Introduced configurable fixed time step

src/common/version.h

@@ -4,7 +4,7 @@
 /* Auto generated version file. DO NOT MODIFY */
 #define SYMMETRY_VERSION_MAJOR 0
 #define SYMMETRY_VERSION_MINOR 1
-#define SYMMETRY_VERSION_REVISION 318
+#define SYMMETRY_VERSION_REVISION 319
 #define SYMMETRY_VERSION_BRANCH "dev"
 
 #endif

src/game/enemy.c

@@ -8,11 +8,15 @@
 #include "../common/hashmap.h"
 #include "../common/parser.h"
 #include "event.h"
+#include "../system/platform.h"
+#include "debug_vars.h"
 
 #include <string.h>
+#include <math.h>
 
 static void enemy_on_scene_loaded(struct Event* event, void* enemy_ptr);
-static void enemy_update_turret(struct Enemy* enemy, struct Game_State* game_state, float dt);
+static void enemy_update_physics_turret(struct Enemy* enemy, struct Game_State* game_state, float fixed_dt);
+static void enemy_update_ai_turret(struct Enemy* enemy, struct Game_State* game_state, float dt);
 
 void enemy_init(struct Enemy* enemy, int type)
 {
@@ -77,7 +81,17 @@ void enemy_update(struct Enemy* enemy, struct Scene* scene, float dt)
 
 	switch(enemy->type)
 	{
-	case ENEMY_TURRET: enemy_update_turret(enemy, game_state, dt); break;
+	case ENEMY_TURRET: enemy_update_ai_turret(enemy, game_state, dt); break;
+	}
+
+}
+
+void enemy_update_physics(struct Enemy* enemy, struct Scene* scene, float fixed_dt)
+{
+	struct Game_State* game_state = game_state_get();
+	switch(enemy->type)
+	{
+	case ENEMY_TURRET: enemy_update_physics_turret(enemy, game_state, fixed_dt); break;
 	}
 
 }
@@ -160,8 +174,9 @@ void enemy_on_scene_loaded(struct Event* event, void* enemy_ptr)
 	// Do other post-scene-load initialization stuff per enemy type here
 }
 
-void enemy_update_turret(struct Enemy* enemy, struct Game_State* game_state, float dt)
+void enemy_update_physics_turret(struct Enemy* enemy, struct Game_State* game_state, float dt)
 {
+	/* Turning/Rotation */
 	static vec3 turn_axis = { 0.f, 1.f, 0.f };
 	float current_yaw = quat_get_yaw(&enemy->base.transform.rotation);
 
@@ -183,4 +198,19 @@ void enemy_update_turret(struct Enemy* enemy, struct Game_State* game_state, flo
 
 	if(yaw != 0.f)
 		transform_rotate(enemy, &turn_axis, yaw, TS_LOCAL);
+
+	/* Movement */
+	float ticks = (float)platform_ticks_get();
+	float pulsate_speed = 50.f;
+	vec3 translation = { 0.f };
+	transform_get_absolute_position(enemy, &translation);
+	translation.y += sinf(TO_RADIANS(ticks)) * dt * pulsate_speed;
+	debug_vars_show_float("T", sinf(TO_RADIANS(ticks * dt * pulsate_speed)));
+	transform_set_position(enemy, &translation);
+	//transform_translate(enemy, &translation, TS_LOCAL);
+}
+
+void enemy_update_ai_turret(struct Enemy* enemy, struct Game_State* game_state, float dt)
+{
+
 }

src/game/enemy.h

@@ -8,6 +8,7 @@ struct Entity;
 struct Hashmap;
 
 void          enemy_init(struct Enemy* enemy, int type);
+void          enemy_update_physics(struct Enemy* enemy, struct Scene* scene, float dt);
 void          enemy_update(struct Enemy* enemy, struct Scene* scene, float dt);
 void          enemy_reset(struct Enemy* enemy);
 struct Enemy* enemy_read(struct Parser_Object* object, const char* name, struct Entity* parent_entity);

src/game/game.c

@@ -43,6 +43,7 @@
 #define LEN(a) (sizeof(a)/sizeof(a)[0])
 
