Lots a changes

1 files changed, 148 insertions, 5 deletions

diff --git a/tvg/src/commands.rs b/tvg/src/commands.rs
index f316a53..c21099b 100644
--- a/tvg/src/commands.rs
+++ b/tvg/src/commands.rs
@@ -1,24 +1,101 @@
 use std::io::{self, Read};
+use std::ops::{Add, Mul, Sub};
 
 use byteorder::ReadBytesExt;
 use raise::yeet;
 
-use crate::{header::TvgHeader, path::Path, read_unit, read_varuint, Decode, Point, TvgError};
+use crate::{
+	colors::{self, Color, ColorTable},
+	header::TvgHeader,
+	path::Path,
+	read_unit, read_varuint, Decode, TvgError,
+};
+
+/// A X and Y coordinate pair.
+#[derive(Debug, Clone, Copy)]
+pub struct Vector {
+	/// Horizontal distance of the point to the origin.
+	pub x: f64,
+	/// Vertical distance of the point to the origin.
+	pub y: f64,
+}
+
+impl Vector {
+	pub fn magnitude(&self) -> f64 {
+		(self.x * self.x + self.y * self.y).sqrt()
+	}
+
+	pub fn scale(&self, scale: f64) -> Vector {
+		Vector {
+			x: self.x * scale,
+			y: self.y * scale,
+		}
+	}
+}
+
+impl Mul for Vector {
+	type Output = f64;
+
+	fn mul(self, rhs: Self) -> Self::Output {
+		self.x * rhs.x + self.y * rhs.y
+	}
+}
+
+/// A X and Y coordinate pair.
+#[derive(Debug, Clone, Copy)]
+pub struct Point {
+	/// Horizontal distance of the point to the origin.
+	pub x: f64,
+	/// Vertical distance of the point to the origin.
+	pub y: f64,
+}
+
+impl Sub for Point {
+	type Output = Vector;
+
+	fn sub(self, rhs: Self) -> Self::Output {
+		Vector {
+			x: self.x - rhs.x,
+			y: self.y - rhs.y,
+		}
+	}
+}
+
+impl Add<Vector> for Point {
+	type Output = Self;
+
+	fn add(self, vector: Vector) -> Self::Output {
+		Self {
+			x: self.x + vector.x,
+			y: self.y + vector.y,
+		}
+	}
+}
+
+impl Decode for Point {
+	fn read(reader: &mut impl Read, header: &TvgHeader) -> io::Result<Self> {
+		Ok(Self {
+			x: read_unit(reader, header)?,
+			y: read_unit(reader, header)?,
+		})
+	}
+}
 
 #[derive(Debug, Clone, Copy, PartialEq)]
 pub struct Rectangle {
 	/// Horizontal distance of the left side to the origin.
-	x: f64,
+	pub x: f64,
 	/// Vertical distance of the upper side to the origin.
-	y: f64,
+	pub y: f64,
 	/// Horizontal extent of the rectangle.
-	width: f64,
+	pub width: f64,
 	/// Vertical extent of the rectangle.
-	height: f64,
+	pub height: f64,
 }
 
 impl Decode for Rectangle {
 	fn read(reader: &mut impl Read, header: &TvgHeader) -> io::Result<Self> {
+		let x = 5;
 		Ok(Self {
 			x: read_unit(reader, header)?,
 			y: read_unit(reader, header)?,
@@ -203,6 +280,72 @@ impl Style {
 			color_index_1: read_varuint(reader)?,
 		})
 	}
+
+	fn linear_get_color_at<C: Color + Clone>(
+		&self,
+		color_table: &ColorTable<C>,
+		point: Point,
+	) -> Option<C> {
+		let Self::LinearGradient {
+			point_0,
+			point_1,
+			color_index_0,
+			color_index_1 } = self else { panic!() };
+
+		// TODO remove these unwraps
+		let color_0 = color_table.get(*color_index_0 as usize)?;
+		let color_1 = color_table.get(*color_index_1 as usize)?;
+
+		let direction = *point_1 - *point_0;
+		let delta = point - *point_0;
+
+		if direction * delta <= 0.0 {
+			return Some(color_0.clone());
+		} else if direction * (point - *point_1) >= 0.0 {
+			return Some(color_1.clone());
+		}
+
+		let gradient_length = direction.magnitude();
+		let proj = (direction * delta) / (direction * direction);
+		let gradient_position = direction.scale(proj).magnitude();
+		let f = gradient_position / gradient_length;
+
+		Some(colors::lerp(color_0, color_1, f))
+	}
+
+	fn radial_get_color_at<C: Color>(
+		&self,
+		color_table: &ColorTable<C>,
+		point: Point,
+	) -> Option<C> {
+		let Self::RadialGradient {
+			point_0,
+			point_1,
+			color_index_0,
+			color_index_1 } = self else { panic!() };
+
+		// TODO remove these unwraps
+		let color_0 = color_table.get(*color_index_0 as usize)?;
+		let color_1 = color_table.get(*color_index_1 as usize)?;
+
+		let distance_max = (*point_1 - *point_0).magnitude();
+		let distance_is = (point - *point_0).magnitude();
+		let f = distance_is / distance_max;
+
+		Some(colors::lerp(color_0, color_1, f))
+	}
+
+	pub fn get_color_at<C: Color + Clone>(
+		&self,
+		color_table: &ColorTable<C>,
+		point: Point,
+	) -> Option<C> {
+		match self {
+			Self::FlatColored { color_index } => color_table.get(*color_index as usize).cloned(),
+			Self::LinearGradient { .. } => self.linear_get_color_at(color_table, point),
+			Self::RadialGradient { .. } => self.radial_get_color_at(color_table, point),
+		}
+	}
 }
 
 /// TinyVG files contain a sequence of draw commands that must be executed in