quat: fix quat_for and quat_forp implementations

include/cglm/call/quat.h

@@ -131,11 +131,11 @@ glmc_quat_look(vec3 eye, versor ori, mat4 dest);
 
 CGLM_EXPORT
 void
-glmc_quat_for(vec3 dir, vec3 fwd, vec3 up, versor dest);
+glmc_quat_for(vec3 dir, vec3 up, versor dest);
 
 CGLM_EXPORT
 void
-glmc_quat_forp(vec3 from, vec3 to, vec3 fwd, vec3 up, versor dest);
+glmc_quat_forp(vec3 from, vec3 to, vec3 up, versor dest);
 
 CGLM_EXPORT
 void

include/cglm/cam.h

@@ -319,10 +319,7 @@ glm_perspective_resize(float aspect, mat4 proj) {
  */
 CGLM_INLINE
 void
-glm_lookat(vec3 eye,
+glm_lookat(vec3 eye, vec3 center, vec3 up, mat4 dest) {
-           vec3 center,
-           vec3 up,
-           mat4 dest) {
   CGLM_ALIGN(8) vec3 f, u, s;
 
   glm_vec3_sub(center, eye, f);

include/cglm/quat.h

@@ -693,32 +693,23 @@ glm_quat_look(vec3 eye, versor ori, mat4 dest) {
  * @brief creates look rotation quaternion
  *
  * @param[in]   dir   direction to look
- * @param[in]   fwd   forward vector
  * @param[in]   up    up vector
  * @param[out]  dest  destination quaternion
  */
 CGLM_INLINE
 void
-glm_quat_for(vec3 dir, vec3 fwd, vec3 up, versor dest) {
+glm_quat_for(vec3 dir, vec3 up, versor dest) {
-  CGLM_ALIGN(8) vec3 axis;
+  CGLM_ALIGN_MAT mat3 m;
-  float dot, angle;
 
-  dot = glm_vec3_dot(dir, fwd);
+  glm_vec3_normalize_to(dir, m[2]); 
-  if (fabsf(dot + 1.0f)  < 0.000001f) {
-    glm_quat_init(dest, up[0], up[1], up[2], GLM_PIf);
-    return;
-  }
 
-  if (fabsf(dot - 1.0f) < 0.000001f) {
+  /* No need to negate in LH, but we use RH here */
-    glm_quat_identity(dest);
+  glm_vec3_negate(m[2]);
-    return;
+  
-  }
+  glm_vec3_crossn(up, m[2], m[0]);
+  glm_vec3_cross(m[2], m[0], m[1]);
 
-  angle = acosf(dot);
+  glm_mat3_quat(m, dest);
-  glm_cross(fwd, dir, axis);
-  glm_normalize(axis);
-
-  glm_quatv(dest, angle, axis);
 }
 
 /*!
@@ -733,10 +724,10 @@ glm_quat_for(vec3 dir, vec3 fwd, vec3 up, versor dest) {
  */
 CGLM_INLINE
 void
-glm_quat_forp(vec3 from, vec3 to, vec3 fwd, vec3 up, versor dest) {
+glm_quat_forp(vec3 from, vec3 to, vec3 up, versor dest) {
   CGLM_ALIGN(8) vec3 dir;
   glm_vec3_sub(to, from, dir);
-  glm_quat_for(dir, fwd, up, dest);
+  glm_quat_for(dir, up, dest);
 }
 
 /*!

include/cglm/struct/quat.h

@@ -443,9 +443,9 @@ glms_quat_look(vec3s eye, versors ori) {
  */
 CGLM_INLINE
 versors
-glms_quat_for(vec3s dir, vec3s fwd, vec3s up) {
+glms_quat_for(vec3s dir, vec3s up) {
   versors dest;
-  glm_quat_for(dir.raw, fwd.raw, up.raw, dest.raw);
+  glm_quat_for(dir.raw, up.raw, dest.raw);
   return dest;
 }
 
@@ -461,9 +461,9 @@ glms_quat_for(vec3s dir, vec3s fwd, vec3s up) {
  */
 CGLM_INLINE
 versors
-glms_quat_forp(vec3s from, vec3s to, vec3s fwd, vec3s up) {
+glms_quat_forp(vec3s from, vec3s to, vec3s up) {
   versors dest;
-  glm_quat_forp(from.raw, to.raw, fwd.raw, up.raw, dest.raw);
+  glm_quat_forp(from.raw, to.raw, up.raw, dest.raw);
   return dest;
 }
 

src/quat.c

@@ -184,14 +184,14 @@ glmc_quat_look(vec3 eye, versor ori, mat4 dest) {
 
 CGLM_EXPORT
 void
-glmc_quat_for(vec3 dir, vec3 fwd, vec3 up, versor dest) {
+glmc_quat_for(vec3 dir, vec3 up, versor dest) {
-  glm_quat_for(dir, fwd, up, dest);
+  glm_quat_for(dir, up, dest);
 }
 
