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Code Issues Releases Wiki Activity

Tweaks

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This commit is contained in:
Bradlee Speice
2024-11-18 22:08:23 -05:00
parent e1735404ae
commit 431ba2d0f4
1 changed files with 8 additions and 22 deletions
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blog/2024-11-15-playing-with-fire/2-transforms/index.mdx
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@ -25,15 +25,6 @@ $$
F_i(x,y) = (a_i \cdot x + b_i \cdot y + c_i, \hspace{0.2cm} d_i \cdot x + e_i \cdot y + f_i)
$$
Let's also start defining some types we can use in our code. The transform coefficients are a good place to start:
```typescript
interface Coefs {
a: number, b: number, c: number,
d: number, e: number, f: number
}
```
We also introduced the Sierpinski Gasket functions ($F_0$, $F_1$, and $F_2$), demonstrating how they are related to
the general format. For example:
@ -57,18 +48,12 @@ The fractal flame paper lists 49 variation functions ($V_j$ above), but the sky'
For example, the official `flam3` implementation supports
[98 variations](https://github.com/scottdraves/flam3/blob/7fb50c82e90e051f00efcc3123d0e06de26594b2/variations.c).
In code, variations are pretty easy:
```typescript
type Variation = (x: number, y: number) => [number, number];
````
Our reference image will focus on just four variations:
### Linear (variation 0)
This variation returns the $x$ and $y$ coordinates as-is. In a way, the Sierpinski Gasket is
a fractal flame using only the linear variation.
This variation returns the $x$ and $y$ coordinates as-is. As mentioned, the Sierpinski Gasket is
a fractal flame using only the linear variation:
$$
V_0(x,y) = (x,y)
@ -82,7 +67,7 @@ function linear(x: number, y: number) {
### Julia (variation 13)
This variation still uses just the $x$ and $y$ coordinates, but does some crazy things with them:
This variation still uses just the $x$ and $y$ coordinates, but does crazy things with them:
<small>TODO: Is this related to the Julia set?</small>
@ -116,17 +101,18 @@ function julia(x: number, y: number) {
### Popcorn (variation 17)
This is known as a "dependent variation" because it depends on knowing the transform coefficients:
This is known as a "dependent variation" because it depends on knowing the transform coefficients
(specifically, $c$ and $f$):
$$
V_{17}(x,y) = (x + c \cdot \text{sin}(\text{tan }3y), y + f \cdot \text{sin}(\text{tan }3x))
$$
```typescript
function popcorn({c, f}: Coefs) {
function popcorn(coefs: {c: number, f: number}) {
return (x: number, y: number) => [
x + c * Math.sin(Math.tan(3 * y)),
y + f * Math.sin(Math.tan(3 * x))
x + coefs.c * Math.sin(Math.tan(3 * y)),
y + coefs.f * Math.sin(Math.tan(3 * x))
]
}
```