G12_C4_For Teacher Reference
Flying the spaceship with function
| Activity Flow | Slide No. | Topic | Time |
|---|---|---|---|
| TA | 4-8 | Last class revision+quiz | 1 min |
| 9-15 | Functions introduction | 6 min | |
| 16-19 | Calculation of new x,y | 6 min | |
| 21-25 | Teacher activity | 8 min | |
| SA | 26-31 | Student activity | 8 min |
| Wrap - Up | 32-35 | Quiz | 5 min |
| 36-40 | Additional activity | 10 min |
Class Structure
| Slide No. | Topic |
|---|---|
| 13-14 | Function intro code |
| 21-25 | TA- Code |
Preparation and Reference
Prerequisites
FOR STUDENTS
-
Computer with Internet connection.
-
Spyder IDE installed.
-
"pygame" package installed.
FOR TEACHER
-
Computer with Internet connection.
-
Latest browser installed.
-
"pygame" package installed.
-
Spyder IDE installed.
What we did in the last class?
(WARM-UP QUIZ)
Which function do we use to rotate the image?
A
pygame.transform.rotate()
pygame.transform.rotate()
screen.flip()
Q.1
A
pygame.rotate()
B
C
transform.rotate() function rotates the image at the given angle.
So option A is correct.
Which of these events will occur if we press a key?
B
Quit
KEYDOWN
MOSE MOVEMENT
Q.2
A
KEYDOWN
B
C
When a key is pressed KEYDOWN event occurs and when the key is released KEYUP event occurs. Therefore option B is correct.
John has moved to new house!
B
John does not like the walls
B
What are functions?
B
painter()
electrician()
Calling
Function
Function
Defining a function
Let's take an example
Definition of function
Function calling and storing returned value in c variable
Teacher Activity - finding the sum of two numbers using function.
Assigning values to variable
printing variable
GREAT!
John is playing football
Guess the location of the ball
y-axis
x-axis
(x, y)
(xnew, ynew)
distance
x' = distance * cos(angle)
y' = distance * sin(angle)
angle
x'
y'
xnew= x +x'
ynew= y+y'
+
+
Can't use player.y=player.y+speed
Use angle and distance to find new x and y
0°
40°
5
x' = distance * cos(angle)
y' = distance * sin(angle)
xnew= x +x'
ynew= y+y'
5
Teacher Activity - player movement
Game loop
include math library to use cos() and sin() functions.
define a function newxy() that takes four variables and returns nx.
define distance=5 this is how much player will move after each frame.
Teacher Activity - player movement
Game loop
Convert the angle from degrees to radians.
This is to be done as the formula as it works with radian angle only.
Note: We have written angle+90 as in our game 0 degrees is towards up but in the formula it should be towards the right.
0 degree in game
0 degree in formula
Teacher Activity - player movement
Game loop
Create a variable forward, which will tell if the player should move forward or not.
Set it to false as at the beginning of the game player is not moving.
Checking if the up arrow key is pressed and then making forward =True, to indicate that the player should move forwards.
Make forward = False when the up arrow key is released.
Checking if forward =True, and then calling the newxy() function to get new value for the player.x
B
Hint: We can update the newxy() function with the y-axis formula as we did for the x-axis.
Task: Change player's y-axis value to make the player move in y-axis.
y' = distance * sin(angle)
ynew= y+y'
Student Activity-1
Return and use the new y position as well
calculate the new y position by using the formula.
Code for generating new value of y and returning it.
Coordinate system in formula
Coordinate system in game
x-axis
y-axis
(0,0)
(0,0)
Different coordinate system
ynew= y - y'
Instead of adding y', we will subtract it to compensate for the direction of the y-axis.
Which of these is a right way to define a function?
def name():
body of function
Q.1
A
C
B
D
Syntax for defining
a function is:
def function_name():
function body
C
def name:
body of function
def():
body of function
function name():
body of function
Which mathematical function can help in finding the x-axis location if angle and distance travelled by the object is given?
cos()
sin()
tan()
Q.2
None
A
C
B
D
Formula to find new x is:
newx =oldx+(distance*cos(angle))
A
B
Hint:
1. Check if the player reached the left/right edge by checking if the x-axis value is 0 or 400
2. Make player.x=400 when it reaches left edge and player.x=0 when it reaches the right edge.
Task: Make the player spaceship move to alternate edges when it goes from the left or right edge.
ADDITIONAL ACTIVITY - 1
Solution:
B
Task: Make the player spaceship move to alternate edges when it goes from the top or bottom edge.
Hint:
1. Check if the player reached the top/bottom edge by checking if the y-axis value is 0 or 600
2. Make player.y=600 when it reaches top edge and player.x=0 when it reaches bottom edge.
ADDITIONAL ACTIVITY - 2
Solution:
| Activity | Activity Name | Link |
|---|---|---|
| Teacher Activity 1 | Asteroid3 | |
| Teacher Activity 2 | Asteroid 4 -final solution after the class | |
| Teacher Activity 3 | AA-1 Solution | |
| Teacher Activity 4 | AA-2 Solution | |
| Student Activity 1 | Asteroid3.5 |
Links Table
Copy of G12_C4_For_Teacher
By anjali_sharma
