combat: add hit chance & damage variance to make combat more engaging

Signed-off-by: NotAShelf <raf@notashelf.dev>
Change-Id: Ia1e0a503dba03e5df7b863b97db962e36a6a6964

src/combat.c

@@ -1,5 +1,6 @@
 #include "combat.h"
 #include "common.h"
+#include "rng.h"
 #include <stddef.h>
 
 // Track combat events for feedback
@@ -7,9 +8,10 @@ typedef struct {
   const char *message;
   int damage;
   int is_player_damage;
+  int is_critical;
 } CombatEvent;
 
-static CombatEvent last_event = {NULL, 0, 0};
+static CombatEvent last_event = {NULL, 0, 0, 0};
 
 const char *combat_get_last_message(void) {
   return last_event.message;
@@ -23,25 +25,48 @@ int combat_was_player_damage(void) {
   return last_event.is_player_damage;
 }
 
+int combat_was_critical(void) {
+  return last_event.is_critical;
+}
+
 void combat_player_attack(Player *p, Enemy *e) {
   if (e == NULL || !e->alive)
     return;
 
-  // Deal damage
+  last_event.is_critical = 0;
-  int damage = p->attack;
-  e->hp -= damage;
 
-  // Set combat event
+  // 90% hit chance
+  if (rng_int(0, 99) < 90) {
+    // calculate damage with variance from player stats
+    int base_damage = p->attack;
+    int variance = rng_int(p->dmg_variance_min, p->dmg_variance_max);
+    int damage = (base_damage * variance) / 100;
+    if (damage < 1)
+      damage = 1;
+
+    // 10% critical hit chance for 1.5x
+    if (rng_int(0, 9) == 0) {
+      damage = (damage * 3) / 2;
+      last_event.is_critical = 1;
+    }
+
+    e->hp -= damage;
     last_event.damage = damage;
     last_event.is_player_damage = 0;
 
-  // Check if enemy died
     if (e->hp <= 0) {
       e->hp = 0;
       e->alive = 0;
       last_event.message = "Enemy killed!";
+    } else if (last_event.is_critical) {
+      last_event.message = "Critical hit!";
     } else {
-    last_event.message = "You hit the enemy";
+      last_event.message = "You hit";
+    }
+  } else {
+    last_event.damage = 0;
+    last_event.is_player_damage = 0;
+    last_event.message = "You missed";
   }
 }
 
@@ -51,22 +76,42 @@ void combat_enemy_attack(Enemy *e, Player *p) {
   if (p == NULL)
     return;
 
-  // Deal damage reduced by defense (minimum 1 damage)
+  last_event.is_critical = 0;
-  int damage = e->attack - p->defense;
+
+  // 85% hit chance for enemies
+  if (rng_int(0, 99) < 85) {
+    // calculate damage with variance
+    int base_damage = e->attack - p->defense;
+    if (base_damage < 1)
+      base_damage = 1;
+
+    int variance = rng_int(80, 120);
+    int damage = (base_damage * variance) / 100;
     if (damage < 1)
       damage = 1;
-  p->hp -= damage;
 
-  // Set combat event
+    // 5% critical hit chance for enemies
+    if (rng_int(0, 19) == 0) {
+      damage = (damage * 3) / 2;
+      last_event.is_critical = 1;
+    }
+
+    p->hp -= damage;
     last_event.damage = damage;
     last_event.is_player_damage = 1;
 
-  // Check if player died
     if (p->hp <= 0) {
       p->hp = 0;
       last_event.message = "You died!";
+    } else if (last_event.is_critical) {
+      last_event.message = "Critical!";
     } else {
-    last_event.message = "Enemy attacks!";
+      last_event.message = "Hit";
+    }
+  } else {
+    last_event.damage = 0;
+    last_event.is_player_damage = 1;
+    last_event.message = "Missed";
   }
 }
 
@@ -74,4 +119,5 @@ void combat_reset_event(void) {
   last_event.message = NULL;
   last_event.damage = 0;
   last_event.is_player_damage = 0;
+  last_event.is_critical = 0;
 }

src/combat.h

@@ -12,10 +12,13 @@ int combat_get_last_damage(void);
 // Was last damage to player?
 int combat_was_player_damage(void);
 
