Add killing enemies.

17 files changed, 294 insertions, 21 deletions

diff --git a/Makefile b/Makefile
index 581c027..4fe54fd 100644
--- a/Makefile
+++ b/Makefile
@@ -89,7 +89,9 @@ sources = \
   animation_system.c \
   asset.c \
   bullet.c \
+  collision_system.c \
   enemy.c \
+  fx.c \
   main.c \
   malware.c \
   platform.c \
diff --git a/animation.c b/animation.c
index 6dbb08f..6cf2584 100644
--- a/animation.c
+++ b/animation.c
@@ -43,6 +43,16 @@ static const Animation animations[] = {
 		1,
 		1
 	},
+	/* animation_enemy_bullet_explode */
+	{
+		{
+			{ 24, 0, 7, 7 },
+			{ 31, 0, 7, 7 },
+			{ 38, 0, 7, 7 }
+		},
+		3,
+		5
+	}
 };
 
 const Animation* get_animation(Animation_ID id) {
diff --git a/animation.h b/animation.h
index e9e1399..65956a6 100644
--- a/animation.h
+++ b/animation.h
@@ -8,7 +8,8 @@ typedef enum {
 	animation_player_walk_left = 0,
 	animation_player_walk_right,
 	animation_player_idle_left,
-	animation_player_idle_right
+	animation_player_idle_right,
+	animation_enemy_bullet_explode
 } Animation_ID;
 
 typedef struct {
diff --git a/animation_system.c b/animation_system.c
index 22317ac..8411e64 100644
--- a/animation_system.c
+++ b/animation_system.c
@@ -23,6 +23,11 @@ void animation_system(World* world) {
 			}
 
 			if (animated->frame >= animation->frame_count) {
+				if (bits & ctype_destroy_on_anim_done) {
+					destroy_entity(world, i);
+					continue;
+				}
+
 				animated->frame = 0;
 				animated->timer = 0;
 			}
diff --git a/bullet.c b/bullet.c
index a2f1c66..b3182ea 100644
--- a/bullet.c
+++ b/bullet.c
@@ -3,6 +3,7 @@
 #include "error.h"
 #include "platform.h"
 #include "sprite.h"
+#include "standard.h"
 #include "world.h"
 
 Entity new_player_bullet(
@@ -17,6 +18,7 @@ Entity new_player_bullet(
 	CBullet* bullet;
 	CPosition* pos;
 	CSprite* sprite;
+	CCollider* col;
 	Sprite_ID sprid;
 
 	e = new_entity(world);
@@ -27,11 +29,13 @@ Entity new_player_bullet(
 		ctype_sprite        |
 		ctype_position      |
 		ctype_bullet        |
-		ctype_player_bullet
+		ctype_player_bullet |
+		ctype_collider
 	);
 	pos = &world->positions[e];
 	sprite = &world->sprites[e];
 	bullet = &world->bullets[e];
+	col = &world->colliders[e];
 	pos->x = x;
 	pos->y = y;
 
@@ -39,14 +43,25 @@ Entity new_player_bullet(
 	bullet->vy = vy;
 	bullet->life = life;
 
+	col->x = 0;
+	col->y = 0;
+
 	if (vx < 0) {
 		sprid = sprite_player_bullet_left;
+		col->w = 9  << fbits;
+		col->h = 14 << fbits;
 	} else if (vx > 0) {
 		sprid = sprite_player_bullet_right;
+		col->w = 9  << fbits;
+		col->h = 14 << fbits;
 	} else if (vy < 0) {
 		sprid = sprite_player_bullet_up;
+		col->w = 9  << fbits;
+		col->h = 14 << fbits;
 	} else if (vy > 0) {
 		sprid = sprite_player_bullet_down;
+		col->w = 9  << fbits;
+		col->h = 14 << fbits;
 	}
 #ifdef DEBUG
 	else {
@@ -71,6 +86,7 @@ int new_enemy_bullet(
 	CBullet* bullet;
 	CPosition* pos;
 	CSprite* sprite;
+	CCollider* col;
 
 	e = new_entity(world);
 
@@ -80,11 +96,13 @@ int new_enemy_bullet(
 		ctype_sprite        |
 		ctype_position      |
 		ctype_bullet        |
-		ctype_enemy_bullet
+		ctype_enemy_bullet  |
+		ctype_collider
 	);
 	pos = &world->positions[e];
 	sprite = &world->sprites[e];
 	bullet = &world->bullets[e];
+	col = &world->colliders[e];
 	pos->x = x;
 	pos->y = y;
 
