From 6062f3a48818af755ebea1781d5e475d3537af1d Mon Sep 17 00:00:00 2001
From: MihailRis <mexaruc@gmail.com>
Date: Mon, 17 Jun 2024 22:19:21 +0300
Subject: [PATCH] add mat4.mul

---
 src/logic/scripting/lua/libmat4.cpp  | 32 +++++++++++++++++++++++++
 src/logic/scripting/lua/lua_util.hpp | 36 ++++++++++++++++++++++++++--
 2 files changed, 66 insertions(+), 2 deletions(-)

diff --git a/src/logic/scripting/lua/libmat4.cpp b/src/logic/scripting/lua/libmat4.cpp
index 1a2e477a..ae70f581 100644
--- a/src/logic/scripting/lua/libmat4.cpp
+++ b/src/logic/scripting/lua/libmat4.cpp
@@ -7,6 +7,37 @@ static int l_idt(lua::State* L) {
     return lua::pushmat4(L, glm::mat4(1.0f));
 }
 
+static int l_mul(lua::State* L) {
+    uint argc = lua::gettop(L);
+    if (argc < 2 || argc > 3) {
+        throw std::runtime_error("invalid arguments number (2 or 3 expected)");
+    }
+    auto matrix1 = lua::tomat4(L, 1);
+    uint len2 = lua::objlen(L, 2);
+    if (len2 < 3) {
+        throw std::runtime_error("argument #2: vec3 or vec4 expected");
+    }
+    switch (argc) {
+        case 2: {
+            if (len2 == 4) {
+               return lua::pushvec4(L, matrix1 * lua::tovec4(L, 2));
+            } else if (len2 == 3) {
+               return lua::pushvec3(L, matrix1 * glm::vec4(lua::tovec3(L, 2), 1.0f));
+            }
+            return lua::pushmat4(L, matrix1 * lua::tomat4(L, 2));
+        }
+        case 3: {
+            if (len2 == 4) {
+               return lua::setvec4(L, 3, matrix1 * lua::tovec4(L, 2));
+            } else if (len2 == 3) {
+               return lua::setvec3(L, 3, matrix1 * glm::vec4(lua::tovec3(L, 2), 1.0f));
+            }
+            return lua::setmat4(L, 3, matrix1 * lua::tomat4(L, 2));
+        }
+    }
+    return 0;
+}
+
 /// Overloads:
 /// mat4.<func>(vec: float[3]) -> float[16] - creates transform matrix
 /// mat4.<func>(matrix: float[16], vec: float[3]) -> float[16] - creates transformed copy of matrix
@@ -83,6 +114,7 @@ static int l_tostring(lua::State* L) {
 
 const luaL_Reg mat4lib [] = {
     {"idt", lua::wrap<l_idt>},
+    {"mul", lua::wrap<l_mul>},
     {"scale", lua::wrap<l_transform_func<glm::scale>>},
     {"rotate", lua::wrap<l_rotate>},
     {"translate", lua::wrap<l_transform_func<glm::translate>>},
diff --git a/src/logic/scripting/lua/lua_util.hpp b/src/logic/scripting/lua/lua_util.hpp
index 79b649c3..c98af803 100644
--- a/src/logic/scripting/lua/lua_util.hpp
+++ b/src/logic/scripting/lua/lua_util.hpp
@@ -221,6 +221,24 @@ namespace lua {
         }
         return 1;
     }
+    /// @brief pushes vector table to the stack and updates it with glm vec4 
+    inline int setvec4(lua::State* L, int idx, glm::vec4 vec) {
+        pushvalue(L, idx);
+        for (uint i = 0; i < 4; i++) {
+            pushnumber(L, vec[i]);
+            rawseti(L, i+1);
+        }
+        return 1;
+    }
+    /// @brief pushes vector table to the stack and updates it with glm vec3 
+    inline int setvec3(lua::State* L, int idx, glm::vec3 vec) {
+        pushvalue(L, idx);
+        for (uint i = 0; i < 3; i++) {
+            pushnumber(L, vec[i]);
+            rawseti(L, i+1);
+        }
+        return 1;
+    }
     inline int pushcfunction(lua::State* L, lua_CFunction func) {
         lua_pushcfunction(L, func);
         return 1;
@@ -331,7 +349,6 @@ namespace lua {
         pop(L);
         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) {
@@ -346,7 +363,22 @@ namespace lua {
         pop(L);
         return glm::vec3(x, y, z);
     }
-
+    inline glm::vec4 tovec4(lua::State* L, int idx) { 
+        pushvalue(L, idx);
+        if (!istable(L, idx) || objlen(L, idx) < 4) {
+            throw std::runtime_error("value must be an array of four 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);
+        rawgeti(L, 4);
+        auto w = tonumber(L, -1); pop(L);
+        pop(L);
+        return glm::vec4(x, y, z, w);
+    }
     inline glm::mat4 tomat4(lua::State* L, int idx) {
         pushvalue(L, idx);
         if (!istable(L, idx) || objlen(L, idx) < 16) {