Add an animation system.

12 files changed, 177 insertions, 7 deletions

diff --git a/Makefile b/Makefile
index 5bc01bf..d9c53b0 100644
--- a/Makefile
+++ b/Makefile
@@ -85,6 +85,8 @@ endif
 all: $(target)
 
 sources = \
+  animation.c \
+  animation_system.c \
   asset.c \
   main.c \
   malware.c \
diff --git a/animation.c b/animation.c
new file mode 100644
index 0000000..6dbb08f
--- /dev/null
+++ b/animation.c
@@ -0,0 +1,50 @@
+#include "animation.h"
+
+static const Animation animations[] = {
+	/* animation_player_walk_left */
+	{
+		{
+			{ 0,  16, 16, 16 },
+			{ 16, 16, 16, 16 },
+			{ 16, 16, 16, 16 },
+			{ 0,  16, 16, 16 },
+			{ 32, 16, 16, 16 },
+			{ 32, 16, 16, 16 }
+		},
+		6,
+		3
+	},
+	/* animation_player_walk_right */
+	{
+		{
+			{ 0,  0,  16, 16 },
+			{ 16, 0,  16, 16 },
+			{ 16, 0,  16, 16 },
+			{ 0,  0,  16, 16 },
+			{ 32, 0,  16, 16 },
+			{ 32, 0,  16, 16 }
+		},
+		6,
+		3
+	},
+	/* animation_player_idle_left */
+	{
+		{
+			{ 0,  16, 16, 16 },
+		},
+		1,
+		1
+	},
+	/* animation__player_idle_right */
+	{
+		{
+			{ 0,  0, 16, 16 },
+		},
+		1,
+		1
+	},
+};
+
+const Animation* get_animation(Animation_ID id) {
+	return &animations[id];
+}
diff --git a/animation.h b/animation.h
new file mode 100644
index 0000000..e9e1399
--- /dev/null
+++ b/animation.h
@@ -0,0 +1,22 @@
+#ifndef animation_h
+#define animation_h
+
+#include "config.h"
+#include "rect.h"
+
+typedef enum {
+	animation_player_walk_left = 0,
+	animation_player_walk_right,
+	animation_player_idle_left,
+	animation_player_idle_right
+} Animation_ID;
+
+typedef struct {
+	Rectangle frames[animation_max_frames];
+	int frame_count;
+	int slowness;
+} Animation;
+
+const Animation* get_animation(Animation_ID id);
+
+#endif
diff --git a/animation_system.c b/animation_system.c
new file mode 100644
index 0000000..22317ac
--- /dev/null
+++ b/animation_system.c
@@ -0,0 +1,33 @@
+#include "animation.h"
+#include "components.h"
+#include "world.h"
+
+void animation_system(World* world) {
+	int i;
+	unsigned bits;
+	CSprite* sprite;
+	CAnimated* animated;
+	const Animation* animation;
+
+	for (i = 0; i < world->entity_count; i++) {
+		bits = world->bitmask[i];
+		if ((bits & ctype_sprite) && (bits & ctype_animated)) {
+			sprite = &world->sprites[i];
+			animated = &world->animateds[i];
+			animation = get_animation(animated->id);
+
+			animated->timer++;
+			if (animated->timer > animation->slowness) {
+				animated->frame++;
+				animated->timer = 0;
+			}
+
+			if (animated->frame >= animation->frame_count) {
+				animated->frame = 0;
+				animated->timer = 0;
+			}
+
+			sprite->rect = animation->frames[animated->frame];
+		}
+	}
+}
diff --git a/components.h b/components.h
index cdd7c46..84cfc54 100644
--- a/components.h
+++ b/components.h
@@ -1,6 +1,7 @@
 #ifndef components_h
 #define components_h
 
+#include "animation.h"
 #include "asset.h"
 #include "rect.h"
 
@@ -13,9 +14,17 @@ typedef struct {
 	Rectangle rect;
 } CSprite;
 
+typedef struct {
+	Animation_ID id;
+
+	int frame;
+	int timer;
+} CAnimated;
+
 typedef enum {
 	ctype_sprite   = 1 << 0,
-	ctype_position = 1 << 1
+	ctype_position = 1 << 1,
+	ctype_animated = 1 << 2
 } CType;
 
 #endif
diff --git a/config.h b/config.h
index 91363a9..273f9a5 100644
--- a/config.h
+++ b/config.h
@@ -15,4 +15,6 @@
 /* 16 KB should be enough. */
 #define asset_memory (1024 * 1024 * 16)
 
