MTKTextureLoader fails for 16-big images

Question

hyperknot OP

Created Feb ’18

Replies 1

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MTKTextureLoader.newTexture fails to load 16-bit CGImages.

 let path = "test.scnassets/test16.png"
let image = UIImage(named: path)!
 
 
let textureLoader = MTKTextureLoader(device: defaultDevice)
let texture = try! textureLoader.newTexture(cgImage: image.cgImage!, options: [:])

Results in error:

Error Domain=MTKTextureLoaderErrorDomain Code=0 "Image decoding failed" UserInfo={NSLocalizedDescription=Image decoding failed, MTKTextureLoaderErrorKey=Image decoding failed}

Now my question is, if not like this, then how can I create a texture, manually, using a proper 16 bit pixel format.

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Answer 1

Mikl OP

Apr ’18

I got it working by looping over the raw UIImage data (data stored as rgb uint8 little endian) and creating a uint16 array to feed the texture with.

 let textureDescriptor = MTLTextureDescriptor.texture2DDescriptor(pixelFormat: MTLPixelFormat.rgba16Uint, width: imageWidth, height: imageHeight, mipmapped: false) guard let texture: MTLTexture = device.makeTexture(descriptor: textureDescriptor) else { return nil }
let region = MTLRegionMake2D(0, 0, Int(imageWidth), Int(imageHeight))
texture.replace(region: region, mipmapLevel: 0, withBytes: &textureData, bytesPerRow: 8 * imageWidth)

0

	let path = "test.scnassets/test16.png"
	let image = UIImage(named: path)!


	let textureLoader = MTKTextureLoader(device: defaultDevice)
	let texture = try! textureLoader.newTexture(cgImage: image.cgImage!, options: [:])

	let textureDescriptor = MTLTextureDescriptor.texture2DDescriptor(pixelFormat: MTLPixelFormat.rgba16Uint, width: imageWidth, height: imageHeight, mipmapped: false) guard let texture: MTLTexture = device.makeTexture(descriptor: textureDescriptor) else { return nil }
	let region = MTLRegionMake2D(0, 0, Int(imageWidth), Int(imageHeight))
	texture.replace(region: region, mipmapLevel: 0, withBytes: &textureData, bytesPerRow: 8 * imageWidth)