wheel_base = 50.0f;
     return (uint64_t)e;
 }
 

code/game/src/world/blocks_list.c

@@ -2,7 +2,7 @@
 
 static block blocks[] = {
     {.name = "base-ground", .flags = 0, .kind = BLOCK_KIND_GROUND, .biome = 0, .symbol = '.', .drag = 1.0f},
-    {.name = "base-dirt", .flags = 0, .kind = BLOCK_KIND_DIRT, .biome = 0, .symbol = ',', .drag = 4.0f },
+    {.name = "base-dirt", .flags = 0, .kind = BLOCK_KIND_DIRT, .biome = 0, .symbol = ',', .drag = 2.1f },
     {.name = "base-wall", .flags = BLOCK_FLAG_COLLISION, .kind = BLOCK_KIND_WALL, .biome = 0, .symbol = '#', .drag = 1.0f },
     {.name = "base-hill", .flags = BLOCK_FLAG_COLLISION, .kind = BLOCK_KIND_HILL, .biome = 0, .symbol = '^', .drag = 1.0f },
     {.name = "base-hill-snow", .flags = BLOCK_FLAG_COLLISION, .kind = BLOCK_KIND_HILL_SNOW, .biome = 0, .symbol = '*', .drag = 1.0f },

code/game/src/world/worldgen/worldgen_test.c

@@ -98,6 +98,10 @@ static WORLD_BLOCK_OBSERVER(shaper_noise50) {
 static WORLD_BLOCK_OBSERVER(shaper_noise33) {
     return world_perlin_cond(block_idx, 0.33) ? shaper(id, block_idx) : BLOCK_INVALID;
 }
+
+static WORLD_BLOCK_OBSERVER(shaper_noise05) {
+    return world_perlin_cond(block_idx, 0.05) ? shaper(id, block_idx) : BLOCK_INVALID;
+}
 #else
 static WORLD_BLOCK_OBSERVER(shaper_noise80) {
     return rand()%10 < 8 ? shaper(id, block_idx) : BLOCK_INVALID;
@@ -139,7 +143,7 @@ int32_t worldgen_test(world_data *wld) {
     
     // ground
     world_fill_rect(grnd_id, 1, 1, world->dim-2, world->dim-2, NULL);
-    world_fill_rect(dirt_id, 1, 1, world->dim-2, world->dim-2, shaper_noise33);
+    world_fill_rect(dirt_id, 1, 1, world->dim-2, world->dim-2, shaper_noise05);
     
     // water
 #if 1

code/modules/modules/components.h

@@ -52,7 +52,7 @@ ECS_STRUCT(Classify, {
 ECS_STRUCT(Vehicle, {
                uint64_t seats[4];
                
-               float speed;
+               float force;
                float heading;
                float steer;
                float wheel_base;

code/modules/modules/systems.c

@@ -11,17 +11,9 @@
 #define PHY_LOOKAHEAD(x) (zpl_sign(x)*16.0f)
 #define PHY_CORRECTION(x) ((zpl_max(0.0f, (WORLD_BLOCK_SIZE/2.0f) - zpl_abs(x))*zpl_sign(x)))*(WORLD_BLOCK_SIZE/2.0f)
 
-void MoveWalk(ecs_iter_t *it) {
+#include "source/system_onfoot.c"
-    Position *p = ecs_column(it, Position, 1);
+#include "source/system_demo.c"
-    Velocity *v = ecs_column(it, Velocity, 2);
+#include "source/system_vehicle.c"
-    
-    for (int i = 0; i < it->count; i++) {
-        world_block_lookup lookup = world_block_from_realpos(p[i].x, p[i].y);
-        float drag = blocks_get_drag(lookup.block_id);
-        v[i].x = zpl_lerp(v[i].x, 0.0f, PHY_WALK_DRAG*drag);
-        v[i].y = zpl_lerp(v[i].y, 0.0f, PHY_WALK_DRAG*drag);
-    }
-}
 
 void IntegratePositions(ecs_iter_t *it) {
     profile(PROF_INTEGRATE_POS) {
@@ -70,47 +62,6 @@ void UpdateTrackerPos(ecs_iter_t *it) {
     }
 }
 