 CGLM_EXPORT
 void
-glmc_quat_forp(vec3 from, vec3 to, vec3 fwd, vec3 up, versor dest) {
+glmc_quat_forp(vec3 from, vec3 to, vec3 up, versor dest) {
-  glm_quat_forp(from, to, fwd, up, dest);
+  glm_quat_forp(from, to, up, dest);
 }
 
 CGLM_EXPORT

test/src/test_quat.h

@@ -760,3 +760,48 @@ TEST_IMPL(GLM_PREFIX, quat_look) {
 
   TEST_SUCCESS
 }
+
+TEST_IMPL(GLM_PREFIX, quat_for) {
+  versor q1, q2;
+
+  glm_quat(q1, glm_rad(90.0f), 0.0f, 1.0f, 0.0f);
+  GLM(quat_for)((vec3){-1.0f, 0.0f, 0.0f}, (vec3){0.0f, 1.0f, 0.0f}, q2);
+  ASSERTIFY(test_assert_quat_eq(q1, q2));
+
+  glm_quat(q2, glm_rad(90.0f), 1.0f, 0.0f, 0.0f);
+  GLM(quat_for)((vec3){0.0f, 1.0f, 0.0f}, (vec3){0.0f, 0.0f, 1.0f}, q1);
+  ASSERTIFY(test_assert_quat_eq(q1, q2));
+
+  glm_quat(q2, glm_rad(180.0f), 1.0f, 0.0f, 0.0f);
+  GLM(quat_for)((vec3){0.0f, 0.0f, 1.0f}, (vec3){0.0f, -1.0f, 0.0f}, q1);
+  ASSERTIFY(test_assert_quat_eq(q1, q2));
+
+  TEST_SUCCESS
+}
+
+TEST_IMPL(GLM_PREFIX, quat_forp) {
+  versor q1, q2;
+
+  glm_quat(q1, glm_rad(90.0f), 0.0f, 1.0f, 0.0f);
+  GLM(quat_forp)((vec3){2.0f, 0.0f, 0.0f},
+                 (vec3){1.0f, 0.0f, 0.0f}, 
+                 (vec3){0.0f, 1.0f, 0.0f}, 
+                 q2);
+  ASSERTIFY(test_assert_quat_eq(q1, q2));
+
+  glm_quat(q2, glm_rad(90.0f), 1.0f, 0.0f, 0.0f);
+  GLM(quat_forp)((vec3){0.0f, 1.0f, 0.0f}, 
+                 (vec3){0.0f, 2.0f, 0.0f},
+                 (vec3){0.0f, 0.0f, 1.0f},
+                 q1);
+  ASSERTIFY(test_assert_quat_eq(q1, q2));
+
+  glm_quat(q2, glm_rad(180.0f), 1.0f, 0.0f, 0.0f);
+  GLM(quat_forp)((vec3){0.0f, 1.0f, 1.0f}, 
+                 (vec3){0.0f, 1.0f, 2.0f},
+                 (vec3){0.0f, -1.0f, 0.0f},
+                 q1);
+  ASSERTIFY(test_assert_quat_eq(q1, q2));
+
+  TEST_SUCCESS
+}

test/tests.h

@@ -163,6 +163,8 @@ TEST_DECLARE(glm_quat_lerp)
 TEST_DECLARE(glm_quat_lerpc)
 TEST_DECLARE(glm_quat_slerp)
 TEST_DECLARE(glm_quat_look)
+TEST_DECLARE(glm_quat_for)
+TEST_DECLARE(glm_quat_forp)
 
 TEST_DECLARE(glmc_quat_identity)
 TEST_DECLARE(glmc_quat_identity_array)
@@ -193,6 +195,8 @@ TEST_DECLARE(glmc_quat_lerp)
 TEST_DECLARE(glmc_quat_lerpc)
 TEST_DECLARE(glmc_quat_slerp)
 TEST_DECLARE(glmc_quat_look)
+TEST_DECLARE(glmc_quat_for)
+TEST_DECLARE(glmc_quat_forp)
 
 /* bezier */
 TEST_DECLARE(bezier)
@@ -671,6 +675,8 @@ TEST_LIST {
   TEST_ENTRY(glm_quat_lerpc)
   TEST_ENTRY(glm_quat_slerp)
   TEST_ENTRY(glm_quat_look)
+  TEST_ENTRY(glm_quat_for)
+  TEST_ENTRY(glm_quat_forp)
 
   TEST_ENTRY(glmc_quat_identity)
   TEST_ENTRY(glmc_quat_identity_array)
@@ -701,6 +707,8 @@ TEST_LIST {
   TEST_ENTRY(glmc_quat_lerpc)
   TEST_ENTRY(glmc_quat_slerp)
   TEST_ENTRY(glmc_quat_look)
+  TEST_ENTRY(glmc_quat_for)
+  TEST_ENTRY(glmc_quat_forp)
 
   /* bezier */
   TEST_ENTRY(bezier)