oklab <-> linear, linear <-> srgb

src/base/base_math.c

@@ -480,7 +480,9 @@ internal Rng2F32 intersect_2f32(Rng2F32 a, Rng2F32 b)           {Rng2F32 c; c.p0
 internal Vec2F32 clamp_2f32(Rng2F32 r, Vec2F32 v)               {v.x = Clamp(r.min.x, v.x, r.max.x); v.y = Clamp(r.min.y, v.y, r.max.y); return v;}
 
 ////////////////////////////////
-//~ rjf: Miscellaneous Ops
+//~ rjf: Color Operations
+
+//- rjf: hsv <-> rgb
 
 internal Vec3F32
 hsv_from_rgb(Vec3F32 rgb)
@@ -567,16 +569,102 @@ rgba_from_hsva(Vec4F32 hsva)
   return rgba;
 }
 
-internal Vec4F32
-rgba_from_u32(U32 hex)
+//- rjf: srgb <-> linear
+
+internal Vec3F32
+linear_from_srgb(Vec3F32 srgb)
 {
-  Vec4F32 result = v4f32(((hex&0xff000000)>>24)/255.f,
-                         ((hex&0x00ff0000)>>16)/255.f,
-                         ((hex&0x0000ff00)>> 8)/255.f,
-                         ((hex&0x000000ff)>> 0)/255.f);
+  Vec3F32 result;
+  for EachElement(idx, srgb.v)
+  {
+    result.v[idx] = (srgb.v[idx] < 0.0404482362771082f ? srgb.v[idx] / 12.92f : pow_f32((srgb.v[idx] + 0.055f) / 1.055f, 2.4f));
+  }
   return result;
 }
 
+internal Vec3F32
+srgb_from_linear(Vec3F32 linear)
+{
+  Vec3F32 result;
+  for EachElement(idx, linear.v)
+  {
+    result.v[idx] = (0 <= linear.v[idx] && linear.v[idx] < 0.00313066844250063) ? linear.v[idx]*12.92f : 1.05f * pow_f32(linear.v[idx], 1.f/2.4f) - 0.055f;
+  }
+  return result;
+}
+
+internal Vec4F32
+linear_from_srgba(Vec4F32 srgba)
+{
+  Vec4F32 result;
+  result.xyz = linear_from_srgb(srgba.xyz);
+  result.w = srgba.w;
+  return result;
+}
+
+internal Vec4F32
+srgba_from_linear(Vec4F32 linear)
+{
+  Vec4F32 result;
+  result.xyz = srgb_from_linear(linear.xyz);
+  result.w = linear.w;
+  return result;
+}
+
+//- rjf: oklab <-> linear
+
+internal Vec3F32
+oklab_from_linear(Vec3F32 linear)
+{
+  F32 l = (0.4122214708f * linear.x + 0.5363325363f * linear.y + 0.0514459929f * linear.z);
+	F32 m = (0.2119034982f * linear.x + 0.6806995451f * linear.y + 0.1073969566f * linear.z);
+	F32 s = (0.0883024619f * linear.x + 0.2817188376f * linear.y + 0.6299787005f * linear.z);
+  F32 l_ = cbrt_f32(l);
+  F32 m_ = cbrt_f32(m);
+  F32 s_ = cbrt_f32(s);
+  Vec3F32 result;
+  result.x = 0.2104542553f*l_ + 0.7936177850f*m_ - 0.0040720468f*s_;
+  result.y = 1.9779984951f*l_ - 2.4285922050f*m_ + 0.4505937099f*s_;
+  result.z = 0.0259040371f*l_ + 0.7827717662f*m_ - 0.8086757660f*s_;
+  return result;
+}
+
+internal Vec3F32
+linear_from_oklab(Vec3F32 oklab)
+{
+  F32 l_ = oklab.x + 0.3963377774f * oklab.y + 0.2158037573f * oklab.z;
+  F32 m_ = oklab.x - 0.1055613458f * oklab.y - 0.0638541728f * oklab.z;
+  F32 s_ = oklab.x - 0.0894841775f * oklab.y - 1.2914855480f * oklab.z;
+  F32 l = l_*l_*l_;
+  F32 m = m_*m_*m_;
+  F32 s = s_*s_*s_;
+  Vec3F32 result;
+  result.x = +4.0767416621f * l - 3.3077115913f * m + 0.2309699292f * s;
+  result.y = -1.2684380046f * l + 2.6097574011f * m - 0.3413193965f * s;
+  result.z = -0.0041960863f * l - 0.7034186147f * m + 1.7076147010f * s;
+  return result;
+}
+
+internal Vec4F32
+oklab_from_lineara(Vec4F32 lineara)
+{
+  Vec4F32 result;
+  result.xyz = oklab_from_linear(lineara.xyz);
+  result.w = lineara.w;
+  return result;
+}
+
+internal Vec4F32
+lineara_from_oklab(Vec4F32 oklab)
+{
+  Vec4F32 result;
+  result.xyz = linear_from_oklab(oklab.xyz);
+  result.w = oklab.w;
+  return result;
+}
+
+//- rjf: rgba <-> u32
+
 internal U32
 u32_from_rgba(Vec4F32 rgba)
 {
@@ -588,6 +676,16 @@ u32_from_rgba(Vec4F32 rgba)
   return result;
 }
 
