From 2ef9c23a6c9a8bd2f96f7310f0a3397b32af4d59 Mon Sep 17 00:00:00 2001
From: Recep Aslantas <info@recp.me>
Date: Thu, 6 Dec 2018 18:01:52 +0300
Subject: [PATCH] vec: normalize cross product helper

---
 docs/source/vec3.rst     | 20 ++++++++++++----
 include/cglm/call/vec3.h |  6 ++++-
 include/cglm/cam.h       |  4 +---
 include/cglm/vec3.h      | 49 ++++++++++++++++++++++++++--------------
 include/cglm/vec4.h      |  1 -
 src/vec3.c               | 10 ++++++--
 6 files changed, 61 insertions(+), 29 deletions(-)

diff --git a/docs/source/vec3.rst b/docs/source/vec3.rst
index a625f5c..b431528 100644
--- a/docs/source/vec3.rst
+++ b/docs/source/vec3.rst
@@ -39,7 +39,6 @@ Functions:
 #. :c:func:`glm_vec3_zero`
 #. :c:func:`glm_vec3_one`
 #. :c:func:`glm_vec3_dot`
-#. :c:func:`glm_vec3_cross`
 #. :c:func:`glm_vec3_norm2`
 #. :c:func:`glm_vec3_norm`
 #. :c:func:`glm_vec3_add`
@@ -65,6 +64,8 @@ Functions:
 #. :c:func:`glm_vec3_negate_to`
 #. :c:func:`glm_vec3_normalize`
 #. :c:func:`glm_vec3_normalize_to`
+#. :c:func:`glm_vec3_cross`
+#. :c:func:`glm_vec3_crossn`
 #. :c:func:`glm_vec3_distance2`
 #. :c:func:`glm_vec3_distance`
 #. :c:func:`glm_vec3_angle`
@@ -125,12 +126,21 @@ Functions documentation
 
 .. c:function:: void  glm_vec3_cross(vec3 a, vec3 b, vec3 d)
 
-    cross product
+    cross product of two vector (RH)
 
     Parameters:
-      | *[in]*  **a**  source 1
-      | *[in]*  **b**  source 2
-      | *[out]* **d**  destination
+      | *[in]*  **a**     vector 1
+      | *[in]*  **b**     vector 2
+      | *[out]* **dest**  destination
+
+.. c:function:: void  glm_vec3_crossn(vec3 a, vec3 b, vec3 dest)
+
+    cross product of two vector (RH) and normalize the result
+
+    Parameters:
+      | *[in]*  **a**     vector 1
+      | *[in]*  **b**     vector 2
+      | *[out]* **dest**  destination
 
 .. c:function:: float  glm_vec3_norm2(vec3 v)
 
diff --git a/include/cglm/call/vec3.h b/include/cglm/call/vec3.h
index 5b77170..9763403 100644
--- a/include/cglm/call/vec3.h
+++ b/include/cglm/call/vec3.h
@@ -42,7 +42,11 @@ glmc_vec3_dot(vec3 a, vec3 b);
 
 CGLM_EXPORT
 void
-glmc_vec3_cross(vec3 a, vec3 b, vec3 d);
+glmc_vec3_cross(vec3 a, vec3 b, vec3 dest);
+
+CGLM_EXPORT
+void
+glmc_vec3_crossn(vec3 a, vec3 b, vec3 dest);
 
 CGLM_EXPORT
 float
diff --git a/include/cglm/cam.h b/include/cglm/cam.h
index acfa970..9bb3cdf 100644
--- a/include/cglm/cam.h
+++ b/include/cglm/cam.h
@@ -323,9 +323,7 @@ glm_lookat(vec3 eye,
   glm_vec3_sub(center, eye, f);
   glm_vec3_normalize(f);
 
-  glm_vec3_cross(f, up, s);
-  glm_vec3_normalize(s);
-
+  glm_vec3_crossn(f, up, s);
   glm_vec3_cross(s, f, u);
 
