some utils jazz

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 }
+        }
+    };
+}