add 16 wide, 2 deep tree with RLE at the end. turns out to be worse than other algs

encoder/src/dec.rs

@@ -251,8 +251,8 @@ pub fn rle_vertical_ext(_prev_frame: &Frame, encoded: &[u8], reader: &mut usize)
 		let mut run = byte as u16;
 		if byte == 0 && encoded[i] == 0 {
 			// 16 bit run length
-			let upper = (encoded[i+1] as u16) << 8;
+			let upper = (encoded[i + 1] as u16) << 8;
-			if upper > 0{
+			if upper > 0 {
 				let lower = encoded[i + 2] as u16;
 				i += 3;
 				run = upper | lower;
@@ -281,10 +281,10 @@ pub fn rle_vertical_16(_prev_frame: &Frame, encoded: &[u8], reader: &mut usize)
 
 	while x < WIDTH {
 		let upper = encoded[i] as u16;
-		let lower = encoded[i+1] as u16;
+		let lower = encoded[i + 1] as u16;
 		i += 2;
 
-		let run = (upper<<8) | lower;
+		let run = (upper << 8) | lower;
 		for _ in 0..run {
 			frame[x][y] = color;
 			y += 1;
@@ -299,6 +299,72 @@ pub fn rle_vertical_16(_prev_frame: &Frame, encoded: &[u8], reader: &mut usize)
 	frame
 }
 
+pub fn tree_16(_prev_frame: &Frame, encoded: &[u8], reader: &mut usize) -> Frame {
+	let fg = 1;
+	let mut frame = [[1-fg; HEIGHT]; WIDTH];
+	let top_node = ((encoded[0] as u16) << 8) | encoded[1] as u16;
+	let mut i = 2;
+	let mut nodes = [0u16; 16];
+	for cx in 0..4 {
+		for cy in 0..4 {
+			let index = cy * 4 + cx;
+			let has_node = (top_node & (1 << index)) != 0;
+			if has_node {
+				let node = ((encoded[i] as u16) << 8) | encoded[i + 1] as u16;
+				i += 2;
+				nodes[index] = node;
+				// temp fill for visualisation:
+				// for px in 0..(WIDTH / 4) {
+				// 	let x = cx * (WIDTH / 4) + px;
+				// 	for py in 0..(HEIGHT / 4) {
+				// 		let y = cy * (HEIGHT / 4) + py;
+				// 		frame[x][y] = 1;
+				// 	}
+				// }
+			}
+		}
+	}
+	let mut color = fg;
+	let mut run = 0;
+	for cx in 0..4 {
+		for cy in 0..4 {
+			let index = cy * 4 + cx;
+			let node = nodes[index];
+			if node != 0 {
+				for ccx in 0..4 {
+					for ccy in 0..4 {
+						let x = cx * (WIDTH / 4) + ccx * (WIDTH / 16);
+						let y = cy * (HEIGHT / 4) + ccy * (HEIGHT / 16);
+
+						let lower_index = ccy * 4 + ccx;
+						if node & (1 << lower_index) != 0 {
+							// leaf node exists, fill from RLE
+							let mut px = 0;
+							let mut py = 0;
+							while px < WIDTH / 16 {
+								while run == 0 {
+									run = encoded[i];
+									i += 1;
+									color = 1 - color;
+								}
+								run -= 1;
+								frame[x + px][y + py] = color;
+								py += 1;
+								if py == HEIGHT / 16 {
+									py = 0;
+									px += 1;
+								}
+							}
+						}
+					}
+				}
+			}
+		}
+	}
+	*reader += i;
+
+	frame
+}
 
 pub fn fill_white(_prev_frame: &Frame, _encoded: &[u8], _reader: &mut usize) -> Frame {
 	FRAME_1

encoder/src/enc.rs

@@ -293,6 +293,71 @@ pub fn rle_horizontal(_prev_frame: &Frame, frame: &Frame) -> EncodedFrame {
 	}
 }
 
