From 7c5207d2d36faf106e6a160c4ea559c2b3042ee4 Mon Sep 17 00:00:00 2001
From: Myriad-Dreamin <35292584+Myriad-Dreamin@users.noreply.github.com>
Date: Sat, 11 Nov 2023 12:31:02 +0800
Subject: [PATCH] dev(pkg::core): render optional canvas body (#405)

* dev: remove console_log

* dev: optional rendering body

* dev: edit warning
---
 packages/renderer/src/render/canvas.rs   | 41 ++++++++++++------------
 packages/typst.ts/src/options.render.mts |  2 +-
 packages/typst.ts/src/renderer.mts       | 11 ++++++-
 3 files changed, 31 insertions(+), 23 deletions(-)

diff --git a/packages/renderer/src/render/canvas.rs b/packages/renderer/src/render/canvas.rs
index fb859457..131789ad 100644
--- a/packages/renderer/src/render/canvas.rs
+++ b/packages/renderer/src/render/canvas.rs
@@ -29,7 +29,7 @@ impl TypstRenderer {
     pub async fn render_page_to_canvas(
         &mut self,
         ses: &RenderSession,
-        canvas: &web_sys::CanvasRenderingContext2d,
+        canvas: Option<web_sys::CanvasRenderingContext2d>,
         options: Option<RenderPageImageOptions>,
     ) -> ZResult<JsValue> {
         let (fingerprint, text_content, annotation_list, ..) = self
@@ -53,7 +53,7 @@ impl TypstRenderer {
     pub async fn render_page_to_canvas_internal<Feat: ExportFeature>(
         &mut self,
         ses: &RenderSession,
-        canvas: &web_sys::CanvasRenderingContext2d,
+        canvas: Option<web_sys::CanvasRenderingContext2d>,
         options: Option<RenderPageImageOptions>,
     ) -> ZResult<(Fingerprint, JsValue, JsValue, Option<HashMap<String, f64>>)> {
         let rect_lo_x: f32 = -1.;
@@ -69,16 +69,13 @@ impl TypstRenderer {
         let mut client = ses.canvas_kern.lock().unwrap();
         client.set_pixel_per_pt(ses.pixel_per_pt.unwrap_or(3.));
         client.set_fill(ses.background_color.as_deref().unwrap_or("ffffff").into());
-        // console_log!(
-        //     "background_color: {:?}",
-        //     ses.background_color.as_deref().unwrap_or("ffffff")
-        // );
 
         let data_selection = options
             .as_ref()
             .and_then(|o| o.data_selection)
             .unwrap_or(u32::MAX);
 
+        let should_render_body = (data_selection & (1 << 0)) != 0;
         let mut tc = ((data_selection & (1 << 1)) != 0).then(TextContent::default);
         let mut annotations = ((data_selection & (1 << 2)) != 0).then(AnnotationList::default);
 
@@ -124,20 +121,22 @@ impl TypstRenderer {
             page_off = None;
         }
 
-        let cached = options
-            .and_then(|o| o.cache_key)
-            .map(|c| c == fingerprint.as_svg_id("c"))
-            .unwrap_or(false);
-
-        console_log!("cached: {}", cached);
-
-        if !cached {
-            if let Some(page_off) = page_off {
-                client
-                    .render_page_in_window(&mut kern, canvas, page_off, rect)
-                    .await?;
-            } else {
-                client.render_in_window(&mut kern, canvas, rect).await;
+        if should_render_body {
+            let cached = options
+                .and_then(|o| o.cache_key)
+                .map(|c| c == fingerprint.as_svg_id("c"))
+                .unwrap_or(false);
+
+            let canvas = &canvas.ok_or_else(|| error_once!("Renderer.MissingCanvasForBody"))?;
+
+            if !cached {
+                if let Some(page_off) = page_off {
+                    client
+                        .render_page_in_window(&mut kern, canvas, page_off, rect)
+                        .await?;
+                } else {
+                    client.render_in_window(&mut kern, canvas, rect).await;
+                }
             }
         }
 
@@ -295,7 +294,7 @@ mod tests {
             let prepare = performance.now();
 
             let (_fingerprint, res, _, perf_events) = renderer
-                .render_page_to_canvas_internal::<CIRenderFeature>(&session, &context, None)
+                .render_page_to_canvas_internal::<CIRenderFeature>(&session, Some(context), None)
                 .await
                 .unwrap();
             let end = performance.now();
diff --git a/packages/typst.ts/src/options.render.mts b/packages/typst.ts/src/options.render.mts
index 49293e93..1c5776f5 100644
--- a/packages/typst.ts/src/options.render.mts
+++ b/packages/typst.ts/src/options.render.mts
@@ -115,7 +115,7 @@ export interface ManipulateDataOptions {
  * @property {number} page_off - The page offset to render.
  */
 export class RenderCanvasOptions {
-  canvas: CanvasRenderingContext2D;
+  canvas?: CanvasRenderingContext2D;
 
   /**
    * The page offset to render.
diff --git a/packages/typst.ts/src/renderer.mts b/packages/typst.ts/src/renderer.mts
index 665d130c..38b776f0 100644
--- a/packages/typst.ts/src/renderer.mts
+++ b/packages/typst.ts/src/renderer.mts
@@ -507,6 +507,8 @@ function randstr(prefix?: string): string {
     .replace('0.', prefix || '');
 }
 
+let warnOnceCanvasSet = true;
+
 class TypstRendererDriver {
   renderer: typst.TypstRenderer;
   rendererJs: typeof typst;
@@ -558,6 +560,9 @@ class TypstRendererDriver {
         let encoded = 0;
         if (options.dataSelection.body) {
           encoded |= 1 << 0;
+        } else if (options.canvas && warnOnceCanvasSet) {
+          warnOnceCanvasSet = false;
+          console.warn('dataSelection.body is not set but providing canvas for body');
         }
         if (options.dataSelection.text) {
           encoded |= 1 << 1;
@@ -567,7 +572,11 @@ class TypstRendererDriver {
         }
         rustOptions.data_selection = encoded;
       }
-      return this.renderer.render_page_to_canvas(sessionRef[kObject], options.canvas, rustOptions);
+      return this.renderer.render_page_to_canvas(
+        sessionRef[kObject],
+        options.canvas || undefined,
+        rustOptions,
+      );
     });
   }