feat: add quat/mat4. fromPointToPoint

Author: dmnsgn

mat4.js

@@ -885,3 +885,75 @@ export function targetTo(
   a[15] = 1;
   return a;
 }
+
+/**
+ * Sets a matrix from a point to another.
+ * @param {import("./types.js").mat4} a
+ * @param {import("./types.js").vec3} from
+ * @param {import("./types.js").vec3} to
+ * @param {import("./types.js").vec3} [up=Y_UP]
+ * @returns {import("./types.js").mat4}
+ */
+export function fromPointToPoint(
+  a,
+  [eyex, eyey, eyez],
+  [targetx, targety, targetz],
+  [upx, upy, upz] = Y_UP
+) {
+  let z0 = targetx - eyex;
+  let z1 = targety - eyey;
+  let z2 = targetz - eyez;
+
+  let len = z0 * z0 + z1 * z1 + z2 * z2;
+
+  if (len > 0) {
+    len = 1 / Math.sqrt(len);
+    z0 *= len;
+    z1 *= len;
+    z2 *= len;
+  }
+
+  let x0 = upy * z2 - upz * z1;
+  let x1 = upz * z0 - upx * z2;
+  let x2 = upx * z1 - upy * z0;
+
+  len = x0 * x0 + x1 * x1 + x2 * x2;
+
+  if (len > 0) {
+    len = 1 / Math.sqrt(len);
+    x0 *= len;
+    x1 *= len;
+    x2 *= len;
+  }
+
+  upx = z1 * x2 - z2 * x1;
+  upy = z2 * x0 - z0 * x2;
+  upz = z0 * x1 - z1 * x0;
+
+  len = upx * upx + upy * upy + upz * upz;
+
+  if (len > 0) {
+    len = 1 / Math.sqrt(len);
+    upx *= len;
+    upy *= len;
+    upz *= len;
+  }
+
+  a[0] = x0;
+  a[1] = x1;
+  a[2] = x2;
+  a[3] = 0;
+  a[4] = upx;
+  a[5] = upy;
+  a[6] = upz;
+  a[7] = 0;
+  a[8] = z0;
+  a[9] = z1;
+  a[10] = z2;
+  a[11] = 0;
+  a[12] = 0;
+  a[13] = 0;
+  a[14] = 0;
+  a[15] = 1;
+  return a;
+}

quat.js

@@ -288,6 +288,18 @@ export function targetTo(a, eye, target, up) {
   return fromMat4(a, mat4.targetTo(TEMP_MAT4, eye, target, up));
 }
 
+/**
+ * Sets a quaternion from a point to another.
+ * @param {import("./types.js").quat} a
+ * @param {import("./types.js").vec3} eye
+ * @param {import("./types.js").vec3} target
+ * @param {import("./types.js").vec3} [up=Y_UP]
+ * @returns {import("./types.js").quat}
+ */
+export function fromPointToPoint(a, eye, target, up) {
+  return fromMat4(a, mat4.fromPointToPoint(TEMP_MAT4, eye, target, up));
+}
+
 /**
  * Spherical linear interpolates between two quaternions.
  * @param {import("./types.js").quat} a