From ccf290f0703b6c5c9ce6cf56c1b0d93ce968196e Mon Sep 17 00:00:00 2001
From: Spencer Killen <sjkillen@ualberta.ca>
Date: Tue, 2 Jan 2024 10:19:11 -0700
Subject: [PATCH] Adjust

---
 src/lib.rs        | 15 +++++++++------
 tools/src/main.rs | 21 ++++++++++-----------
 2 files changed, 19 insertions(+), 17 deletions(-)

diff --git a/src/lib.rs b/src/lib.rs
index 5a61333..cc9626b 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -51,6 +51,8 @@ pub struct AnimationInfo {
     pub total_points: usize,
     pub start_frame: usize,
     pub end_frame: usize,
+    // MDD file format supports varying FPS , but Blender's exporter does not
+    // FPS is only correct if it's not varying, see individual frame times for more granularity
     pub fps: f32,
 }
 
@@ -206,13 +208,14 @@ impl PointCache for MDDSeekableFile {
         let mut fps: f32 = -1.0;
         let mut prev_frame = frames.next().ok_or(EmptyAnimationError)??;
         let start_frame = prev_frame.frame_idx;
-        if let Some(second_frame) = frames.next() {
-            let second_frame = second_frame?;
-            fps = 1.0 / (second_frame.time - prev_frame.time);
-            prev_frame = second_frame;
-        }
+        // TODO: sometimes the time difference between frames is 0, not sure why
+        // Need to rely on later frames to avoid divide by zero
         for next_frame in frames {
-            prev_frame = next_frame?;
+            let next_frame = next_frame?;
+            if fps < 0.0 && (next_frame.time - prev_frame.time) > 0.0 {
+                fps = 1.0 / (next_frame.time - prev_frame.time);
+            }
+            prev_frame = next_frame;
         }
         let end_frame = prev_frame.frame_idx;
 
diff --git a/tools/src/main.rs b/tools/src/main.rs
index e97e2f6..3e4bdb7 100644
--- a/tools/src/main.rs
+++ b/tools/src/main.rs
@@ -126,7 +126,6 @@ impl PointState {
     }
 }
 
-
 fn main() {
     let basename = std::env::args()
         .nth(1)
@@ -134,11 +133,11 @@ fn main() {
 
     let mdd_filename = basename.clone() + ".mdd";
 
-    let mut mdd_file = File::open(mdd_filename).expect("Mdd filename is not valid");
+    let mdd_file = File::open(mdd_filename).expect("Mdd filename is not valid");
 
-    let (total_frames, total_points) = MDDSeekableFile::read_header(&mut mdd_file).unwrap();
+    let info = MDDSeekableFile::read_animation_info(mdd_file.try_clone().unwrap()).unwrap();
 
-    let mut mask_last: Vec<PointState> = vec![Unseen; total_points as usize];
+    let mut mask_last: Vec<PointState> = vec![Unseen; info.total_points];
     let pc = MDDSeekableFile::read_frames(mdd_file.try_clone().unwrap()).unwrap();
     let mut total_varying = 0;
     for frame in pc {
@@ -168,11 +167,11 @@ fn main() {
     write_mask_image(
         &(basename.clone() + "_mask.exr"),
         &mask,
-        total_points as usize,
+        info.total_points,
     )
     .unwrap();
 
-    let mut pixels: Vec<Point> = Vec::with_capacity(total_varying * (total_frames as usize));
+    let mut pixels: Vec<Point> = Vec::with_capacity(total_varying * (info.total_frames));
 
     let pc = MDDSeekableFile::read_frames(mdd_file.try_clone().unwrap()).unwrap();
     let pc: Vec<_> = pc.collect();
@@ -183,7 +182,7 @@ fn main() {
         .cloned()
         .max()
         .unwrap();
-    assert_eq!(max_point_idx + 1, total_points as usize);
+    assert_eq!(max_point_idx + 1, info.total_points);
 
     let pc = pc.into_iter();
 
@@ -198,7 +197,7 @@ fn main() {
         }
     }));
 
-    assert!(pixels.len() == total_varying * (total_frames as usize));
+    assert!(pixels.len() == total_varying * (info.total_frames));
 
     if total_varying == 0 {
         eprintln!("No varying frames, not outputting .exr image");
@@ -209,13 +208,13 @@ fn main() {
         &(basename + ".exr"),
         &pixels,
         total_varying,
-        total_frames as usize,
+        info.total_frames,
     )
     .unwrap();
 
     println!(
         "Total {} varying points of {} total points",
-        total_varying, total_points
+        total_varying, info.total_points
     );
-    println!()
+    println!("{:?}", info);
 }