-#define PLR_MOVE_SPEED 50.0
-#define PLR_MOVE_SPEED_MULT 4.0
-
-void MovementImpulse(ecs_iter_t *it) {
-    Input *in = ecs_column(it, Input, 1);
-    Velocity *v = ecs_column(it, Velocity, 2);
-    
-    for (int i = 0; i < it->count; i++) {
-        if (ecs_is_alive(world_ecs(), in[i].parent)) continue;
-        double speed = PLR_MOVE_SPEED * (in[i].sprint ? PLR_MOVE_SPEED_MULT : 1.0);
-        if (zpl_abs(v[i].x) < speed && in[i].x)
-            v[i].x = in[i].x*speed;
-        if (zpl_abs(v[i].y) < speed && in[i].y)
-            v[i].y = in[i].y*speed;
-    }
-}
-
-#define DEMO_NPC_CHANGEDIR_FACTOR 0.1
-#define DEMO_NPC_MOVE_SPEED 1500
-
-void DemoNPCMoveAround(ecs_iter_t *it) {
-    Velocity *v = ecs_column(it, Velocity, 1);
-    for (int i = 0; i < it->count; i++) {
-        v[i].x = zpl_lerp(v[i].x, (rand()%3-1)*DEMO_NPC_MOVE_SPEED, DEMO_NPC_CHANGEDIR_FACTOR);
-        v[i].y = zpl_lerp(v[i].y, (rand()%3-1)*DEMO_NPC_MOVE_SPEED, DEMO_NPC_CHANGEDIR_FACTOR);
-    }
-}
-
-void DemoPlaceIceBlock(ecs_iter_t *it) {
-    Input *in = ecs_column(it, Input, 1);
-    Position *p = ecs_column(it, Position, 2);
-    uint8_t watr_id = blocks_find(BLOCK_BIOME_DEV, BLOCK_KIND_WATER);
-    
-    for (int i = 0; i < it->count; i++) {
-        if (in[i].use) {
-            world_block_lookup l = world_block_from_realpos(p[i].x, p[i].y);
-            world_chunk_replace_block(l.chunk_id, l.id, watr_id); 
-        }
-    }
-}
-
 #define HAZARD_BLOCK_TIME 1.0f
 #define HAZARD_BLOCK_DMG 5.0f
 
