1 files changed, 4 insertions, 5 deletions
diff --git a/src/vec4ops/vec4ops.cpp b/src/vec4ops/vec4ops.cpp
index 9bd29e8..cf0900a 100644
--- a/src/vec4ops/vec4ops.cpp
+++ b/src/vec4ops/vec4ops.cpp
@@ -23,7 +23,6 @@ glm::vec4 Vec4Ops::cross4(
     result[1] = -(u[0] * f) + (u[2] * c) - (u[3] * b);
     result[2] = (u[0] * e) - (u[1] * c) + (u[3] * a);
     result[3] = -(u[0] * d) + (u[1] * b) - (u[2] * a);
-
     return result;
 }
 
@@ -34,23 +33,23 @@ glm::vec4 Vec4Ops::dot4(
 }
 
 glm::mat4 Vec4Ops::getViewMatrix4(
-        glm::vec4 upVector,
         glm::vec4 lookVector,
+        glm::vec4 upVector,
         glm::vec4 overVector) {
     // start with the e3 basis vector, the normalized look vector
-    glm::vec4 e3 = glm::normalize(lookVector);
+    glm::vec4 e3 = glm::normalize(-lookVector);
 
     // calculate e0 basis vector, from the combinatory cross of up and over with e3
     glm::vec4 e0 = cross4(upVector, overVector, e3);
     e0 = glm::normalize(e0);
-    if (glm::distance(e0, glm::vec4{0, 0, 0, 0}) < 0.0001f) {
+    if (glm::isnan(e0[0]) || glm::isnan(e0[1]) || glm::isnan(e0[2]) || glm::isnan(e0[3])) {
         throw std::runtime_error("invalid up vector");
     }
 
     // calculate e1 basis vector, from the cross of only the over vector
     glm::vec4 e1 = cross4(overVector, e3, e0);
     e1 = glm::normalize(e1);
-    if (glm::distance(e1, glm::vec4{0, 0, 0, 0}) < 0.0001f) {
+    if (glm::isnan(e1[0]) || glm::isnan(e1[1]) || glm::isnan(e1[2]) || glm::isnan(e1[3])) {
         throw std::runtime_error("invalid over vector");
     }