From 4d9003dc1dce7047b67a263d7348eb216c8b1f5f Mon Sep 17 00:00:00 2001
From: Mitya Selivanov <automainint@guattari.tech>
Date: Sun, 24 Sep 2023 08:58:18 +0200
Subject: Update math, docs

---
 README            |  1 +
 source/kit/math.h | 35 ++++++++++++++++++++++++-----------
 2 files changed, 25 insertions(+), 11 deletions(-)

diff --git a/README b/README
index 51e37ba..afa93cf 100644
--- a/README
+++ b/README
@@ -26,6 +26,7 @@ Features
   - Input buffer
   - Random number generation
   - Async functions (coroutines)
+  - Vector and color math
   - XML
 
 Preprocessor options
diff --git a/source/kit/math.h b/source/kit/math.h
index 8deff05..45508b7 100644
--- a/source/kit/math.h
+++ b/source/kit/math.h
@@ -3,12 +3,18 @@
 
 #include "types.h"
 
-#define _USE_MATH_DEFINES
+#ifndef _USE_MATH_DEFINES
+#  define _USE_MATH_DEFINES
+#endif
 #include <math.h>
 
 #include <assert.h>
 #include <string.h>
 
+//  TODO
+//  - Gamma correction.
+//
+
 #ifdef __cplusplus
 extern "C" {
 #endif
@@ -25,7 +31,7 @@ extern "C" {
 #  define KIT_VEC_TYPE f32
 #endif
 
-#define KIT_EPSILON .0001
+#define KIT_EPSILON .00001
 
 #define KIT_COLOR_REF_X 95.047f
 #define KIT_COLOR_REF_Y 100.0f
@@ -34,23 +40,14 @@ extern "C" {
 typedef KIT_VEC_TYPE vec_t;
 
 typedef union {
-  struct {
-    vec_t x, y;
-  };
   vec_t v[2];
 } vec2_t;
 
 typedef union {
-  struct {
-    vec_t x, y, z;
-  };
   vec_t v[3];
 } vec3_t;
 
 typedef struct {
-  struct {
-    vec_t x, y, z, w;
-  };
   vec_t v[4];
 } vec4_t, quat_t;
 
@@ -594,6 +591,10 @@ static quat_t quat_slerp(quat_t q0, quat_t q1, vec_t t) {
 }
 
 static vec3_t rgb_to_xyz(vec3_t rgb) {
+  //  FIXME
+  //  Remove unnecessary x100 scaling.
+  //
+
   vec_t red   = rgb.v[0];
   vec_t green = rgb.v[1];
   vec_t blue  = rgb.v[2];
@@ -627,6 +628,10 @@ static vec3_t rgb_to_xyz(vec3_t rgb) {
 }
 
 static vec3_t xyz_to_rgb(vec3_t xyz) {
+  //  FIXME
+  //  Remove unnecessary x100 scaling.
+  //
+
   vec_t x = xyz.v[0] / 100.f;
   vec_t y = xyz.v[1] / 100.f;
   vec_t z = xyz.v[2] / 100.f;
@@ -659,6 +664,10 @@ static vec3_t xyz_to_rgb(vec3_t xyz) {
 }
 
 static vec3_t lab_to_xyz(vec3_t lab) {
+  //  FIXME
+  //  Remove unnecessary x100 scaling.
+  //
+
   vec_t lightness = lab.v[0];
   vec_t a         = lab.v[1];
   vec_t b         = lab.v[2];
@@ -687,6 +696,10 @@ static vec3_t lab_to_xyz(vec3_t lab) {
 }
 
 static vec3_t xyz_to_lab(vec3_t xyz) {
+  //  FIXME
+  //  Remove unnecessary x100 scaling.
+  //
+
   vec_t x = (xyz.v[0] / KIT_COLOR_REF_X);
   vec_t y = (xyz.v[1] / KIT_COLOR_REF_Y);
   vec_t z = (xyz.v[2] / KIT_COLOR_REF_Z);
-- 
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