add quat Lua library

src/logic/scripting/lua/api_lua.hpp

@@ -31,6 +31,7 @@ extern const luaL_Reg jsonlib [];
 extern const luaL_Reg mat4lib [];
 extern const luaL_Reg packlib [];
 extern const luaL_Reg playerlib [];
+extern const luaL_Reg quatlib []; // quat.cpp
 extern const luaL_Reg timelib [];
 extern const luaL_Reg tomllib [];
 extern const luaL_Reg vec2lib []; // vecn.cpp

src/logic/scripting/lua/libquat.cpp

@@ -0,0 +1,50 @@
+#include "api_lua.hpp"
+
+#define GLM_ENABLE_EXPERIMENTAL
+#include <glm/ext/matrix_transform.hpp>
+#include <glm/gtx/quaternion.hpp>
+
+static int l_from_mat4(lua::State* L) {
+    uint argc = lua::check_argc(L, 1, 2);
+    auto matrix = lua::tomat4(L, 1);
+    if (argc == 1) {
+        return lua::pushquat(L, glm::toQuat(matrix));
+    } else {
+        return lua::setquat(L, 2, glm::toQuat(matrix));
+    }
+}
+
+static int l_slerp(lua::State* L) {
+    uint argc = lua::check_argc(L, 3, 4);
+    auto quat1 = lua::toquat(L, 1);
+    auto quat2 = lua::toquat(L, 2);
+    float t = lua::tonumber(L, 3);
+    if (argc == 3) {
+        return lua::pushquat(L, glm::slerp(quat1, quat2, t));
+    } else {
+        return lua::setquat(L, 4, glm::slerp(quat1, quat2, t));
+    }
+}
+
+static int l_tostring(lua::State* L) {
+    lua::check_argc(L, 1);
+    auto quat = lua::toquat(L, 1);
+
+    std::stringstream ss;
+    ss << "quat" << "{";
+    for (int i = 0; i < 4; i++) {
+        if (i > 0) {
+            ss << ", ";
+        }
+        ss << quat[i];
+    }
+    ss << "}";
+    return lua::pushstring(L, ss.str());
+}
+
+const luaL_Reg quatlib [] = {
+    {"from_mat4", lua::wrap<l_from_mat4>},
+    {"slerp", lua::wrap<l_slerp>},
+    {"tostring", lua::wrap<l_tostring>},
+    {NULL, NULL}
+};

src/logic/scripting/lua/lua_engine.cpp

@@ -40,6 +40,7 @@ static void create_libs(lua::State* L) {
     openlib(L, "mat4", mat4lib);
     openlib(L, "pack", packlib);
     openlib(L, "player", playerlib);
+    openlib(L, "quat", quatlib);
     openlib(L, "time", timelib);
     openlib(L, "toml", tomllib);
     openlib(L, "vec2", vec2lib);

src/logic/scripting/lua/lua_util.hpp

@@ -196,7 +196,14 @@ namespace lua {
         }
         return 1;
     }
-
+    inline int setquat(lua::State* L, int idx, glm::quat quat) {
+        pushvalue(L, idx);
+        for (int i = 0; i < 4; i++) {
+            pushnumber(L, quat[i]);
+            rawseti(L, i+1);
+        }
+        return 1;
+    }
     inline int pushmat4(lua::State* L, glm::mat4 matrix) {
         createtable(L, 16, 0);
         for (uint y = 0; y < 4; y++) {