Convert Figma nodes with image fills into Penpot images by exporting the node to png

Signed-off-by: Ryan Breen <rbreen@zmags.com>

package.json

@@ -30,6 +30,7 @@
     "@types/react-dom": "^17.0.9",
     "crypto": "^1.0.1",
     "crypto-browserify": "^3.12.0",
+    "pngjs": "^6.0.0",
     "react": "^17.0.2",
     "react-dev-utils": "^11.0.4",
     "react-dom": "^17.0.2",

src/code.ts

@@ -53,20 +53,22 @@ function traverse(node): NodeData {
   }
 
   if (node.fills && Array.isArray(node.fills)){
-    for (const paint of node.fills) {
-      if (paint.type === 'IMAGE') {
-        // Get the (encoded) bytes for this image.
-        const image = figma.getImageByHash(paint.imageHash);
-        image.getBytesAsync().then((value) => {
+
+    // Find any fill of type image
+    const imageFill = node.fills.find(fill => fill.type === "IMAGE");
+    if (imageFill) {
+      // An "image" in Figma is a shape with one or more image fills, potentially blended with other fill
+      // types.  Given the complexity of mirroring this exactly in Penpot, which treats images as first-class
+      // objects, we're going to simplify this by exporting this shape as a PNG image.
+      node.exportAsync({format: "PNG"}).then((value) => {
         const b64 = figma.base64Encode(value);
         figma.ui.postMessage({type: "IMAGE", data: {
-            imageHash: paint.imageHash,
+          id: node.id,
           value: "data:" + detectMimeType(b64) + ";base64," + b64
         }});
       });
     }
   }
-  }
 
   if (node.type == "TEXT") {
     const styledTextSegments = node.getStyledTextSegments(["fontName", "fontSize", "fontWeight", "lineHeight", "letterSpacing", "fills"]);

src/ui.tsx

@@ -12,12 +12,18 @@ declare function require(path: string): any;
 type PenpotExporterProps = {
 }
 
+type FigmaImageData = {
+  value: string,
+  width: number,
+  height: number
+}
+
 type PenpotExporterState = {
   isDebug: boolean,
   penpotFileData: string
   figmaFileData: string
   figmaRootNode: NodeData
-  images: { [id: string] : string; };
+  images: { [id: string] : FigmaImageData; };
 }
 
 export default class PenpotExporter extends React.Component<PenpotExporterProps, PenpotExporterState> {
@@ -77,6 +83,7 @@ export default class PenpotExporter extends React.Component<PenpotExporterProps,
   }
 
   translateFill(fill, width, height){
+
     if (fill.type === "SOLID"){
       return this.translateSolidFill(fill);
     } else if (fill.type === "GRADIENT_LINEAR"){
@@ -211,17 +218,51 @@ export default class PenpotExporter extends React.Component<PenpotExporterProps,
   }
 
   createPenpotImage(file, node, baseX, baseY, image){
-    file.createImage({ name: node.name, x: node.x + baseX, y: node.y + baseY, width: node.width, height: node.height,
+    file.createImage({ name: node.name, x: node.x + baseX, y: node.y + baseY, width: image.width, height: image.height,
       metadata: {
-        width: node.width,
-        height: node.height
+        width: image.width,
+        height: image.height
       },
-      dataUri: image
+      dataUri: image.value
     });
   }
 
+  calculateAdjustment(node){
+    // For each child, check whether the X or Y position is less than 0 and less than the
+    // current adjustment.
+    let adjustedX = 0;
+    let adjustedY = 0;
+    for (var child of node.children){
+      if (child.x < adjustedX){
+        adjustedX = child.x;
+      }
+      if (child.y < adjustedY){
+        adjustedY = child.y;
+      }
+    }
+    return [adjustedX, adjustedY];
+  }
+
   createPenpotItem(file, node, baseX, baseY){
-    if (node.type == "PAGE"){
+
+    // We special-case images because an image in figma is a shape with one or many
+    // image fills.  Given that handling images in Penpot is a bit different, we
+    // rasterize a figma shape with any image fills to a PNG and then add it as a single
+    // Penpot image.  Implication is that any node that has an image fill will only be
+    // treated as an image, so we skip node type checks.
+    const hasImageFill = node.fills?.some(fill => fill.type === "IMAGE");
+    if (hasImageFill){
+
+      // If the nested frames extended the bounds of the rasterized image, we need to
+      // account for this both in position on the canvas and the calculated width and
+      // height of the image.
+      const [adjustedX, adjustedY] = this.calculateAdjustment(node);
+      const width = node.width + Math.abs(adjustedX);
+      const height = node.height + Math.abs(adjustedY);
+
+      this.createPenpotImage(file, node, baseX + adjustedX, baseY + adjustedY, this.state.images[node.id]);
+    }
+    else if (node.type == "PAGE"){
       this.createPenpotPage(file, node);
     }
     else if (node.type == "FRAME"){
@@ -231,14 +272,8 @@ export default class PenpotExporter extends React.Component<PenpotExporterProps,
       this.createPenpotGroup(file, node,baseX, baseY);
     }
     else if (node.type == "RECTANGLE"){
-      // Find a fill of type IMAGE (note, a Figma node can have only one IMAGE fill)
-      const imageFill = node.fills.find((fill) => fill.type === "IMAGE");
-      if (imageFill){
-        this.createPenpotImage(file, node, baseX, baseY, this.state.images[imageFill.imageHash]);
-      } else {
       this.createPenpotRectangle(file, node, baseX, baseY);
     }
-    }
     else if (node.type == "ELLIPSE"){
       this.createPenpotCircle(file, node, baseX, baseY);
     }
@@ -274,13 +309,26 @@ export default class PenpotExporter extends React.Component<PenpotExporterProps,
         figmaRootNode: event.data.pluginMessage.data}));
     }
     else if (event.data.pluginMessage.type == "IMAGE") {
+
       const data = event.data.pluginMessage.data;
-      this.setState(state =>
+      const image = document.createElement('img');
+      const thisObj = this;
+
+      image.addEventListener('load', function() {
+        // Get byte array from response
+        thisObj.setState(state =>
             {
-          state.images[data.imageHash] = data.value;
+              state.images[data.id] = {
+                value: data.value,
+                width: image.naturalWidth,
+                height: image.naturalHeight
+              };
               return state;
             }
-      ) ;
+        );
+      });
+      image.src = data.value;
+
     }
   }