add mat4 library

src/logic/scripting/lua/api_lua.hpp

@@ -17,6 +17,7 @@ extern const luaL_Reg inputlib [];
 extern const luaL_Reg inventorylib [];
 extern const luaL_Reg itemlib [];
 extern const luaL_Reg jsonlib [];
+extern const luaL_Reg mat4lib [];
 extern const luaL_Reg packlib [];
 extern const luaL_Reg playerlib [];
 extern const luaL_Reg timelib [];

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}
+};
+

src/logic/scripting/lua/lua_engine.cpp

@@ -37,6 +37,7 @@ static void create_libs(lua::State* L) {
     openlib(L, "inventory", inventorylib);
     openlib(L, "item", itemlib);
     openlib(L, "json", jsonlib);
+    openlib(L, "mat4", mat4lib);
     openlib(L, "pack", packlib);
     openlib(L, "player", playerlib);
     openlib(L, "time", timelib);

src/logic/scripting/lua/lua_util.hpp

@@ -195,6 +195,17 @@ namespace lua {
         rawseti(L, 4);
         return 1;
     }
+    inline int pushmat4(lua::State* L, glm::mat4 matrix) {
+        createtable(L, 16, 0);
+        for (uint y = 0; y < 4; y++) {
+            for (uint x = 0; x < 4; x++) {
+                uint i = y * 4 + x;
+                pushnumber(L, matrix[y][x]);
+                rawseti(L, i+1);
+            }
+        }
+        return 1;
+    }
     inline int pushcfunction(lua::State* L, lua_CFunction func) {
         lua_pushcfunction(L, func);
         return 1;
@@ -310,6 +321,38 @@ namespace lua {
         return glm::vec2(x, y);
     }
 
+    inline glm::vec3 tovec3(lua::State* L, int idx) { 
+        pushvalue(L, idx);
+        if (!istable(L, idx) || objlen(L, idx) < 3) {
+            throw std::runtime_error("value must be an array of three numbers");
+        }
+        rawgeti(L, 1);
+        auto x = tonumber(L, -1); pop(L);
+        rawgeti(L, 2);
+        auto y = tonumber(L, -1); pop(L);
+        rawgeti(L, 3);
+        auto z = tonumber(L, -1); pop(L);
+        pop(L);
+        return glm::vec3(x, y, z);
+    }
+
+    inline glm::mat4 tomat4(lua::State* L, int idx) {
+        pushvalue(L, idx);
+        if (!istable(L, idx) || objlen(L, idx) < 16) {
+            throw std::runtime_error("value must be an array of 16 numbers");
+        }
+        glm::mat4 matrix;
+        for (uint y = 0; y < 4; y++) {
+            for (uint x = 0; x < 4; x++) {
+                uint i = y * 4 + x;
+                rawgeti(L, i+1);
+                matrix[y][x] = static_cast<float>(tonumber(L, -1));
+                pop(L);
+            }
+        }
+        return matrix;
+    }
+
     inline glm::vec4 tocolor(lua::State* L, int idx) {
         pushvalue(L, idx);
         if (!istable(L, -1) || objlen(L, idx) < 4) {