102 lines
4.3 KiB
Swift
102 lines
4.3 KiB
Swift
//
|
|
// Terrain.swift
|
|
// Terrain
|
|
//
|
|
// Created by Eryn Wells on 11/3/18.
|
|
// Copyright © 2018 Eryn Wells. All rights reserved.
|
|
//
|
|
|
|
import Cocoa
|
|
import MetalKit
|
|
|
|
class Terrain: NSObject {
|
|
|
|
/// Create a Metal vertex descriptor specifying how vertices will by laid out for input into our render pipeline and how we'll layout our Model IO vertices.
|
|
class func buildVertexDescriptor() -> MTLVertexDescriptor {
|
|
let desc = MTLVertexDescriptor()
|
|
|
|
desc.attributes[VertexAttribute.position.rawValue].format = .float3
|
|
desc.attributes[VertexAttribute.position.rawValue].offset = 0
|
|
desc.attributes[VertexAttribute.position.rawValue].bufferIndex = BufferIndex.meshPositions.rawValue
|
|
|
|
desc.attributes[VertexAttribute.texcoord.rawValue].format = .float2
|
|
desc.attributes[VertexAttribute.texcoord.rawValue].offset = 0
|
|
desc.attributes[VertexAttribute.texcoord.rawValue].bufferIndex = BufferIndex.meshGenerics.rawValue
|
|
|
|
desc.attributes[VertexAttribute.gridCoord.rawValue].format = .uint2
|
|
desc.attributes[VertexAttribute.gridCoord.rawValue].offset = 0
|
|
desc.attributes[VertexAttribute.gridCoord.rawValue].bufferIndex = BufferIndex.meshGridCoords.rawValue
|
|
|
|
desc.layouts[BufferIndex.meshPositions.rawValue].stride = 12
|
|
desc.layouts[BufferIndex.meshPositions.rawValue].stepRate = 1
|
|
desc.layouts[BufferIndex.meshPositions.rawValue].stepFunction = .perVertex
|
|
|
|
desc.layouts[BufferIndex.meshGenerics.rawValue].stride = 8
|
|
desc.layouts[BufferIndex.meshGenerics.rawValue].stepRate = 1
|
|
desc.layouts[BufferIndex.meshGenerics.rawValue].stepFunction = .perVertex
|
|
|
|
desc.layouts[BufferIndex.meshGridCoords.rawValue].stride = MemoryLayout<uint2>.stride
|
|
desc.layouts[BufferIndex.meshGridCoords.rawValue].stepRate = 1
|
|
desc.layouts[BufferIndex.meshGridCoords.rawValue].stepFunction = .perVertex
|
|
|
|
return desc
|
|
}
|
|
|
|
/// Create and condition mesh data to feed into a pipeline using the given vertex descriptor.
|
|
///
|
|
/// - parameter dimensions: Coordinate dimensions of the plane.
|
|
/// - parameter segments: Number of segments to divide each dimension into.
|
|
/// - parameter device: Metal device.
|
|
/// - parameter vertexDescriptor: Description of how to lay out vertex data in GPU memory.
|
|
class func buildMesh(withDimensions dimensions: float2, segments: uint2, device: MTLDevice, vertexDescriptor: MTLVertexDescriptor) throws -> MTKMesh {
|
|
let metalAllocator = MTKMeshBufferAllocator(device: device)
|
|
|
|
let plane = MDLMesh.newPlane(withDimensions: dimensions,
|
|
segments: segments,
|
|
geometryType: .triangles,
|
|
allocator: metalAllocator)
|
|
|
|
let mdlVertexDescriptor = MTKModelIOVertexDescriptorFromMetal(vertexDescriptor)
|
|
|
|
guard let attributes = mdlVertexDescriptor.attributes as? [MDLVertexAttribute] else {
|
|
throw RendererError.badVertexDescriptor
|
|
}
|
|
attributes[VertexAttribute.position.rawValue].name = MDLVertexAttributePosition
|
|
attributes[VertexAttribute.texcoord.rawValue].name = MDLVertexAttributeTextureCoordinate
|
|
attributes[VertexAttribute.gridCoord.rawValue].name = "Grid Coordinate"
|
|
|
|
plane.vertexDescriptor = mdlVertexDescriptor
|
|
|
|
return try MTKMesh(mesh:plane, device:device)
|
|
}
|
|
|
|
private static let heightMapSize = MTLSize(width: 512, height: 512, depth: 1)
|
|
|
|
let dimensions: float2
|
|
let segments: uint2
|
|
let vertexDescriptor: MTLVertexDescriptor
|
|
let mesh: MTKMesh
|
|
|
|
var algorithm: Algorithm
|
|
|
|
init?(dimensions dim: float2, segments seg: uint2, device: MTLDevice, library: MTLLibrary) {
|
|
dimensions = dim
|
|
segments = seg
|
|
vertexDescriptor = Terrain.buildVertexDescriptor()
|
|
|
|
do {
|
|
mesh = try Terrain.buildMesh(withDimensions: dimensions, segments: segments, device: device, vertexDescriptor: vertexDescriptor)
|
|
} catch let e {
|
|
print("Couldn't create mesh. Error: \(e)")
|
|
return nil
|
|
}
|
|
|
|
guard let alg = ZeroAlgorithm(device: device, library: library) else {
|
|
print("Couldn't create algorithm")
|
|
return nil
|
|
}
|
|
algorithm = alg
|
|
|
|
super.init()
|
|
}
|
|
}
|