/*

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

 See LICENSE.txt for this sample’s licensing information

 Abstract:

 Simple Utility class for creating a 2d texture

 */

#ifdef TARGET_IOS

#import <UIKit/UIKit.h>

#else

#import <AppKit/AppKit.h>

#endif

#import "AAPLArrayTexture.h"

@implementation AAPLArrayTexture

{

@private

    uint32_t         _width;

    uint32_t         _height;

}

- (instancetype)initWithTextureWidth:(NSUInteger)width textureHeight:(NSUInteger)height arrayLength:(NSUInteger)length device:(id <MTLDevice>)device

{

    if (self = [super init])

    {

        _width    = (uint32_t)(width);

        _height   = (uint32_t)(height);

        MTLTextureDescriptor *pTexDesc = [MTLTextureDescriptor new];

        pTexDesc.textureType = MTLTextureType2DArray;

        pTexDesc.pixelFormat = MTLPixelFormatRGBA8Unorm;

        pTexDesc.width = _width;

        pTexDesc.height = _height;

        pTexDesc.arrayLength = length;

        _texture = [device newTextureWithDescriptor:pTexDesc];

    }

    return self;

}

- (BOOL)setSlice:(NSUInteger)slice withContentsOfFile:(NSString *)path

{

#if TARGET_IOS

    UIImage* pImage = [[UIImage alloc] initWithContentsOfFile:path];

#else

    NSImage *nsimage = [[NSImage alloc] initWithContentsOfFile:path];

    NSBitmapImageRep *pImage = [[NSBitmapImageRep alloc] initWithData:[nsimage TIFFRepresentation]];

    nsimage = nil;

#endif

    if(!pImage)

    {

        return NO;

    }

    CGColorSpaceRef pColorSpace = CGColorSpaceCreateDeviceRGB();

    if(!pColorSpace)

    {

        return NO;

    }

    uint32_t width    = _width;

    uint32_t height   = _height;

    uint32_t rowBytes = width * 4;

    CGContextRef pContext = CGBitmapContextCreate(NULL,

                                                  width,

                                                  height,

                                                  8,

                                                  rowBytes,

                                                  pColorSpace,

                                                  CGBitmapInfo(kCGImageAlphaPremultipliedLast));

    CGColorSpaceRelease(pColorSpace);

    if(!pContext)

    {

        return NO;

    }

    CGRect bounds = CGRectMake(0.0f, 0.0f, width, height);

    CGContextClearRect(pContext, bounds);

    // flip

    CGContextTranslateCTM(pContext, width, height);

    CGContextScaleCTM(pContext, -1.0, -1.0);

    CGContextDrawImage(pContext, bounds, pImage.CGImage);

    const void *pPixels = CGBitmapContextGetData(pContext);

    if(pPixels != NULL)

    {

        MTLRegion region = MTLRegionMake2D(0, 0, _width, _height);

        [_texture replaceRegion:region

                    mipmapLevel:0

                          slice:slice

                      withBytes:pPixels

                    bytesPerRow:rowBytes

                  bytesPerImage:rowBytes*height];

    }

    CGContextRelease(pContext);

    return YES;

}

- (void) dealloc

{

    _texture = nil;

}

@end