From 1f451f10be01680fc12ca5b33f187836e72585f0 Mon Sep 17 00:00:00 2001
From: DavoSK <david.svitana@gmail.com>
Date: Thu, 2 Feb 2023 15:41:16 +0100
Subject: [PATCH] added weapon knife system

---
 code/foundation/src/models/components.h |  9 +++++-
 code/games/survival/src/game.c          | 10 +++++++
 code/games/survival/src/system_weapon.c | 37 +++++++++++++++++++++++++
 3 files changed, 55 insertions(+), 1 deletion(-)
 create mode 100644 code/games/survival/src/system_weapon.c

diff --git a/code/foundation/src/models/components.h b/code/foundation/src/models/components.h
index d7661cd..8bb0f75 100644
--- a/code/foundation/src/models/components.h
+++ b/code/foundation/src/models/components.h
@@ -228,9 +228,15 @@ typedef struct {
 } MobHuntPlayer;
 
 typedef struct { 
-	char _unused; 
+    char _unused; 
 } MobMelee;
 
+typedef struct {
+    uint16_t projectile_count;
+    uint8_t damage;
+    uint8_t spawn_delay;
+} WeaponKnife;
+
 #define _COMPS\
 	X(Vector2D)\
 	X(Position)\
@@ -247,6 +253,7 @@ typedef struct {
 	X(Mob)\
 	X(MobHuntPlayer)\
 	X(MobMelee)\
+    X(WeaponKnife)\
 	X(Classify)\
 	X(Vehicle)\
 	X(IsInVehicle)\
diff --git a/code/games/survival/src/game.c b/code/games/survival/src/game.c
index ec08b59..8b49b7c 100644
--- a/code/games/survival/src/game.c
+++ b/code/games/survival/src/game.c
@@ -10,11 +10,13 @@
 
 // custom systems
 #include "system_mob.c"
+#include "system_weapon.c"
 
 void mob_systems(ecs_world_t *ecs) {
 	ECS_SYSTEM_TICKED_EX(ecs, MobDetectPlayers, EcsPostUpdate, 100.0f, components.Position, components.Mob);
 	ECS_SYSTEM(ecs, MobMovement, EcsPostUpdate, components.Velocity, components.Position, components.MobHuntPlayer);
 	ECS_SYSTEM_TICKED(ecs, MobMeleeAtk, EcsPostUpdate, components.Position, components.Mob, components.MobHuntPlayer, components.MobMelee);
+	ECS_SYSTEM_TICKED(ecs, WeaponKnifeMechanic, EcsPostUpdate, components.WeaponKnife, components.Position, components.Input);
 	//ECS_OBSERVER(ecs, MobDetectPlayers1, EcsOnAdd, components.Mob);
 }
 
@@ -36,6 +38,14 @@ void game_setup_ecs() {
 
 void game_player_joined(uint64_t ent) {
 	notification_push("test1", "Hello World!");
+
+	//NOTE(DavoSK): add weapon component for testing
+	ecs_world_t* world = world_ecs();
+	ecs_set(world, (ecs_entity_t)ent, WeaponKnife, {
+		.projectile_count = 1,
+		.damage = 10,
+		.spawn_delay = WEAPON_KNIFE_SPAWN_DELAY
+	});
 }
 
 void game_player_departed(uint64_t ent) {
diff --git a/code/games/survival/src/system_weapon.c b/code/games/survival/src/system_weapon.c
new file mode 100644
index 0000000..b226f70
--- /dev/null
+++ b/code/games/survival/src/system_weapon.c
@@ -0,0 +1,37 @@
+#define WEAPON_KNIFE_SPAWN_DELAY 20
+#define WEAPON_PROJECTILE_POS_OFFSET 0.2f
+#define WEAPON_PROJECTILE_SPEED 10.0f
+
+//TODO(DavoSK): move to helpers, add srand
+float get_rand_between(float min, float max) {
+    float scale = rand() / (float) RAND_MAX; /* [0, 1.0] */
+    return min + scale * ( max - min );      /* [min, max] */
+}
+
+void WeaponKnifeMechanic(ecs_iter_t *it) {
+	WeaponKnife *weapon = ecs_field(it, WeaponKnife, 1);
+	const Position *pos = ecs_field(it, Position, 2);
+    const Input *input = ecs_field(it, Input, 3);
+
+	for (int i = 0; i < it->count; i++) {
+		if (weapon[i].spawn_delay > 0) {
+			TICK_VAR(weapon[i].spawn_delay);
+            continue;
+		}
+
+        for(int j = 0; j < weapon[i].projectile_count; j++) {
+            ecs_entity_t projectile_entity = ecs_new_entity(it->world, "WeaponProjectile");
+            ecs_set(it->world, projectile_entity, Position, { 
+                .x=pos[i].x, 
+                .y=pos[i].y+get_rand_between(-WEAPON_PROJECTILE_POS_OFFSET, WEAPON_PROJECTILE_POS_OFFSET)
+            });
+            
+            ecs_set(it->world, projectile_entity, Velocity, {
+                .x=input[i].x*WEAPON_PROJECTILE_SPEED,
+                .y=input[i].y*WEAPON_PROJECTILE_SPEED
+            });
+        }
+
+		weapon[i].spawn_delay = WEAPON_KNIFE_SPAWN_DELAY;
+	}
+}
\ No newline at end of file