+#define animation_max_frames 8
+
 #endif
diff --git a/game_config.h b/game_config.h
new file mode 100644
index 0000000..c4efee7
--- /dev/null
+++ b/game_config.h
@@ -0,0 +1,6 @@
+#ifndef game_config_h
+#define game_config_h
+
+#define player_move_speed (3 << fbits)
+
+#endif
diff --git a/main.c b/main.c
index b106978..7cfaf83 100644
--- a/main.c
+++ b/main.c
@@ -22,6 +22,7 @@ void on_init(int argc, char** argv) {
 void on_update() {
 	renderer_begin_frame();
 	update_player(&world.player, &world);
+	animation_system(&world);
 	sprite_system(&world);
 }
 
diff --git a/player.c b/player.c
index e5a0853..801dc33 100644
--- a/player.c
+++ b/player.c
@@ -1,4 +1,6 @@
+#include "animation.h"
 #include "components.h"
+#include "game_config.h"
 #include "input.h"
 #include "player.h"
 #include "standard.h"
@@ -7,28 +9,45 @@
 void init_player(Player* player, World* world) {
 	CSprite* sprite;
 	CPosition* pos;
+	CAnimated* animated;
 	Entity e;
 
 	e = new_entity(world);
 	player->entity = e;
-	add_components(world, e, ctype_sprite | ctype_position);
+	add_components(
+		world,
+		e,
+		ctype_sprite |
+		ctype_position |
+		ctype_animated
+	);
+	pos = &world->positions[e];
 	sprite = &world->sprites[e];
+	animated = &world->animateds[e];
 
-	pos = &world->positions[e];
 	pos->x = 32;
 	pos->y = 70;
 
 	sprite->id = asset_id_char;
 	sprite->rect = make_rect(0, 16, 16, 16);
+
+	animated->id = animation_player_walk_left;
+	animated->frame = 0;
+	animated->timer = 0;
+
+	player->face = 0;
 }
 
 void update_player(Player* player, World* world) {
 	int dx, dy;
+	int face, moving = 0;
 	Entity e;
 	CPosition* pos;
+	CAnimated* animated;
 
 	e = player->entity;
 	pos = &world->positions[e];
+	animated = &world->animateds[e];
 
 	dx = dy = 0;
 	if (button_pressed(btn_dpad_left)) {
@@ -47,10 +66,33 @@ void update_player(Player* player, World* world) {
 		dy += 1 << fbits;
 	}
 
-	if (dx != 0 || dy != 0) {
+	if (dx || dy) {
 		vec_nrmise(&dx, &dy);
 
-		pos->x += dx;
-		pos->y += dy;
+		if (dx) {
+			face = dx < 0 ? 0 : 1;
+		} else {
+			face = player->face;
+		}
+
+		pos->x += (dx * player_move_speed) >> fbits;
+		pos->y += (dy * player_move_speed) >> fbits;
+
+		moving = 1;
+	}
+
+	if (!moving) {
+		animated->frame = 0;
+		animated->id =
+			player->face ?	
+			animation_player_idle_right :
+			animation_player_idle_left;
+	} else {
+		player->face = face;
+
+		animated->id =
+			player->face ?
+			animation_player_walk_right :
+			animation_player_walk_left;
 	}
 }
diff --git a/player.h b/player.h
index 37a7f2a..8412bde 100644
--- a/player.h
+++ b/player.h
@@ -5,6 +5,7 @@ struct World;
 
 typedef struct {
 	int entity;
+	int face;
 } Player;
 
 void init_player(Player* player, struct World* world);
diff --git a/systems.h b/systems.h
index 15abce1..24bc9c2 100644
--- a/systems.h
+++ b/systems.h
@@ -3,6 +3,7 @@
 
 #include "world.h"
 
+void animation_system(World* world);
 void sprite_system(const World* world);
 
 #endif
diff --git a/world.h b/world.h
index 7dbcb4d..9871e9b 100644
--- a/world.h
+++ b/world.h
@@ -15,8 +15,9 @@ struct World {
 
 	unsigned char bitmask[max_entities];
 
-	CSprite sprites[max_entities];
+	CSprite   sprites  [max_entities];
 	CPosition positions[max_entities];
+	CAnimated animateds[max_entities];
 
 	Player player;
 };