Description
Provided Files
● main.c
● myLib.c
● myLib.h
● game.c
● game.h
● text.c
● text.h
● font.c
● font.h
● kirby.png
● start.png
Files to Edit/Add
● main.c
● myLib.c
● kirby.c
● kirby.h
● start.c
● start.h
● Makefile
● .vscode
○ tasks.json
Instructions
In this lab, you’ll be completing several different TODOs, which will piece by piece add
Mode 4 drawing to a simple game. Each TODO represents a component of this
improvement, and is broken down into sub-TODOs. Your code may not compile until you
complete an entire TODO block, at which point the game should compile with the new
CS 2261 Spring 2021
drawing function working as expected.
After downloading and unzipping the files, if you take a look at the code, what you see
should be familiar. It’s a completed Lab04 with a bit of a fun spin! It has a few new features
to highlight and test some Mode 4 functionality. If you were to build it right now, however,
it will be a blank screen. Complete the TODOs in order, paying close attention to the
instructions.
Note: Make sure to copy over your Makefile and .vscode/tasks.json from one of your
previous assignments.
TODO 1.0 – SetPixel4
For us to be able to set pixels in Mode 4, we need to account for the additional cases that
Mode 4 requires, so we’re making a new function.
● In myLib.c, complete setPixel4()
● Build and run. If you press START, you should be able to travel to the game state and
see that the text is drawing correctly (drawChar4 and drawString4 have already
been written for you). If not, fix this before going further.
○ The states will be black screens besides the game state (where you should
see text drawn)
TODO 2.0 – fillScreen4
We want to be able to see the rest of the states, so we need to fill the screen next.
● TODO 2.0
○ In myLib.c, complete fillScreen4()
● TODO 2.1
○ At this point, if you compile and run, you won’t see anything. That’s because
our goTo state functions are only filling the screen once (on the hidden page),
then doing nothing. To fix this, we need to flip the page with flipPage() after
doing our drawing and after we wait for VBlank.
○ In main.c, in the goToStart function, wait for VBlank, then flip the page.
● TODO 2.2
○ Do the same for goToPause
● TODO 2.3:
○ Do the same for goToWin
● TODO 2.4:
○ Do the same for goToLose
● Build and run your lab thus far. You should be able to travel through all the states
you just edited and see their titles printed on them (except for Start because
drawFullScreenImage is still blank). If not, fix this before going further.
CS 2261 Spring 2021
TODO 3.0 – drawFullscreenImage4
We want to actually be able to see the start screen. Let’s make it so we can draw fullscreen
images!
● TODO 3.0
○ In myLib.c, complete drawFullScreenImage4()
● TODO 3.1
○ This isn’t worth anything if we don’t have an image to draw. Open
start.png in Usenti.
○ No need to resize this image, as it is already 240x160px (the size of the
screen).
● TODO 3.2
○ We are in Mode 4, so the image can only use a MAX of 256 colors. Usenti has a
tool to reduce the number of colors.
○ Go to Palette > Requantize. Type 256 and hit OK
● TODO 3.3
○ Export your image (Image > Export).
○ You will save it as a GBA source file in the Lab05 folder.
○ In the export settings, select bitmap(GBA) and “8bpp” (8 bits per pixel
means that it’s a char for each pixel, like Mode 4 wants).
○ Also make sure that Pal (top right) is checked. This will include the palette
in the .c file as an array of 256 shorts.
● TODO 3.4
○ #include start.h at the top of main.c
○ We need to be able to load the image’s palette (located in start.c) in the
game so that the hardware knows what colors to use.
○ In main.c, in the goToStart function, write a single call to DMANow() that
will copy the entire start image palette into the game’s PALETTE
■ You can find the necessary image information declared in start.h
● TODO 3.5
○ Uncomment the call to drawFullScreenImage4 in the goToStart
function.
● Build and run your lab. You should be able to see all the states now (except for the
moving elements in Game). If not, fix this before going further.
TODO 4.0 – drawImage4
We want to be able to draw smaller images as well.
● TODO 4.0
CS 2261 Spring 2021
○ In myLib.c, complete drawImage4()
● TODO 4.1
○ Open kirby.png in Usenti. This one was drawn using a small enough
palette and size, so there is no need to resize or requantize.
● TODO 4.2
○ Export this image the same way you did the last one, making sure that Pal is
checked.
○ In initGame(), write the same DMANow() call you wrote to load in the
palette last time, this time loading in kirbyPal.
○ Note: this time, after we load in the palette, we also put some of our own
colors in there (you can view this in game.c. It looks super complicated, and
you don’t have to do it this way when you are making your games). It has
already been done for you.
● TODO 4.3
○ Include kirby.h at the top of game.c
○ Uncomment the rest of drawBall()
● Build and run. When you reach the game state, you should see one kirby ball
bouncing around. If not, fix this before going further.
TODO 5.0 – drawRect4
For our last touch, we need to be able to draw Rectangles
● In myLib.c, complete drawRect4()
○ This will be by far the longest function you code in this lab. You need to
account for ALL cases where you have to set pixels in front or behind each
row.
■ HINT: draw lots of pictures. There are 4 col/width cases, so make
sure you identify and account for all of them.
○ You also need to make sure it still works if you draw a rectangle of small
width (1 or 2)
● Build and run.
○ If you shoot, the bullets are now of different widths, and they don’t fly
straight up when you are moving; they lean in the direction you were moving
when you shot. If any of your homeworks are like this, we will assume
you copied code, and penalize heavily. These additions are to help you test
drawRect.
○ The rectangles should all be correctly sized, and they should not wiggle when
they move diagonally (they should move smoothly in that direction).
CS 2261 Spring 2021
○ When you shoot the rectangles, they should turn into kirby images
● If all this works, submit your lab.
You will know if it runs correctly if:
● You see a fullscreen image on the start state
● When you reach the game state, you see rectangles you are familiar with and the
images
● When you shoot the clutter rectangles, they transform into kirby images. Transform
all clutter into kirby to win the game.
● If you shoot, a number of different sized bullets show up and you DO NOT see just a
white screen when trying to shoot bullets
Tips
● Review lecture and recitation materials for how we deal with Mode 4 pixels
● Review how to use Usenti to export a bitmap image
● Follow each TODO in order, and only move forward if everything is correct
Submission Instructions
Zip up your entire project folder, including all source files, the Makefile, and everything
produced during compilation (including the .gba file). Submit this zip on Canvas. Name
your submission Lab05_FirstameLastname, for example: “Lab05_DamacyKing.zip”.
