Scene prefabs

src/duskrpg/entity/component/overworld/entityplayer.c

@@ -11,10 +11,13 @@
 #include "entity/component/display/entitycamera.h"
 #include "entity/component/display/entityposition.h"
 #include "input/input.h"
+#include "time/time.h"
 #include "util/memory.h"
+#include "util/math.h"
 
 #define ENTITY_PLAYER_MOVE_SPEED_DEFAULT 4.0f
 #define ENTITY_PLAYER_JUMP_IMPULSE_DEFAULT 6.0f
+#define ENTITY_PLAYER_TURN_SPEED_DEFAULT 10.0f
 
 // Below this squared magnitude, movement input is treated as "not moving"
 // and the player keeps facing whichever way it last faced, rather than
@@ -32,6 +35,7 @@ void entityPlayerInit(
 
   player->moveSpeed = ENTITY_PLAYER_MOVE_SPEED_DEFAULT;
   player->jumpImpulse = ENTITY_PLAYER_JUMP_IMPULSE_DEFAULT;
+  player->turnSpeed = ENTITY_PLAYER_TURN_SPEED_DEFAULT;
 
   entityUpdateAdd(mgr, entityId, entityPlayerUpdate, componentId, NULL);
 }
@@ -109,7 +113,16 @@ void entityPlayerUpdate(
   // faces the opposite way), which for a pure yaw rotation works out to
   // (sin(yaw), 0, cos(yaw)) -- invert that to solve for the yaw facing
   // moveDir.
-  rotation[1] = atan2f(moveDir[0], moveDir[1]);
+  float_t targetYaw = atan2f(moveDir[0], moveDir[1]);
+
+  // Turn towards targetYaw at turnSpeed rad/s instead of snapping to it:
+  // wrap the shortest signed delta into [-PI, PI), then clamp the step.
+  float_t yawDelta = mathModFloat(
+    targetYaw - rotation[1] + (float_t)MATH_PI, 2.0f * (float_t)MATH_PI
+  ) - (float_t)MATH_PI;
+  float_t maxStep = player->turnSpeed * TIME.delta;
+  rotation[1] += mathClamp(yawDelta, -maxStep, maxStep);
+
   entityPositionSetLocalRotation(mgr, entityId, posComp, rotation);
 }
 
@@ -124,6 +137,7 @@ errorret_t entityPlayerSerialize(
 
   yyjson_mut_obj_add_real(doc, json, "moveSpeed", player->moveSpeed);
   yyjson_mut_obj_add_real(doc, json, "jumpImpulse", player->jumpImpulse);
+  yyjson_mut_obj_add_real(doc, json, "turnSpeed", player->turnSpeed);
 
   errorOk();
 }
@@ -143,6 +157,9 @@ errorret_t entityPlayerDeserialize(
   if((v = yyjson_obj_get(json, "jumpImpulse"))) {
     player->jumpImpulse = (float_t)yyjson_get_num(v);
   }
+  if((v = yyjson_obj_get(json, "turnSpeed"))) {
+    player->turnSpeed = (float_t)yyjson_get_num(v);
+  }
 
   errorOk();
 }

src/duskrpg/entity/component/overworld/entityplayer.h

@@ -13,11 +13,14 @@
 typedef struct {
   float_t moveSpeed;
   float_t jumpImpulse;
+
+  /** Yaw turn rate, in radians/second, when facing the movement direction. */
+  float_t turnSpeed;
 } entityplayer_t;
 
 /**
- * Initializes the player component: sets default move speed and jump
- * impulse.
+ * Initializes the player component: sets default move speed, jump
+ * impulse, and turn speed.
  *
  * @param mgr The entity manager that owns the entity.
  * @param entityId The entity ID.
@@ -53,7 +56,8 @@ entityplayer_t *entityPlayerGet(
  * axes. No-op if the entity has no physics component.
  *
  * Also yaws the entity's position component (if any) to face the
- * direction of movement. Facing is only updated while there's actual
+ * direction of movement, turning at most turnSpeed radians/second rather
+ * than snapping instantly. Facing is only updated while there's actual
  * movement input -- releasing input leaves the entity facing whichever
  * way it last moved, rather than snapping to a default orientation.
  *
@@ -72,8 +76,8 @@ void entityPlayerUpdate(
 );
 
