Basic fade in/out of gifs

rog-anime/src/data.rs

@@ -1,7 +1,18 @@
+use std::{
+    sync::{
+        atomic::{AtomicBool, Ordering},
+        Arc,
+    },
+    thread::sleep,
+    time::{Duration, Instant},
+};
+
 use serde_derive::{Deserialize, Serialize};
 #[cfg(feature = "dbus")]
 use zvariant_derive::Type;
 
+use crate::{error::AnimeError, AnimTime, AnimeGif};
+
 /// The first 7 bytes of a USB packet are accounted for by `USB_PREFIX1` and `USB_PREFIX2`
 const BLOCK_START: usize = 7;
 /// *Not* inclusive, the byte before this is the final for each "pane"
@@ -79,3 +90,93 @@ impl From<AnimeDataBuffer> for AnimePacketType {
         buffers
     }
 }
+
+/// This runs the animations as a blocking loop by using the `callback` to write data
+pub fn run_animation(
+    frames: &AnimeGif,
+    do_early_return: Arc<AtomicBool>,
+    callback: &dyn Fn(AnimeDataBuffer),
+) -> Result<(), AnimeError> {
+    let mut count = 0;
+    let start = Instant::now();
+
+    let mut timed = false;
+    let mut run_time = frames.total_frame_time();
+    println!("Real gif run length = {:?}", run_time);
+    if let AnimTime::Fade(time) = frames.duration() {
+        if let Some(middle) = time.show_for() {
+            run_time = middle + time.total_fade_time();
+        }
+        timed = true;
+    } else if let AnimTime::Time(time) = frames.duration() {
+        run_time = time;
+        timed = true;
+    }
+
+    // After setting up all the data
+    let mut fade_in = Duration::from_millis(0);
+    let mut fade_out = Duration::from_millis(0);
+    let mut fade_in_step = 0.0;
+    let mut fade_in_accum = 0.0;
+    let mut fade_out_step = 0.0;
+    let mut fade_out_accum;
+    if let AnimTime::Fade(time) = frames.duration() {
+        fade_in = time.fade_in();
+        fade_out = time.fade_out();
+        fade_in_step = 1.0 / fade_in.as_secs_f32();
+        fade_out_step = 1.0 / fade_out.as_secs_f32();
+
+        if time.total_fade_time() > run_time {
+            println!("Total fade in/out time larger than gif run time. Setting fades to half");
+            fade_in = run_time / 2;
+            fade_in_step = 1.0 / (run_time / 2).as_secs_f32();
+
+            fade_out = run_time / 2;
+            fade_out_step = 1.0 / (run_time / 2).as_secs_f32();
+        }
+    }
+
+    'animation: loop {
+        for frame in frames.frames() {
+            let frame_start = Instant::now();
+            if do_early_return.load(Ordering::SeqCst) {
+                return Ok(());
+            }
+            let mut output = frame.frame().clone();
+
+            if let AnimTime::Fade(_) = frames.duration() {
+                if frame_start <= start + fade_in {
+                    for pixel in output.get_mut() {
+                        *pixel = (*pixel as f32 * fade_in_accum) as u8;
+                    }
+                    fade_in_accum = fade_in_step * (frame_start - start).as_secs_f32();
+                } else if frame_start > (start + run_time) - fade_out {
+                    if run_time > (frame_start - start) {
+                        fade_out_accum =
+                            fade_out_step * (run_time - (frame_start - start)).as_secs_f32();
+                    } else {
+                        fade_out_accum = 0.0;
+                    }
+                    for pixel in output.get_mut() {
+                        *pixel = (*pixel as f32 * fade_out_accum) as u8;
+                    }
+                }
+            }
+
+            callback(output);
+
+            if timed && Instant::now().duration_since(start) > run_time {
+                break 'animation;
+            }
+
+            sleep(frame.delay());
+        }
+        if let AnimTime::Count(times) = frames.duration() {
+            count += 1;
+            if count >= times {
+                break 'animation;
+            }
+        }
+    }
+    Ok(())
+}