From 954037b4ea3729b834237fe8b63c442c504e080f Mon Sep 17 00:00:00 2001
From: Gregory Wells <me@gregorywells.dev>
Date: Sun, 15 Jun 2025 18:51:30 -0400
Subject: [PATCH] some utils jazz

---
 utils/math/gryphn_mat4.h | 49 ++++++++++++++++++++++++++++++++++++++++
 utils/math/gryphn_math.h |  3 +++
 utils/math/gryphn_vec2.h |  2 ++
 utils/math/gryphn_vec3.h | 11 +++++++++
 4 files changed, 65 insertions(+)
 create mode 100644 utils/math/gryphn_math.h

diff --git a/utils/math/gryphn_mat4.h b/utils/math/gryphn_mat4.h
index 2a0b1d1..687730f 100644
--- a/utils/math/gryphn_mat4.h
+++ b/utils/math/gryphn_mat4.h
@@ -1,5 +1,6 @@
 #pragma once
 #include "math.h"
+#include "gryphn_vec3.h"
 
 typedef struct gnMat4x4 {
     float mat[4][4];
@@ -45,3 +46,51 @@ static inline const gnMat4x4 gnProjection(
         }
     };
 }
+
+static inline const gnMat4x4 gnTranslate(gnVec3 translation) {
+    return (gnMat4x4) {
+        .mat = {
+            { 1.0f, 0.0f, 0.0f, 0.0f },
+            { 0.0f, 1.0f, 0.0f, 0.0f },
+            { 0.0f, 0.0f, 1.0f, 0.0f },
+            { translation.x, translation.y, translation.z, 1.0f }
+        }
+    };
+}
+
+static inline const gnMat4x4 gnRotate(gnVec3 axis, float rotation) {
+    float c = cos(rotation), s = sin(rotation);
+
+    axis = gnVec3Normalize(axis);
+	gnVec3 temp = {
+    	((1.0f - c) * axis.x),
+    	((1.0f - c) * axis.y),
+    	((1.0f - c) * axis.z)
+	};
+
+	gnMat4 rotate = {
+	    .mat = {
+			{ c + temp.x * axis.x, temp.x * axis.y + s * axis.z, temp.x * axis.z - s * axis.y, 0.0f },
+			{ temp.y * axis.x - s * axis.z, c + temp.y * axis.y, temp.y * axis.z + s * axis.x, 0.0f },
+			{ temp.z * axis.x + s * axis.y, temp.z * axis.y - s * axis.x, c + temp.z * axis.z, 0.0f },
+			{ 0.0f, 0.0f, 0.0f, 1.0f },
+		}
+	};
+	return rotate;
+}
+
+// used GLMs lookAtLH from /glm/ext/matrix_transform.inl as a base
+static inline const gnMat4x4 gnLookAt(gnVec3 eye, gnVec3 center, gnVec3 up) {
+    const gnVec3 f = gnVec3Normalize(gnVec3Subtract(center, eye));
+    const gnVec3 s = gnVec3Normalize(gnVec3Cross(f, up));
+    const gnVec3 u = gnVec3Cross(s, f);
+
+    return (gnMat4x4) {
+        .mat = {
+            { s.x, u.x, -f.x, 0.0f },
+            { s.y, u.y, -f.y, 0.0f },
+            { s.z, u.z, -f.z, 0.0f },
+            { -gnVec3Dot(s, eye), -gnVec3Dot(u, eye), gnVec3Dot(f, eye), 1.0f }
+        }
+    };
+}
diff --git a/utils/math/gryphn_math.h b/utils/math/gryphn_math.h
new file mode 100644
index 0000000..220031d
--- /dev/null
+++ b/utils/math/gryphn_math.h
@@ -0,0 +1,3 @@
+#pragma once
+
+static const inline float gnRadians(const float degrees) { return degrees * (3.14159265358979323846f / 180.0f); }
diff --git a/utils/math/gryphn_vec2.h b/utils/math/gryphn_vec2.h
index c3c8541..31cf1ed 100644
--- a/utils/math/gryphn_vec2.h
+++ b/utils/math/gryphn_vec2.h
@@ -25,6 +25,8 @@ typedef struct gnVec2 {
 #endif
 } gnVec2;
 
+static inline const gnVec2 gnVec2Subtract(gnVec2 a, gnVec2 b) { return (gnVec2){ a.x - b.x, a.y - b.y }; }
+
 typedef gnVec2 gnFVec2;
 typedef gnVec2 gnFloat2;
 
diff --git a/utils/math/gryphn_vec3.h b/utils/math/gryphn_vec3.h
index 7f424e1..1f7a25f 100644
--- a/utils/math/gryphn_vec3.h
+++ b/utils/math/gryphn_vec3.h
@@ -1,5 +1,6 @@
 #pragma once
 #include "stdint.h"
+#include "math.h"
 
 typedef struct gnVec3 {
     union {
@@ -26,6 +27,16 @@ typedef struct gnVec3 {
 #endif
 } gnVec3;
 
+static const inline gnVec3 gnVec3Subtract(gnVec3 a, gnVec3 b) { return (gnVec3){ a.x - b.x, a.y - b.y, a.z - b.z }; }
+static const inline gnVec3 gnVec3Add(gnVec3 a, gnVec3 b) { return (gnVec3){ a.x + b.x, a.y + b.y, a.z + b.z }; }
+static const inline gnVec3 gnVec3Normalize(gnVec3 in) {
+    float lengthOfVector = sqrt((in.x * in.x) + (in.y * in.y) + (in.z * in.z));
+    return (gnVec3){in.x / lengthOfVector, in.y / lengthOfVector, in.z / lengthOfVector};
+}
+static const inline gnVec3 gnVec3Cross(gnVec3 a, gnVec3 b) { return (gnVec3){a.y * b.z - a.z * b.y, a.z * b.x - a.x * b.z, a.x * b.y - a.y * b.x}; }
+static const inline float gnVec3Dot(gnVec3 a, gnVec3 b) { return a.x * b.x + a.y * b.y + a.z * b.z; }
+
+
 typedef gnVec3 gnFVec3;
 typedef gnVec3 gnFloat3;