Files
mandelia/mandelia_renderer/src/transform.rs

130 lines
3.8 KiB
Rust

use num::Num;
use super::{Float, Point};
pub type MTransform = nalgebra::Matrix5<Float>;
#[derive(Debug)]
pub enum Type {
Rotation(u8, u8, Float),
Translation(u8, Float),
CoordSwap(u8, u8),
Scale(Float),
}
impl From<Type> for MTransform {
fn from(ty: Type) -> Self {
match ty {
Type::Rotation(a0, a1, _) if a0 == a1=> MTransform::identity(),
Type::Rotation(a0, a1, delta) => {
let a0 = a0 as usize;
let a1 = a1 as usize;
let delta = delta.to_radians();
let s = delta.sin();
let c = delta.cos();
let mut m = MTransform::identity();
m[(a0,a0)] = c;
m[(a0,a1)] = -s;
m[(a1,a0)] = s;
m[(a1,a1)] = c;
m
}
Type::Translation(a, delta) => {
let mut m = MTransform::identity();
m[(4, a as usize)] = -delta;
m
}
Type::CoordSwap(a, b) => {
let mut m = MTransform::identity();
let a = a as usize;
let b = b as usize;
m[(a,a)] = 0.;
m[(b,b)] = 0.;
m[(a,b)] = 1.;
m[(b,a)] = 1.;
m
}
Type::Scale(delta) => {
let mut xf = MTransform::identity() / delta;
xf[(4,4)] = 1.;
xf
}
}
}
}
fn parse_axis(c: char) -> Option<u8> {
Some(match c {
'x' => 0,
'y' => 1,
'X' => 2,
'Y' => 3,
_ => return None,
})
}
/// We take a type and distance.
/// We have four axes, x,y,X,Y. The first two adjust the base point; the second two adjust the delta.
///
/// Given that, a plane can be defined with two axes, and a translation can be defined with one.
///
/// TODO: replace this with a nom parser
pub fn parse_step(s: &str) -> Option<Type> {
if let Some(r) = s.strip_prefix("z") {
return Float::from_str_radix(r, 10).ok().map(Type::Scale);
}
if s.len() < 2 {
return None;
}
let mut chars = s.chars();
let axis0 = chars.next().and_then(parse_axis)?;
Some(match chars.clone().next()? {
'=' => {
chars.next();
let axis1 = chars.next().and_then(parse_axis)?;
Type::CoordSwap(axis0, axis1)
}
'x' | 'X' | 'y' | 'Y' => {
chars.next();
let axis1 = chars.next().and_then(parse_axis)?;
if axis0 == axis1 {
return None;
}
let val = Float::from_str_radix(chars.as_str().trim(), 10).ok()?;
Type::Rotation(axis0, axis1, val)
}
'0' ..= '9' => {
let val = Float::from_str_radix(chars.as_str().trim(), 10).ok()?;
Type::Translation(axis0, val)
}
_ => return None,
})
}
pub fn transform_to_coords(mat: &MTransform) -> super::Transform {
let bx = Point::new(mat[(0,0)], mat[(0,1)]);
let by = Point::new(mat[(1,0)], mat[(1,1)]);
let bd = Point::new(mat[(4,0)], mat[(4,1)]);
let cx = Point::new(mat[(0,2)], mat[(0,3)]);
let cy = Point::new(mat[(1,2)], mat[(1,3)]);
let cd = Point::new(mat[(4,2)], mat[(4,3)]);
[
(bx, cx),
(by, cy),
(bd, cd),
]
}
pub fn parse_transforms<'a>(transforms: impl Iterator<Item=impl AsRef<str>>) ->anyhow::Result<super::Transform> {
let mat = transforms
.map(|s| parse_step(s.as_ref())
.ok_or_else(|| anyhow::anyhow!("Invalid step: {:?}", s.as_ref())))
.try_fold(MTransform::identity(),
|acc, new| new.map(|new| acc * MTransform::from(new)))?;
Ok(transform_to_coords(&mat))
}
pub fn parse_transform(s: &str) -> anyhow::Result<super::Transform> {
parse_transforms(s.split_whitespace())
}