From e9f0bc17a6f57249317c08c11dfc910656f4faac Mon Sep 17 00:00:00 2001
From: Patrick Schwarzer <patrickschwarzer2000@gmail.com>
Date: Thu, 1 May 2025 03:52:12 +0200
Subject: [PATCH] Implement KeyPressed

---
 engine/input.cpp | 30 ++++++++++++++++++++++++++----
 test.lua         |  4 ++--
 2 files changed, 28 insertions(+), 6 deletions(-)

diff --git a/engine/input.cpp b/engine/input.cpp
index 502f512..9f6efbe 100644
--- a/engine/input.cpp
+++ b/engine/input.cpp
@@ -1,6 +1,7 @@
 
 
 #include <SDL.h>
+#include <unordered_set>
 
 extern "C" {
     #include <lua.h>
@@ -11,35 +12,56 @@ extern "C" {
 
 #include "input.h"
 
-// Implement KeyPressed that basically just gets called once on process_input down = true
-// resets when the key is released again
+static std::unordered_set<int> heldKeys;
 
 void process_input(SDL_Keysym &keysym, bool down, lua_State *luaState) {
     lua_getglobal(luaState, "engine");
 
     if (lua_istable(luaState, -1)) {
+        int scancode = keysym.scancode;
+
         if (down) {
             lua_getfield(luaState, -1, "KeyDown");
             if (lua_isfunction(luaState, -1)) {
-                lua_pushinteger(luaState, keysym.scancode);
+                lua_pushinteger(luaState, scancode);
 
                 if (lua_pcall(luaState, 1, 0, 0) != LUA_OK) {
                     const char* error = lua_tostring(luaState, -1);
                     std::cerr << "Lua error in engine.KeyDown: " << error << std::endl;
                 }
             }
+
+            if (heldKeys.find(scancode) == heldKeys.end()){
+                heldKeys.insert(scancode);
+
+                lua_pop(luaState, 1);
+
+                lua_getfield(luaState, -1, "KeyPressed");
+                if (lua_isfunction(luaState, -1)) {
+                    lua_pushinteger(luaState, scancode);
+    
+                    if (lua_pcall(luaState, 1, 0, 0) != LUA_OK) {
+                        const char* error = lua_tostring(luaState, -1);
+                        std::cerr << "Lua error in engine.KeyPressed: " << error << std::endl;
+                    }
+                }
+            }
         }
         else
         {
             lua_getfield(luaState, -1, "KeyReleased");
             if (lua_isfunction(luaState, -1)) {
-                lua_pushinteger(luaState, keysym.scancode);
+                lua_pushinteger(luaState, scancode);
 
                 if (lua_pcall(luaState, 1, 0, 0) != LUA_OK) {
                     const char* error = lua_tostring(luaState, -1);
                     std::cerr << "Lua error in engine.KeyReleased: " << error << std::endl;
                 }
             }
+
+            heldKeys.erase(scancode);
         }
     }
+
+    lua_pop(luaState, 1);
 }
diff --git a/test.lua b/test.lua
index c4255c3..4c617be 100644
--- a/test.lua
+++ b/test.lua
@@ -3,6 +3,6 @@ function engine.KeyReleased(key)
     print("Released key: " .. key)
 end
 
-function engine.KeyDown(key)
-    print("Key down: " .. key)
+function engine.KeyPressed(key)
+    print("Pressed key: " .. key)
 end
\ No newline at end of file