add guide

include/Camera.hpp

@@ -2,7 +2,7 @@
 
 #include <glm/glm.hpp>
 
-namespace planetarium {
+namespace engine {
 
 // -----------------------------------------------------------------------
 // Camera
@@ -59,4 +59,4 @@ private:
     static constexpr float kSmoothingSpeed = 6.0f;
 };
 
-}  // namespace planetarium
+}  // namespace engine

include/Engine.hpp

@@ -6,7 +6,7 @@
 
 struct GLFWwindow;
 
-namespace planetarium {
+namespace engine {
 
 // -----------------------------------------------------------------------
 // Engine
@@ -15,9 +15,9 @@ namespace planetarium {
 // routing between raw GLFW callbacks and the Camera. This is the only
 // class that knows about GLFW directly.
 //
-// This is the reusable "engine" half of the original Planetarium project
-// with every game-specific piece (SolarSystem, Planet, UI, picking)
-// removed. Hook your own logic in via setUpdateCallback/setRenderCallback:
+// A generic reusable "engine" shell: window/context setup, the main loop,
+// and camera input routing, with no game-specific logic baked in. Hook
+// your own logic in via setUpdateCallback/setRenderCallback:
 //
 //     Engine engine;
 //     engine.initialize(1600, 900, "My App");
@@ -74,4 +74,4 @@ private:
     double lastFrameTime_ = 0.0;
 };
 
-}  // namespace planetarium
+}  // namespace engine

include/GLFunctions.hpp

@@ -13,7 +13,7 @@
 // loaders are mixed in the same program - see the comment at the top of
 // that file for details.
 //
-// Usage: call planetarium::gl::loadGLFunctions() exactly once, right
+// Usage: call engine::gl::loadGLFunctions() exactly once, right
 // after the GLFW OpenGL context has been made current and before any
 // other GL call in the project's own rendering code.
 // -----------------------------------------------------------------------
@@ -68,7 +68,7 @@ typedef char GLchar;
 typedef ptrdiff_t GLsizeiptr;
 typedef ptrdiff_t GLintptr;
 
-namespace planetarium::gl {
+namespace engine::gl {
 
 using PFNGLGENVERTEXARRAYS = void (*)(GLsizei, GLuint*);
 using PFNGLBINDVERTEXARRAY = void (*)(GLuint);
@@ -143,4 +143,4 @@ extern PFNGLGENERATEMIPMAP glGenerateMipmap;
 // required entry point could not be resolved.
 bool loadGLFunctions();
 
-}  // namespace planetarium::gl
+}  // namespace engine::gl

include/Mesh.hpp

@@ -5,7 +5,7 @@
 #include <glm/glm.hpp>
 #include <vector>
 
-namespace planetarium {
+namespace engine {
 
 // -----------------------------------------------------------------------
 // Mesh
@@ -51,4 +51,4 @@ private:
     bool isLineStrip_ = false;
 };
 
-}  // namespace planetarium
+}  // namespace engine

include/Shader.hpp

@@ -5,7 +5,7 @@
 #include <glm/glm.hpp>
 #include <string>
 
-namespace planetarium {
+namespace engine {
 
 // -----------------------------------------------------------------------
 // Shader
@@ -42,4 +42,4 @@ private:
     GLint locationOf(const std::string& name) const;
 };
 
-}  // namespace planetarium
+}  // namespace engine