Mhmm, in my first simple Test I tried:
@MainActor
private static func generateTexture(width: Int, height: Int) throws -> LowLevelTexture {
return try LowLevelTexture(descriptor: .init(pixelFormat: .rgba8Unorm_srgb,
width: width,
height: height,
depth: 1,
mipmapLevelCount: 1,
textureUsage: [.shaderWrite, .shaderRead]))
}
@MainActor
init(textureSize: SIMD2<Int>) async throws {
lowLevelTexture = try Self.generateTexture(width: textureSize.x, height: textureSize.y)
let textureResource = try await TextureResource(from: lowLevelTexture)
var descriptor = UnlitMaterial.Program.Descriptor()
descriptor.blendMode = .add
let program = await UnlitMaterial.Program(descriptor: descriptor)
material = UnlitMaterial(program: program)
material.color = .init(texture: .init(textureResource))
material.opacityThreshold = 0.0 // Enable transparency
material.blending = .transparent(opacity: 1.0)
}
@MainActor
mutating func setTextureSize(_ textureSize: SIMD2<Int>) throws {
lowLevelTexture = try Self.generateTexture(width: textureSize.x, height: textureSize.y)
let textureResource = try TextureResource(from: lowLevelTexture)
material.color = .init(texture: .init(textureResource))
}
mutating func blitMTLTextureIntoLowLevelTexture(_ mtlTexture: MTLTexture) {
let size = self.textureSize
guard mtlTexture.width == size.x, mtlTexture.height == size.y else {
Logger.ar.error("MTLTexture size \(mtlTexture.width)x\(mtlTexture.height) does not match LowLevelTexture size \(size.x)x\(size.y)")
return
}
MetalHelper.blitTextures(from: mtlTexture, to: lowLevelTexture)
}
And then the blit method:
static func blitTextures(from inTexture: MTLTexture, to lowLevelTexture: LowLevelTexture) {
guard let commandQueue = sharedCommandQueue else {
Logger.ml.error("Failed to get command queue")
return
}
guard let commandBuffer = commandQueue.makeCommandBuffer() else {
Logger.ml.error("Failed to create command buffer")
return
}
guard let blitEncoder = commandBuffer.makeBlitCommandEncoder() else {
Logger.ml.error("Failed to create compute encoder")
return
}
commandBuffer.enqueue()
defer {
blitEncoder.endEncoding()
commandBuffer.commit()
}
let outTexture: MTLTexture = lowLevelTexture.replace(using: commandBuffer)
blitEncoder.copy(from: inTexture, to: outTexture)
}
which compiles and runs without error, but I only see a pink mesh.