@@ -92,6 +110,11 @@ int new_enemy_bullet(
 	bullet->vy = vy;
 	bullet->life = 500;
 
+	col->x = 1 << fbits;
+	col->y = 1 << fbits;
+	col->w = 3 << fbits;
+	col->h = 3 << fbits;
+
 	init_csprite(sprite, sprite_enemy_bullet);
 
 	return e;
diff --git a/collision_system.c b/collision_system.c
new file mode 100644
index 0000000..abd5dc9
--- /dev/null
+++ b/collision_system.c
@@ -0,0 +1,105 @@
+#ifndef systems_h
+#define systems_h
+
+#include "config.h"
+#include "fx.h"
+#include "rect.h"
+#include "world.h"
+
+static void handle_bullet_vs_player(
+	World* world,
+	Entity bullet,
+	Entity player
+) {
+	const CPosition* pos;
+
+	pos = &world->positions[bullet];
+
+	destroy_entity(world, bullet);
+	new_enemy_bullet_explosion(world, pos->x, pos->y);
+}
+
+static void handle_bullet_vs_enemy(
+	World* world,
+	Entity bullet,
+	Entity enemy
+) {
+	CEnemy* e;
+
+	e = &world->enemies[enemy];
+	e->hp--;
+	destroy_entity(world, bullet);
+}
+
+static void handle(World* world, Entity a, Entity b) {
+	unsigned ab, bb;
+
+	ab = world->bitmask[a];
+	bb = world->bitmask[b];
+
+	if ((ab & ctype_enemy_bullet) && (bb & ctype_player)) {
+		handle_bullet_vs_player(world, a, b);
+		return;
+	}
+
+	if ((ab & ctype_player) && (bb & ctype_enemy_bullet)) {
+		handle_bullet_vs_player(world, b, a);
+		return;
+	}
+
+	if ((ab & ctype_player_bullet) && (bb & ctype_enemy)) {
+		handle_bullet_vs_enemy(world, a, b);
+		return;
+	}
+
+	if ((ab & ctype_enemy) && (bb & ctype_player_bullet)) {
+		handle_bullet_vs_enemy(world, b, a);
+		return;
+	}
+}
+
+void collision_system(World* world) {
+	int i, j, p0x, p0y;
+	unsigned bits;
+	const CPosition* pos0, * pos1;
+	const CCollider* col0, * col1;
+
+	for (i = 0; i < world->entity_count; i++) {
+		bits = world->bitmask[i];
+		if (
+			!(bits & ctype_collider) ||
+			!(bits & ctype_position)
+		) { continue; }
+
+		pos0 = &world->positions[i];
+		col0 = &world->colliders[i];
+		p0x = pos0->x + col0->x;
+		p0y = pos0->y + col0->y;
+
+		for (j = i + 1; j < world->entity_count; j++) {
+			bits = world->bitmask[j];
+			if (
+				!(bits & ctype_collider) ||
+				!(bits & ctype_position)
+			) { continue; }
+
+			pos1 = &world->positions[j];
+			col1 = &world->colliders[j];
+
+			if (rects_overlap2(
+				p0x,
+				p0y,
+				col0->w,
+				col0->h,
+				pos1->x + col1->x,
+				pos1->y + col1->y,
+				col1->w,
+				col1->h
+			)) {
+				handle(world, i, j);
+			}
+		}
+	}
+}
+
+#endif
diff --git a/components.h b/components.h
index d288ac5..f23b35e 100644
--- a/components.h
+++ b/components.h
@@ -39,16 +39,23 @@ typedef struct {
 	int vx, vy;
 } CDebris;
 
+typedef struct {
+	int x, y, w, h;
+} CCollider;
+
 typedef enum {
-	ctype_sprite        = 1 << 0,
-	ctype_position      = 1 << 1,
-	ctype_animated      = 1 << 2,
-	ctype_bullet        = 1 << 3,
-	ctype_player_bullet = 1 << 4,
-	ctype_enemy_bullet  = 1 << 5,
-	ctype_enemy         = 1 << 6,
-	ctype_skull         = 1 << 7,
-	ctype_debris        = 1 << 8
+	ctype_sprite               = 1 << 0,
+	ctype_position             = 1 << 1,
+	ctype_animated             = 1 << 2,
+	ctype_bullet               = 1 << 3,
+	ctype_player_bullet        = 1 << 4,
+	ctype_enemy_bullet         = 1 << 5,
+	ctype_enemy                = 1 << 6,
+	ctype_skull                = 1 << 7,
+	ctype_debris               = 1 << 8,
+	ctype_collider             = 1 << 9,
+	ctype_player               = 1 << 10,
+	ctype_destroy_on_anim_done = 1 << 11
 } CType;
 
