Refactored + Renamed + Added Docs

4 files changed, 239 insertions, 0 deletions

diff --git a/src/display/components.rs b/src/display/components.rs
new file mode 100644
index 0000000..4459325
--- /dev/null
+++ b/src/display/components.rs
@@ -0,0 +1,72 @@
+use bevy::{prelude::*, render::render_resource::{Extent3d, TextureDescriptor, TextureDimension, TextureFormat, TextureUsages}};
+use bevy_dither_post_process::components::DitherPostProcessSettings;
+use bevy_framebuffer_extract::{components::{ExtractFramebufferBundle, FramebufferExtractDestination}, render_assets::FramebufferExtractSource};
+
+/// Marker component for terminal display
+#[derive(Component)]
+pub struct TerminalDisplay;
+
+/// Bundle for terminal display, contains a handle to an image to be used as a render target to
+/// render to the terminal
+#[derive(Bundle)]
+pub struct TerminalDisplayBundle {
+    _terminal_display: TerminalDisplay,
+    extract_framebuffer_bundle: ExtractFramebufferBundle,
+    dither_post_process_settings: DitherPostProcessSettings,
+    image_handle: Handle<Image>,
+}
+
+impl TerminalDisplayBundle {
+    /// Create a new terminal display with the given dither level. A higher level exponentially
+    /// increases the size of the bayer matrix used in the ordered dithering calculations. If in
+    /// doubt, 3 is a good starting value to test with.
+    pub fn new(dither_level: u32, asset_server: &AssetServer) -> Self {
+        let terminal_size = crossterm::terminal::size().unwrap();
+        let size = Extent3d {
+            width: (terminal_size.0 as u32) * 2,
+            height: (terminal_size.1 as u32) * 4,
+            depth_or_array_layers: 1,
+        };
+
+        let mut image = Image {
+            texture_descriptor: TextureDescriptor {
+                label: None,
+                size,
+                dimension: TextureDimension::D2,
+                format: TextureFormat::R8Unorm,
+                mip_level_count: 1,
+                sample_count: 1,
+                usage: TextureUsages::TEXTURE_BINDING
+                    | TextureUsages::COPY_SRC
+                    | TextureUsages::RENDER_ATTACHMENT,
+                view_formats: &[],
+            },
+            ..default()
+        };
+
+        image.resize(size);
+        let image_handle = asset_server.add(image);
+
+        let framebuffer_extract_source =
+            asset_server.add(FramebufferExtractSource(image_handle.clone()));
+
+        Self {
+            _terminal_display: TerminalDisplay,
+            extract_framebuffer_bundle: ExtractFramebufferBundle {
+                source: framebuffer_extract_source,
+                dest: FramebufferExtractDestination::default(),
+            },
+            image_handle,
+            dither_post_process_settings: DitherPostProcessSettings::new(
+                dither_level,
+                asset_server,
+            ),
+        }
+    }
+
+    /// Retrieves the handle to this display's target image. Anything written here will be
+    /// displayed.
+    pub fn image_handle(&self) -> Handle<Image> {
+        self.image_handle.clone()
+    }
+}
diff --git a/src/display/mod.rs b/src/display/mod.rs
new file mode 100644
index 0000000..ae45445
--- /dev/null
+++ b/src/display/mod.rs
@@ -0,0 +1,8 @@
+/// Components for this module
+pub mod components;
+
+/// Resources for this module
+pub mod resources;
+
+/// Systems for this module
+pub(crate) mod systems;
diff --git a/src/display/resources.rs b/src/display/resources.rs
new file mode 100644
index 0000000..7321aea
--- /dev/null
+++ b/src/display/resources.rs
@@ -0,0 +1,43 @@
+use std::io::{stdout, Stdout};
+
+use bevy::prelude::*;
+use crossterm::{
+    event::{
+        DisableMouseCapture, EnableMouseCapture, KeyboardEnhancementFlags,
+        PopKeyboardEnhancementFlags, PushKeyboardEnhancementFlags,
+    },
+    terminal::{disable_raw_mode, enable_raw_mode, EnterAlternateScreen, LeaveAlternateScreen},
+    ExecutableCommand,
+};
+use ratatui::backend::CrosstermBackend;
+
+/// Ratatui terminal instance. Enters alternate screen when constructed, and exits once dropped.
