Setup Sky Renderer

Release 0.9.0-Preview.2

SuperRealism+

• Add two utilities, STPCamera and an inheritied class STPPerspectiveCamera.
• Refactor the directory structure and group classes into folders.
• Refactor three shader managers in SuperRealism+ using pure RAII given greater flexibility.
• Add a simple wrapper STPDebugCallback for handling OpenGL debug output automatically.
• Add a simple context manager STPContextManager for storing current context state and issues context state change functions whenever necessary.
• Add STPIndirectCommand as an indirect rendering command wrapper according to GL specification.

All wrappers are trivally implemented and only functionalities used within this project are written, so they are not complete for the sake of development time.

GL object management

• Add more GL object wrappers to SuperRealism+ library:
  • STPBuffer for GL buffer object such as vertex buffer and element buffer.
  • STPVertexArray for vertex array buffer object.
• Add more GL compatibility types to STPOpenGL.

Sky renderer

• Add a new setting STPAtomsphereSetting for storing atomsphere rendering parameters.
• Setup shader STPSun for physically-based atomsphere scattering.
• Setup rendering pass for STPSun.

General fixes and improvement

• Add a new exception STPGLError to the main engine.
• CMake config file include directory overhaul. Config files are now all placed into different directories distinguished by configuration such that #include in source code can remain unchanged when build configuration changes.
  • As a refactorisation, config template is placed into a separate interface target.
• Add a simple file IO utility STPFile for reading all contents in the file quickly.
• Fix an issue where STPNullablePrimitive cannot be assigned to nullptr.