Frmandy

Cartesi is designed for doing computation off-chain that would be otherwise be difficult in the EVM. A Mandelbrot set is a classic example. Although we could generate a Madelbrot set escape time plot in the EVM, writing the resulting PNG file would be a challenge. In this hypothetical example, we make a NFT that sells off portions of the set such as "seahorse valley" (--0.75:0.1:10.0) to collectors. In an ideal scenario, we could use Cartesi to write a file to IPFS and publish the URL on the chain by use of Cartesi's unique voucher system.

Rust is the ideal language for these computational loads having a good degree of stability and an established set of libraries such as the PNG library used in this example.

The core code of this contract is as follows:

fn escape_time(cx: f64, cy: f64) -> u8 { let mut zx = cx; let mut zy = cy; let mut res = 0; loop { (zx, zy) = (zxzx - zyzy + cx, 2.0zyzx + cy ); if zxzx + zyzy > 4.0 || res == 255 { return res; } res += 1; } }

We give three parameters to the contract: x, y and zoom. This determines the generated image.

In a more complex example, we could composite SVG images to create mutations of comic book characters or sell off images of plots of land on Mars.

There is a small demo UI which intereacts with the emulator directly as testing the smart contracts end to end was a challenge given the many moving parts. Hopefully this demonstrates the core concepts. Next step would be to deploy to chain.