RIP to Float16, it's sad that Intel doesn't support you.

Sources/Voxelotl/Chunk.swift

@@ -123,7 +123,7 @@ public struct Chunk: Hashable {
 
 public enum BlockType: Hashable {
   case air
-  case solid(_ color: Color<Float16>)
+  case solid(_ color: Color<Float>)
 }
 
 public struct Block: Hashable {

Sources/Voxelotl/Game.swift

@@ -4,13 +4,13 @@ struct Instance {
   let position: SIMD3<Float>
   let scale: SIMD3<Float>
   let rotation: simd_quatf
-  let color: Color<Float16>
+  let color: Color<Float>
 
   init(
     position: SIMD3<Float> = .zero,
     scale: SIMD3<Float> = .one,
     rotation: simd_quatf = .identity,
-    color: Color<Float16> = .white
+    color: Color<Float> = .white
   ) {
     self.position = position
     self.scale = scale

Sources/Voxelotl/Renderer/Material.swift

@@ -1,7 +1,7 @@
 
 public struct Material {
-  public var ambient: Color<Float16>
+  public var ambient: Color<Float>
-  public var diffuse: Color<Float16>
+  public var diffuse: Color<Float>
-  public var specular: Color<Float16>
+  public var specular: Color<Float>
   public var gloss: Float
 }

Sources/Voxelotl/Renderer/Mesh.swift

@@ -18,6 +18,6 @@ public struct VertexPositionNormalTexcoord: Vertex {
 public struct VertexPositionNormalColorTexcoord: Vertex {
   var position: SIMD3<Float>
   var normal:   SIMD3<Float>
-  var color:    SIMD4<Float16>
+  var color:    SIMD4<Float>
   var texCoord: SIMD2<Float>
 }

Sources/Voxelotl/Renderer/Renderer.swift

@@ -141,7 +141,7 @@ public class Renderer {
     if mesh.vertices.isEmpty || mesh.indices.isEmpty { return nil }
 
     let vertices = mesh.vertices.map {
-      ShaderVertex(position: $0.position, normal: $0.normal, color: $0.color.reinterpretUShort, texCoord: $0.texCoord)
+      ShaderVertex(position: $0.position, normal: $0.normal, color: $0.color, texCoord: $0.texCoord)
     }
     guard let vtxBuffer = self.device.makeBuffer(
       bytes: vertices,
@@ -165,9 +165,9 @@ public class Renderer {
   func createMesh(_ mesh: Mesh<VertexPositionNormalTexcoord, UInt16>) -> RendererMesh? {
     if mesh.vertices.isEmpty || mesh.indices.isEmpty { return nil }
 
-    let color = Color<Float16>.white.reinterpretUShort
+    let color = Color<Float>.white
     let vertices = mesh.vertices.map {
-      ShaderVertex(position: $0.position, normal: $0.normal, color: color, texCoord: $0.texCoord)
+      ShaderVertex(position: $0.position, normal: $0.normal, color: color.values, texCoord: $0.texCoord)
     }
     guard let vtxBuffer = self.device.makeBuffer(
       bytes: vertices,
@@ -341,21 +341,21 @@ public class Renderer {
     }
   }
 
-  func draw(model: matrix_float4x4, color: Color<Float16>, mesh: RendererMesh, material: Material, environment: Environment, camera: Camera) {
+  func draw(model: matrix_float4x4, color: Color<Float>, mesh: RendererMesh, material: Material, environment: Environment, camera: Camera) {
     assert(self._encoder != nil, "draw can't be called outside of a frame being rendered")
 
     var vertUniforms = VertexShaderUniforms(projView: camera.viewProjection)
     var fragUniforms = FragmentShaderUniforms(
       cameraPosition: camera.position,
       directionalLight: normalize(environment.lightDirection),
-      ambientColor:  material.ambient.reinterpretUShort,
+      ambientColor:  material.ambient.values,
-      diffuseColor:  material.diffuse.reinterpretUShort,
+      diffuseColor:  material.diffuse.values,
-      specularColor: material.specular.reinterpretUShort,
+      specularColor: material.specular.values,
       specularIntensity: material.gloss)
     var instance = VertexShaderInstance(
       model:       model,
       normalModel: model.inverse.transpose,
-      color:       color.reinterpretUShort)
+      color:       color.values)
 
     self._encoder.setCullMode(.init(environment.cullFace))
 
@@ -386,9 +386,9 @@ public class Renderer {
     var fragUniforms = FragmentShaderUniforms(
       cameraPosition: camera.position,
       directionalLight: normalize(environment.lightDirection),
-      ambientColor:  material.ambient.reinterpretUShort,
+      ambientColor:  material.ambient.values,
-      diffuseColor:  material.diffuse.reinterpretUShort,
+      diffuseColor:  material.diffuse.values,
-      specularColor: material.specular.reinterpretUShort,
+      specularColor: material.specular.values,
       specularIntensity: material.gloss)
 
     let numInstances = instances.count
@@ -417,7 +417,7 @@ public class Renderer {
           .scale(instance.scale)
         data[i] = VertexShaderInstance(
           model: model, normalModel: model.inverse.transpose,
-          color: instance.color.reinterpretUShort)
+          color: instance.color.values)
       }
     }
     instanceBuffer.didModifyRange(0..<instancesBytes)
@@ -468,13 +468,13 @@ fileprivate extension MTLCullMode {
   }
 }
 
