@import UIKit;

@import Metal;

@import QuartzCore.CAMetalLayer;

@protocol MBEMetalViewDelegate;

@interface MBEMetalView : UIView

/// The delegate of this view, responsible for drawing

@property (nonatomic, weak) id<MBEMetalViewDelegate> delegate;

/// The Metal layer that backs this view

@property (nonatomic, readonly) CAMetalLayer *metalLayer;

/// The target frame rate (in Hz). For best results, this should

/// be a number that evenly divides 60 (e.g., 60, 30, 15).

@property (nonatomic) NSInteger preferredFramesPerSecond;

/// The desired pixel format of the color attachment

@property (nonatomic) MTLPixelFormat colorPixelFormat;

/// The color to which the color attachment should be cleared at the start of

/// a rendering pass

@property (nonatomic, assign) MTLClearColor clearColor;

/// The duration (in seconds) of the previous frame. This is valid only in the context

/// of a callback to the delegate's -drawInView: method.

@property (nonatomic, readonly) NSTimeInterval frameDuration;

/// The view's layer's current drawable. This is valid only in the context

/// of a callback to the delegate's -drawInView: method.

@property (nonatomic, readonly) id<CAMetalDrawable> currentDrawable;

/// A render pass descriptor configured to use the current drawable's texture

/// as its primary color attachment and an internal depth texture of the same

/// size as its depth attachment's texture

@property (nonatomic, readonly) MTLRenderPassDescriptor *currentRenderPassDescriptor;

@end

@protocol MBEMetalViewDelegate <NSObject>

/// This method is called once per frame. Within the method, you may access

/// any of the properties of the view, and request the current render pass

/// descriptor to get a descriptor configured with renderable color and depth

/// textures.

- (void)drawInView:(MBEMetalView *)view;

@end