weapon hit system

code/foundation/src/models/components.h

@@ -123,6 +123,10 @@ typedef struct {
 	uint8_t _unused;
 } HealthDecreased;
 
+typedef struct {
+    uint8_t amount;
+} Damage;
+
 typedef struct {
     uint16_t id;
 } Classify;
@@ -283,6 +287,7 @@ typedef struct {
 	X(HealthRegen)\
 	X(HealDelay)\
 	X(HealthDecreased)\
+    X(Damage)\
 	X(Mob)\
 	X(MobHuntPlayer)\
 	X(MobMelee)\

code/games/survival/src/game.c

@@ -8,6 +8,8 @@
 
 #include "gui/notifications.h"
 
+static ecs_query_t *ecs_mobpos_query = NULL;
+
 // custom systems
 #include "system_mob.c"
 #include "system_weapon.c"
@@ -18,9 +20,10 @@ void mob_systems(ecs_world_t *ecs) {
 	ECS_SYSTEM_TICKED(ecs, MobMeleeAtk, EcsPostUpdate, components.Position, components.Mob, components.MobHuntPlayer, components.MobMelee);
 	
 	//NOTE(DavoSK): weapons
+	ecs_mobpos_query = ecs_query_new(world_ecs(), "components.Mob, components.Position");
 	ECS_SYSTEM_TICKED(ecs, WeaponKnifeMechanic, EcsPostUpdate, components.WeaponKnife, components.Position, components.Input);
+	ECS_SYSTEM_TICKED(ecs, WeaponProjectileHit, EcsPostUpdate, components.WeaponProjectile, components.Position, components.Rotation);
 	ECS_SYSTEM_TICKED(ecs, WeaponProjectileExpire, EcsPostUpdate, components.WeaponProjectile, components.Position);
-	
 	//ECS_OBSERVER(ecs, MobDetectPlayers1, EcsOnAdd, components.Mob);
 }
 

code/games/survival/src/system_weapon.c

@@ -1,3 +1,7 @@
+ZPL_DIAGNOSTIC_PUSH_WARNLEVEL(0)
+#include "tinyc2.h"
+ZPL_DIAGNOSTIC_POP
+
 #define WEAPON_KNIFE_SPAWN_DELAY 20
 #define WEAPON_PROJECTILE_POS_OFFSET 200.0f
 #define WEAPON_PROJECTILE_SPEED 500.0f
@@ -71,7 +75,92 @@ void WeaponProjectileExpire(ecs_iter_t *it) {
     }
 }
 
-void WeaponProjectileHit(ecs_iter_t *it) {
-    //TODO(DavoSK): hit entity, attach take damage component
-    //remove projectile
+zpl_vec2 rotate_point(float cx, float cy, float angle, zpl_vec2 p){
+    return (zpl_vec2) {
+        .x = zpl_cos(angle) * (p.x - cx) - zpl_sin(angle) * (p.y - cy) + cx,
+        .y = zpl_sin(angle) * (p.x - cx) + zpl_cos(angle) * (p.y - cy) + cy
+    };
+}
+
+void WeaponProjectileHit(ecs_iter_t *it) {
+    const WeaponProjectile *weapon = ecs_field(it, WeaponProjectile, 1);
+	const Position *pos = ecs_field(it, Position, 2);
+    const Rotation *rot = ecs_field(it, Rotation, 3);
+
+    for (int i = 0; i < it->count; i++) {
+        ecs_iter_t it2 = ecs_query_iter(world_ecs(), ecs_mobpos_query);
+        while (ecs_query_next(&it2)) {
+            Mob *mob = ecs_field(&it2, Mob, 1);
+            Position *mob_pos = ecs_field(&it2, Position, 2);
+            
+            for (int j = 0; j < it2.count; j++) {
+                float p_x = pos[i].x;
+                float p_y = pos[i].y;
+                float p2_x = mob_pos[j].x /*+ v2[j].x*/;
+                float p2_y = mob_pos[j].y /*+ v2[j].y*/;
+
+                //NOTE(DavoSK): since our weapon has also rotation 
+                //we need to rotate its bbox by rot
+                float rot_radians = zpl_to_radians(rot[i].angle);
+                zpl_vec2 bbox_min = rotate_point(p_x, p_y, rot_radians, (zpl_vec2){ 
+                    .x = p_x - WORLD_BLOCK_SIZE / 2, 
+                    .y = p_y - WORLD_BLOCK_SIZE / 4 
+                });
+                
+                zpl_vec2 bbox_max = rotate_point(p_x, p_y, rot_radians, (zpl_vec2){ 
+                    .x = p_x + WORLD_BLOCK_SIZE / 2, 
+                    .y = p_y + WORLD_BLOCK_SIZE / 4 
+                });
+
+                c2AABB box_a = {
+                    .min = { .x = bbox_min.x, .y = bbox_min.y },
+                    .max = { .x = bbox_max.x, .y = bbox_max.y }
+                };
+
+                c2AABB box_b = {
+                    .min = { p2_x - WORLD_BLOCK_SIZE / 2, p2_y - WORLD_BLOCK_SIZE / 4 },
+                    .max = { p2_x + WORLD_BLOCK_SIZE / 2, p2_y + WORLD_BLOCK_SIZE / 4 },
+                };
+
+                float r1x = (box_a.max.x-box_a.min.x);
+                float r1y = (box_a.max.y-box_a.min.y);
+                float r1 = (r1x*r1x + r1y*r1y)*.5f;
+
+                float r2x = (box_b.max.x-box_b.min.x);
+                float r2y = (box_b.max.y-box_b.min.y);
+                float r2 = (r2x*r2x + r2y*r2y)*.5f;
+
+                {
+                    float dx = (p2_x-p_x);
+                    float dy = (p2_y-p_y);
+                    float d = (dx*dx + dy*dy);
+
+                    if (d > r1 && d > r2)
+                        continue;
+                }
+
+                // c2Circle circle_a = { 
+                //     .p = { p_x, p_y },
+                //     .r = r1/2.f,
+                // };
+
+                // c2Circle circle_b = {
+                //     .p = { p2_x, p2_y },
+                //     .r = r2/2.f,
+                // };
+
+
+                // const void *shapes_a[] = { &circle_a, &box_a };
+                // const void *shapes_b[] = { &circle_b, &box_b };
+                
+                c2Manifold m = { 0 };
+                c2Collide(&box_a, 0, C2_TYPE_AABB, &box_b, 0, C2_TYPE_AABB, &m);
+
+                if(m.count) {
+                    ecs_set(it->world, it2.entities[j], Damage, { .amount = weapon[i].damage });
+                    entity_despawn(it->entities[i]);
+                }
+            }
+        }
+    }
 }