Add ECS.

7 files changed, 119 insertions, 7 deletions

diff --git a/Makefile b/Makefile
index d7224bc..7ea122c 100644
--- a/Makefile
+++ b/Makefile
@@ -91,7 +91,9 @@ sources = \
   platform.c \
   rect.c \
   render.c \
+  sprite_system.c \
   standard.c \
+  world.c \
 
 
 assets  = $(wildcard $(data_dir)/*)
diff --git a/components.h b/components.h
new file mode 100644
index 0000000..cdd7c46
--- /dev/null
+++ b/components.h
@@ -0,0 +1,21 @@
+#ifndef components_h
+#define components_h
+
+#include "asset.h"
+#include "rect.h"
+
+typedef struct {
+	int x, y;
+} CPosition;
+
+typedef struct {
+	Asset_ID id;
+	Rectangle rect;
+} CSprite;
+
+typedef enum {
+	ctype_sprite   = 1 << 0,
+	ctype_position = 1 << 1
+} CType;
+
+#endif
diff --git a/main.c b/main.c
index c9cede7..499f313 100644
--- a/main.c
+++ b/main.c
@@ -1,20 +1,33 @@
 #include "asset.h"
 #include "render.h"
+#include "systems.h"
+#include "world.h"
+
+World world;
+Entity player;
 
 void on_init(int argc, char** argv) {
+	CSprite* sprite;
+	CPosition* pos;
+
 	init_renderer();
 
 	load_assets();
-}
 
-void on_update() {
-	const Bitmap* b = get_bitmap(asset_id_usr);
-	Rectangle r;
+	init_world(&world);
 
-	r = make_rect(0, 0, 189, 89);
+	player = new_entity(&world);
+	add_components(&world, player, ctype_sprite | ctype_position);
+	sprite = &world.sprites[player];
+	pos = &world.positions[player];
+	pos->x = 32;
+	pos->y = 70;
+	sprite->id = asset_id_char;
+	sprite->rect = make_rect(0, 16, 16, 16);
+}
 
-	renderer_begin_frame();
-	render_bitmap(b, 0, 0, &r);
+void on_update() {
+	sprite_system(&world);
 }
 
 void on_deinit() {
diff --git a/sprite_system.c b/sprite_system.c
new file mode 100644
index 0000000..99360fc
--- /dev/null
+++ b/sprite_system.c
@@ -0,0 +1,23 @@
+#include "asset.h"
+#include "components.h"
+#include "render.h"
+#include "world.h"
+
+void sprite_system(const World* world) {
+	int i;
+	unsigned bits;
+	const CSprite* sprite;
+	const CPosition* pos;
+	const Bitmap* b;
+
+	for (i = 0; i < world->entity_count; i++) {
+		bits = world->bitmask[i];
+		if ((bits & ctype_position) && (bits & ctype_sprite)) {
+			pos = &world->positions[i];
+			sprite = &world->sprites[i];
+
+			b = get_bitmap(sprite->id);
+			render_bitmap(b, pos->x, pos->y, &sprite->rect);
+		}
+	}
+}
diff --git a/systems.h b/systems.h
new file mode 100644
index 0000000..15abce1
--- /dev/null
+++ b/systems.h
@@ -0,0 +1,8 @@
+#ifndef systems_h
+#define systems_h
+
+#include "world.h"
+
+void sprite_system(const World* world);
+
+#endif
diff --git a/world.c b/world.c
new file mode 100644
index 0000000..b271c3d
--- /dev/null
+++ b/world.c
@@ -0,0 +1,21 @@
+#include "world.h"
+
+void init_world(World* world) {
+	world->entity_count = 0;
+}
+
+Entity new_entity(World* world) {
+	Entity e;
+
+	e = world->entity_count++;
+	world->bitmask[e] = 0;
+	return e;
+}
+
+void add_components(World* world, Entity e, CType bits) {
+	world->bitmask[e] |= bits;
+}
+
+void remove_components(World* world, Entity e, CType bits) {
+	world->bitmask[e] &= ~bits;
+}
diff --git a/world.h b/world.h
new file mode 100644
index 0000000..7f19520
--- /dev/null
+++ b/world.h
@@ -0,0 +1,24 @@
+#ifndef world_h
+#define world_h
+
+#include "components.h"
+
+#define max_entities 256
+
+typedef int Entity;
+
+typedef struct {
+	int entity_count;
+
+	unsigned char bitmask[max_entities];
+
+	CSprite sprites[max_entities];
+	CPosition positions[max_entities];
+} World;
+
+void init_world(World* world);
+Entity new_entity(World* world);
+void add_components(World* world, Entity e, CType bits);
+void remove_components(World* world, Entity e, CType bits);
+
+#endif