Quiz 7b

Quiz 7b#

Question 1#

The class code provided for this week’s mini-project supports an ImageInfo class to organize the data associated with the image. Consider an ImageInfo object of the following form:

ImageInfo([45, 45], [90, 90], 35)

What is the radius of the shape associated with this ImageInfo object?

Enter answer here:\

35

ImageInfo and Sprite

Question 2#

Consider the provided ImageInfo and Sprite class code. Assume we want ten asteroids on the screen, each looking exactly alike and using the same image file. How many ImageInfo objects and how many Sprite objects should we create?

ten ImageInfo objects, one Sprite object
one ImageInfo object, ten Sprite objects
ten ImageInfo objects, ten Sprite objects
one ImageInfo object, one Sprite object \

one ImageInfo object, ten Sprite objects \

Each sprite uses the same asteroid image. An image does not have any position and velocity but a sprite does.

Question 3#

The version of Rice Rocks that we will implement uses only a single asteroid image and spawns multiple instances of the provided Sprite class using this image. In the original Asteroids , a large asteroid split into two medium asteroids which themselves split into two small asteroids.

If we only had one image and wanted to implement asteroids of varying sizes in our version, how should we do this?

Store the size in a global variable. Use this variable when drawing a sprite.
Add a size attribute in the Sprite class and a size parameter to Sprite.__init__. Use the size attribute when drawing the sprite.
Store a list of sizes for each asteroid in a global variable. Use the corresponding size when drawing a sprite.
Add a size attribute in the ImageInfo class and a size parameter to ImageInfo.__init__. Use this attribute when drawing the sprite. \

Add a size attribute in the Sprite class and a size parameter to Sprite.__init__. Use the size attribute when drawing the sprite. \

Question 4#

What is the supported range of sound volumes in set_volume? You can find out in the CodeSkulptor documentation .

0 to 1
0 to 10
-1 to 1
1 to 100 \

0 to 1 \

sound.set_volume

Question 5#

Assume you have code that loads and plays a sound. Unfortunately, you don’t hear anything. Which of the following could be a reason?

The given URL exists, but is inaccessible due to network problems.
A file found with the given URL isn’t a sound file recognized by your browser.
No file is found with the given URL.
You have set the volume level to 0.
Your browser is loading a big sound file. Wait longer. \

all of them

Question 6#

Which of the following are valid HTML representations of the color blue?

Refer to this page on HTML color values .

"Red"
"#0000FF"
"#00FF00"
"Blue"
"rgb(0, 0, 255)" \

"#0000FF"
"Blue"
"rgb(0, 0, 255)" \

According to CSS Legal Color Values rgb(0, 0, 255) is also correct.

Question 7#

Imagine we are writing code for something like Rice Rocks , where things are moving in 2D toroidal space, i.e., the wrap around all four sides of the screen. How can we eliminate the duplicated code in the following function?

def move(position, vector):
    """Moves the position by the given vector in 2D toroidal space."""
    position[0] = (position[0] + vector[0]) % SCREEN_SIZE[0]
    position[1] = (position[1] + vector[1]) % SCREEN_SIZE[1]

  NUM_DIMENSIONS = 2
def move(position, vector):
    """Moves the position by the given vector in 2D toroidal space."""
    for d in range(NUM_DIMENSIONS):
        position[d] = (position[d] + vector[d]) % SCREEN_SIZE[d]

\

  def move_dimension(dimension, position, vector):
    """Moves the position component by the given vector component in 1D toroidal space."""
    position[dimension] = (position[dimension] + vector[dimension]) % SCREEN_SIZE[dimension]

def move(position, vector):
    """Moves the position by the given vector in 2D toroidal space."""
    move_dimension(0, position, vector)
    move_dimension(1, position, vector)

\

  def move(position, vector):
    """Moves the position by the given vector in 2D toroidal space."""
    position = (position + vector) % SCREEN_SIZE

\

  NUM_DIMENSIONS = 2
def move(position, vector):
    for d in range(NUM_DIMENSIONS):
        return position[d] = (position[d] + vector[d]) % SCREEN_SIZE[d]

\

  def move(position, vector):
    position = [(pos + vec) % size for pos in position for vec in vector for size in SCREEN_SIZE]

\

NUM_DIMENSIONS = 2
def move(position, vector):
    """Moves the position by the given vector in 2D toroidal space."""
    for d in range(NUM_DIMENSIONS):
        position[d] = (position[d] + vector[d]) % SCREEN_SIZE[d]

def move_dimension(dimension, position, vector):
    """Moves the position component by the given vector component in 1D toroidal space."""
    position[dimension] = (position[dimension] + vector[dimension]) % SCREEN_SIZE[dimension]

def move(position, vector):
    """Moves the position by the given vector in 2D toroidal space."""
    move_dimension(0, position, vector)
    move_dimension(1, position, vector)

  • in the third and fifth example we cannot add the position and vector together like shown, because they are tuples

  • In the fourth example, return statement immediately exits the function

Question 8#

What is the primary reason for not duplicating code? It was the only reason mentioned in the Programming Tips #7 video.

It leads to faster code.
You only need to get the code correct once .
It takes less time to write the code. \

You only need to get the code correct once . \

Question 9#

What is Mike Massimino’s greatest accomplishment?

Fixing the Hubble Space Telescope in space
Being the first person to use Twitter in space
Receiving his PhD from MIT
Appearing on The Big Bang Theory
Appearing on An Introduction to Interactive Programming in Python \

He appears in the mini-project video

He was even a professor at Rice, how cool!

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