   dest[0][0] = s[0];
diff --git a/include/cglm/vec3.h b/include/cglm/vec3.h
index e5994ba..c53c8ab 100644
--- a/include/cglm/vec3.h
+++ b/include/cglm/vec3.h
@@ -21,7 +21,6 @@
    CGLM_INLINE void  glm_vec3_zero(vec3 v);
    CGLM_INLINE void  glm_vec3_one(vec3 v);
    CGLM_INLINE float glm_vec3_dot(vec3 a, vec3 b);
-   CGLM_INLINE void  glm_vec3_cross(vec3 a, vec3 b, vec3 d);
    CGLM_INLINE float glm_vec3_norm2(vec3 v);
    CGLM_INLINE float glm_vec3_norm(vec3 v);
    CGLM_INLINE void  glm_vec3_add(vec3 a, vec3 b, vec3 dest);
@@ -47,6 +46,8 @@
    CGLM_INLINE void  glm_vec3_inv_to(vec3 v, vec3 dest);
    CGLM_INLINE void  glm_vec3_normalize(vec3 v);
    CGLM_INLINE void  glm_vec3_normalize_to(vec3 v, vec3 dest);
+   CGLM_INLINE void  glm_vec3_cross(vec3 a, vec3 b, vec3 d);
+   CGLM_INLINE void  glm_vec3_crossn(vec3 a, vec3 b, vec3 dest);
    CGLM_INLINE float glm_vec3_distance(vec3 a, vec3 b);
    CGLM_INLINE float glm_vec3_angle(vec3 a, vec3 b);
    CGLM_INLINE void  glm_vec3_rotate(vec3 v, float angle, vec3 axis);
@@ -166,22 +167,6 @@ glm_vec3_dot(vec3 a, vec3 b) {
   return a[0] * b[0] + a[1] * b[1] + a[2] * b[2];
 }
 
-/*!
- * @brief vec3 cross product
- *
- * @param[in]  a source 1
- * @param[in]  b source 2
- * @param[out] d destination
- */
-CGLM_INLINE
-void
-glm_vec3_cross(vec3 a, vec3 b, vec3 d) {
-  /* (u2.v3 - u3.v2, u3.v1 - u1.v3, u1.v2 - u2.v1) */
-  d[0] = a[1] * b[2] - a[2] * b[1];
-  d[1] = a[2] * b[0] - a[0] * b[2];
-  d[2] = a[0] * b[1] - a[1] * b[0];
-}
-
 /*!
  * @brief norm * norm (magnitude) of vec
  *
@@ -521,6 +506,36 @@ glm_vec3_normalize_to(vec3 v, vec3 dest) {
   glm_vec3_scale(v, 1.0f / norm, dest);
 }
 
+/*!
+ * @brief cross product of two vector (RH)
+ *
+ * @param[in]  a    vector 1
+ * @param[in]  b    vector 2
+ * @param[out] dest destination
+ */
+CGLM_INLINE
+void
+glm_vec3_cross(vec3 a, vec3 b, vec3 dest) {
+  /* (u2.v3 - u3.v2, u3.v1 - u1.v3, u1.v2 - u2.v1) */
+  dest[0] = a[1] * b[2] - a[2] * b[1];
+  dest[1] = a[2] * b[0] - a[0] * b[2];
+  dest[2] = a[0] * b[1] - a[1] * b[0];
+}
+
+/*!
+ * @brief cross product of two vector (RH) and normalize the result
+ *
+ * @param[in]  a    vector 1
+ * @param[in]  b    vector 2
+ * @param[out] dest destination
+ */
+CGLM_INLINE
+void
+glm_vec3_crossn(vec3 a, vec3 b, vec3 dest) {
+  glm_vec3_cross(a, b, dest);
+  glm_vec3_normalize(dest);
+}
+
 /*!
  * @brief angle betwen two vector
  *
diff --git a/include/cglm/vec4.h b/include/cglm/vec4.h
index 97a915b..0c4f613 100644
--- a/include/cglm/vec4.h
+++ b/include/cglm/vec4.h
@@ -426,7 +426,6 @@ glm_vec4_divs(vec4 v, float s, vec4 dest) {
 #endif
 }
 
-
 /*!
  * @brief add two vectors and add result to sum
  *
diff --git a/src/vec3.c b/src/vec3.c
index 7b20888..14edaf6 100644
--- a/src/vec3.c
+++ b/src/vec3.c
@@ -40,8 +40,14 @@ glmc_vec3_dot(vec3 a, vec3 b) {
 
 CGLM_EXPORT
 void
-glmc_vec3_cross(vec3 a, vec3 b, vec3 d) {
-  glm_vec3_cross(a, b, d);
+glmc_vec3_cross(vec3 a, vec3 b, vec3 dest) {
+  glm_vec3_cross(a, b, dest);
+}
+
+CGLM_EXPORT
+void
+glmc_vec3_crossn(vec3 a, vec3 b, vec3 dest) {
+  glm_vec3_crossn(a, b, dest);
 }
 
 CGLM_EXPORT