Lesson for C# Programming by making the text-based game in the Unity (Gold Miner Game)

1. Lecture 2: C# Programming
by Making Gold Miner Game
Dr. Kobkrit Viriyayudhakorn
iApp Technology Limited
kobkrit@iapp.co.th
ITS488 (Digital Content Creation with Unity - Game and VR Programming)

2. Troubleshooting
• Confuse? Read a manual at https://docs.unity3d.com/2017.1/
Documentation/Manual/UnityManual.html
• Get any problem? Google it: "DOING ANYTHING in unity"

3. Review: Writing Code in Unity
Right click at Project Window Name it as "ConsolePrinter"

4. Start writing a code
• Double Click at the ConsolePrinter.cs
• The MonoDevelop-Unity IDE will be show up and you can make the first
program.

5. Code structure

6. Printing a Text
Save and Go back to Unity

7. Create
a New
Game
Object
Right click Select
Rename + Enter
Inspect Window
on the right.

8. Attaching Script to A Game Object
1. Drag the
ConsolePrinter
script and drop
onto
ConsolePrinterGO
in Hierarchy
Window
2. Or Drag onto
Inspector
Window

9. Start Running
• Click on Run Button
• Switch to Console Window, you will see "Hello World!" text.

10. Print Statement
Output Console

11. Variable #1: int
Output Console

12. Variable #2: int & float & string
Output Console

13. Variable #3: int & float oper.
Output Console

14. Variable #4: string & bool oper.
Output Console

15. Type Represents Range Default
Value
bool Boolean value True or False FALSE
byte 8-bit unsigned integer 0 to 255 0
char 16-bit Unicode character U +0000 to U +ffff '0’
decimal 128-bit precise decimal values with
28-29 significant digits
(-7.9 x 1028
to 7.9 x 1028
) / 100 to 28 0.0M
double 64-bit double-precision floating point
type
(+/-)5.0 x 10-324
to (+/-)1.7 x 10308
0.0D
float 32-bit single-precision floating point
type
-3.4 x 1038
to + 3.4 x 1038
0.0F
int 32-bit signed integer type -2,147,483,648 to 2,147,483,647 0
long 64-bit signed integer type -9,223,372,036,854,775,808 to
9,223,372,036,854,775,807
0L
sbyte 8-bit signed integer type -128 to 127 0
short 16-bit signed integer type -32,768 to 32,767 0
uint 32-bit unsigned integer type 0 to 4,294,967,295 0
ulong 64-bit unsigned integer type 0 to 18,446,744,073,709,551,615 0
ushort 16-bit unsigned integer type 0 to 65,535 0

16. if-else oper.
Output Console

17. Game Planning
• You are a gold miner and you want to find
a gold pit.
• You can move up, down, left, and right.
• Movement is a fixed distance.
• After each turn, your distance from the
gold pit is displayed.
• You win when you get the gold pit.
• Your score is how many turns it took.

18. Rough Pseudo Code
• Set Start Location
• Calculate distance from Gold pit.
• Print the distance
• Read player’s move
• Update location from the Gold pit.
• Repeat.

19. Start Writing a Game Logic
Output Console

20. If we change loc = 10.3
Output Console

21. Rough Pseudo Code
• Set Start Location
• Calculate distance from Gold pit.
• Print the distance
• Read player’s move
• Update location from the Gold pit.
• Repeat.

22. Input.GetKeyDown

23. Reading User Input
Output Console
(After press left arrow couple times)
Make sure you select the Game tab
Before pressing the left key. ->

24. Adding more Keydown
Output Console
(After press left+right arrow couple times)
* Make sure you select the Game tab
Before pressing the left key.

25. Update Location
Output Console

26. Variable Scope: loc
Scope of loc

27. Make it class variable
Scope of loc
Move the variable declaration from within
"Start()" Method to within "GoldMiner" class.
(Outer the "Start()" method)
Output Console

28. Class variable assignment
• Can not be the product from the
computation.
• Can be a constant or not
assignment at all.
• You can re-assign the class
variable in any function body.

29. Do Distance Calculation when a key is pressed.
Output Console
Now it is playable!

30. Too much duplicate code!
• Using a method /
function for repeatedly
run code.
• Make code much
shorter. Easier to
manage the code
structure.
Function!

31. • Return nothing, just
print the message out.
• Use "void" return type.
• Call it when you want to
re-calculate the
distance.
• Call it when you want to
print out the distance
result.
Create calculateDistance Function

32. Completed Game for 1D world.
Keep pressing
right arrow

33. Programming C# for 2D world

34. Vectors
X
(4,3)
y=3
x=4
(0,0)

35. Vectors Addition
a
b
a+b(0,0)

36. Vectors Reduction
a
b
a+b
-b
a-b
(0,0)

37. Finding Distance of Two Vectors
Gold
Miner
(0,0)
Gold
Pit
- Gold Miner + Gold Pit

38. Objects and Class
Class Car
Class = Template
Object = Product
new

39. Methods and Attributes

40. Converting from 1d to 2d
• Using the Vector2 instead of float (Don’t forget the new keyword)
• Update distance to be pathToGoldPit Vector2
• Compute the distance by using Vector2 magnitude property.
• Remove all non make-sense code (written for 1d world).

41. Converting from 1d to 2d
the magnitude of vector = the length of the vector

42. Converting from 1d to 2d
Since we could not compare less than and greater than in the Vector2 class,
the code in the block need to be removed, otherwise, the complication errors.

43. Update the location in Vector2
X Y

44. Testing
Haha! We forgot Up and Down button. We can not win!

45. Public variables
Inspector Panel
All public variable will be debuggable in the Inspector Panel.
You can change the value and
see the change in real time!

46. Exercise I
• Implement Up and Down button, so the player can completed the game.
• Starting code is located at https://github.com/kobkrit/vr2017class/blob/
master/exercise1.cs

47. Glossary 1
Name Meaning Example
Value Numbers, text, etc. “Hello world”, 3.14f, 1
Type The “shape” of the value. int, float, string
Variable
The correctly typed box for the
values.
int anInteger;
Statement A command to the computer. print("hello")
Expression
A command that evaluates to a
value.
homeLocation - location
"Distance:" + distance

48. Glossary 2
Name Meaning Example
Method
A factory which something to
input to get output.
Input.GetKeyDown(...)
Arguments The inputs to a method KeyCode.RightArrow
Return value The output of a method if(Input.GetKeyDown(...))
Operation
Like a method but with an
operator rather than a name.
Often ‘infix’.
1 + 2

49. Glossary 3
Name Meaning Example
Object
A collection of variables with
values and methods that act on
those variables.
The actual house.
Class
The blueprint of the variables and
methods.
An architect's drawing of a
house.
Instantiation
The process of making an object
from a class.
new Vector2(2.0f, 3.0f)
Instance
Same as an object. Often used to
say “an instance of a class X”.
The actual house according to
drawings X.

50. Homework
• Can we print out the location into the console?
• If we have multiple gold pits?
• If we have traps?
• When an user fells to the traps, GAME OVER!