perf(rendering): precompute cursor spring for preview/thumbnail

crates/editor/src/thumbnail.rs

@@ -1,6 +1,8 @@
 use crate::{EditorInstance, editor::RendererTransitionInput};
 use cap_project::{ProjectConfiguration, XY};
-use cap_rendering::{ProjectUniforms, RenderedFrame, ZoomTransformTimeline};
+use cap_rendering::{
+    PrecomputedCursorTimeline, ProjectUniforms, RenderedFrame, ZoomTransformTimeline,
+};
 use std::{io::Write, path::Path, sync::Arc};
 
 const THUMBNAIL_SIZE: XY<u32> = XY { x: 640, y: 640 };
@@ -85,7 +87,8 @@ impl EditorInstance {
             segment.recording_clip,
         );
         zoom.ensure_precomputed_until(1.0 / THUMBNAIL_FPS as f32);
-        let uniforms = ProjectUniforms::new(
+        let cursor_timeline = PrecomputedCursorTimeline::from_project(&media.cursor, &project);
+        let uniforms = ProjectUniforms::new_with_precomputed_cursor(
             &self.render_constants,
             &project,
             0,
@@ -95,6 +98,7 @@ impl EditorInstance {
             &frames,
             duration,
             &zoom,
+            &cursor_timeline,
         );
         let frame = self
             .renderer

crates/export/src/preview.rs

@@ -4,8 +4,9 @@ use base64::{Engine, engine::general_purpose::STANDARD};
 use cap_editor::EditorInstance;
 use cap_project::{CursorEvents, ProjectConfiguration, RecordingMeta, TimelineFrameMapping, XY};
 use cap_rendering::{
-    FrameRenderer, ProjectUniforms, RecordingSegmentDecoders, RenderVideoConstants, RenderedFrame,
-    RendererLayers, TransitionRenderInput, ZoomTransformTimeline,
+    FrameRenderer, PrecomputedCursorTimeline, ProjectUniforms, RecordingSegmentDecoders,
+    RenderVideoConstants, RenderedFrame, RendererLayers, TransitionRenderInput,
+    ZoomTransformTimeline,
 };
 use image::{
     Rgba,
@@ -277,7 +278,9 @@ async fn render_preview_frame(
     );
     zoom_timeline.ensure_precomputed_until((frame_number as f32 + 1.0) / settings.fps as f32);
 
-    let uniforms = ProjectUniforms::new(
+    let cursor_timeline =
+        PrecomputedCursorTimeline::from_project(segment_media.cursor, project_config);
+    let uniforms = ProjectUniforms::new_with_precomputed_cursor(
         render_constants,
         project_config,
         frame_number,
@@ -287,6 +290,7 @@ async fn render_preview_frame(
         &segment_frames,
         total_duration,
         &zoom_timeline,
+        &cursor_timeline,
     );
 
     let mut frame_renderer = FrameRenderer::new(render_constants);
@@ -341,7 +345,16 @@ async fn render_preview_frame(
             outgoing.segment.recording_clip,
         );
         outgoing_zoom.ensure_precomputed_until((frame_number as f32 + 1.0) / settings.fps as f32);
-        let outgoing_uniforms = ProjectUniforms::new(
+        let outgoing_cursor_timeline = if outgoing.segment.recording_clip == segment.recording_clip
+        {
+            None
+        } else {
+            Some(PrecomputedCursorTimeline::from_project(
+                outgoing_media.cursor,
+                project_config,
+            ))
+        };
+        let outgoing_uniforms = ProjectUniforms::new_with_precomputed_cursor(
             render_constants,
             project_config,
             frame_number,
@@ -351,6 +364,9 @@ async fn render_preview_frame(
             &outgoing_frames,
             total_duration,
             &outgoing_zoom,
+            outgoing_cursor_timeline
+                .as_ref()
+                .unwrap_or(&cursor_timeline),
         );
 
         frame_renderer