From 9d2a730e40da333e91a342cf171a5bfca331edce Mon Sep 17 00:00:00 2001
From: itsjunetime <junewelker@gmail.com>
Date: Wed, 19 Feb 2025 15:24:27 -0700
Subject: [PATCH] Implement inverting colors

---
 CHANGELOG.md    |  1 +
 Cargo.lock      | 30 ++++++++++++++++++++++++++++++
 src/main.rs     |  1 +
 src/renderer.rs | 16 +++++++++++++++-
 src/tui.rs      |  4 +++-
 5 files changed, 50 insertions(+), 2 deletions(-)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index 0ce2cb5..58c3425 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -3,6 +3,7 @@
 - Update ratatui(-image) dependencies
 - Enable Ctrl+Z/Suspend functionality
 - Rewrite with mupdf as the backend for much better performance and rendering quality
+- Support easy inversion of colors via `i` keypress
 
 # v0.2.0
 
diff --git a/Cargo.lock b/Cargo.lock
index fb720d2..50d8266 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -889,6 +889,15 @@ version = "2.3.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "37909eebbb50d72f9059c3b6d82c0463f2ff062c9e95845c43a6c9c0355411be"
 
+[[package]]
+name = "fdeflate"
+version = "0.3.7"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "1e6853b52649d4ac5c0bd02320cddc5ba956bdb407c4b75a2c6b75bf51500f8c"
+dependencies = [
+ "simd-adler32",
+]
+
 [[package]]
 name = "filedescriptor"
 version = "0.8.3"
@@ -1344,6 +1353,7 @@ dependencies = [
  "bytemuck",
  "byteorder-lite",
  "num-traits",
+ "png",
  "ravif",
  "rayon",
  "zune-core",
@@ -1719,6 +1729,7 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "b3b1c9bd4fe1f0f8b387f6eb9eb3b4a1aa26185e5750efb9140301703f62cd1b"
 dependencies = [
  "adler2",
+ "simd-adler32",
 ]
 
 [[package]]
@@ -2181,6 +2192,19 @@ dependencies = [
  "plotters-backend",
 ]
 
+[[package]]
+name = "png"
+version = "0.17.16"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "82151a2fc869e011c153adc57cf2789ccb8d9906ce52c0b39a6b5697749d7526"
+dependencies = [
+ "bitflags 1.3.2",
+ "crc32fast",
+ "fdeflate",
+ "flate2",
+ "miniz_oxide",
+]
+
 [[package]]
 name = "powerfmt"
 version = "0.2.0"
@@ -2718,6 +2742,12 @@ dependencies = [
  "libc",
 ]
 
+[[package]]
+name = "simd-adler32"
+version = "0.3.7"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "d66dc143e6b11c1eddc06d5c423cfc97062865baf299914ab64caa38182078fe"
+
 [[package]]
 name = "simd_helpers"
 version = "0.1.0"
diff --git a/src/main.rs b/src/main.rs
index f8fb145..805cabd 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -191,6 +191,7 @@ async fn main() -> Result<(), Box<dyn std::error::Error>> {
 							to_converter.send(ConverterMsg::GoToPage(page))?;
 						},
 						InputAction::Search(term) => tui_tx.send(RenderNotif::Search(term))?,
+						InputAction::Invert => tui_tx.send(RenderNotif::Invert)?
 					}
 				}
 			},
diff --git a/src/renderer.rs b/src/renderer.rs
index 0c6e6cc..df17f65 100644
--- a/src/renderer.rs
+++ b/src/renderer.rs
@@ -10,7 +10,8 @@ pub enum RenderNotif {
 	Area(Rect),
 	JumpToPage(usize),
 	Search(String),
-	Reload
+	Reload,
+	Invert
 }
 
 #[derive(Debug)]
@@ -90,6 +91,7 @@ pub fn start_rendering(
 	let col_h = size.height / size.rows;
 
 	let mut stored_doc = None;
+	let mut invert = false;
 
 	'reload: loop {
 		let doc = match Document::open(path) {
@@ -154,6 +156,13 @@ pub fn start_rendering(
 				($notif:ident) => {
 					match $notif {
 						RenderNotif::Reload => continue 'reload,
+						RenderNotif::Invert => {
+							invert = !invert;
+							for page in &mut rendered {
+								page.successful = false;
+							}
+							continue 'render_pages;
+						}
 						RenderNotif::Area(new_area) => {
 							let bigger =
 								new_area.width > area.width || new_area.height > area.height;
@@ -252,6 +261,7 @@ pub fn start_rendering(
 					&page,
 					search_term.as_deref(),
 					rendered_with_no_results,
+					invert,
 					(area_w, area_h)
 				) {
 					// If we've already rendered it just fine and we don't need to render it again,
@@ -319,6 +329,7 @@ fn render_single_page_to_ctx(
 	page: &Page,
 	search_term: Option<&str>,
 	already_rendered_no_results: bool,
+	invert: bool,
 	(area_w, area_h): (f32, f32)
 ) -> Result<Option<RenderedContext>, mupdf::error::Error> {
 	let mut max_hits = 10;
@@ -378,6 +389,9 @@ fn render_single_page_to_ctx(
 	let matrix = Matrix::new_scale(scale_factor, scale_factor);
 
 	let mut pixmap = page.to_pixmap(&matrix, &colorspace, 0.0, false)?;
+	if invert {
+		pixmap.invert()?;
+	}
 
 	let (x_res, y_res) = pixmap.resolution();
 	let new_x = (x_res as f32 * scale_factor) as i32;
diff --git a/src/tui.rs b/src/tui.rs
index 08ad556..8dcfdfb 100644
--- a/src/tui.rs
+++ b/src/tui.rs
@@ -414,6 +414,7 @@ impl Tui {
 								)));
 								Some(InputAction::Redraw)
 							}
+							'i' => Some(InputAction::Invert),
 							'n' if self.page < self.rendered.len() - 1 => {
 								// TODO: If we can't find one, then maybe like block until we've verified
 								// all the pages have been checked?
@@ -604,7 +605,8 @@ pub enum InputAction {
 	Redraw,
 	JumpingToPage(usize),
 	Search(String),
-	QuitApp
+	QuitApp,
+	Invert
 }
 
 #[derive(Copy, Clone)]