 static void game_update(float dt, bool* window_should_close);
+static void game_update_physics(float fixed_dt);
 static void game_post_update(float dt);
 static void game_render(void);
 static void game_debug(float dt);
@@ -69,6 +70,7 @@ bool game_init(struct Window* window, struct Hashmap* cvars)
 		game_state->window           = window;
 		game_state->cvars            = cvars;
 		game_state->is_initialized   = false;
+		game_state->fixed_delta_time = 1.f / 60.f;
 		game_state->game_mode        = GAME_MODE_GAME;
 		game_state->renderer         = calloc(1, sizeof(*game_state->renderer));
 		game_state->scene            = calloc(1, sizeof(*game_state->scene));
@@ -512,21 +514,31 @@ void game_debug(float dt)
 
 bool game_run(void)
 {
-    uint32 last_time = platform_ticks_get();
+    uint32 previous_time       = platform_ticks_get();
+	float  accumulator         = 0.f;
 	bool   should_window_close = false;
+
     while(!should_window_close)
     {
-        uint32 curr_time = platform_ticks_get();
-		float delta_time = (float)(curr_time - last_time) / 1000.f;
-		last_time = curr_time;
-		if(delta_time > MAX_FRAME_TIME) delta_time = (1.f / 60.f); /* To deal with resuming from breakpoint we artificially set delta time */
+        uint32 current_time = platform_ticks_get();
+		float frame_time = (float)(current_time - previous_time) / 1000.f;
+		previous_time = current_time;
+		if(frame_time > MAX_FRAME_TIME) frame_time = (1.f / 60.f); /* To deal with resuming from breakpoint we artificially set delta time */
+		accumulator += frame_time;
 
 		gui_input_begin(game_state->gui);
 		event_manager_poll_events(game_state->event_manager, &should_window_close);
 		gui_input_end(game_state->gui);
 
-		game_update(delta_time, &should_window_close);
-		game_post_update(delta_time);
+		struct Game_State* game_state = game_state_get();
+		while(accumulator >= game_state->fixed_delta_time)
+		{
+			game_update_physics(game_state->fixed_delta_time);
+			accumulator -= game_state->fixed_delta_time;
+		}
+		
+		game_update(frame_time, &should_window_close);
+		game_post_update(frame_time);
 		game_render();
 		window_swap_buffers(game_state->window);
     }
@@ -1983,3 +1995,9 @@ void game_on_log_error(const char* context, const char* error_message, va_list a
 {
     console_on_log_error(game_state->console, context, error_message, args);
 }
+
+void game_update_physics(float fixed_dt)
+{
+	struct Game_State* game_state = game_state_get();
+	scene_update_physics(game_state->scene, fixed_dt);
+}

src/game/game.h

@@ -25,6 +25,7 @@ struct Game_State
 {
 	bool                  is_initialized;
 	int                   game_mode;
+	float                 fixed_delta_time;
 	struct Window*        window;
 	struct Renderer*      renderer;
 	struct Scene*         scene;

src/game/player.c

@@ -80,7 +80,7 @@ void player_destroy(struct Player* player)
     player->base.flags = EF_NONE;
 }
 
-void player_update(struct Player* player, struct Scene* scene, float dt)
+void player_update_physics(struct Player* player, struct Scene* scene, float fixed_dt)
 {
     /* Look around */
 	float total_pitch    = quat_get_pitch(&player->camera->base.transform.rotation);
@@ -103,8 +103,8 @@ void player_update(struct Player* player, struct Scene* scene, float dt)
 		cursor_yaw = cursor_pitch = 0;
 	}
 
-	pitch = -cursor_pitch * player->turn_speed * dt;
-	yaw = cursor_yaw * player->turn_speed * dt;
+	pitch = -cursor_pitch * player->turn_speed * fixed_dt;
+	yaw = cursor_yaw * player->turn_speed * fixed_dt;
 
     total_pitch += pitch;
     if(total_pitch >= max_pitch)
@@ -221,9 +221,9 @@ void player_update(struct Player* player, struct Scene* scene, float dt)
     vec3 translation = {0.f, 0.f, 0.f};
 	vec3_assign(&translation, &move_direction);
 
