Correct for non uniform scale in lighting

core/Shaders/Shader.cpp

@@ -53,6 +53,10 @@ void Shader::UpdateProjection(Matrix projection) {
   glUniformMatrix4fv(glGetUniformLocation(id, "PROJECTION"), 1, GL_FALSE, glm::value_ptr(projection));
 }
 
+void Shader::UpdateNormal(glm::mat3 normal) {
+  glUniformMatrix3fv(glGetUniformLocation(id, "NORMAL"), 1, GL_FALSE, glm::value_ptr(normal));
+}
+
 void Shader::UpdateMaterial(Material material) {
   glUniform1i(glGetUniformLocation(id, "material.usesTex"), (int) material.usesTex);
   if (material.usesTex) {

core/Shaders/Shader.h

@@ -16,6 +16,7 @@ public:
   void UpdateView(Matrix view);
   void UpdateModel(Matrix model);
   void UpdateProjection(Matrix projection);
+  void UpdateNormal(glm::mat3 normal);
 
   void UpdateMaterial(Material material);
   

core/Skybox.cpp

@@ -74,6 +74,9 @@ Skybox *Skybox::FromFiles(const char *right, const char* left, const char* top,
   const char* files[] = {right, left, top, bottom, front, back};
   for (int i = 0; i < 6; i++) {
     data = stbi_load(files[i], &width, &height, &nrChannels, 3);
+    if (!data) {
+      Util::Die("Could not load skybox image ", files[i]);
+    }
     glTexImage2D(GL_TEXTURE_CUBE_MAP_POSITIVE_X + i,
 		 0, GL_RGB, width, height, 0, GL_RGB, GL_UNSIGNED_BYTE, data);
     stbi_image_free(data);

core/couch.cpp

@@ -46,6 +46,7 @@ void render(Node *curr, Shader *shader, Matrix model) {
       model = glm::translate(model, spatial->transform.position);
       model = glm::scale(model, spatial->transform.scale);
       shader->UpdateModel(model);
+      shader->UpdateNormal(glm::mat3(glm::transpose(glm::inverse(model))));
     }
     Mesh *mesh = dynamic_cast<Mesh*>(curr);
     mesh->Draw(shader);