 /**
- * Serializes the player's "moveSpeed" and "jumpImpulse" into the given
- * JSON object.
+ * Serializes the player's "moveSpeed", "jumpImpulse", and "turnSpeed"
+ * into the given JSON object.
  *
  * @param mgr The entity manager that owns the entity.
  * @param entityId The entity ID.
@@ -91,9 +95,9 @@ errorret_t entityPlayerSerialize(
 );
 
 /**
- * Reads "moveSpeed" and "jumpImpulse" (see entityPlayerSerialize()) from
- * the given JSON object and applies whichever are present, leaving the
- * rest at their current values.
+ * Reads "moveSpeed", "jumpImpulse", and "turnSpeed" (see
+ * entityPlayerSerialize()) from the given JSON object and applies
+ * whichever are present, leaving the rest at their current values.
  *
  * @param mgr The entity manager that owns the entity.
  * @param entityId The entity ID.

src/duskrpg/entity/gameprefablist.h

@@ -8,9 +8,11 @@
 // Game-specific prefabs, appended after the engine's inbuilt prefabs in
 // entity/entityprefablist.h.
 #include "entity/prefab/entityprefabplayer.h"
+#include "entity/prefab/entityprefaboverworldcamera.h"
 
 // Name (Uppercase)
 // Extends (name of another prefab to apply first, or "" for none)
 // Apply function
 
 X(PLAYER, "", entityPrefabPlayerApply)
+X(OVERWORLD_CAMERA, "", entityPrefabOverworldCameraApply)

src/duskrpg/entity/prefab/CMakeLists.txt

@@ -6,4 +6,5 @@
 target_sources(${DUSK_LIBRARY_TARGET_NAME}
   PUBLIC
     entityprefabplayer.c
+    entityprefaboverworldcamera.c
 )

src/duskrpg/entity/prefab/entityprefaboverworldcamera.c

@@ -0,0 +1,37 @@
+/**
+ * Copyright (c) 2026 Dominic Masters
+ *
+ * This software is released under the MIT License.
+ * https://opensource.org/licenses/MIT
+ */
+
+#include "entityprefaboverworldcamera.h"
+#include "entity/entitymanager.h"
+#include "entity/component/display/entityposition.h"
+#include "entity/component/display/entitycamera.h"
+
+errorret_t entityPrefabOverworldCameraApply(
+  entitymanager_t *mgr,
+  const entityid_t entityId
+) {
+  componentid_t posComp = entityAddComponent(
+    mgr, entityId, COMPONENT_TYPE_POSITION
+  );
+  vec3 eye = { 10.0f, 10.0f, 10.0f };
+  vec3 target = { 0.0f, 0.0f, 0.0f };
+  vec3 up = { 0.0f, 1.0f, 0.0f };
+  entityPositionLookAt(mgr, entityId, posComp, eye, target, up);
+
+  componentid_t camComp = entityAddComponent(
+    mgr, entityId, COMPONENT_TYPE_CAMERA
+  );
+  entitycamera_t *cam = componentGetData(
+    mgr, entityId, camComp, COMPONENT_TYPE_CAMERA
+  );
+  cam->projType = ENTITY_CAMERA_PROJECTION_TYPE_PERSPECTIVE;
+  cam->nearClip = 0.1f;
+  cam->farClip = 1000.0f;
+  cam->perspective.fov = 0.9f;
+
+  errorOk();
+}