-	translation.x *= move_speed * dt;
-	translation.z *= move_speed * dt;
-	translation.y = move_speed_vertical * dt;
+	translation.x *= move_speed * fixed_dt;
+	translation.z *= move_speed * fixed_dt;
+	translation.y = move_speed_vertical * fixed_dt;
 	transform_translate(player, &translation, TS_WORLD);
 
 	debug_vars_show_bool("Grounded", player->grounded);

src/game/player.h

@@ -6,6 +6,6 @@ struct Scene;
 
 void player_init(struct Player* player, struct Scene* scene);
 void player_destroy(struct Player* player);
-void player_update(struct Player* player, struct Scene* scene, float dt);
+void player_update_physics(struct Player* player, struct Scene* scene, float dt);
 
 #endif

src/game/scene.c

@@ -366,7 +366,6 @@ void scene_update(struct Scene* scene, float dt)
 {
 	if(game_state_get()->game_mode == GAME_MODE_GAME) 
 	{
-		player_update(&scene->player, scene, dt);
 		for(int i = 0; i < MAX_SCENE_ENEMIES; i++)
 		{
 			if(scene->enemies[i].base.flags & EF_ACTIVE)
@@ -375,6 +374,19 @@ void scene_update(struct Scene* scene, float dt)
 	}
 }
 
+void scene_update_physics(struct Scene* scene, float fixed_dt)
+{
+	if(game_state_get()->game_mode == GAME_MODE_GAME) 
+	{
+		player_update_physics(&scene->player, scene, fixed_dt);
+		for(int i = 0; i < MAX_SCENE_ENEMIES; i++)
+		{
+			if(scene->enemies[i].base.flags & EF_ACTIVE)
+				enemy_update_physics(&scene->enemies[i], scene, fixed_dt);
+		}
+	}
+}
+
 void scene_post_update(struct Scene* scene)
 {
 	assert(scene);

src/game/scene.h

@@ -28,6 +28,7 @@ bool scene_load(struct Scene* scene, const char* filename, int directory_type);
 bool scene_save(struct Scene* scene, const char* filename, int directory_type);
 void scene_destroy(struct Scene* scene);
 void scene_update(struct Scene* scene, float dt);
+void scene_update_physics(struct Scene* scene, float fixed_dt);
 void scene_post_update(struct Scene* scene);
 
 struct Entity*       scene_entity_duplicate(struct Scene* scene, struct Entity* entity);

src/system/config_vars.c

@@ -31,9 +31,9 @@ void config_vars_init(struct Hashmap* cvars)
     hashmap_vec4_setf(cvars, "debug_draw_color",              0.8f, 0.4f, 0.1f, 1.f);
     hashmap_float_set(cvars, "player_move_speed",             20.f);
     hashmap_float_set(cvars, "player_move_speed_multiplier",  1.75f);
-    hashmap_float_set(cvars, "player_turn_speed",             45.f);
+    hashmap_float_set(cvars, "player_turn_speed",             25.f);
     hashmap_float_set(cvars, "player_jump_speed",             50.f);
-    hashmap_float_set(cvars, "player_gravity",               -0.25f);
+    hashmap_float_set(cvars, "player_gravity",               -2.5f);
     hashmap_float_set(cvars, "player_min_forward_distance",   5.f);
     hashmap_float_set(cvars, "player_min_downward_distance",  2.f);
 }

todo.txt

@@ -1,4 +1,6 @@
 Todo:
+	- Make movement framerate independent
+	- Implement displaying bounding boxes as a command which should work in game mode
 	- Enemy ray casting and shooting
 	- Player shooting
 	- Player jump cooldown, don't allow jump until a certian time interval has passed, even if we're grounded
@@ -13,6 +15,7 @@ Todo:
 		- Main Menu Scene
 		? Split this todo into gameplay/engine todos
 	- Check if running in a lower frame rate affects movement
+	- Remove ODE completely
 	? Write entity flags to scene file or when saving entity to file?
 	? Add scene init/de-init function hashmap that maps a function that should be called when scene is loaded and unloaded. Save this to file for every scene or map functions based on the name of the scene?
 	- Release mouse when window loses focus and limit fps
@@ -406,3 +409,4 @@ Done:
 	* Imlemented reading/writing enemy mesh and weapon sound to file and resetting it in code
 	* Implemented on_load and on_update callbacks for enemies. Different enemy types have different callbacks that are assigned when they are created.
 	* Added Scene reload command
+	* Introduced fixed time step interval which can be configured and be used for movement and other physics related updates