feat: reorganize source code + cleanup

src/renderer/debug.cpp

@@ -0,0 +1,22 @@
+#include "renderer/debug.h"
+
+void MessageCallback(GLenum source,
+                     GLenum type,
+                     GLuint id,
+                     GLenum severity,
+                     GLsizei length,
+                     const GLchar* message,
+                     const void* userParam)
+{
+    (void) source;
+    (void) id;
+    (void) length;
+    (void) userParam;
+    std::cerr << "GL CALLBACK: " << (type == GL_DEBUG_TYPE_ERROR ? "** GL ERROR **" : "")
+              << " type = 0x" << type
+              << ", severity = 0x" << severity
+              << ", message = " << message << std::endl;
+    // std::cerr << "GL CALLBACK: %s type = 0x%x, severity = 0x%x, message = %s\n",
+    //         (type == GL_DEBUG_TYPE_ERROR ? "** GL ERROR **" : ""),
+    //         type, severity, message);
+}