Fix GCC compilation errors

src/lightmap/gpuraytracer.cpp

@@ -13,6 +13,7 @@
 #include <limits>
 #include <condition_variable>
 #include <mutex>
+#include <thread>
 #include "glsl_rgen_bounce.h"
 #include "glsl_rgen_light.h"
 #include "glsl_rgen_ambient.h"

src/lightmap/lightmaptexture.h

@@ -1,6 +1,7 @@
 
 #pragma once
 
+#include <cstdint>
 #include <vector>
 
 class LightmapTexture

src/lightmap/pngwriter.h

@@ -13,7 +13,7 @@ public:
 		DataBuffer(int size) : size(size) { data = new uint8_t[size]; }
 		~DataBuffer() { delete[] data; }
 		int size;
-		void* data;
+		uint8_t* data;
 	};
 
 private: