eryn/metaballs
1
0
Fork 0
Code Issues Pull requests Projects Releases Packages Wiki Activity Actions

Render sampled grid with colors and stuff!

Browse source
This commit is contained in:
Eryn Wells 2018-10-14 12:51:24 -07:00
parent 7694a641a0
commit 720e3b1b64
3 changed files with 55 additions and 82 deletions
Download patch file Download diff file Expand all files Collapse all files

95
MetaballsKit/MarchingSquares.swift
View file

@ -13,12 +13,13 @@ class MarchingSquares {
private var field: Field
private var sampleGridSize = Size(16)
private var semaphore: DispatchSemaphore
/// Samples of the field's current state.
private(set) var samples: MTLTexture?
private(set) var samplesBuffer: MTLBuffer?
/// Indexes of geometry to render.
private(set) var indexes: MTLTexture?
private var lastGridCount: Int = 0
private(set) var gridGeometry: MTLBuffer?
private var xSamples: Int {
@ -29,12 +30,15 @@ class MarchingSquares {
return Int(field.size.y / sampleGridSize.y)
}
private var lastSamplesCount = 0
var samplesCount: Int {
return xSamples * ySamples
}
init(field: Field) {
self.field = field
semaphore = DispatchSemaphore(value: 1)
}
func setupMetal(withDevice device: MTLDevice) {
@ -54,15 +58,16 @@ class MarchingSquares {
}
func fieldDidResize() {
guard let gridGeometry = gridGeometry else {
guard let device = gridGeometry?.device else {
return
}
createGridGeometryBuffer(withDevice: gridGeometry.device)
populateGrid(withDevice: gridGeometry.device)
populateGrid(withDevice: device)
populateSamples(withDevice: device)
lastSamplesCount = samplesCount
}
func populateGrid(withDevice device: MTLDevice) {
guard lastGridCount != samplesCount else {
guard lastSamplesCount != samplesCount else {
return
}
@ -77,7 +82,8 @@ class MarchingSquares {
for y in 0..<ySamples {
for x in 0..<xSamples {
let transform = Matrix4x4.translation(dx: Float(x) * gridSizeX, dy: Float(y) * gridSizeY, dz: 0.0) * Matrix4x4.scale(x: gridSizeX, y: gridSizeY, z: 1)
let rect = Rect(transform: transform, color: Float4(1.0))
let color = Float4(r: 0, g: 1, b: 0, a: 1)
let rect = Rect(transform: transform, color: color)
grid.append(rect)
}
}
@ -88,72 +94,29 @@ class MarchingSquares {
} else {
fatalError("Couldn't create buffer for grid rects")
}
lastGridCount = samplesCount
}
private func createGridGeometryBuffer(withDevice device: MTLDevice) {
// Allocate a buffer with enough space for the rect vertex data, and all the rect instances we need to render.
// [rect] [rect] ...
func populateSamples(withDevice device: MTLDevice) {
print("Populating samples buffer with \(samplesCount) values")
}
var samples = [Float]()
samples.reserveCapacity(samplesCount)
func sampleField() {
guard let samples = samples else { return }
let bytesPerRow = samples.width * MemoryLayout<Float>.stride
for xSample in 0..<samples.width {
let x = Float(xSample * Int(sampleGridSize.x))
for ySample in 0..<samples.height {
let y = Float(ySample * Int(sampleGridSize.y))
let sample = [field.sample(at: Float2(x: x, y: y))]
let origin = MTLOrigin(x: xSample, y: ySample, z: 0)
let size = MTLSize(width: 1, height: 1, depth: 1)
let region = MTLRegion(origin: origin, size: size)
samples.replace(region: region, mipmapLevel: 0, withBytes: sample, bytesPerRow: bytesPerRow)
for ys in 0..<ySamples {
let y = Float(ys * Int(sampleGridSize.y))
for xs in 0..<xSamples {
let x = Float(xs * Int(sampleGridSize.x))
let sample = field.sample(at: Float2(x: x, y: y))
samples.append(sample)
}
}
}
func populateIndexes() {
guard let indexes = indexes else { return }
let bytesPerRow = indexes.width * MemoryLayout<UInt8>.stride
for x in 0..<indexes.width {
for y in 0..<indexes.height {
guard let samples = getSampleBlock(x: x, y: y) else {
continue
}
let index = (samples[0] > 1.0 ? 0b1000 : 0) +
(samples[1] > 1.0 ? 0b0100 : 0) +
(samples[2] > 1.0 ? 0b0001 : 0) +
(samples[3] > 1.0 ? 0b0010 : 0)
let origin = MTLOrigin(x: x, y: y, z: 0)
let size = MTLSize(width: 1, height: 1, depth: 1)
let region = MTLRegion(origin: origin, size: size)
let indexArr = [index]
indexes.replace(region: region, mipmapLevel: 0, withBytes: indexArr, bytesPerRow: bytesPerRow)
}
let samplesLength = MemoryLayout<Float>.stride * samplesCount
if let buffer = device.makeBuffer(length: MemoryLayout<Float>.stride * samples.count, options: .storageModeShared) {
memcpy(buffer.contents(), samples, samplesLength)
samplesBuffer = buffer
} else {
fatalError("Couldn't create buffer for samples")
}
}
private func getSampleBlock(x: Int, y: Int) -> [Float]? {
guard let samples = samples else {
return nil
}
var block: [Float] = [0, 0, 0, 0]
let bytesPerRow = samples.width * MemoryLayout<Float>.stride
let origin = MTLOrigin(x: x, y: y, z: 0)
let size = MTLSize(width: 2, height: 2, depth: 1)
let region = MTLRegion(origin: origin, size: size)
samples.getBytes(&block, bytesPerRow: bytesPerRow, from: region, mipmapLevel: 0)
return block
}
}