Prepare for user saving of anime sequences

rog-anime/src/anime_gif.rs

@@ -0,0 +1,61 @@
+use serde_derive::{Deserialize, Serialize};
+use std::{fs::File, path::{Path}, time::Duration};
+
+use crate::{error::AnimeError, AniMeDataBuffer, AniMeDiagonal};
+
+#[derive(Debug, Clone, Deserialize, Serialize)]
+pub struct AniMeFrame {
+    data: AniMeDataBuffer,
+    delay: Duration,
+}
+
+impl AniMeFrame {
+    pub fn frame(&self) -> &AniMeDataBuffer {
+        &self.data
+    }
+
+    pub fn delay(&self) -> Duration {
+        self.delay
+    }
+}
+
+#[derive(Debug, Clone, Deserialize, Serialize)]
+pub struct AniMeGif(Vec<AniMeFrame>);
+
+impl AniMeGif {
+    pub fn new(file_name: &Path, brightness: f32) -> Result<Self, AnimeError> {
+        let mut frames = Vec::new();
+        let mut matrix = AniMeDiagonal::new();
+
+        let mut decoder = gif::DecodeOptions::new();
+        // Configure the decoder such that it will expand the image to RGBA.
+        decoder.set_color_output(gif::ColorOutput::RGBA);
+        // Read the file header
+        let file = File::open(file_name)?;
+        let mut decoder = decoder.read_info(file)?;
+
+        while let Some(frame) = decoder.read_next_frame()? {
+            let wait = frame.delay * 10;
+            for (y, row) in frame.buffer.chunks(frame.width as usize * 4).enumerate() {
+                for (x, px) in row.chunks(4).enumerate() {
+                    if px[3] != 255 {
+                        // should be t but not in some gifs? What, ASUS, what?
+                        continue;
+                    }
+                    matrix.get_mut()[y + frame.top as usize][x + frame.left as usize] =
+                        (px[0] as f32 * brightness) as u8;
+                }
+            }
+
+            frames.push(AniMeFrame {
+                data: <AniMeDataBuffer>::from(&matrix),
+                delay: Duration::from_millis(wait as u64),
+            });
+        }
+        Ok(Self(frames))
+    }
+
+    pub fn frames(&self) -> &[AniMeFrame] {
+        &self.0
+    }
+}