From 9ee79a8b132973c4a52d3d4a28364a40c428a765 Mon Sep 17 00:00:00 2001
From: Recep Aslantas <info@recp.me>
Date: Wed, 10 Jan 2018 00:26:13 +0300
Subject: [PATCH 1/5] possible orthogonal/perpendicular vector

---
 include/cglm/vec3.h | 15 +++++++++++++++
 1 file changed, 15 insertions(+)

diff --git a/include/cglm/vec3.h b/include/cglm/vec3.h
index e6dff8f..e951ea9 100644
--- a/include/cglm/vec3.h
+++ b/include/cglm/vec3.h
@@ -42,6 +42,7 @@
    CGLM_INLINE void  glm_vec_center(vec3 v1, vec3 v2, vec3 dest);
    CGLM_INLINE void  glm_vec_maxv(vec3 v1, vec3 v2, vec3 dest);
    CGLM_INLINE void  glm_vec_minv(vec3 v1, vec3 v2, vec3 dest);
+   CGLM_INLINE void  glm_vec_ortho(vec3 v, vec3 dest);
  */
 
 #ifndef cglm_vec3_h
@@ -456,4 +457,18 @@ glm_vec_minv(vec3 v1, vec3 v2, vec3 dest) {
     dest[2] = v2[2];
 }
 
+/*!
+ * @brief possible orthogonal/perpendicular vector
+ *
+ * @param[in]  v    vector
+ * @param[out] dest orthogonal/perpendicular vector
+ */
+CGLM_INLINE
+void
+glm_vec_ortho(vec3 v, vec3 dest) {
+  dest[0] = v[1] - v[2];
+  dest[1] = v[2] - v[0];
+  dest[2] = v[0] - v[1];
+}
+
 #endif /* cglm_vec3_h */

From 61ac032751ef288c10ef6c8b9916b63fe93c42f5 Mon Sep 17 00:00:00 2001
From: Recep Aslantas <info@recp.me>
Date: Wed, 10 Jan 2018 22:02:14 +0300
Subject: [PATCH 2/5] new wrappers for lookat

---
 include/cglm/call/cam.h | 13 +++++++++----
 include/cglm/cam.h      | 37 +++++++++++++++++++++++++++++++++++++
 test/src/test_cam.c     | 17 ++++++++++++++++-
 test/src/test_main.c    |  5 ++---
 test/src/test_tests.h   |  3 +++
 5 files changed, 67 insertions(+), 8 deletions(-)

diff --git a/include/cglm/call/cam.h b/include/cglm/call/cam.h
index 7b2c409..f8d0b07 100644
--- a/include/cglm/call/cam.h
+++ b/include/cglm/call/cam.h
@@ -43,10 +43,15 @@ glmc_perspective(float fovy,
 
 CGLM_EXPORT
 void
-glmc_lookat(vec3 eye,
-            vec3 center,
-            vec3 up,
-            mat4 dest);
+glmc_lookat(vec3 eye, vec3 center, vec3 up, mat4 dest);
+
+CGLM_EXPORT
+void
+glmc_look(vec3 eye, vec3 dir, vec3 up, mat4 dest);
+
+CGLM_EXPORT
+void
+glmc_look_any(vec3 eye, vec3 dir, mat4 dest);
 
 CGLM_EXPORT
 void
diff --git a/include/cglm/cam.h b/include/cglm/cam.h
index a65847c..1ca4360 100644
--- a/include/cglm/cam.h
+++ b/include/cglm/cam.h
@@ -303,6 +303,43 @@ glm_lookat(vec3 eye,
   dest[3][3] = 1.0f;
 }
 
+/*!
+ * @brief set up view matrix
+ *
+ * convenient wrapper for lookat: if you only have direction not target self
+ * then this might be useful. Because you need to get target from direction.
+ *
+ * @param[in]  eye    eye vector
+ * @param[in]  dir    direction vector
+ * @param[in]  up     up vector
+ * @param[out] dest   result matrix
+ */
+CGLM_INLINE
+void
+glm_look(vec3 eye, vec3 dir, vec3 up, mat4 dest) {
+  vec3 target;
+  glm_vec_add(eye, dir, target);
+  glm_lookat(eye, target, up, dest);
+}
+
+/*!
+ * @brief set up view matrix
+ *
+ * convenient wrapper for look: if you only have direction and if you don't
+ * care what UP vector is then this might be useful to create view matrix
+ *
+ * @param[in]  eye    eye vector
+ * @param[in]  dir    direction vector
+ * @param[out] dest   result matrix
+ */
+CGLM_INLINE
+void
+glm_look_any(vec3 eye, vec3 dir, mat4 dest) {
+  vec3 up;
+  glm_vec_ortho(dir, up);
+  glm_look(eye, dir, up, dest);
+}
+
 /*!
  * @brief decomposes frustum values of perspective projection.
  *
diff --git a/test/src/test_cam.c b/test/src/test_cam.c
index 9df4b53..d368ad2 100644
--- a/test/src/test_cam.c
+++ b/test/src/test_cam.c
@@ -7,6 +7,22 @@
 
 #include "test_common.h"
 
+void
+test_camera_lookat(void **state) {
+  mat4  view1, view2;
+  vec3 eye    = {0.024f, 14.6f, 67.04f},
+       dir    = {0.0f, 0.0f, -1.0f},
+       up     = GLM_YUP,
+       center;
+
+  glm_vec_add(eye, dir, center);
+  glm_lookat(eye, center, up, view1);
+
+  glm_look(eye, dir, up, view2);
+
+  test_assert_mat4_eq(view1, view2);
+}
+
 void
 test_camera_decomp(void **state) {
   mat4  proj, proj2;
@@ -35,4 +51,3 @@ test_camera_decomp(void **state) {
 
   test_assert_mat4_eq(proj, proj2);
 }
-
diff --git a/test/src/test_main.c b/test/src/test_main.c
index 25c7d17..5d59cfd 100644
--- a/test/src/test_main.c
+++ b/test/src/test_main.c
@@ -13,10 +13,9 @@ main(int argc, const char * argv[]) {
     cmocka_unit_test(test_mat4),
 
