/*

 Copyright (C) 2015-2016 Apple Inc. All Rights Reserved.

 See LICENSE.txt for this sample’s licensing information

 Abstract:

 Utility class for creating a sampler.

 */

#import "MetalNBodySampler.h"

@implementation MetalNBodySampler

{

@private

    BOOL _haveSampler;

    id<MTLSamplerState>  _sampler;

}

- (instancetype) init

{

    self = [super init];

    if(self)

    {

        _haveSampler = NO;

        _sampler     = nil;

    } // if

    return self;

} // init

- (BOOL) _acquire:(nullable id<MTLDevice>)device

{

    if(device)

    {

        MTLSamplerDescriptor* pDescriptor = [MTLSamplerDescriptor new];

        if(!pDescriptor)

        {

            NSLog(@">> ERROR: Failed to instantiate sampler descriptor!");

            return NO;

        } // if

        pDescriptor.minFilter             = MTLSamplerMinMagFilterLinear;

        pDescriptor.magFilter             = MTLSamplerMinMagFilterLinear;

        pDescriptor.sAddressMode          = MTLSamplerAddressModeRepeat;

        pDescriptor.tAddressMode          = MTLSamplerAddressModeRepeat;

        pDescriptor.mipFilter             = MTLSamplerMipFilterNotMipmapped;

        pDescriptor.maxAnisotropy         = 1U;

        pDescriptor.normalizedCoordinates = YES;

        pDescriptor.lodMinClamp           = 0.0;

        pDescriptor.lodMaxClamp           = 255.0;

        _sampler = [device newSamplerStateWithDescriptor:pDescriptor];

        if(!_sampler)

        {

            NSLog(@">> ERROR: Failed to instantiate sampler state with descriptor!");

            return NO;

        } // else

        return YES;

    } // else

    else

    {

        NSLog(@">> ERROR: Metal device is nil!");

    } // if

    return NO;

} // _acquire

- (void) acquire:(nullable id<MTLDevice>)device

{

    if(!_haveSampler)

    {

        _haveSampler = [self _acquire:device];

    } // if

} // acquire

@end