Add Lua bindings and mesh loading functionality for enhanced scripting support

src/script/lua_helpers.cpp

@@ -0,0 +1,77 @@
+#include "script/lua_helpers.hpp"
+
+#include <lua.hpp>
+#include <stdexcept>
+
+namespace sdl3cpp::script {
+
+std::array<float, 3> ReadVector3(lua_State* L, int index) {
+    std::array<float, 3> result{};
+    int absIndex = lua_absindex(L, index);
+    size_t len = lua_rawlen(L, absIndex);
+    if (len != 3) {
+        throw std::runtime_error("Expected vector with 3 components");
+    }
+    for (size_t i = 1; i <= 3; ++i) {
+        lua_rawgeti(L, absIndex, static_cast<int>(i));
+        if (!lua_isnumber(L, -1)) {
+            lua_pop(L, 1);
+            throw std::runtime_error("Vector component is not a number");
+        }
+        result[i - 1] = static_cast<float>(lua_tonumber(L, -1));
+        lua_pop(L, 1);
+    }
+    return result;
+}
+
+std::array<float, 4> ReadQuaternion(lua_State* L, int index) {
+    std::array<float, 4> result{};
+    int absIndex = lua_absindex(L, index);
+    size_t len = lua_rawlen(L, absIndex);
+    if (len != 4) {
+        throw std::runtime_error("Expected quaternion with 4 components");
+    }
+    for (size_t i = 1; i <= 4; ++i) {
+        lua_rawgeti(L, absIndex, static_cast<int>(i));
+        if (!lua_isnumber(L, -1)) {
+            lua_pop(L, 1);
+            throw std::runtime_error("Quaternion component is not a number");
+        }
+        result[i - 1] = static_cast<float>(lua_tonumber(L, -1));
+        lua_pop(L, 1);
+    }
+    return result;
+}
+
+std::array<float, 16> ReadMatrix(lua_State* L, int index) {
+    std::array<float, 16> result{};
+    int absIndex = lua_absindex(L, index);
+    size_t len = lua_rawlen(L, absIndex);
+    if (len != 16) {
+        throw std::runtime_error("Expected 4x4 matrix with 16 components");
+    }
+    for (size_t i = 1; i <= 16; ++i) {
+        lua_rawgeti(L, absIndex, static_cast<int>(i));
+        if (!lua_isnumber(L, -1)) {
+            lua_pop(L, 1);
+            throw std::runtime_error("Matrix component is not a number");
+        }
+        result[i - 1] = static_cast<float>(lua_tonumber(L, -1));
+        lua_pop(L, 1);
+    }
+    return result;
+}
+
+std::string GetLuaError(lua_State* L) {
+    const char* message = lua_tostring(L, -1);
+    return message ? message : "unknown lua error";
+}
+
+std::array<float, 16> IdentityMatrix() {
+    return {1.0f, 0.0f, 0.0f, 0.0f,
+            0.0f, 1.0f, 0.0f, 0.0f,
+            0.0f, 0.0f, 1.0f, 0.0f,
+            0.0f, 0.0f, 0.0f, 1.0f};
+}
+
+} // namespace sdl3cpp::script