Study of Design Patterns 01: Factory Method

Recently I’ve been feeling the urgent need to study design patterns, memory and performance stuff in a more structured way. Here are my notes about the design pattern Factory Method. I’ll try to put it straightforward:


Factory Method


The description from Gang Of Four :

Define an interface for creating an object, but let sub-classes decide which class to instantiate. The Factory method lets a class defer instantiation it uses to sub-classes.

It looks like creating an abstract class as structure of objects, and then factory calls which objects to produce. It’s still not clear enough, what exactly does it mean?


Imagine that you are the factory manager and there are a list of products in the fruit factory. One day you want to request the factory for certain products, like “OK Factory, give me 2 organic strawberries and 2 California oranges”. Then the factory will produce and package these products for you in the next few hours.


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Make 360 Video for Your Game with the 360 Capture SDK by Facebook

Hey guys! I just had a great 360-video-making experience with this “newly”-released 360 Capture SDK by Facebook! Here is a link to get hyped: Make 360 Video for your Game with 360 Capture SDK.

Basically, this SDK enables you to capture, record, and encode 360 photos and videos with the relevant metadata necessary for detection, where the devs utilized the cube map solution. Videos, screenshots and audio will be saved locally along with the project. Currently the SDK supports Unity, Unreal and native engines. For hardware compatibility issues, please refer to this link.

This tutorial will walk you through the whole process from importing the kit in Unity to publishing your video content on Youtube. Let’s get it started!

There are six main steps to get it to work:

  1. Download the SDK
  2. Open a scene in Unity
  3. Set up encode environment
  4. Set up camera to capture
  5. Record
  6. Publish a 360 video on Youtube

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“error LNK2019: unresolved external symbol” in Visual Studio 2015

When I tried to create folders to organize my C++ code in Visual Studio 2015, I did this in the file explorer: made several folders and dropped files in. Like this:

So the Solution Explorer in VS2015 looked like this:

It looked perfect, all filtered into folders I created. However, it threw some error when I ran the program (“xxxx” is something specifically related to the code):

Error LNK2019 unresolved external symbol “public: void __cdecl xxxxxxxxxxxx referenced in function main”

So this is saying, some functions or variables were not defined so the main() function did not recognize them. Wait, I had already defined those in the files and it ran perfectly when I had not created the folders.

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