src/duskrpg/entity/prefab/entityprefaboverworldcamera.h

@@ -0,0 +1,25 @@
+/**
+ * Copyright (c) 2026 Dominic Masters
+ *
+ * This software is released under the MIT License.
+ * https://opensource.org/licenses/MIT
+ */
+
+#pragma once
+#include "entity/entitybase.h"
+#include "error/error.h"
+
+/**
+ * Applies the OVERWORLD_CAMERA prefab: a POSITION at (10, 10, 10) looking
+ * at the world origin, and a perspective CAMERA (0.1/1000 near/far clip,
+ * 0.9 fov). C-coded equivalent of the hand-authored "camera" entity
+ * previously in assets/scenes/test.json.
+ *
+ * @param mgr The entity manager that owns the entity.
+ * @param entityId The ID of the entity to apply the prefab to.
+ * @return Error state.
+ */
+errorret_t entityPrefabOverworldCameraApply(
+  entitymanager_t *mgr,
+  const entityid_t entityId
+);

src/duskrpg/scene/CMakeLists.txt

@@ -7,3 +7,5 @@ target_sources(${DUSK_LIBRARY_TARGET_NAME}
   PUBLIC
     overworldscene.c
 )
+
+add_subdirectory(prefab)

src/duskrpg/scene/gameprefablist.h

@@ -0,0 +1,16 @@
+/**
+ * Copyright (c) 2026 Dominic Masters
+ *
+ * This software is released under the MIT License.
+ * https://opensource.org/licenses/MIT
+ */
+
+// Game-specific scene prefabs, appended after the engine's inbuilt scene
+// prefabs in scene/sceneprefablist.h.
+#include "scene/prefab/sceneprefaboverworldscene.h"
+
+// Name (Uppercase)
+// Extends (name of another prefab to apply first, or "" for none)
+// Apply function
+
+X(OVERWORLDSCENE, "", scenePrefabOverworldSceneApply)

src/duskrpg/scene/prefab/CMakeLists.txt

@@ -0,0 +1,9 @@
+# Copyright (c) 2026 Dominic Masters
+#
+# This software is released under the MIT License.
+# https://opensource.org/licenses/MIT
+
+target_sources(${DUSK_LIBRARY_TARGET_NAME}
+  PUBLIC
+    sceneprefaboverworldscene.c
+)

src/duskrpg/scene/prefab/sceneprefaboverworldscene.c

@@ -0,0 +1,26 @@
+/**
+ * Copyright (c) 2026 Dominic Masters
+ *
+ * This software is released under the MIT License.
+ * https://opensource.org/licenses/MIT
+ */
+
+#include "sceneprefaboverworldscene.h"
+#include "scene/scene.h"
+#include "entity/entityprefab.h"
+
+errorret_t scenePrefabOverworldSceneApply(const sceneid_t sceneId) {
+  entitymanager_t *mgr = sceneGetEntities(sceneId);
+
+  entityid_t cameraEntity = entityManagerAdd(mgr);
+  entitySetName(mgr, cameraEntity, "camera");
+  errorChain(
+    entityPrefabResolveAndApply(mgr, cameraEntity, "OVERWORLD_CAMERA")
+  );
+
+  entityid_t playerEntity = entityManagerAdd(mgr);
+  entitySetName(mgr, playerEntity, "player");
+  errorChain(entityPrefabResolveAndApply(mgr, playerEntity, "PLAYER"));
+
+  errorOk();
+}

src/duskrpg/scene/prefab/sceneprefaboverworldscene.h

@@ -0,0 +1,20 @@
+/**
+ * Copyright (c) 2026 Dominic Masters
+ *
+ * This software is released under the MIT License.
+ * https://opensource.org/licenses/MIT
+ */
+
+#pragma once
+#include "scene/scenebase.h"
+#include "error/error.h"
+
+/**
+ * Applies the OVERWORLDSCENE prefab: spawns a "camera" entity (see
+ * entityPrefabOverworldCameraApply()) and a "player" entity (see
+ * entityPrefabPlayerApply()) into the scene.
+ *
+ * @param sceneId The ID of the scene to apply the prefab to.
+ * @return Error state.
+ */
+errorret_t scenePrefabOverworldSceneApply(const sceneid_t sceneId);