+// Was it a critical hit?
+int combat_was_critical(void);
+
 // Reset combat event
 void combat_reset_event(void);
 
-// Player attacks enemy
+// Player attacks enemy (pass player for damage variance)
 void combat_player_attack(Player *p, Enemy *e);
 
 // Enemy attacks player

src/common.h

@@ -53,6 +53,9 @@ typedef struct {
   int has_armor;
   Item inventory[MAX_INVENTORY];
   int inventory_count;
+  // damage variance range (0.8 to 1.2 = 80 to 120)
+  int dmg_variance_min;  // minimum damage multiplier (80 = 0.8x)
+  int dmg_variance_max;  // maximum damage multiplier (120 = 1.2x)
 } Player;
 
 // Enemy types
@@ -70,6 +73,14 @@ typedef struct {
   int cooldown;  // countdown to next action
 } Enemy;
 
+// Floating damage text
+typedef struct {
+  int x, y;
+  int value;
+  int lifetime;  // frames remaining
+  int is_critical;
+} FloatingText;
+
 // GameState - encapsulates all game state for testability and save/load
 typedef struct {
   Player player;
@@ -87,6 +98,16 @@ typedef struct {
   int awaiting_descend;  // 0 = normal, 1 = waiting for Y/N
   int show_inventory;    // 0 = hidden, 1 = show overlay
   int inv_selected;      // currently selected inventory index
+  // action log
+  char action_log[5][128];
+  int log_count;
+  int log_head;
+  // visual effects
+  FloatingText floating_texts[8];
+  int floating_count;
+  int screen_shake;  // frames of screen shake remaining
+  int shake_x;
+  int shake_y;
 } GameState;
 
 #endif  // COMMON_H

src/player.c

@@ -25,6 +25,8 @@ void player_init(Player *p, int x, int y) {
   p->equipped_weapon.picked_up = 1;
   p->equipped_armor.picked_up = 1;  // mark as invalid
   p->inventory_count = 0;
+  p->dmg_variance_min = 80;
+  p->dmg_variance_max = 120;
 
   // Initialize inventory to empty
   for (int i = 0; i < MAX_INVENTORY; i++) {
@@ -186,6 +188,16 @@ int player_equip_item(Player *p, int inv_index) {
     p->equipped_weapon = *item;
     p->has_weapon = 1;
     p->attack += item->power;
+    // Adjust damage variance based on weapon power
+    // Higher power = wider range (more swingy but higher potential)
+    int min_var = 100 - (item->power * 3);
+    int max_var = 100 + (item->power * 5);
+    if (min_var < 60)
+      min_var = 60;
+    if (max_var > 150)
+      max_var = 150;
+    p->dmg_variance_min = min_var;
+    p->dmg_variance_max = max_var;
     // Remove from inventory
     player_remove_inventory_item(p, inv_index);
     return 1;
@@ -205,5 +217,32 @@ int player_equip_item(Player *p, int inv_index) {
     return 1;
   }
 
-  return 0;  // Not equippable (potion)
+  return 0;  // not equippable (potion)
+}
+
+int player_drop_item(Player *p, int inv_index, Item *items, int item_count) {
+  if (p == NULL)
+    return 0;
+  if (inv_index < 0 || inv_index >= MAX_INVENTORY)
+    return 0;
+
+  Item *item = player_get_inventory_item(p, inv_index);
+  if (item == NULL)
+    return 0;
+
+  // Find an empty slot in items array to place the dropped item
+  for (int i = 0; i < item_count; i++) {
+    if (items[i].picked_up) {
+      // Place dropped item at this position
+      items[i] = *item;
+      items[i].x = p->x;
+      items[i].y = p->y;
+      items[i].picked_up = 0;
+      // Remove from inventory
+      player_remove_inventory_item(p, inv_index);
+      return 1;
+    }
+  }
+
+  return 0;  // no room to drop
 }

src/player.h

@@ -33,4 +33,7 @@ void player_remove_inventory_item(Player *p, int index);
 // Equip weapon/armor from inventory, return 1 if successful
 int player_equip_item(Player *p, int inv_index);
 
+// Drop item from inventory at index (returns it to floor), return 1 if successful
+int player_drop_item(Player *p, int inv_index, Item *items, int item_count);
+
 #endif  // PLAYER_H