+#[derive(Resource)]
+pub struct Terminal(pub ratatui::Terminal<CrosstermBackend<Stdout>>);
+
+impl Default for Terminal {
+    fn default() -> Self {
+        stdout().execute(EnterAlternateScreen).unwrap();
+        stdout().execute(EnableMouseCapture).unwrap();
+        stdout()
+            .execute(PushKeyboardEnhancementFlags(
+                KeyboardEnhancementFlags::REPORT_EVENT_TYPES,
+            ))
+            .unwrap();
+        enable_raw_mode().unwrap();
+        let mut terminal = ratatui::Terminal::new(CrosstermBackend::new(stdout()))
+            .expect("Failed to create terminal");
+        terminal.clear().expect("Failed to clear terminal");
+        Self(terminal)
+    }
+}
+
+impl Drop for Terminal {
+    fn drop(&mut self) {
+        let mut stdout = stdout();
+        let _ = stdout.execute(PopKeyboardEnhancementFlags);
+        let _ = stdout.execute(DisableMouseCapture);
+        let _ = stdout.execute(LeaveAlternateScreen);
+        let _ = disable_raw_mode();
+    }
+}
diff --git a/src/display/systems.rs b/src/display/systems.rs
new file mode 100644
index 0000000..a768af5
--- /dev/null
+++ b/src/display/systems.rs
@@ -0,0 +1,116 @@
+use bevy::{
+    prelude::*,
+    render::render_resource::{Extent3d, TextureFormat},
+};
+use crossterm::event::Event;
+use bevy_framebuffer_extract::{
+    components::FramebufferExtractDestination, render_assets::FramebufferExtractSource,
+};
+use ratatui::{
+    style::Stylize,
+    widgets::{Paragraph, Wrap},
+};
+
+use crate::input::events::TerminalInputEvent;
+
+use super::resources::Terminal;
+
+const BRAILLE_CODE_MIN: u16 = 0x2800;
+const BRAILLE_CODE_MAX: u16 = 0x28FF;
+
+/// 0 3
+/// 1 4
+/// 2 5
+/// 6 7
+const BRAILLE_DOT_BIT_POSITIONS: [u8; 8] = [0, 1, 2, 6, 3, 4, 5, 7];
+
+/// Prints out the contents of a render image to the terminal as braille characters
+pub fn print_to_terminal(
+    mut terminal: ResMut<Terminal>,
+    image_exports: Query<&FramebufferExtractDestination>,
+) {
+    for image_export in image_exports.iter() {
+        let mut image = image_export
+            .0
+            .lock()
+            .expect("Failed to get lock on output texture");
+        if image.texture_descriptor.format != TextureFormat::R8Unorm {
+            warn_once!("Extracted framebuffer texture is not R8Unorm format. Will attempt conversion, but consider changing your render texture's format.");
+            info_once!("{:?}", image);
+            match image.convert(TextureFormat::R8Unorm) {
+                Some(img) => *image = img,
+                None => error_once!(
+                    "Could not convert to R8Unorm texture format. Unexpected output may occur."
+                ),
+            };
+        }
+
+        let mut output_buffer = Vec::<char>::new();
+        let width = image.width();
+        let height = image.height();
+        let data = &image.data;
+        for character_y in (0..height).step_by(4) {
+            for character_x in (0..width).step_by(2) {
+                let mut mask: u8 = 0;
+                for offset_x in 0..2 {
+                    for offset_y in 0..4 {
+                        let x = character_x + offset_x;
+                        let y = character_y + offset_y;
+                        if x < width && y < height && data[(y * width + x) as usize] == 0xFF {
+                            mask |= 1
+                                << (BRAILLE_DOT_BIT_POSITIONS[(offset_x * 4 + offset_y) as usize]);
+                        }
+                    }
+                }
+                output_buffer.push(braille_char(mask));
+            }
+        }
+
+        let string = output_buffer.into_iter().collect::<String>();
+        terminal
+            .0
+            .draw(|frame| {
+                frame.render_widget(
+                    Paragraph::new(string)
+                        .white()
+                        .bold()
+                        .wrap(Wrap { trim: true }),
+                    frame.size(),
+                );
+            })
+            .expect("Failed to draw terminal frame");
+    }
+}
+
+/// Utility function to convert a u8 into the corresponding braille character
+fn braille_char(mask: u8) -> char {
+    match char::from_u32((BRAILLE_CODE_MIN + mask as u16) as u32) {
+        Some(character) => {
+            if character as u16 > BRAILLE_CODE_MAX {
+                panic!("Number too big!")
+            }
+            character
+        }
+        None => panic!("Error converting character!"),
+    }
+}
+
+/// Watches for terminal resize events and resizes the render image accordingly
+pub fn resize_handling(
+    mut images: ResMut<Assets<Image>>,
+    mut sources: ResMut<Assets<FramebufferExtractSource>>,
+    mut event_reader: EventReader<TerminalInputEvent>,
+) {
+    for event in event_reader.read() {
+        if let Event::Resize(w, h) = event.0 {
+            for source in sources.iter_mut() {
+                let image = images.get_mut(&source.1 .0).unwrap();
+                image.resize(Extent3d {
+                    width: w as u32 * 2,
+                    height: h as u32 * 4,
+                    depth_or_array_layers: 1,
+                });
+            }
+        }
+    }
+}