@@ -148,121 +99,6 @@ void RegenerateHP(ecs_iter_t *it) {
     }
 }
 
-#define VEH_ENTER_RADIUS 45.0f
-
-void EnterOrLeaveVehicle(ecs_iter_t *it) {
-    Input *in = ecs_column(it, Input, 1);
-    Position *p = ecs_column(it, Position, 2);
-    
-    for (int i = 0; i < it->count; i++) {
-        if (!in[i].use) continue;
-        
-        if (!ecs_is_alive(world_ecs(), in[i].parent)) {
-            size_t ents_count;
-            int64_t *ents = world_chunk_query_entities(it->entities[i], &ents_count, 2);
-            
-            for (size_t j = 0; j < ents_count; j++) {
-                if (ecs_get(world_ecs(), ents[j], Vehicle)) {
-                    Vehicle *veh = ecs_get_mut(world_ecs(), ents[j], Vehicle, NULL);
-                    Position const* p2 = ecs_get(world_ecs(), ents[j], Position);
-                    
-                    float dx = p2->x - p[i].x;
-                    float dy = p2->y - p[i].y;
-                    float range = zpl_sqrt(dx*dx + dy*dy);
-                    if (range <= VEH_ENTER_RADIUS) {
-                        for (int k = 0; k < 4; k++) {
-                            if (veh->seats[k] != 0) continue;
-                            
-                            // NOTE(zaklaus): We can enter the vehicle, yay!
-                            veh->seats[k] = it->entities[i];
-                            in[i].parent = ents[j];
-                            p[i] = *p2;
-                            break;
-                        }
-                    }
-                }
-            }
-        } else {
-            if (ecs_get(world_ecs(), in[i].parent, Vehicle)) {
-                Vehicle *veh = ecs_get_mut(world_ecs(), in[i].parent, Vehicle, NULL);
-                
-                for (int k = 0; k < 4; k++) {
-                    if (veh->seats[k] == it->entities[i]) {
-                        veh->seats[k] = 0;
-                        break;
-                    }
-                }
-                
-                in[i].parent = 0;
-            } else {
-                ZPL_PANIC("unreachable code");
-            }
-        }
-    }
-}
-
-#define VEHICLE_MAX_SPEED 500.0f
-#define VEHICLE_ACCEL 2.1f
-#define VEHICLE_STEER 0.01f
-
-void VehicleHandling(ecs_iter_t *it) {
-    Vehicle *veh = ecs_column(it, Vehicle, 1);
-    Position *p = ecs_column(it, Position, 2);
-    Velocity *v = ecs_column(it, Velocity, 3);
-    
-    for (int i = 0; i < it->count; i++) {
-        Vehicle *car = &veh[i];
-        
-        // NOTE(zaklaus): Apply friction
-        car->speed *= 0.99f;
-        car->steer *= 0.97f;
-        
-        for (int j = 0; j < 4; j++) {
-            // NOTE(zaklaus): Perform seat cleanup
-            if (!ecs_is_alive(world_ecs(), veh[i].seats[j])) {
-                veh[i].seats[j] = 0;
-                continue;
-            }
-            
-            ecs_entity_t pe = veh[i].seats[j];
-            
-            // NOTE(zaklaus): Update passenger position
-            {
-                Position *p2 = ecs_get_mut(world_ecs(), pe, Position, NULL);
-                Velocity *v2 = ecs_get_mut(world_ecs(), pe, Velocity, NULL);
-                *p2 = p[i];
-                *v2 = v[i];
-            }
-            
-            // NOTE(zaklaus): Handle driver input
-            if (j == 0) {
-                Input const* in = ecs_get(world_ecs(), pe, Input);
-                
-                car->speed += in->y * VEHICLE_ACCEL;
-                car->speed = zpl_clamp(car->speed, -VEHICLE_MAX_SPEED, VEHICLE_MAX_SPEED);
-                car->steer += in->x * -VEHICLE_STEER * (zpl_abs(car->speed*2.5f) / VEHICLE_MAX_SPEED);
-                car->steer = zpl_clamp(car->steer, -40.0f, 40.0f);
-            }
-        }
-        
-        // NOTE(zaklaus): Vehicle physics
-        float fr_x = p[i].x + (car->wheel_base/2.0f) * zpl_cos(car->heading);
-        float fr_y = p[i].y + (car->wheel_base/2.0f) * zpl_sin(car->heading);
-        
-        float bk_x = p[i].x - (car->wheel_base/2.0f) * zpl_cos(car->heading);
-        float bk_y = p[i].y - (car->wheel_base/2.0f) * zpl_sin(car->heading);
-        
-        bk_x += car->speed * zpl_cos(car->heading);
-        bk_y += car->speed * zpl_sin(car->heading);
-        fr_x += car->speed * zpl_cos(car->heading + zpl_to_radians(car->steer));
-        fr_y += car->speed * zpl_sin(car->heading + zpl_to_radians(car->steer));
-        
-        v[i].x = (fr_x + bk_x) / 2.0f - p[i].x;
-        v[i].y = (fr_y + bk_y) / 2.0f - p[i].y;
-        car->heading = zpl_arctan2(fr_y - bk_y, fr_x - bk_x);
-    }
-}
-
 void SystemsImport(ecs_world_t *ecs) {
     ECS_MODULE(ecs, Systems);
     ECS_IMPORT(ecs, Components);
@@ -272,7 +108,7 @@ void SystemsImport(ecs_world_t *ecs) {
     ECS_SYSTEM(ecs, DemoNPCMoveAround, EcsOnLoad, components.Velocity, components.EcsDemoNPC);
     ECS_SYSTEM(ecs, EnterOrLeaveVehicle, EcsOnLoad, components.Input, components.Position);
     
