Refactored Graphics to allow Renderer choice at runtime

include/blah/app.h

@@ -10,74 +10,20 @@ namespace Blah
 	// Application Logging Functions
 	using AppLogFn = Func<void(const char* message, Log::Category category)>;
 
-	// Application Configuration
-	struct Config
-	{
-		// Application name.
-		// This has no default and must be set.
-		const char* name;
-
-		// Starting width, in pixels.
-		// Depending on the OS DPI, the true window size may be a multiple of this.
-		// This has no default and must be set.
-		int width;
-
-		// Starting height, in pixels.
-		// Depending on the OS DPI, the true window size may be a multiple of this.
-		// This has no default and must be set.
-		int height;
-
-		// maximum updates to run before "giving up" and reducing frame rate.
-		// this avoids the 'spiral of death'.
-		// defaults to 5.
-		int max_updates;
-
-		// target framerate.
-		// defaults to 60.
-		int target_framerate;
-
-		// Callback on application startup
-		// Defaults to nothing.
-		AppEventFn on_startup;
-
-		// Callback on application shutdown
-		// Defaults to nothing.
-		AppEventFn on_shutdown;
-
-		// Callback on application update
-		// Defaults to nothing.
-		AppEventFn on_update;
-
-		// Callback on application render
-		// Defaults to nothing.
-		AppEventFn on_render;
-
-		// Callback when the user has requested the application close.
-		// For example, pressing the Close button, ALT+F4, etc
-		// By default this calls `App::exit()`
-		AppEventFn on_exit_request;
-
-		// Callback when the application logs info/warning/errors
-		// Defaults to printf.
-		AppLogFn on_log;
-
-		// Default config setup
-		Config();
-	};
-
-	// Renderer the Application is using
-	enum class Renderer
+	// Type of Renderer the Application is using
+	enum class RendererType
 	{
 		None = -1,
 		OpenGL,
 		D3D11,
-		Metal,
-		Count
 	};
 
-	// Features available on the current Renderer
+	// Renderer Information
 	struct RendererFeatures
 	{
+		// The type of Renderer being used
+		RendererType type = RendererType::None;
+
 		// Whether Mesh Instancing is available
 		bool instancing = false;
 
@@ -89,6 +35,55 @@ namespace Blah
 		int max_texture_size = 0;
 	};
 
+	// Application Configuration
+	struct Config
+	{
+		// Application name.
+		const char* name = "blah";
+		
+		// Which renderer to use
+		// Default depends on the Platform
+		RendererType renderer_type = RendererType::None;
+
+		// Starting width, in pixels.
+		// Depending on the OS DPI, the true window size may be a multiple of this.
+		int width = 1280;
+
+		// Starting height, in pixels.
+		// Depending on the OS DPI, the true window size may be a multiple of this.
+		int height = 720;
+
+		// maximum updates to run before "giving up" and reducing frame rate.
+		// this avoids the 'spiral of death'.
+		// defaults to 5.
+		int max_updates = 5;
+
+		// target framerate.
+		// defaults to 60.
+		int target_framerate = 60;
+
+		// Callback on application startup
+		AppEventFn on_startup = nullptr;
+
+		// Callback on application shutdown
+		AppEventFn on_shutdown = nullptr;
+
+		// Callback on application update
+		AppEventFn on_update = nullptr;
+
+		// Callback on application render
+		AppEventFn on_render = nullptr;
+
+		// Callback when the user has requested the application close.
+		// For example, pressing the Close button, ALT+F4, etc
+		// By default this calls `App::exit()`
+		AppEventFn on_exit_request = nullptr;
+
+		// Callback when the application logs info/warning/errors
+		// Defaults to printf.
+		AppLogFn on_log = nullptr;
+	};
+
 	// Forward declare Target for the BackBuffer
 	class Target;
 	using TargetRef = Ref<Target>;
@@ -119,31 +114,22 @@ namespace Blah
 		// Sets the Window Title
 		void set_title(const char* title);
 
-		// Gets the Window Position
+		// Gets the Window Position in Screen Coordinates
 		Point get_position();
 
-		// Sets the Window Position
+		// Sets the Window Position in Screen Coordinates
 		void set_position(Point point);
 
-		// Gets the Window Size
+		// Gets the size of the Window in Screen Coordinates.
+		// On High DPI displays this may not be 1:1 with pixels.
+		// For the size in pixels, use App::get_backbuffer_size()
 		Point get_size();
 
-		// Sets the Window Size
+		// Sets the Window Size in Screen Coordinates
 		void set_size(Point point);
 
-		// Gets the width of the window
-		int width();
-
-		// Gets the height of the window
-		int height();
-		
-		// Gets the drawable width of the window, in pixels.
-		// This may differ from the width when on platforms with High DPI Displays.
-		int draw_width();
-
-		// Gets the drawable height of the window, in pixels.
-		// This may differ from the height when on platforms with High DPI Displays.
-		int draw_height();
+		// Gets the size of the BackBuffer, in pixels
+		Point get_backbuffer_size();
 
 		// Gets the content scale based on the platform.
 		// macOS is usually 2.0, other platforms vary.
@@ -156,14 +142,11 @@ namespace Blah
 		// Otherwise this function does nothing.
 		void fullscreen(bool enabled);
 
-		// Returns the Rendering API in use
-		Renderer renderer();
-
 		// Retrieves the Renderer Features
-		const RendererFeatures& renderer_features();
+		const RendererFeatures& renderer();
 
-		// Reference to the window's back buffer
-		extern const TargetRef backbuffer;
+		// Gets the BackBuffer
+		const TargetRef& backbuffer();
 	}
 
 	namespace System

include/blah/graphics/batch.h

@@ -128,7 +128,7 @@ namespace Blah
 		void set_sampler(const TextureSampler& sampler);
 
 		// Draws the batch to the given target
-		void render(const TargetRef& target = App::backbuffer);
+		void render(const TargetRef& target = nullptr);
 
 		// Draws the batch to the given target, with the provided matrix
 		void render(const TargetRef& target, const Mat4x4f& matrix);