From 242724d7fd2053acc76959846828d8e59f959615 Mon Sep 17 00:00:00 2001
From: CrispyPin <crispin@tasa.se>
Date: Fri, 12 Apr 2024 17:43:49 +0200
Subject: [PATCH] switch 8x8 cell diff to vertical

---
 .gitignore          |  3 +++
 encoder/src/dec.rs  | 20 ++++++--------------
 encoder/src/enc.rs  | 23 +++++++++++++++--------
 encoder/src/main.rs | 10 +++++-----
 4 files changed, 29 insertions(+), 27 deletions(-)

diff --git a/.gitignore b/.gitignore
index 93108d3..ba51260 100644
--- a/.gitignore
+++ b/.gitignore
@@ -5,3 +5,6 @@
 *.map
 *.pdf
 target/
+*.png
+*.mp4
+*.webm
diff --git a/encoder/src/dec.rs b/encoder/src/dec.rs
index cca9602..244c3ea 100644
--- a/encoder/src/dec.rs
+++ b/encoder/src/dec.rs
@@ -1,6 +1,6 @@
 use crate::*;
 
-pub fn cell_diff_8_horizontal(prev_frame: &Frame, encoded: &[u8], reader: &mut usize) -> Frame {
+pub fn cell_diff_8_vertical(prev_frame: &Frame, encoded: &[u8], reader: &mut usize) -> Frame {
 	let bitmap = {
 		*reader += 3;
 		let mut bitmap = (encoded[0] as u32) << 16;
@@ -15,23 +15,15 @@ pub fn cell_diff_8_horizontal(prev_frame: &Frame, encoded: &[u8], reader: &mut u
 	*reader += runs;
 
 	let cells_x = WIDTH / 8;
-	let cells_y = HEIGHT / 8;
 	let mut index = 0;
 
-	for celly in 0..cells_y {
-		for cellx in 0..cells_x {
+	for x in 0..WIDTH {
+		for y in 0..HEIGHT {
+			let cellx = x / 8;
+			let celly = y / 8;
 			let is_changed = (bitmap >> (cellx + cells_x * celly)) & 1;
 			if is_changed == 1 {
-				let pixels = &new_pixels[(index * 8 * 8)..((index + 1) * 8 * 8)];
-				let mut i = 0;
-				for dx in 0..8 {
-					for dy in 0..8 {
-						let x = cellx * 8 + dx;
-						let y = celly * 8 + dy;
-						frame[x][y] = pixels[i];
-						i += 1;
-					}
-				}
+				frame[x][y] = new_pixels[index];
 				index += 1;
 			}
 		}
diff --git a/encoder/src/enc.rs b/encoder/src/enc.rs
index 2c29754..c45caea 100644
--- a/encoder/src/enc.rs
+++ b/encoder/src/enc.rs
@@ -1,6 +1,6 @@
 use crate::*;
 
-pub fn cell_diff_8_horizontal(prev_frame: &Frame, frame: &Frame) -> EncodedFrame {
+pub fn cell_diff_8_vertical(prev_frame: &Frame, frame: &Frame) -> EncodedFrame {
 	let cells_x = WIDTH / 8;
 	let cells_y = HEIGHT / 8;
 	let loss = 0;
@@ -8,17 +8,15 @@ pub fn cell_diff_8_horizontal(prev_frame: &Frame, frame: &Frame) -> EncodedFrame
 	let mut bitmap: u32 = 0;
 	let mut changed_pixels = Vec::new();
 
-	for celly in 0..cells_y {
-		for cellx in 0..cells_x {
+	for cellx in 0..cells_x {
+		for celly in 0..cells_y {
 			let mut changed = 0;
-			let mut cell_contents = Vec::new();
-			// todo try encoding the cells in frame space instead of one cell at a time
 			for dx in 0..8 {
 				for dy in 0..8 {
 					let x = cellx * 8 + dx;
 					let y = celly * 8 + dy;
 					let pixel = frame[x][y];
-					cell_contents.push(pixel);
+
 					if pixel != prev_frame[x][y] {
 						changed += 1;
 					}
@@ -26,14 +24,23 @@ pub fn cell_diff_8_horizontal(prev_frame: &Frame, frame: &Frame) -> EncodedFrame
 			}
 			if changed > loss {
 				bitmap |= 1 << (cellx + cells_x * celly);
-				changed_pixels.extend_from_slice(&cell_contents);
+			}
+		}
+	}
+	for x in 0..WIDTH {
+		for y in 0..HEIGHT {
+			let cellx = x / 8;
+			let celly = y / 8;
+			let bit = 1 << (cellx + cells_x * celly);
+			if (bitmap & bit) != 0 {
+				changed_pixels.push(frame[x][y]);
 			}
 		}
 	}
 	let mut data = vec![(bitmap >> 16) as u8, (bitmap >> 8) as u8, bitmap as u8];
 	data.extend_from_slice(&rle_255_encode(&changed_pixels));
 	EncodedFrame {
-		encoding: Encoding::CellDiff8H,
+		encoding: Encoding::CellDiff8V,
 		data,
 	}
 }
diff --git a/encoder/src/main.rs b/encoder/src/main.rs
index 60e9e52..4eb64bc 100644
--- a/encoder/src/main.rs
+++ b/encoder/src/main.rs
@@ -57,7 +57,7 @@ fn encode(frames: &[Frame]) -> Vec<u8> {
 		enc::rle_diff_horizontal,
 		enc::rle_diff_vertical,
 		enc::bg_strips_horizontal,
-		enc::cell_diff_8_horizontal,
+		enc::cell_diff_8_vertical,
 	];
 
 	let mut last_frame = FRAME_0;
@@ -109,8 +109,8 @@ enum Encoding {
 	// BGStripsV,
 	// QuadTree,
 	// DrawCommands,
-	CellDiff8H,
-	// CellDiff8V,
+	// CellDiff8H,
+	CellDiff8V,
 	// CellDiff4HH,
 	// CellDiff4HV,
 	// CellDiff4VH,
@@ -129,8 +129,8 @@ fn get_matching_decoder(encoding: Encoding) -> FrameDecoder {
 		// Encoding::BGStripsV => todo!(),
 		// Encoding::QuadTree => todo!(),
 		// Encoding::DrawCommands => todo!(),
-		Encoding::CellDiff8H => dec::cell_diff_8_horizontal,
-		// Encoding::CellDiff8V => todo!(),
+		// Encoding::CellDiff8H => todo!(),
+		Encoding::CellDiff8V => dec::cell_diff_8_vertical,
 		// Encoding::CellDiff4HH => todo!(),
 		// Encoding::CellDiff4HV => todo!(),
 		// Encoding::CellDiff4VH => todo!(),