MGLLayer.h

//
// Copyright 2019 Le Hoang Quyen. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
//

// We don't use GLES from Apple framework.
// Instead we use GLES provided by MetalANGLE.

#import <Foundation/Foundation.h>
#import <QuartzCore/CALayer.h>

#import "MGLKitPlatform.h"

NS_ASSUME_NONNULL_BEGIN

@class MGLContext;

typedef enum MGLDrawableColorFormat : int
{
    MGLDrawableColorFormatRGBA8888  = 32,
    MGLDrawableColorFormatSRGBA8888 = -32,
    MGLDrawableColorFormatRGB565    = 16,
} MGLDrawableColorFormat;

typedef enum MGLDrawableStencilFormat : int
{
    MGLDrawableStencilFormatNone = 0,
    MGLDrawableStencilFormat8    = 8,
} MGLDrawableStencilFormat;

typedef enum MGLDrawableDepthFormat : int
{
    MGLDrawableDepthFormatNone = 0,
    MGLDrawableDepthFormat16   = 16,
    MGLDrawableDepthFormat24   = 24,
} MGLDrawableDepthFormat;

typedef enum MGLDrawableMultisample : int
{
    MGLDrawableMultisampleNone = 0,
    MGLDrawableMultisample4X   = 4,
} MGLDrawableMultisample;

@interface MGLLayer : CALayer

// Return the size of the OpenGL framebuffer.
@property(readonly) CGSize drawableSize;
// Default OpenGL id of the framebuffer storing content of this layer.
// Might not necessary be zero.
@property(readonly) uint32_t defaultOpenGLFrameBufferID;

@property(nonatomic) MGLDrawableColorFormat drawableColorFormat;      // Default is RGBA8888
@property(nonatomic) MGLDrawableDepthFormat drawableDepthFormat;      // Default is DepthNone
@property(nonatomic) MGLDrawableStencilFormat drawableStencilFormat;  // Default is StencilNone
@property(nonatomic)
    MGLDrawableMultisample drawableMultisample;  // Default is MGLDrawableMultisampleNone

// Default value is NO. Setting to YES will keep the framebuffer data after presenting.
// Doing so will reduce performance and increase memory usage.
@property(nonatomic) BOOL retainedBacking;

// Present the content of OpenGL backed framebuffer on screen as soon as possible.
- (BOOL)present;

// Bind default framebuffer. Use this after drawing to offscreen FBO.
- (void)bindDefaultFrameBuffer;

@end

NS_ASSUME_NONNULL_END