-    ECS_SYSTEM(ecs, MoveWalk, EcsOnUpdate, components.Position, components.Velocity, !components.Vehicle);
+    ECS_SYSTEM(ecs, MoveWalk, EcsOnUpdate, components.Position, components.Velocity);
     ECS_SYSTEM(ecs, HurtOnHazardBlock, EcsOnUpdate, components.Position, components.Health);
     ECS_SYSTEM(ecs, RegenerateHP, EcsOnUpdate, components.Health);
     ECS_SYSTEM(ecs, VehicleHandling, EcsOnUpdate, components.Vehicle, components.Position, components.Velocity);

code/modules/source/system_demo.c

@@ -0,0 +1,24 @@
+
+#define DEMO_NPC_CHANGEDIR_FACTOR 0.1
+#define DEMO_NPC_MOVE_SPEED 1500
+
+void DemoNPCMoveAround(ecs_iter_t *it) {
+    Velocity *v = ecs_column(it, Velocity, 1);
+    for (int i = 0; i < it->count; i++) {
+        v[i].x = zpl_lerp(v[i].x, (rand()%3-1)*DEMO_NPC_MOVE_SPEED, DEMO_NPC_CHANGEDIR_FACTOR);
+        v[i].y = zpl_lerp(v[i].y, (rand()%3-1)*DEMO_NPC_MOVE_SPEED, DEMO_NPC_CHANGEDIR_FACTOR);
+    }
+}
+
+void DemoPlaceIceBlock(ecs_iter_t *it) {
+    Input *in = ecs_column(it, Input, 1);
+    Position *p = ecs_column(it, Position, 2);
+    uint8_t watr_id = blocks_find(BLOCK_BIOME_DEV, BLOCK_KIND_WATER);
+    
+    for (int i = 0; i < it->count; i++) {
+        if (in[i].use) {
+            world_block_lookup l = world_block_from_realpos(p[i].x, p[i].y);
+            world_chunk_replace_block(l.chunk_id, l.id, watr_id); 
+        }
+    }
+}

code/modules/source/system_onfoot.c

@@ -0,0 +1,29 @@
+
+void MoveWalk(ecs_iter_t *it) {
+    Position *p = ecs_column(it, Position, 1);
+    Velocity *v = ecs_column(it, Velocity, 2);
+    
+    for (int i = 0; i < it->count; i++) {
+        world_block_lookup lookup = world_block_from_realpos(p[i].x, p[i].y);
+        float drag = blocks_get_drag(lookup.block_id);
+        v[i].x = zpl_lerp(v[i].x, 0.0f, PHY_WALK_DRAG*drag);
+        v[i].y = zpl_lerp(v[i].y, 0.0f, PHY_WALK_DRAG*drag);
+    }
+}
+
+#define PLR_MOVE_SPEED 50.0
+#define PLR_MOVE_SPEED_MULT 4.0
+
+void MovementImpulse(ecs_iter_t *it) {
+    Input *in = ecs_column(it, Input, 1);
+    Velocity *v = ecs_column(it, Velocity, 2);
+    
+    for (int i = 0; i < it->count; i++) {
+        if (ecs_is_alive(world_ecs(), in[i].parent)) continue;
+        double speed = PLR_MOVE_SPEED * (in[i].sprint ? PLR_MOVE_SPEED_MULT : 1.0);
+        if (zpl_abs(v[i].x) < speed && in[i].x)
+            v[i].x = in[i].x*speed;
+        if (zpl_abs(v[i].y) < speed && in[i].y)
+            v[i].y = in[i].y*speed;
+    }
+}

