Description
Input and Collision
Provided Files
- c
- c
- h
Files to Edit/Add
- c
- c
- h
- Makefile
- .vscode
○ tasks.json
Instructions
Note: Make sure to copy over your Makefile and .vscode/tasks.json from one of your previous assignments.
TODO 1.0
- void drawRect(int col, int row)
○ Complete this function in myLib.c (right under the setPixel function). You should already know how to do this from your last lab, and it should for a filled in rectangle.
○ In main.c, find and uncomment UNCOMMENT #1. You should see a yellow rectangle in the bottom half of the screen.
TODO 2.0
- void fillScreen(unsigned short color)
○ Head back to myLib.c, find fillScreen (right beneath drawRect) and complete it.
○ You may only use a single loop (one for-loop) to complete this one.
■ Hint: the GBA screen has a total of 240 x 160 pixels which is equal to 38400.
○ Enter main.c and uncomment UNCOMMENT #2. The background of your game should now be a beautiful shade of blue, and you should see two new rectangles. There should be one green “land” rectangle at the bottom of the screen, and one white “cloud” rectangle towards the top of the screen that moves horizontally. There should also still be the yellow rectangle in the center of the screen.
TODO 3.0-3.2
This one requires a lot of moving parts to work, so it is broken into three parts.
- TODO 0
- Open h, find the button macros, and complete them.
○ For BUTTON_PRESSED, assume that buttons and oldButtons have been set up appropriately.
- TODO 1
- Since buttons and oldButtons haven’t been set up correctly (yet!), head on back to c and initialize them in the initialize function.
○ They have already been declared in main.c (and in myLib.h as extern variables), so you don’t have to worry about that part this time, but you will when you code things yourself for your homeworks.
- TODO 2
- The buttons still won’t do anything unless you update them each frame, so do that in the main while-loop.
○ After you have completed these tasks, find UNCOMMENT #3 in the update function and do the thing.
○ Run it, and now you can press button A to toggle the clouds between white and gray, as if they are switching between light, fluffy white clouds and gray clouds preparing for rainfall.
○ Holding down the A button for a long time should have the same effect as just tapping it a single time. If that is not the case, you did one of these three TODOs incorrectly. TODO 4.0
- Now that you can take button input, find TODO 0 in the update function and complete it so that the yellow rectangle can move up, down, left, and right if you press the corresponding arrow key.
- This time, it should move for as long as the key is held, meaning that if you tap it once quickly, it will barely move, but if you press it for several seconds, it will move a If not, fix that.
- Compile and run, and you should be able to move the yellow rectangle anywhere on the
TODO 5.0-5.2
This is the most exhaustive part of the lab, but also the most important.
- TODO 0
- At the bottom of c, implement the collision function. It takes in the positions and dimensions of two rectangles, and returns a 1 if they are colliding, or a 0 if not.
■ Hint: using graph paper, or drawing a grid yourself, is extremely useful. This function should work regardless of the size or velocity of the rectangle (if one is moving).
- TODO 1
- Now that you have the collision function implemented, use it in the update If the yellow rectangle collides with the moving cloud rectangle, reset the yellow rectangle’s position to where it was first initialized (refer to the initialize function to see the exact location). Also, make the cloud rectangle stop moving (the cloud’s horizontal velocity variable is cCDel) if it’s moving. If the cloud is not moving, make it start moving horizontally to the right side of the screen.
- TODO 2
- Now use the collision function to account for if the yellow rectangle collides with the land Additionally, if lColor (the land’s current color) is green, change it to black. If it is already black, change it to green.
■ Hint: you can refer to the logic that was used to make the clouds change colors when you press A.
○ Compile and run. Verify that it runs correctly, and then you are done.
- Hint: since there are two separate rectangles for which you need to detect a collision, you’ll need to use the collision function two separate
You will know if it runs correctly if you can:
- Move the yellow rectangle using the arrow
- Press A to change the cloud color from white to gray, and vice
- Make the yellow rectangle collide with any of the other rectangles and be transported to its initial
- Collide with the land rectangle at the bottom, changing the color from black to green, or vice
- Collide with the moving cloud rectangle at the top, making the cloud stop moving or start moving to the right side of the
Tips
- Start early, and attend
- Use graph paper and draw pictures to conceptualize what is
- Follow each TODO in order, and only move forward if everything is
