Add gif components

1 files changed, 67 insertions, 0 deletions

diff --git a/src/components/colortable.rs b/src/components/colortable.rs
new file mode 100644
index 0000000..f756169
--- /dev/null
+++ b/src/components/colortable.rs
@@ -0,0 +1,67 @@
+use std::ops::Deref;
+pub use super::Color;
+
+pub struct ColorTable {
+	table: Vec<Color>
+}
+
+impl ColorTable {
+	pub fn new() -> Self {
+		Self {
+			table: vec![]
+		}
+	}
+
+	/// Returns the number of colors in the color table as used by the packed
+	/// fields in the Logical Screen Descriptor and Image Descriptor. You can
+	/// get the actual size with the [`len`](struct.ColorTable.html#method.len) method.
+	pub fn packed_len(&self) -> u8 {
+		((self.table.len() as f32).log2().ceil() - 1f32) as u8
+	}
+
+	/// Returns the number of items in the table
+	pub fn len(&self) -> usize {
+		self.table.len()
+	}
+
+	/// Pushes a color on to the end of the table
+	pub fn push(&mut self, color: Color) {
+		self.table.push(color);
+	}
+}
+
+impl Deref for ColorTable {
+	type Target = [Color];
+
+	fn deref(&self) -> &Self::Target {
+		&self.table
+	}
+}
+
+impl From<Vec<Color>> for ColorTable {
+	fn from(table: Vec<Color>) -> Self{
+		ColorTable {
+			table
+		}
+	}
+}
+
+impl From<&ColorTable> for Box<[u8]> {
+	fn from(table: &ColorTable) -> Self {
+		let mut vec = vec![];
+
+		for color in table.iter() {
+			vec.extend_from_slice(&[color.r, color.g, color.b]);
+		}
+
+		let packed_len = 2u8.pow(table.packed_len() as u32 + 1);
+		let padding = (packed_len as usize - table.len()) * 3;
+		if padding > 0 {
+			vec.extend_from_slice(&vec![0; padding]);
+		}
+
+		vec.into_boxed_slice()
+	}
+}
+
+//TODO: TryFrom Vec<u8> (must be multiple of 3 len) and From Vec<Color>
\ No newline at end of file