 #endif
diff --git a/enemy.c b/enemy.c
index 9a67cba..6729862 100644
--- a/enemy.c
+++ b/enemy.c
@@ -9,6 +9,7 @@ Entity new_skull(World* world, int x, int y) {
 	CSprite* sprite;
 	CPosition* pos;
 	CEnemy* enemy;
+	CCollider* col;
 	Entity e;
 
 	e = new_entity(world);
@@ -18,15 +19,22 @@ Entity new_skull(World* world, int x, int y) {
 		ctype_position |
 		ctype_sprite |
 		ctype_enemy |
-		ctype_skull
+		ctype_skull |
+		ctype_collider
 	);
 	pos = &world->positions[e];
 	sprite = &world->sprites[e];
 	enemy = &world->enemies[e];
+	col = &world->colliders[e];
 
 	pos->x = x;
 	pos->y = y;
 
+	col->x = 2  << fbits;
+	col->y = 2  << fbits;
+	col->w = 14 << fbits;
+	col->h = 14 << fbits;
+
 	init_csprite(sprite, sprite_skull_right);
 
 	enemy->hp = skull_hp;
@@ -44,13 +52,22 @@ void enemy_system(World* world) {
 	Player* player;
 	CPosition* ppos;
 	int dpx, dpy, tpx, tpy, d;
-	char buf[32];
 
 	player = &world->player;
 	ppos = &world->positions[player->entity];
 
 	for (i = 0; i < world->entity_count; i++) {
 		bits = world->bitmask[i];
+		if (bits & ctype_enemy) {
+			enemy = &world->enemies[i];
+			if (enemy->hp <= 0) {
+				destroy_entity(world, i);
+			}
+		}
+	}
+
+	for (i = 0; i < world->entity_count; i++) {
+		bits = world->bitmask[i];
 		if (
 			(bits & ctype_position) &&
 			(bits & ctype_enemy) &&
@@ -59,8 +76,8 @@ void enemy_system(World* world) {
 			pos = &world->positions[i];
 			enemy = &world->enemies[i];
 
-			dpx = (ppos->x - pos->x) >> 4;
-			dpy = (ppos->y - pos->y) >> 4;
+			dpx = ((ppos->x - pos->x) >> 4) + 256;
+			dpy = ((ppos->y - pos->y) >> 4) + 256;
 			tpx = dpx;
 			tpy = dpy;
 			d = ((dpx * dpx) >> fbits) + ((dpy * dpy) >> fbits);
@@ -89,8 +106,8 @@ void enemy_system(World* world) {
 
 				new_enemy_bullet(
 					world,
-					pos->x,
-					pos->y,
+					pos->x + 2560,
+					pos->y + 2560,
 					tpx * enemy_bullet_speed,
 					tpy * enemy_bullet_speed
 				);
diff --git a/fx.c b/fx.c
new file mode 100644
index 0000000..f2a5f54
--- /dev/null
+++ b/fx.c
@@ -0,0 +1,40 @@
+#include "components.h"
+#include "fx.h"
+#include "world.h"
+
+int new_enemy_bullet_explosion(
+	World* world,
+	int x,
+	int y
+) {
+	Entity e;
+	CPosition* pos;
+	CSprite* sprite;
+	CAnimated* animated;
+
+	e = new_entity(world);
+	add_components(
+		world,
+		e,
+		ctype_sprite |
+		ctype_position |
+		ctype_animated |
+		ctype_destroy_on_anim_done
+	);
+
+	pos = &world->positions[e];
+	sprite = &world->sprites[e];
+	animated = &world->animateds[e];
+
+	pos->x = x;
+	pos->y = y;
+
+	sprite->id = asset_id_bullet;
+	sprite->rect = make_rect(0, 0, 16, 16);
+
+	animated->id = animation_enemy_bullet_explode;
+	animated->frame = 0;
+	animated->timer = 0;
+
+	return e;
+}
diff --git a/fx.h b/fx.h
new file mode 100644
index 0000000..acbde30
--- /dev/null
+++ b/fx.h
@@ -0,0 +1,14 @@
+#ifndef fx_h
+#define fx_h
+
+#include "animation.h"
+
+struct World;
+
+int new_enemy_bullet_explosion(
+	struct World* world,
+	int x,
+	int y
+);
+
+#endif
diff --git a/intermediate/bullet.bmp b/intermediate/bullet.bmp
index e6735ce..e92d3fb 100644
--- a/intermediate/bullet.bmp
+++ b/intermediate/bullet.bmp
diff --git a/main.c b/main.c
index ef757b2..9d2aff8 100644
--- a/main.c
+++ b/main.c
@@ -27,6 +27,7 @@ void on_update() {
 	update_player(&world.player, &world);
 	enemy_system(&world);
 	bullet_system(&world);
+	collision_system(&world);
 	animation_system(&world);
 	sprite_system(&world);
 }
diff --git a/player.c b/player.c
index b723849..b2dbf29 100644
--- a/player.c
+++ b/player.c
@@ -11,6 +11,7 @@ void init_player(Player* player, World* world) {
 	CSprite* sprite;
 	CPosition* pos;
 	CAnimated* animated;
+	CCollider* col;
 	Entity e;
 
