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C# Intermediate - Threads, Part 1


A thread is defined as a path of execution of a program. Each thread has a unique flow of control.
Threads are most useful in applications where complicated and time consuming operations are performed. These operations can be split up into smaller chunks and each chunk is operated by a single thread. So multiple chunks can be operated upon by a series of threads.
One common example of use of thread is implementation of concurrent programming by modern operating systems. Good usage of threads can lead to better utilization of CPU cycles as well as creation of highly efficient applications.
If you have been following the blog, we have been working with programs that only execute on a single thread ( main thread ). However, this way the application can perform only one job at a time. To make it execute more than one task at a time, it could be divided into smaller tasks and each of those tasks given to different threads.
Thread Life Cycle 
  1. Unstarted State : Instance of thread created but 'Start' function not yet called. 
  2. Ready State : Ready to run but it's waiting for CPU cycle. 
  3. Not Runnable State : Not currently possible to run the thread because of I/O blocking or if it's sleeping.
  4. Dead State : Execution has completed or the thread has been aborted.
Basics Of Using Threads In C#
We need to use System.Threading in order to access threads.
We create a thread like this : Thread thread  =  new Thread( method to invoke )
The method will be executed parallel after we start the thread.
We start the execution of the thread like this : thread.Start().
Now the thread has started executing the method that was passed to it.
But the thing with threads is that you can not predetermine how long a thread will take to finish the task, so in order to make sure our program does not end before the work of the thread is done, we have to make sure it waits for the thread work to be done.
To do that we tell the running thread to join the execution path of the main thread.
So we write this : thread.Join().
If we want the execution of the thread to stop mid-way, then we can call abort, which will stop thread execution permanently. This is done like this : thread.Abort().

*just for now, Thread.Sleep(int milliseconds) :- Makes the thread sleep for that many milliseconds ( acts as a placeholder for a complex and long running task)
Example Program
using System;
using System.Threading;

namespace BitShiftProgrammer
    public class Program
        static void PrintHelloA()
            Console.WriteLine("Printed Hello A");
        static void PrintHelloB()
            Console.WriteLine("Printed Hello B");
        public static void Main(string[] args)
            Thread th1 = new Thread(PrintHelloA);
            Thread th2 = new Thread(PrintHelloB);
Printed Hello B
Printed Hello A
As you can see execution of th2 ended earlier than th1 even though th1 was called earlier. This can often be the case with threads. There is not predictable order of execution end, so we often have mechanisms in place which allow us to deal with these kinds of situations. We will go over them later.
More thread related tutorials will show up in the future.
For more C# tutorials head on over HERE.
For Unity tutorials check THIS.


Assets Worth Checking Out


Pixelation Shader - Unity Shader

Pixelation Shader This is the correct way (one of many) of showing pixelation as a post-processing effect. This effect will work in any aspect ratio without any pixel size scaling issues as well as it is very minimal in terms of coding it up.

In order to get this to work 2 components have to be set up:
1) The pixelation image effect
2) The script - which will be attached to the camera

So let's get started by creating a new image effect shader.
We will take a look at our Shaderlab properties :
_MainTex("Texture", 2D) = "white" {} That's it, Everything else will be private and not shown in the editor.
Now we will see what are defined along with the _MainTex but are private.
sampler2D _MainTex; int _PixelDensity; float2 _AspectRatioMultiplier; We will pass _PixelDensity & _AspectRatioMultiplier values from the script.
As this is an image effect there is no need to play around with the vertex shader.
Let's take a look at our fragment shader:
fixed4 frag (…

Toon Liquid Shader - Unity Shader

Toon Liquid Shader This is how the shader will end up looking :
This shader is pretty neat and somewhat easy to implement as well as to understand. Since we will be adding some basic physics to the toon water as it is moved about we will have to support that in the vertex shader as well.
So let's start by looking at the properties :
Properties { _Colour ("Colour", Color) = (1,1,1,1) _FillAmount ("Fill Amount", Range(-10,10)) = 0.0 [HideInInspector] _WobbleX ("WobbleX", Range(-1,1)) = 0.0 [HideInInspector] _WobbleZ ("WobbleZ", Range(-1,1)) = 0.0 _TopColor ("Top Color", Color) = (1,1,1,1) _FoamColor ("Foam Line Color", Color) = (1,1,1,1) _Rim ("Foam Line Width", Range(0,0.1)) = 0.0 _RimColor ("Rim Color", Color) = (1,1,1,1) _RimPower ("Rim Power", Range(0,10)) = 0.0 } Just the usual stuff that we are used to. The only thing that may stand out is the [HideInInspector] tag, This works j…

Curved Surface Shader [ Unity Implementation ]

Curved Surface Shader This is the shader that we will be having at the end of this tutorial.
 The curved surface shader is capable of achieving really varied visual effects from showing space-time curve due to gravity to a generic curved world shader that is seen in endless runners like Subway Surfers.
The concepts that you learn here can open you up to a new way of looking at shaders and if you didn't think they were the coolest thing ever already, hopefully let this be the turning point.😝.

Both the examples show above use the same exact material is just that different values have been passed to the shader.
Start by creating a new unlit shader in Unity and we will work our way from there.
First we define what the properties are:
_MainTex("Texture", 2D) = "white" {} _BendAmount("Bend Amount", Vector) = (1,1,1,1) _BendOrigin("Bend Origin", Vector) = (0,0,0,0) _BendFallOff("Bend Falloff", float) = 1.0 _BendFallOffStr("Falloff s…

Alto's Adventure Style Procedural Surface Generation Part 1

Alto's Adventure Style - Procedural Surface Generation This game appears to be a strictly 2D game but if you have played it enough you will notice that some of the art assets used look like it's 3D ( I don't know if they are tho ). If you haven't played the game you are missing out on one the most visually pleasing and calming games out there ( There is literally a mode called Zen mode in the game ).
Anyway, I am going to show you how to make a procedural 2D world ( without the trees, buildings and background ) like in Alto's Adventure.
But you may notice I have a plane which is in in the Z-axis giving a depth to the surface which is not there in Alto's Adventure but if you want to know how to do it then that will be in part 2.
To achieve the same effect of Alto's Adventure ( I'm leaving that up to you ) only minimal changes are needed to the code that I am going to explain.
We are going to be using the plane mesh in unity for creating the 2D surface as th…

Advanced Billboard Shader + World-Space UI Support

Advanced Billboard Shader + World-Space UI SupportAs you know billboarding is basically a plane with a texture on it that always facing the camera.These are some examples of what we are going for. This tutorial is going to be pretty straight-forward and easy to follow along you will learn how to make a billboard shader that not only keeps looking at the camera but also keeps its relative scaling intact.We will also provide an option to keep it rendered on top of all the other objects in the scene. This will be most useful for world-space UI that needs to be rendered on top of other geometry.We will be making 2 shaders here,Modified Default Unlit shader :- This one is a general shader ( easy to modify furthur ).Modified Default UI shader :- This one supports whatever a UI shader supports along with our billboarding capabilities. So let's get started with making the first one. As usual create a new Unlit shader and dive into the properties we need.Properties { _MainTex ("Texture…