+/// requires WIDTH and HEIGHT to be multiples of 16
+/// two-level tree with 4x4 branches per level
+pub fn tree_16(_prev_frame: &Frame, frame: &Frame) -> EncodedFrame {
+	let mut top_node: u16 = 0;
+	let mut second_nodes = Vec::new();
+	let mut included_pixels = Vec::new();
+	// todo allow using white as bg
+	let fg = 1;
+	for cx in 0..4 {
+		for cy in 0..4 {
+			let mut any_filled_here = false;
+			'a: for px in 0..(WIDTH / 4) {
+				let x = cx * (WIDTH / 4) + px;
+				for py in 0..(HEIGHT / 4) {
+					let y = cy * (HEIGHT / 4) + py;
+					if frame[x][y] == fg{
+						any_filled_here = true;
+						break 'a;
+					}
+				}
+			}
+			if any_filled_here {
+				top_node |= 1 << (cy * 4 + cx);
+				let mut second_node: u16 = 0;
+				for ccx in 0..4 {
+					for ccy in 0..4 {
+						let mut any_filled_here = false;
+						let mut node_pixels = Vec::new();
+						for px in 0..(WIDTH / 16) {
+							for py in 0..(HEIGHT / 16) {
+								let x = cx * (WIDTH / 4) + ccx * (WIDTH / 16) + px;
+								let y = cy * (HEIGHT / 4) + ccy * (HEIGHT / 16) + py;
+								if frame[x][y] == fg {
+									node_pixels.push(fg);
+									any_filled_here = true;
+								}else{
+									node_pixels.push(1-fg);
+								}
+							}
+						}
+						if any_filled_here {
+							second_node |= 1 << (ccy * 4 + ccx);
+							included_pixels.extend_from_slice(&node_pixels);
+						}
+					}
+				}
+				second_nodes.push(second_node);
+			}
+		}
+	}
+	let mut data = Vec::new();
+	data.push((top_node >>8) as u8);
+	data.push(top_node as u8);
+	for n in second_nodes{
+		data.push((n>>8)as u8);
+		data.push(n as u8);
+	}
+	data.extend_from_slice(&rle_255_encode(&included_pixels));
+
+	EncodedFrame {
+		encoding: Encoding::Tree16,
+		data,
+	}
+}
+
 pub fn rle_vertical(_prev_frame: &Frame, frame: &Frame) -> EncodedFrame {
 	let mut pixels = Vec::new();
 	for x in 0..WIDTH {
@@ -348,7 +413,6 @@ pub fn rle_vertical_ext(_prev_frame: &Frame, frame: &Frame) -> EncodedFrame {
 	}
 }
 
-
 pub fn rle_vertical_16(_prev_frame: &Frame, frame: &Frame) -> EncodedFrame {
 	let mut data = Vec::new();
 	let mut last_pixel = 0;

encoder/src/main.rs

@@ -1,4 +1,4 @@
-use std::{fs::File, io::Write};
+use std::{fs::File, io::{stdout, Write}};
 
 use enum_map::{Enum, EnumMap};
 use num_enum::TryFromPrimitive;
@@ -22,6 +22,7 @@ const LOSSLESS_ENCODINGS: &[FrameEncoder] = &[
 	// enc::rle_diff_vertical,
 	// enc::bg_strips_horizontal_16, // only works for the tiny display
 	enc::bg_strips_horizontal_24, // intended for the 240x320 display
+	// enc::tree_16,// turns out to be useless
 ];
 const LOSSY_ENCODINGS: &[FrameEncoderLossy] = &[
 	enc::fill_white,
@@ -101,7 +102,11 @@ fn main() {
 fn encode(frames: &[Frame]) -> Vec<u8> {
 	let mut out = Vec::new();
 	let mut last_frame = FRAME_0;
+	print!("encoding frames");
+	let frame_count = frames.len();
 	for (_i, frame) in frames.iter().enumerate() {
+		print!("\rencoding frame {_i} of {frame_count}");
+		stdout().flush().unwrap();
 		let mut options = Vec::new();
 		for encode in LOSSLESS_ENCODINGS.iter() {
 			let encoded = encode(&last_frame, frame);
@@ -157,6 +162,7 @@ fn encode(frames: &[Frame]) -> Vec<u8> {
 		out.extend_from_slice(&best_encoding);
 		last_frame = *frame;
 	}
+	println!();
 	out
 }
 
@@ -184,6 +190,7 @@ enum Encoding {
 	// CellDiff4VH,
 	CellDiff4VV,
 	// CellDiff4VV_large,
+	Tree16,
 }
 
 fn get_matching_decoder(encoding: Encoding) -> FrameDecoder {
@@ -208,6 +215,7 @@ fn get_matching_decoder(encoding: Encoding) -> FrameDecoder {
 		// Encoding::CellDiff4HV => todo!(),
 		// Encoding::CellDiff4VH => todo!(),
 		Encoding::CellDiff4VV => dec::cell_diff_4_vertical,
+		Encoding::Tree16 => dec::tree_16,
 	}
 }