From 3dc9070909208a9214b36766f3772a9de526cef3 Mon Sep 17 00:00:00 2001
From: Recep Aslantas <info@recp.me>
Date: Wed, 30 May 2018 23:35:59 +0300
Subject: [PATCH] squared distance for vec3

---
 docs/source/vec3.rst     | 12 ++++++++++++
 include/cglm/call/vec3.h |  4 ++++
 include/cglm/vec3.h      | 19 ++++++++++++++++---
 src/vec3.c               |  6 ++++++
 4 files changed, 38 insertions(+), 3 deletions(-)

diff --git a/docs/source/vec3.rst b/docs/source/vec3.rst
index fcbfbfb..e4a2746 100644
--- a/docs/source/vec3.rst
+++ b/docs/source/vec3.rst
@@ -56,6 +56,7 @@ Functions:
 #. :c:func:`glm_vec_inv_to`
 #. :c:func:`glm_vec_normalize`
 #. :c:func:`glm_vec_normalize_to`
+#. :c:func:`glm_vec_distance2`
 #. :c:func:`glm_vec_distance`
 #. :c:func:`glm_vec_angle`
 #. :c:func:`glm_vec_rotate`
@@ -366,6 +367,17 @@ Functions documentation
       | *[in]*  **v2**    vector2
       | *[out]* **dest**  center point
 
+.. c:function:: float  glm_vec_distance2(vec3 v1, vec3 v2)
+
+    squared distance between two vectors
+
+    Parameters:
+      | *[in]*  **mat**   vector1
+      | *[in]*  **row1**  vector2
+
+    Returns:
+      | squared distance (distance * distance)
+
 .. c:function:: float  glm_vec_distance(vec3 v1, vec3 v2)
 
     distance between two vectors
diff --git a/include/cglm/call/vec3.h b/include/cglm/call/vec3.h
index 50a6b22..ae21620 100644
--- a/include/cglm/call/vec3.h
+++ b/include/cglm/call/vec3.h
@@ -148,6 +148,10 @@ CGLM_EXPORT
 void
 glmc_vec_center(vec3 v1, vec3 v2, vec3 dest);
 
+CGLM_EXPORT
+float
+glmc_vec_distance2(vec3 v1, vec3 v2);
+
 CGLM_EXPORT
 float
 glmc_vec_distance(vec3 v1, vec3 v2);
diff --git a/include/cglm/vec3.h b/include/cglm/vec3.h
index 34a910c..18d8a7b 100644
--- a/include/cglm/vec3.h
+++ b/include/cglm/vec3.h
@@ -633,6 +633,21 @@ glm_vec_center(vec3 v1, vec3 v2, vec3 dest) {
   glm_vec_scale(dest, 0.5f, dest);
 }
 
+/**
+ * @brief squared distance between two vectors
+ *
+ * @param[in] v1 vector1
+ * @param[in] v2 vector2
+ * @return returns squared distance (distance * distance)
+ */
+CGLM_INLINE
+float
+glm_vec_distance2(vec3 v1, vec3 v2) {
+  return glm_pow2(v2[0] - v1[0])
+       + glm_pow2(v2[1] - v1[1])
+       + glm_pow2(v2[2] - v1[2]);
+}
+
 /**
  * @brief distance between two vectors
  *
@@ -643,9 +658,7 @@ glm_vec_center(vec3 v1, vec3 v2, vec3 dest) {
 CGLM_INLINE
 float
 glm_vec_distance(vec3 v1, vec3 v2) {
-  return sqrtf(glm_pow2(v2[0] - v1[0])
-             + glm_pow2(v2[1] - v1[1])
-             + glm_pow2(v2[2] - v1[2]));
+  return sqrtf(glm_vec_distance2(v1, v2));
 }
 
 /*!
diff --git a/src/vec3.c b/src/vec3.c
index 401b983..a2ab499 100644
--- a/src/vec3.c
+++ b/src/vec3.c
@@ -206,6 +206,12 @@ glmc_vec_center(vec3 v1, vec3 v2, vec3 dest) {
   glm_vec_center(v1, v2, dest);
 }
 
+CGLM_EXPORT
+float
+glmc_vec_distance2(vec3 v1, vec3 v2) {
+  return glm_vec_distance2(v1, v2);
+}
+
 CGLM_EXPORT
 float
 glmc_vec_distance(vec3 v1, vec3 v2) {