-fileprivate extension Color where T == Float16 {
+fileprivate extension Color where T == Float {
-  var reinterpretUShort: SIMD4<UInt16> {
+  var reinterpretUInt: SIMD4<UInt32> {
     .init(self.r.bitPattern, self.g.bitPattern, self.b.bitPattern, self.a.bitPattern)
   }
 }
-fileprivate extension SIMD4 where Scalar == Float16 {
+fileprivate extension SIMD4 where Scalar == Float {
-  var reinterpretUShort: SIMD4<UInt16> {
+  var reinterpretUShort: SIMD4<UInt32> {
     .init(self.x.bitPattern, self.y.bitPattern, self.z.bitPattern, self.w.bitPattern)
   }
 }

Sources/Voxelotl/WorldGenerator.swift

@@ -26,9 +26,9 @@ struct WorldGenerator {
           + self.noise.get(fpos * 0.30) * 0.23
       return if value < threshold {
         .solid(.init(
-          hue:        Float16(180 + self.noise2.get(fpos * 0.05) * 180),
+          hue:        Float(180 + self.noise2.get(fpos * 0.05) * 180),
-          saturation: Float16(0.5 + self.noise2.get(SIMD4(fpos * 0.05, 4)) * 0.5),
+          saturation: Float(0.5 + self.noise2.get(SIMD4(fpos * 0.05, 4)) * 0.5),
-          value:      Float16(0.5 + self.noise2.get(SIMD4(fpos * 0.05, 9)) * 0.5).lerp(0.5, 1)).linear)
+          value:      Float(0.5 + self.noise2.get(SIMD4(fpos * 0.05, 9)) * 0.5).lerp(0.5, 1)).linear)
       } else {
         .air
       }

Sources/Voxelotl/shader.metal

@@ -7,7 +7,7 @@ struct FragmentInput {
   float3 world;
   float3 normal;
   float2 texCoord;
-  half4 color;
+  float4 color;
 };
 
 vertex FragmentInput vertexMain(
@@ -29,7 +29,7 @@ vertex FragmentInput vertexMain(
   return out;
 }
 
-fragment half4 fragmentMain(
+fragment float4 fragmentMain(
   FragmentInput in [[stage_in]],
   metal::texture2d<half, metal::access::sample> texture [[texture(0)]],
   constant FragmentShaderUniforms& u [[buffer(FragmentShaderInputIdxUniforms)]]
@@ -45,17 +45,17 @@ fragment half4 fragmentMain(
   // Compute diffuse component
   float lambert = metal::dot(normal, lightVec);
   float diffuseAmount = metal::max(0.0, lambert);
-  half4 diffuse = u.diffuseColor * diffuseAmount;
+  float4 diffuse = u.diffuseColor * diffuseAmount;
 
   // Compute specular component (blinn-phong)
   float specularAngle = metal::max(0.0, metal::dot(halfDir, normal));
   float specularTerm = metal::pow(specularAngle, u.specularIntensity);
   // smoothstep hack to ensure highlight tapers gracefully at grazing angles
   float specularAmount = specularTerm * metal::smoothstep(0, 2, lambert * u.specularIntensity);
-  half4 specular = u.specularColor * specularAmount;
+  float4 specular = u.specularColor * specularAmount;
 
   // Sample texture & vertex color to get albedo
-  half4 albedo = texture.sample(sampler, in.texCoord);
+  float4 albedo = float4(texture.sample(sampler, in.texCoord));
   albedo *= in.color;
 
   return albedo * (u.ambientColor + diffuse) + specular;

Sources/Voxelotl/shadertypes.h

@@ -10,12 +10,7 @@
 
 #include <simd/simd.h>
 
-// HACK: allow passing SIMD4<Float16> to shader while `simd_half4` is beta
+typedef simd_float4 color_float4;
-#ifdef __METAL_VERSION__
-typedef half4 color_half4;
-#else
-typedef simd_ushort4 color_half4;
-#endif
 
 typedef NS_ENUM(NSInteger, VertexShaderInputIdx) {
   VertexShaderInputIdxVertices = 0,
@@ -26,14 +21,14 @@ typedef NS_ENUM(NSInteger, VertexShaderInputIdx) {
 typedef struct {
   vector_float3 position;
   vector_float3 normal;
-  color_half4   color;
+  color_float4   color;
   vector_float2 texCoord;
 } ShaderVertex;
 
 typedef struct {
   matrix_float4x4 model;
   matrix_float4x4 normalModel;
-  color_half4     color;
+  color_float4     color;
 } VertexShaderInstance;
 
 typedef struct {
@@ -46,7 +41,7 @@ typedef NS_ENUM(NSInteger, FragmentShaderInputIdx) {
 
 typedef struct {
   vector_float3 cameraPosition, directionalLight;
-  color_half4 ambientColor, diffuseColor, specularColor;
+  color_float4 ambientColor, diffuseColor, specularColor;
   float specularIntensity;
 } FragmentShaderUniforms;