From 2926166ce6391a536751940f0ca7c598554b0900 Mon Sep 17 00:00:00 2001
From: Godzil <godzil@godzil.net>
Date: Thu, 27 Feb 2020 17:24:40 +0000
Subject: [PATCH] Add Lua dependencies.

Lua is going to be used for both scene description (it will also provide a YAML importer) and some future expansion in the code. Expect some fun surprises!

(just playing with lua on the main app for now)
---
 CMakeLists.txt        | 15 +++++++++++++--
 source/CMakeLists.txt |  6 +++---
 source/main.cpp       | 36 +++++++++++++++++++++++++++++++++++-
 3 files changed, 51 insertions(+), 6 deletions(-)

diff --git a/CMakeLists.txt b/CMakeLists.txt
index 65fbd30..bdc3275 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -40,13 +40,24 @@ if (ENABLE_COVERAGE)
 
 endif()
 
-
-
 # LodePNG don't make a .a or .so, so let's build a library here
 add_library(LodePNG STATIC)
 set(LODEPNG_INCLUDE_FOLDER ${CMAKE_CURRENT_SOURCE_DIR}/external/lodepng)
 target_sources(LodePNG PRIVATE external/lodepng/lodepng.cpp external/lodepng/lodepng.h)
 
+ExternalProject_Add(LuaCore
+        URL "https://www.lua.org/ftp/lua-5.3.5.tar.gz"
+        URL_HASH SHA1=112eb10ff04d1b4c9898e121d6bdf54a81482447
+        SOURCE_DIR ${CMAKE_CURRENT_SOURCE_DIR}/external/lua
+        CONFIGURE_COMMAND ""
+        BUILD_IN_SOURCE True
+        BUILD_COMMAND make generic
+        INSTALL_COMMAND ""
+)
+
+set(LUA_INCLUDE_DIR "${CMAKE_CURRENT_SOURCE_DIR}/external/lua/src")
+set(LUA_LIBRARIES "${CMAKE_CURRENT_SOURCE_DIR}/external/lua/src/liblua.a")
+
 # Main app
 add_subdirectory(source)
 
diff --git a/source/CMakeLists.txt b/source/CMakeLists.txt
index e25cfbb..6010f1f 100644
--- a/source/CMakeLists.txt
+++ b/source/CMakeLists.txt
@@ -20,10 +20,10 @@ target_link_libraries(rayonnement LodePNG)
 if (USE_OPENMP)
   target_link_libraries(rayonnement OpenMP::OpenMP_CXX)
 endif()
-# Second we build the main executable
+
 add_executable(dorayme main.cpp)
-target_include_directories(rayonnement PUBLIC include ${LODEPNG_INCLUDE_FOLDER})
-target_link_libraries(dorayme rayonnement)
+target_include_directories(rayonnement PUBLIC include ${LODEPNG_INCLUDE_FOLDER} ${LUA_INCLUDE_DIR})
+target_link_libraries(dorayme rayonnement ${LUA_LIBRARIES})
 
 if (COVERALLS)
     set(COVERAGE_SRCS ${RAY_HEADERS} ${RAY_SOURCES} ${COVERAGE_SRCS} PARENT_SCOPE)
diff --git a/source/main.cpp b/source/main.cpp
index a950fad..7f941fc 100644
--- a/source/main.cpp
+++ b/source/main.cpp
@@ -8,10 +8,44 @@
  *
  */
 #include <stdio.h>
+#include <string.h>
+#include <math.h>
 
+extern "C" {
+#include <lua.h>
+#include <lauxlib.h>
+#include <lualib.h>
+}
+
+static int l_sin (lua_State *L) {
+    double d = luaL_checknumber(L, 1);  /* get argument */
+    lua_pushnumber(L, sin(d));  /* push result */
+    return 1;  /* number of results */
+}
 
 int main(int argc, char *argv[])
 {
-    printf("Hello !\n");
+    char buff[256];
+    int error;
+    lua_State *L = luaL_newstate();   /* opens Lua */
+    luaL_openlibs(L);             /* opens the basic library */
+
+    lua_pushcfunction(L, l_sin);
+    lua_setglobal(L, "mysin");
+    printf("[0]>");
+
+    while (fgets(buff, sizeof(buff), stdin) != NULL)
+    {
+        error = luaL_loadstring(L, buff) || lua_pcall(L, 0, LUA_MULTRET, 0);
+
+        if (error)
+        {
+            fprintf(stderr, "%s\n", lua_tostring(L, -1));
+            lua_pop(L, 1);  /* pop error message from the stack */
+        }
+        printf("[%d]>", lua_gettop(L));
+    }
+
+    lua_close(L);
     return 0;
 }
\ No newline at end of file