code/modules/source/system_vehicle.c

@@ -0,0 +1,116 @@
+
+#define VEH_ENTER_RADIUS 45.0f
+
+void EnterOrLeaveVehicle(ecs_iter_t *it) {
+    Input *in = ecs_column(it, Input, 1);
+    Position *p = ecs_column(it, Position, 2);
+    
+    for (int i = 0; i < it->count; i++) {
+        if (!in[i].use) continue;
+        
+        if (!ecs_is_alive(world_ecs(), in[i].parent)) {
+            size_t ents_count;
+            int64_t *ents = world_chunk_query_entities(it->entities[i], &ents_count, 2);
+            
+            for (size_t j = 0; j < ents_count; j++) {
+                if (ecs_get(world_ecs(), ents[j], Vehicle)) {
+                    Vehicle *veh = ecs_get_mut(world_ecs(), ents[j], Vehicle, NULL);
+                    Position const* p2 = ecs_get(world_ecs(), ents[j], Position);
+                    
+                    float dx = p2->x - p[i].x;
+                    float dy = p2->y - p[i].y;
+                    float range = zpl_sqrt(dx*dx + dy*dy);
+                    if (range <= VEH_ENTER_RADIUS) {
+                        for (int k = 0; k < 4; k++) {
+                            if (veh->seats[k] != 0) continue;
+                            
+                            // NOTE(zaklaus): We can enter the vehicle, yay!
+                            veh->seats[k] = it->entities[i];
+                            in[i].parent = ents[j];
+                            p[i] = *p2;
+                            break;
+                        }
+                    }
+                }
+            }
+        } else {
+            if (ecs_get(world_ecs(), in[i].parent, Vehicle)) {
+                Vehicle *veh = ecs_get_mut(world_ecs(), in[i].parent, Vehicle, NULL);
+                
+                for (int k = 0; k < 4; k++) {
+                    if (veh->seats[k] == it->entities[i]) {
+                        veh->seats[k] = 0;
+                        break;
+                    }
+                }
+                
+                in[i].parent = 0;
+            } else {
+                ZPL_PANIC("unreachable code");
+            }
+        }
+    }
+}
+
+#define VEHICLE_FORCE 12.8f
+#define VEHICLE_ACCEL 0.17f
+#define VEHICLE_DECEL 0.28f
+#define VEHICLE_STEER 0.11f
+#define VEHICLE_STEER_MUL 0.087f
+
+void VehicleHandling(ecs_iter_t *it) {
+    Vehicle *veh = ecs_column(it, Vehicle, 1);
+    Position *p = ecs_column(it, Position, 2);
+    Velocity *v = ecs_column(it, Velocity, 3);
+    
+    for (int i = 0; i < it->count; i++) {
+        Vehicle *car = &veh[i];
+        
+        // NOTE(zaklaus): Apply friction
+        car->force = zpl_lerp(car->force, 0.0f, VEHICLE_DECEL);
+        car->steer *= 0.97f;
+        
+        for (int j = 0; j < 4; j++) {
+            // NOTE(zaklaus): Perform seat cleanup
+            if (!ecs_is_alive(world_ecs(), veh[i].seats[j])) {
+                veh[i].seats[j] = 0;
+                continue;
+            }
+            
+            ecs_entity_t pe = veh[i].seats[j];
+            
+            // NOTE(zaklaus): Update passenger position
+            {
+                Position *p2 = ecs_get_mut(world_ecs(), pe, Position, NULL);
+                Velocity *v2 = ecs_get_mut(world_ecs(), pe, Velocity, NULL);
+                *p2 = p[i];
+                *v2 = v[i];
+            }
+            
+            // NOTE(zaklaus): Handle driver input
+            if (j == 0) {
+                Input const* in = ecs_get(world_ecs(), pe, Input);
+                
+                car->force += zpl_lerp(0.0f, in->y * VEHICLE_FORCE, VEHICLE_ACCEL);
+                car->steer += in->x * -VEHICLE_STEER;
+                car->steer = zpl_clamp(car->steer, -40.0f, 40.0f);
+            }
+        }
+        
+        // NOTE(zaklaus): Vehicle physics
+        float fr_x = p[i].x + (car->wheel_base/2.0f) * zpl_cos(car->heading);
+        float fr_y = p[i].y + (car->wheel_base/2.0f) * zpl_sin(car->heading);
+        
+        float bk_x = p[i].x - (car->wheel_base/2.0f) * zpl_cos(car->heading);
+        float bk_y = p[i].y - (car->wheel_base/2.0f) * zpl_sin(car->heading);
+        
+        bk_x += car->force * zpl_cos(car->heading);
+        bk_y += car->force * zpl_sin(car->heading);
+        fr_x += car->force * zpl_cos(car->heading + zpl_to_radians(car->steer));
+        fr_y += car->force * zpl_sin(car->heading + zpl_to_radians(car->steer));
+        
+        v[i].x += (fr_x + bk_x) / 2.0f - p[i].x;
+        v[i].y += (fr_y + bk_y) / 2.0f - p[i].y;
+        car->heading = zpl_arctan2(fr_y - bk_y, fr_x - bk_x);
+    }
+}