## Introduction To Bitwise Operations

Bitwise operators are used to change individual bits in an operand.
The main use of bitwise operations are to perform calculations at a more optimized level as these operations are directly supported by the processor.
• & (bitwise AND) Takes two numbers as operands and does AND on every bit of two numbers. The result of AND is 1 only if both bits are 1.
eg: 1010 & 0010 = 0010
• | (bitwise OR) Takes two numbers as operands and does OR on every bit of two numbers. The result of OR is 1 any of the two bits is 1.
eg: 1001 | 0010 = 1011
• ^ (bitwise XOR) Takes two numbers as operands and does XOR on every bit of two numbers. The result of XOR is 1 if the two bits are different.
eg: 0110 ^ 1000 = 1110
• << (left shift) Takes two numbers, left shifts the bits of the first operand, the second operand decides the number of places to shift.
eg: 0101 << 1 = 1010
• >> (right shift) Takes two numbers, right shifts the bits of the first operand, the second operand decides the number of places to shift.
eg: 0010 >> 1 = 0001
• ~ (bitwise NOT) Flips all the bits.
eg : ~1001 = 0110
*Note : When it comes to shifting bits there are mainly 3 types : Arithmetic Shift, Logical Shift & Circular Shift.
These variations are there to handle the cases where the bits at the edge of the bit field are about to be shifted out of the bit field.

### Let's Look At A C# Example

``````using System;
namespace BitshiftProductions
{
public class Program
{
public static void Main(string[] args)
{
int x = 14; // 00001110
int y = 28; // 00011100

Console.WriteLine("x = " + x + " in binary : " + Convert.ToString(x, 2));
Console.WriteLine("y = " + y + " in binary : " + Convert.ToString(y, 2));

int k = x|y;
Console.WriteLine("X OR Y = " + k + " in binary : " + Convert.ToString(k, 2));

k = x&y;
Console.WriteLine("X AND Y = " + k + " in binary : " + Convert.ToString(k, 2));

k = x^y;
Console.WriteLine("X XOR Y = " + k + " in binary : " + Convert.ToString(k, 2));

k = x<<2;
Console.WriteLine("Left Shifted x(14) by 2 places = " + k + " in binary : " + Convert.ToString(k,2));
k = x>>2;
Console.WriteLine("Right Shifted x(14) by 2 places = " + k + " in binary : "+ Convert.ToString(k,2));

k = ~x;
Console.WriteLine("NOT x = " + k + " in binary : "+ Convert.ToString(k,2));
}
}
}
``````
```x = 14 in binary : 1110
y = 28 in binary : 11100
X OR Y = 30 in binary : 11110
X AND Y = 12 in binary : 1100
X XOR Y = 18 in binary : 10010
Left Shifted x(14) by 2 places = 56 in binary : 111000
Right Shifted x(14) by 2 places = 3 in binary : 11
NOT x = -15 in binary : 11111111111111111111111111110001
```
*Note : Leading zeros are not printed with Convert.ToString(object, base) method. All these are 32 bit numbers so the actual bit string would have 32 spaces.

### Common Use Cases Of Bitwise Operations

``````using System;
namespace BitshiftProductions
{
public class Program
{
public static void Main(string[] args)
{
int num = 8;
// 1. Dividing By 2
int k = num >> 1;
Console.WriteLine("Num = 8, Divide By 2 = " + k);
// 2. Multiply By 2
k = num << 1;
Console.WriteLine("Num = 8, Multiply By 2 = " + k);
// 3. Checking If A Number Is Odd Or Even
k = num & 1;//(num & 1) would be non-zero only if x is odd, otherwise the value would be zero.
Console.WriteLine("Is num Odd Or Even : " + ((k != 0)?"Odd":"Even"));
// 4. Check If 2 integers Have Opposite Signs
Console.WriteLine("Do -100 & 50 have same sign ? : " + ((-100 ^ 50) >= 0));
// 5. Find log base 2 of 32 bit integer
int res = 0;
int temp = num;
while (temp > 1)
{
temp = temp >> 1;
res++;
}
Console.WriteLine("Log Base 2 of NUM(8) : " + res);
}
}
}
``````
```Num = 8, Divide By 2 = 4
Num = 8, Multiply By 2 = 16
Is num Odd Or Even : Even
Do -100 & 50 have same sign ? : False
Log Base 2 of NUM(8) : 3
```
I hope to have introduced you to the world of bit manipulation. All the things you learnt today can be easily implemented into your existing projects.
That's it! Hope you learnt something. Support Bitshift Programmer by leaving a like on Bitshift Programmer Facebook Page and be updated as soon as there is a new blog post.
For more C# development tutorials, go : HERE
For Unity development tutorials, go : HERE

### 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…

### How To Animate A Fish Swimming With Shaders

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By the time we are done, it's going to look like this.
You will probably need the fish model used in this tutorial, that can be found HERE. Can use your own model but the shader code might have to be modified accordingly because of the orientation of the model that you might be using ( issues with whether the X axis & Z axis is flipped ).
The shader used way out performs a similar scene with skeletal animations applied on the fish models.
On a previous benchmark I did comparing the shader animation with the skeletal animation there was a difference of 28 FPS( on average ) with 50 fish.
The shader we are going to make is really powerful and flexible and don't think that it's limited to making fishes swim😀.

So this mesh oriented like this when imported into unity and this is important to understand because this means that the model's vertices have to be moved along the X-…

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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 (…

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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…

### Access Reflection Probe Data For Custom Shaders

The Unity shader documentation regarding reflection probes is pretty minimal and not at all comprehensive.
This short tutorial is intended to bring reflection probe functionalities to the forefront your future shader writing endevors which is a fancy way of saying "Look at this cool stuff and go and use it somewhere" 😏
Here we will try just the bare minimum of making a shader that reflects the cubemap data from reflection probe and displays it on the object.

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More information on how reflection probes work in Unity can be found here :
Using Reflection Probes In Unity

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So this is what we will be making:
The reflection probe takes in the cubemap only if it is within it's range otherwise i…