+internal Vec4F32
+rgba_from_u32(U32 hex)
+{
+  Vec4F32 result = v4f32(((hex&0xff000000)>>24)/255.f,
+                         ((hex&0x00ff0000)>>16)/255.f,
+                         ((hex&0x0000ff00)>> 8)/255.f,
+                         ((hex&0x000000ff)>> 0)/255.f);
+  return result;
+}
+
 ////////////////////////////////
 //~ rjf: List Type Functions
 

src/base/base_math.h

@@ -379,6 +379,7 @@ struct Rng1S64Array
 #define abs_s64(v) (S64)llabs(v)
 
 #define sqrt_f32(v)   sqrtf(v)
+#define cbrt_f32(v)   cbrtf(v)
 #define mod_f32(a, b) fmodf((a), (b))
 #define pow_f32(b, e) powf((b), (e))
 #define ceil_f32(v)   ceilf(v)
@@ -396,6 +397,7 @@ struct Rng1S64Array
 #define tan_f32(v)    tanf(radians_from_turns_f32(v))
 
 #define sqrt_f64(v)   sqrt(v)
+#define cbrt_f64(v)   cbrt(v)
 #define mod_f64(a, b) fmod((a), (b))
 #define pow_f64(b, e) pow((b), (e))
 #define ceil_f64(v)   ceil(v)
@@ -651,15 +653,29 @@ internal Rng2F32 intersect_2f32(Rng2F32 a, Rng2F32 b);
 internal Vec2F32 clamp_2f32(Rng2F32 r, Vec2F32 v);
 
 ////////////////////////////////
-//~ rjf: Miscellaneous Ops
+//~ rjf: Color Operations
 
+//- rjf: hsv <-> rgb
 internal Vec3F32 hsv_from_rgb(Vec3F32 rgb);
 internal Vec3F32 rgb_from_hsv(Vec3F32 hsv);
 internal Vec4F32 hsva_from_rgba(Vec4F32 rgba);
 internal Vec4F32 rgba_from_hsva(Vec4F32 hsva);
-internal Vec4F32 rgba_from_u32(U32 hex);
-internal U32 u32_from_rgba(Vec4F32 rgba);
 
+//- rjf: srgb <-> linear
+internal Vec3F32 linear_from_srgb(Vec3F32 srgb);
+internal Vec3F32 srgb_from_linear(Vec3F32 linear);
+internal Vec4F32 linear_from_srgba(Vec4F32 srgba);
+internal Vec4F32 srgba_from_linear(Vec4F32 linear);
+
+//- rjf: oklab <-> linear
+internal Vec3F32 oklab_from_linear(Vec3F32 linear);
+internal Vec3F32 linear_from_oklab(Vec3F32 oklab);
+internal Vec4F32 oklab_from_lineara(Vec4F32 lineara);
+internal Vec4F32 lineara_from_oklab(Vec4F32 oklab);
+
+//- rjf: rgba <-> u32
+internal U32 u32_from_rgba(Vec4F32 rgba);
+internal Vec4F32 rgba_from_u32(U32 hex);
 #define rgba_from_u32_lit_comp(h) { (((h)&0xff000000)>>24)/255.f, (((h)&0x00ff0000)>>16)/255.f, (((h)&0x0000ff00)>> 8)/255.f, (((h)&0x000000ff)>> 0)/255.f }
 
 ////////////////////////////////