Falling snow in TypeScript

To run the project locally

• Open a terminal and run the following commands

  git clone git@github.com:dotnetthailand/falling-snow-in-typescript.git
  cd falling-snow-in-typescript
  yarn
  yarn run serve

• Open a browser and navigate to http://localhost:9999

Example result of snowing in JavaScript code

Equation

• We think snowing has falling pattern like sin graph.
• Let's start by plotting y = sin(x)

y = sin(x)

• As you can see, this is not right.
• Falling of snow is an inversion of relationship y = sin(x).
• Swap y and x in the equation.
• Therefore, the inversion of the relationship y = sin(x) is x = sin(y).

x = sin(y)

The equation of our falling snow is x = sin(y).

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Adjust our graph

To make snow fall naturally, we need to randomly adjust our amplitude (height) and period (width) of a graph.

Adjust amplitude

x = 4sin(y)

x = 1/2sin(y)

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Adjust period

x = sin(2πy)

If y equal 1, it take two PI periods.

x = sin(π/2y)

If y equal 1, it takes half of PI period.

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REF

• Inverse function
• Adjust amplitude and period

Credit

• Original code from https://yagudaev.com/posts/snow-in-javascript/
• Master Off for explaining me the inversion function and sin graph
• https://stackoverflow.com/a/47367655/1872200