Completion

Completion & Discussion Checklist

Before joining the group discussion or concluding this tutorial, ensure you have completed the tasks, investigated the bugs, and are ready to discuss the questions below:

Click to expand Completion & Discussion Checklist (11 Items)

#	Type	Item	Prompt Preview
1	Bug Hunt	Empty Grid Null Check	The code we just added has an error. grid uses null to represent empty spaces. This will cause an error when we try to access particle.color because particle is null.
2	Bug Hunt	Vanishing Water Swap Bug	Run the simulation, create a pool of water, and drop sand particles on top of it. Notice anything strange? The sand falls through, but the water completely vanishes into thin air instead of rising to the surface!
3	Task	Implement checkBounds()	Modify the checkBounds function so it returns true if (row, col) is within the bounds of grid and false otherwise. After writing the function, use it in moveParticle to prevent particles from being moved out of bounds.
4	Task	Fix Particle Streaking	Modify the moveParticle function in canvas.js to stop the particles from streaking as they fall.
5	Task	Prevent Particle Overwrite	Utilizing getParticle (which returns the particle at (row, col)), add a check in the moveParticle function in canvas.js to make sure a particle cannot move on top of another particle.
6	Task	Water Movement Variations	Mess around with water physics! Change the probabilities of movement, add extra movement options, make floating water, or add a random chance to teleport to a random location. Add 3 new behaviors to water’s update function.
7	Task	Create Stone Class	Create a new class called Stone that extends the Particle class. In its constructor, set the color to "gray" and the type to "stone". Make sure to add Stone as an option in checkParticleType.
8	Task	Create Dirt Class	Create a new class called Dirt that extends the Sand class. In its constructor, set the color to "brown" and the type to "dirt". Make sure to add Dirt as an option in checkParticleType.
9	Task	Create Grass Class	Create a new class called Grass in particles.js that extends the Sand class. In its constructor, set the color to "green" and the type to "grass". Grass can ONLY be created when water touches dirt.
10	Challenge	Custom Physics Experimentation	Mess around with the sand physics! What happens if you have the sand move two steps every update (row+2 or col+2), or if you try to move left and right first?
11	Challenge	3 Custom Particles	Add at least 3 new particles and make sure to add interactions with other particles (don’t just add Metal and make it act like Stone). Get creative with it!

Congratulations!

You’ve now taken your Falling Sand simulation to the next level! In this second part of the tutorial, you’ve successfully:

• Introduced a new particle type, Water, and implemented its unique physics, including random movement and interactions with other particles.
• Utilized the getRandomInt() function to add probabilistic behavior to your particles, making the simulation more dynamic and realistic.
• Implemented the swap() function to create interactions between different particle types, allowing Sand to fall through Water.
• Added Stone and Dirt particles, demonstrating how to extend existing classes and create new particle behaviors.
• Created a dynamic interaction between Water and Dirt, resulting in the creation of Grass, showcasing the power of particle interactions.
• Further expanded your understanding of JavaScript classes, inheritance, and object-oriented programming.
• Practiced your problem-solving and debugging skills by experimenting with particle behaviors.

You’ve built a solid foundation for creating even more complex and interesting particle simulations. Now, let’s explore how you can further expand your project with new particles and interactions!