blah/src/internal/blah_renderer.h

#pragma once
#include <blah_app.h>
#include <blah_graphics.h>
#include <blah_color.h>

namespace Blah
{
	class Renderer
	{
	public:

		// Renderer Info
		RendererInfo info;

		// Default Shader for the Batcher
		ShaderRef default_batcher_shader;

		virtual ~Renderer() = default;

		// Initialize the Graphics
		virtual bool init() = 0;

		// Shutdown the Graphics
		virtual void shutdown() = 0;

		// Called once per frame
		virtual void update() = 0;

		// Called before rendering begins
		virtual void before_render() = 0;

		// Called after renderings ends
		virtual void after_render() = 0;

		// Called when the App sets flags
		virtual void set_app_flags(u32 flags) { }

		// Optional implementation to get the drawable backbuffer size in pixels.
		// Not all implementations will use this, so it can be up to the Platform.
		virtual bool get_draw_size(int* w, int* h) { return false; }

		// Performs a draw call
		virtual void render(const DrawCall& pass) = 0;

		// Clears the backbuffer
		virtual void clear_backbuffer(Color color, float depth, u8 stencil, ClearMask mask) = 0;

		// Creates a new Texture.
		// if the Texture is invalid, this should return an empty reference.
		virtual TextureRef create_texture(int width, int height, TextureFormat format) = 0;

		// Creates a new Target.
		// if the Target is invalid, this should return an empty reference.
		virtual TargetRef create_target(int width, int height, const TextureFormat* attachments, int attachment_count) = 0;

		// Creates a new Shader.
		// if the Shader is invalid, this should return an empty reference.
		virtual ShaderRef create_shader(const ShaderData* data) = 0;

		// Creates a new Mesh.
		// if the Mesh is invalid, this should return an empty reference.
		virtual MeshRef create_mesh() = 0;

	private:
		static Renderer* try_make_opengl();
		static Renderer* try_make_d3d11();

	public:
		static Renderer* try_make_renderer(RendererType type)
		{
			switch (type)
			{
			case RendererType::None: return nullptr;
			case RendererType::OpenGL: return try_make_opengl();
			case RendererType::D3D11: return try_make_d3d11();
			}

			return nullptr;
		}

		static RendererType default_type()
		{
#if defined(BLAH_RENDERER_D3D11) && defined(_WIN32)
			return RendererType::D3D11;
#else
			return RendererType::OpenGL;
#endif
		}
	};
}