add mat4 library

src/logic/scripting/lua/libmat4.cpp

@@ -0,0 +1,49 @@
+#include "api_lua.hpp"
+
+#include <sstream>
+#include <glm/ext/matrix_transform.hpp>
+
+static int l_idt(lua::State* L) {
+    return lua::pushmat4(L, glm::mat4(1.0f));
+}
+
+static int l_scale(lua::State* L) {
+    uint argc = lua::gettop(L);
+    switch (argc) {
+        case 1: {
+            auto scale = lua::tovec3(L, 1);
+            return lua::pushmat4(L, glm::scale(glm::mat4(1.0f), scale));
+        }
+        case 2: {
+            auto matrix = lua::tomat4(L, 1);
+            auto scale = lua::tovec3(L, 2);
+            return lua::pushmat4(L, glm::scale(matrix, scale));
+        }
+        default: {
+            throw std::runtime_error("invalid number of arguments (1 or 2 expected)");
+        }
+    }
+    return 0;
+}
+
+static int l_tostring(lua::State* L) {
+    auto matrix = lua::tomat4(L, 1);
+    std::stringstream ss;
+    ss << "mat4 {\n";
+    for (uint y = 0; y < 4; y++) {
+        for (uint x = 0; x < 4; x++) {
+            ss << "\t" << matrix[y][x];
+        }
+        ss << "\n";
+    }
+    ss << "}";
+    return lua::pushstring(L, ss.str());
+}
+
+const luaL_Reg mat4lib [] = {
+    {"idt", lua::wrap<l_idt>},
+    {"scale", lua::wrap<l_scale>},
+    {"tostring", lua::wrap<l_tostring>},
+    {NULL, NULL}
+};
+