Added some code

source/ctr.c

@@ -0,0 +1,30 @@
+#include <lua.h>
+#include <lauxlib.h>
+
+int load_gfx_lib(lua_State *L);
+int load_os_lib(lua_State *L);
+
+static const struct luaL_Reg ctr_lib[] = {
+	{ NULL, NULL }
+};
+
+struct { char *name; int (*load)(lua_State *L); } ctr_libs[] = {
+	{ "gfx", load_gfx_lib },
+	{ NULL, NULL },
+};
+
+int luaopen_ctr_lib(lua_State *L) {
+	luaL_newlib(L, ctr_lib);
+
+	for (int i = 0; ctr_libs[i].name; i++) {
+		ctr_libs[i].load(L);
+		lua_setfield(L, -2, ctr_libs[i].name);
+	}
+
+	return 1;
+}
+
+void load_ctr_lib(lua_State *L) {
+	load_os_lib(L);
+	luaL_requiref(L, "ctr", luaopen_ctr_lib, 0);
+}

source/gfx.c

@@ -0,0 +1,41 @@
+#include <sf2d.h>
+
+#include <lua.h>
+#include <lauxlib.h>
+
+u32 defaultColor = RGBA8(255, 255, 255, 255);
+
+static int gfx_render(lua_State *L) {
+	sf2d_end_frame();
+	sf2d_swapbuffers();
+	sf2d_start_frame(GFX_TOP, GFX_LEFT);
+
+	return 0;
+}
+
+static int gfx_rectangle(lua_State *L) {
+	int x = luaL_checkinteger(L, 1);
+	int y = luaL_checkinteger(L, 2);
+	int width = luaL_checkinteger(L, 3);
+	int height = luaL_checkinteger(L, 4);
+	u32 color = luaL_optinteger(L, 5, defaultColor);
+	
+	sf2d_draw_rectangle(x, y, width, height, color);
+
+	return 0;
+}
+
+static const struct luaL_Reg gfx_lib[] = {
+	{ "render",      gfx_render    },
+	{ "rectangle",   gfx_rectangle },
+	{ NULL, NULL }
+};
+
+int luaopen_gfx_lib(lua_State *L) {
+	luaL_newlib(L, gfx_lib);
+	return 1;
+}
+
+void load_gfx_lib(lua_State *L) {
+	luaL_requiref(L, "ctr.gfx", luaopen_gfx_lib, 0);
+}

source/main.c

@@ -0,0 +1,53 @@
+#include <stdio.h>
+#include <string.h>
+#include <math.h>
+
+#include <3ds.h>
+#include <sf2d.h>
+#include <sftd.h>
+
+#include <lua.h>
+#include <lauxlib.h>
+
+#define BOOT_FILE "/ctruLua/main.lua"
+
+int load_ctr_lib(lua_State *L);
+
+// Display an error
+void error(char *error) {
+	gfxInitDefault();
+
+	consoleInit(GFX_TOP, NULL);
+	printf("------------------ FATAL ERROR -------------------");
+	printf(error);
+	printf("\n--------------------------------------------------");
+	printf("Please exit ctruLua by pressing the home button.");
+
+	while (aptMainLoop()) {
+		gfxFlushBuffers();
+		gfxSwapBuffers();
+		gspWaitForVBlank();
+	}
+}
+
+// Main loop
+int main() {
+	// Init GFX
+	sf2d_init();
+	sftd_init();
+	//sf2d_set_3d(true);
+
+	// Init Lua
+	lua_State *L = luaL_newstate();
+	if (L == NULL) error("memory allocation error while creating a new Lua state");
+	luaL_openlibs(L);
+	load_ctr_lib(L);
+
+	// Do the actual thing
+	luaL_dofile(L, BOOT_FILE);
+
+	// Un-init (?)
+	sftd_fini();
+	sf2d_fini();
+	return 0;
+}

source/os.c

@@ -0,0 +1,22 @@
+#include <3ds.h>
+
+#include <lua.h>
+
+static int os_run(lua_State *L) {
+	bool run = aptMainLoop();
+
+	lua_pushboolean(L, run);
+
+	return 1;
+}
+
+void load_os_lib(lua_State *L) {
+	lua_getglobal(L, "os");
+
+	lua_pushcfunction(L, os_run);
+	lua_setfield(L, -2, "run");
+	
+	lua_pop(L, 1);
+
+	return;
+}