62 lines
2.9 KiB
Swift
62 lines
2.9 KiB
Swift
//
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/**
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* Copyright (c) 2019 Razeware LLC
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*
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* Permission is hereby granted, free of charge, to any person obtaining a copy
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* of this software and associated documentation files (the "Software"), to deal
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* in the Software without restriction, including without limitation the rights
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* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
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* copies of the Software, and to permit persons to whom the Software is
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* furnished to do so, subject to the following conditions:
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*
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* The above copyright notice and this permission notice shall be included in
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* all copies or substantial portions of the Software.
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*
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* Notwithstanding the foregoing, you may not use, copy, modify, merge, publish,
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* distribute, sublicense, create a derivative work, and/or sell copies of the
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* Software in any work that is designed, intended, or marketed for pedagogical or
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* instructional purposes related to programming, coding, application development,
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* or information technology. Permission for such use, copying, modification,
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* merger, publication, distribution, sublicensing, creation of derivative works,
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* or sale is expressly withheld.
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*
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* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
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* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
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* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
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* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
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* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
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* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
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* THE SOFTWARE.
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*/
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import Metal
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extension Renderer {
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static func buildBRDF() -> MTLTexture? {
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let size = 256
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guard let brdfFunction = Renderer.library?.makeFunction(name: "integrateBRDF"),
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let brdfPipelineState = try? Renderer.device.makeComputePipelineState(function: brdfFunction),
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let commandBuffer = Renderer.commandQueue.makeCommandBuffer(),
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let commandEncoder = commandBuffer.makeComputeCommandEncoder() else { return nil }
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let descriptor = MTLTextureDescriptor.texture2DDescriptor(pixelFormat:.rg16Float,
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width: size,
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height: size, mipmapped: false)
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descriptor.usage = [.shaderRead, .shaderWrite]
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let lut = Renderer.device.makeTexture(descriptor: descriptor)
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commandEncoder.setComputePipelineState(brdfPipelineState)
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commandEncoder.setTexture(lut, index: 0)
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let threadsPerThreadgroup = MTLSizeMake(16, 16, 1)
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let threadgroups = MTLSizeMake(size / threadsPerThreadgroup.width,
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size / threadsPerThreadgroup.height, 1)
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commandEncoder.dispatchThreadgroups(threadgroups,
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threadsPerThreadgroup: threadsPerThreadgroup)
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commandEncoder.endEncoding()
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commandBuffer.commit()
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return lut
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}
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}
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