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Generate some random heights to fill the height map texture and ... it works!

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This commit is contained in:
Eryn Wells 2018-11-04 08:25:01 -05:00
parent 18e9d078b0
commit af5e5a6123
2 changed files with 27 additions and 6 deletions
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6
Terrain2/Shaders.metal
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@ -30,7 +30,7 @@ typedef struct
} ColorInOut; } ColorInOut;
vertex ColorInOut vertexShader(Vertex in [[stage_in]], vertex ColorInOut vertexShader(Vertex in [[stage_in]],
texture2d<half> heights [[texture(0)]], texture2d<float> heights [[texture(0)]],
constant Uniforms & uniforms [[buffer(BufferIndexUniforms)]]) constant Uniforms & uniforms [[buffer(BufferIndexUniforms)]])
{ {
constexpr sampler s(coord::pixel, address::clamp_to_zero, filter::linear); constexpr sampler s(coord::pixel, address::clamp_to_zero, filter::linear);
@ -39,9 +39,9 @@ vertex ColorInOut vertexShader(Vertex in [[stage_in]],
// TODO: Concerned about this. // TODO: Concerned about this.
uint2 gridCoord(in.texCoord.x * heights.get_width(), in.texCoord.y * heights.get_height()); uint2 gridCoord(in.texCoord.x * heights.get_width(), in.texCoord.y * heights.get_height());
half4 height = heights.read(gridCoord).rrrr; float4 height = heights.read(gridCoord).rrrr;
float4 position(in.position.x, float(height.r), in.position.z, 1.0); float4 position(in.position.x, height.r, in.position.z, 1.0);
out.position = uniforms.projectionMatrix * uniforms.modelViewMatrix * position; out.position = uniforms.projectionMatrix * uniforms.modelViewMatrix * position;
out.texCoord = in.texCoord; out.texCoord = in.texCoord;

27
Terrain2/Terrain.swift
View file

@ -70,6 +70,28 @@ class Terrain: NSObject {
return try MTKMesh(mesh:plane, device:device) return try MTKMesh(mesh:plane, device:device)
} }
class func buildHeightsTexture(dimensions: uint2, device: MTLDevice) -> MTLTexture? {
let heightsDesc = MTLTextureDescriptor.texture2DDescriptor(pixelFormat: .r32Float, width: Int(dimensions.x), height: Int(dimensions.y), mipmapped: false)
heightsDesc.usage = [.shaderRead, .shaderWrite]
let tex = device.makeTexture(descriptor: heightsDesc)
if let tex = tex {
var initialHeights = [Float]()
let numberOfHeights = tex.height * tex.width
initialHeights.reserveCapacity(numberOfHeights)
for _ in 0..<numberOfHeights {
initialHeights.append(Float.random(in: 0...0.5))
}
let origin = MTLOrigin(x: 0, y: 0, z: 0)
let size = MTLSize(width: tex.width, height: tex.height, depth: 1)
let region = MTLRegion(origin: origin, size: size)
let bytesPerRow = MemoryLayout<Float>.stride * tex.width
tex.replace(region: region, mipmapLevel: 0, withBytes: initialHeights, bytesPerRow: bytesPerRow)
}
return tex
}
let dimensions: float2 let dimensions: float2
let segments: uint2 let segments: uint2
let vertexDescriptor: MTLVertexDescriptor let vertexDescriptor: MTLVertexDescriptor
@ -88,9 +110,8 @@ class Terrain: NSObject {
return nil return nil
} }
let heightsDesc = MTLTextureDescriptor.texture2DDescriptor(pixelFormat: .r16Float, width: Int(segments.x), height: Int(segments.y), mipmapped: false) let heightsDimensions = segments
heightsDesc.usage = [.shaderRead, .shaderWrite] guard let tex = Terrain.buildHeightsTexture(dimensions: heightsDimensions, device: device) else {
guard let tex = device.makeTexture(descriptor: heightsDesc) else {
print("Couldn't create heights texture") print("Couldn't create heights texture")
return nil return nil
} }