     /* camera */
+    cmocka_unit_test(test_camera_lookat),
     cmocka_unit_test(test_camera_decomp)
   };
 
-  return cmocka_run_group_tests(tests,
-                                NULL,
-                                NULL);
+  return cmocka_run_group_tests(tests, NULL, NULL);
 }
diff --git a/test/src/test_tests.h b/test/src/test_tests.h
index a6a8a58..a4e5adb 100644
--- a/test/src/test_tests.h
+++ b/test/src/test_tests.h
@@ -10,6 +10,9 @@
 void test_mat4(void **state);
 
 /* camera */
+void
+test_camera_lookat(void **state);
+
 void
 test_camera_decomp(void **state);
 

From 50c23ce1c076ff3d23ac2ae03f4a1d11c150d0f4 Mon Sep 17 00:00:00 2001
From: Recep Aslantas <info@recp.me>
Date: Wed, 10 Jan 2018 22:42:34 +0300
Subject: [PATCH 3/5] add missing definitions, fix initizlizing vector

---
 src/cam.c           | 12 ++++++++++++
 test/src/test_cam.c |  7 ++++---
 2 files changed, 16 insertions(+), 3 deletions(-)

diff --git a/src/cam.c b/src/cam.c
index 602b1fc..ebf0b3d 100644
--- a/src/cam.c
+++ b/src/cam.c
@@ -67,6 +67,18 @@ glmc_lookat(vec3 eye,
   glm_lookat(eye, center, up, dest);
 }
 
+CGLM_EXPORT
+void
+glmc_look(vec3 eye, vec3 dir, vec3 up, mat4 dest) {
+  glm_look(eye, dir, up, dest);
+}
+
+CGLM_EXPORT
+void
+glmc_look_any(vec3 eye, vec3 dir, mat4 dest) {
+  glm_look_any(eye, dir, dest);
+}
+
 CGLM_EXPORT
 void
 glmc_frustum_planes(mat4 m, vec4 dest[6]) {
diff --git a/test/src/test_cam.c b/test/src/test_cam.c
index d368ad2..f54c984 100644
--- a/test/src/test_cam.c
+++ b/test/src/test_cam.c
@@ -10,10 +10,11 @@
 void
 test_camera_lookat(void **state) {
   mat4  view1, view2;
-  vec3 eye    = {0.024f, 14.6f, 67.04f},
+  vec3 center,
+       eye    = {0.024f, 14.6f, 67.04f},
        dir    = {0.0f, 0.0f, -1.0f},
-       up     = GLM_YUP,
-       center;
+       up     = {0.0f, 1.0f, 0.0f}
+  ;
 
   glm_vec_add(eye, dir, center);
   glm_lookat(eye, center, up, view1);

From 4e6ab470c2445ab4a3270b424879bdb4ec2d5be0 Mon Sep 17 00:00:00 2001
From: Recep Aslantas <info@recp.me>
Date: Fri, 12 Jan 2018 12:52:25 +0300
Subject: [PATCH 4/5] update glm_look_any to glm_look_anyup

---
 include/cglm/cam.h | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/include/cglm/cam.h b/include/cglm/cam.h
index 1ca4360..23504cc 100644
--- a/include/cglm/cam.h
+++ b/include/cglm/cam.h
@@ -334,7 +334,7 @@ glm_look(vec3 eye, vec3 dir, vec3 up, mat4 dest) {
  */
 CGLM_INLINE
 void
-glm_look_any(vec3 eye, vec3 dir, mat4 dest) {
+glm_look_anyup(vec3 eye, vec3 dir, mat4 dest) {
   vec3 up;
   glm_vec_ortho(dir, up);
   glm_look(eye, dir, up, dest);

From 2b7994778d6cadba266ababc9a3f6fe7a95531a5 Mon Sep 17 00:00:00 2001
From: Recep Aslantas <info@recp.me>
Date: Fri, 12 Jan 2018 12:54:33 +0300
Subject: [PATCH 5/5] fix lib call version of look_anyup

---
 include/cglm/call/cam.h | 2 +-
 src/cam.c               | 4 ++--
 2 files changed, 3 insertions(+), 3 deletions(-)

diff --git a/include/cglm/call/cam.h b/include/cglm/call/cam.h
index f8d0b07..dc01f6f 100644
--- a/include/cglm/call/cam.h
+++ b/include/cglm/call/cam.h
@@ -51,7 +51,7 @@ glmc_look(vec3 eye, vec3 dir, vec3 up, mat4 dest);
 
 CGLM_EXPORT
 void
-glmc_look_any(vec3 eye, vec3 dir, mat4 dest);
+glmc_look_anyup(vec3 eye, vec3 dir, mat4 dest);
 
 CGLM_EXPORT
 void
diff --git a/src/cam.c b/src/cam.c
index ebf0b3d..3def839 100644
--- a/src/cam.c
+++ b/src/cam.c
@@ -75,8 +75,8 @@ glmc_look(vec3 eye, vec3 dir, vec3 up, mat4 dest) {
 
 CGLM_EXPORT
 void
-glmc_look_any(vec3 eye, vec3 dir, mat4 dest) {
-  glm_look_any(eye, dir, dest);
+glmc_look_anyup(vec3 eye, vec3 dir, mat4 dest) {
+  glm_look_anyup(eye, dir, dest);
 }
 
 CGLM_EXPORT