diff --git a/src/1.getting_started/4.1.textures/textures.cpp b/src/1.getting_started/4.1.textures/textures.cpp
index 6752e89..1605f20 100644
--- a/src/1.getting_started/4.1.textures/textures.cpp
+++ b/src/1.getting_started/4.1.textures/textures.cpp
@@ -97,7 +97,7 @@ int main()
     glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_REPEAT);	// set texture wrapping to GL_REPEAT (default wrapping method)
     glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_REPEAT);
     // set texture filtering parameters
-    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
+    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR_MIPMAP_LINEAR);
     glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
     // load image, create texture and generate mipmaps
     int width, height, nrChannels;
@@ -169,4 +169,4 @@ void framebuffer_size_callback(GLFWwindow* window, int width, int height)
     // make sure the viewport matches the new window dimensions; note that width and 
     // height will be significantly larger than specified on retina displays.
     glViewport(0, 0, width, height);
-}
\ No newline at end of file
+}
diff --git a/src/4.advanced_opengl/5.2.framebuffers_exercise1/framebuffers_exercise1.cpp b/src/4.advanced_opengl/5.2.framebuffers_exercise1/framebuffers_exercise1.cpp
index 2682a96..c6d30d5 100644
--- a/src/4.advanced_opengl/5.2.framebuffers_exercise1/framebuffers_exercise1.cpp
+++ b/src/4.advanced_opengl/5.2.framebuffers_exercise1/framebuffers_exercise1.cpp
@@ -250,11 +250,9 @@ int main()
         shader.use();
         glm::mat4 model = glm::mat4(1.0f);
         camera.Yaw   += 180.0f; // rotate the camera's yaw 180 degrees around
-        camera.Pitch += 180.0f; // rotate the camera's pitch 180 degrees around
         camera.ProcessMouseMovement(0, 0, false); // call this to make sure it updates its camera vectors, note that we disable pitch constrains for this specific case (otherwise we can't reverse camera's pitch values)
         glm::mat4 view = camera.GetViewMatrix();
         camera.Yaw   -= 180.0f; // reset it back to its original orientation
-        camera.Pitch -= 180.0f;
         camera.ProcessMouseMovement(0, 0, true); 
         glm::mat4 projection = glm::perspective(glm::radians(camera.Zoom), (float)SCR_WIDTH / (float)SCR_HEIGHT, 0.1f, 100.0f);
         shader.setMat4("view", view);
diff --git a/src/8.guest/2020/oit/weighted_blended.cpp b/src/8.guest/2020/oit/weighted_blended.cpp
index 0030244..b382f37 100644
--- a/src/8.guest/2020/oit/weighted_blended.cpp
+++ b/src/8.guest/2020/oit/weighted_blended.cpp
@@ -273,7 +273,7 @@ int main(int argc, char* argv[])
 		// -----
 
 		// set render states
-		glDisable(GL_DEPTH);
+		glDisable(GL_DEPTH_TEST);
 		glDepthMask(GL_TRUE); // enable depth writes so glClear won't ignore clearing the depth buffer
 		glDisable(GL_BLEND);
 
@@ -379,4 +379,4 @@ glm::mat4 calculate_model_matrix(const glm::vec3& position, const glm::vec3& rot
 	trans = glm::scale(trans, scale);
 
 	return trans;
-}
\ No newline at end of file
+}