From d5206234921f931011331d29a264ace09c25bd3b Mon Sep 17 00:00:00 2001
From: a dinosaur <dino@a-dinosaur.com>
Date: Mon, 9 Sep 2024 03:02:31 +1000
Subject: [PATCH] replace expensive srgb conversion with a simple gamma ramp in
 chunk mesh builder

---
 Sources/Voxelotl/ChunkMeshBuilder.swift |  2 +-
 Sources/Voxelotl/Common/Color.swift     | 16 ++++++++++++++--
 2 files changed, 15 insertions(+), 3 deletions(-)

diff --git a/Sources/Voxelotl/ChunkMeshBuilder.swift b/Sources/Voxelotl/ChunkMeshBuilder.swift
index 52054af..423c047 100644
--- a/Sources/Voxelotl/ChunkMeshBuilder.swift
+++ b/Sources/Voxelotl/ChunkMeshBuilder.swift
@@ -13,7 +13,7 @@ struct ChunkMeshBuilder {
               .init(
                 position: SIMD3(position) + $0.position,
                 normal: $0.normal,
-                color: SIMD4(Color<Float>(color).linear),
+                color: SIMD4(Color<Float>(color).pow(2.2)),  //FIXME: Better sRGB approximation when I can be bothered
                 texCoord: $0.texCoord)
             })
             indices.append(contentsOf: sideIndices.map { orig + $0 })
diff --git a/Sources/Voxelotl/Common/Color.swift b/Sources/Voxelotl/Common/Color.swift
index 6aa3d72..ecd4b06 100644
--- a/Sources/Voxelotl/Common/Color.swift
+++ b/Sources/Voxelotl/Common/Color.swift
@@ -139,7 +139,7 @@ public extension Color where T: BinaryFloatingPoint {
     if x < 0.04045 {
       x / 12.92
     } else {
-      T(pow((Double(x) + 0.055) / 1.055, 2.4))
+      T(Darwin.pow((Double(x) + 0.055) / 1.055, 2.4))
     }
   }
 
@@ -151,7 +151,7 @@ public extension Color where T: BinaryFloatingPoint {
     } else if x < 0.0031308 {
       x * 12.92
     } else {
-      T(1.055 * pow(Double(abs(x)), 1 / 2.4) - 0.055)
+      T(1.055 * Darwin.pow(Double(abs(x)), 1 / 2.4) - 0.055)
     }
   }
 }
@@ -195,3 +195,15 @@ public extension Color where T: FloatingPoint {
     }
   }
 }
+
+public extension Color where T == Float {
+  func pow(_ exponent: T) -> Self {
+    Self(r: powf(r, exponent), g: powf(g, exponent), b: powf(b, exponent), a: a)
+  }
+}
+public extension Color where T == Double {
+  func pow(_ exponent: T) -> Self {
+    Self(r: Darwin.pow(r, exponent), g: Darwin.pow(g, exponent), b: Darwin.pow(b, exponent), a: a)
+  }
+}
+