 	e = new_entity(world);
@@ -20,11 +21,14 @@ void init_player(Player* player, World* world) {
 		e,
 		ctype_sprite |
 		ctype_position |
-		ctype_animated
+		ctype_animated |
+		ctype_collider |
+		ctype_player
 	);
 	pos = &world->positions[e];
 	sprite = &world->sprites[e];
 	animated = &world->animateds[e];
+	col = &world->colliders[e];
 
 	pos->x = 32 << fbits;
 	pos->y = 70 << fbits;
@@ -36,6 +40,11 @@ void init_player(Player* player, World* world) {
 	animated->frame = 0;
 	animated->timer = 0;
 
+	col->x = 3  << fbits;
+	col->y = 1  << fbits;
+	col->w = 10 << fbits;
+	col->h = 15 << fbits;
+
 	player->face = 0;
 	player->shoot_cooldown = 15;
 	player->shoot_countdown = 0;
diff --git a/rect.c b/rect.c
index ec755e2..aafa645 100644
--- a/rect.c
+++ b/rect.c
@@ -8,3 +8,28 @@ Rectangle make_rect(int x, int y, int w, int h) {
 	r.h = h;
 	return r;
 }
+
+int rects_overlap(const Rectangle* a, const Rectangle* b) {
+	return
+		a->x + a->w > b->x &&
+		a->y + a->h > b->y &&
+		a->x < b->x + b->w &&
+		a->y < b->y + b->h;
+}
+
+int rects_overlap2(
+	int x0,
+	int y0,
+	int w0,
+	int h0,
+	int x1,
+	int y1,
+	int w1,
+	int h1
+) {
+	return
+		x0 + w0 > x1 &&
+		y0 + h0 > y1 &&
+		x0 < x1 + w1 &&
+		y0 < y1 + h1;
+}
diff --git a/rect.h b/rect.h
index 6f45705..bf494b2 100644
--- a/rect.h
+++ b/rect.h
@@ -7,4 +7,17 @@ typedef struct {
 
 Rectangle make_rect(int x, int y, int w, int h);
 
+int rects_overlap(const Rectangle* a, const Rectangle* b);
+
+int rects_overlap2(
+	int x0,
+	int y0,
+	int w0,
+	int h0,
+	int x1,
+	int y1,
+	int w1,
+	int h1
+);
+
 #endif
diff --git a/systems.h b/systems.h
index 0cc55ec..6bf4edc 100644
--- a/systems.h
+++ b/systems.h
@@ -5,8 +5,8 @@
 
 void animation_system(World* world);
 void bullet_system(World* world);
-void sprite_system(const World* world);
+void collision_system(World* world);
 void enemy_system(World* world);
-
+void sprite_system(const World* world);
 
 #endif
diff --git a/world.h b/world.h
index 9709337..923dc90 100644
--- a/world.h
+++ b/world.h
@@ -21,6 +21,7 @@ struct World {
 	CAnimated      animateds     [max_entities];
 	CBullet        bullets       [max_entities];
 	CEnemy         enemies       [max_entities];
+	CCollider      colliders     [max_entities];
 
 	Player player;
 };