Add clang tidy to build.

This is only a first approxmiation of what I would like for CI. Ideally,
it'd be it's own step that can pass/fail regardless of the build status.
With this setup, it's integrated into the build (and also running tidy
over our vendored dependencies, which are outside our scope).

Something like this: http://www.stablecoder.ca/2018/10/30/full-cmake-helper-suite.html
might be better for the future...

CMakeLists.txt

 cmake_minimum_required(VERSION 3.10)
 
+
 project(FGGL VERSION 0.1 LANGUAGES CXX)
 
 # Set C++ version
@@ -11,6 +12,7 @@ set(CMAKE_EXPORT_COMPILE_COMMANDS ON)
 add_subdirectory(vendor/imgui/)
 
 # engine
+set(CMAKE_CXX_CLANG_TIDY "clang-tidy;-checks=*")
 add_subdirectory(fggl)
 
 # extras

fggl/gfx/input.cpp

@@ -39,7 +39,6 @@ void Input::frame() {
 }
 
 void Input::mousePos(double x, double y) {
-	assert( m_mouse_curr.cursor != nullptr );
 	m_mouse_curr.cursor[0] = x;
 	m_mouse_curr.cursor[1] = y;
 }