Save bitmap selection (#569)

src/containers/paint-editor.jsx

@@ -15,7 +15,7 @@ import {setTextEditTarget} from '../reducers/text-edit-target';
 import {updateViewBounds} from '../reducers/view-bounds';
 
 import {getRaster, hideGuideLayers, showGuideLayers} from '../helper/layer';
-import {convertToBitmap, convertToVector, getHitBounds} from '../helper/bitmap';
+import {commitSelectionToBitmap, convertToBitmap, convertToVector, getHitBounds} from '../helper/bitmap';
 import {performUndo, performRedo, performSnapshot, shouldShowUndo, shouldShowRedo} from '../helper/undo';
 import {bringToFront, sendBackward, sendToBack, bringForward} from '../helper/order';
 import {groupSelection, ungroupSelection} from '../helper/group';
@@ -39,6 +39,8 @@ class PaintEditor extends React.Component {
         super(props);
         bindAll(this, [
             'handleUpdateImage',
+            'handleUpdateBitmap',
+            'handleUpdateVector',
             'handleUndo',
             'handleRedo',
             'handleSendBackward',
@@ -186,13 +188,44 @@ class PaintEditor extends React.Component {
             actualFormat = BitmapModes[this.props.mode] ? Formats.BITMAP : Formats.VECTOR;
         }
         if (isBitmap(actualFormat)) {
-            const rect = getHitBounds(getRaster());
+            this.handleUpdateBitmap(skipSnapshot);
+        } else if (isVector(actualFormat)) {
+            this.handleUpdateVector(skipSnapshot);
+        }
+    }
+    handleUpdateBitmap (skipSnapshot) {
+        if (!getRaster().loaded) {
+            // In general, callers of updateImage should wait for getRaster().loaded = true before
+            // calling updateImage.
+            // However, this may happen if the user is rapidly undoing/redoing. In this case it's safe
+            // to skip the update.
+            log.warn('Bitmap layer should be loaded before calling updateImage.');
+            return;
+        }
+        // Plaster the selection onto the raster layer before exporting, if there is a selection.
+        const plasteredRaster = getRaster().getSubRaster(getRaster().bounds);
+        plasteredRaster.remove(); // Don't insert
+        const selectedItems = getSelectedLeafItems();
+        if (selectedItems.length === 1 && selectedItems[0] instanceof paper.Raster) {
+            if (!selectedItems[0].loaded ||
+                (selectedItems[0].data && selectedItems[0].data.expanded && !selectedItems[0].data.expanded.loaded)) {
+                log.warn('Bitmap layer should be loaded before calling updateImage.');
+                return;
+            }
+            commitSelectionToBitmap(selectedItems[0], plasteredRaster);
+        }
+        const rect = getHitBounds(plasteredRaster);
         this.props.onUpdateImage(
             false /* isVector */,
-                getRaster().getImageData(rect),
+            plasteredRaster.getImageData(rect),
             (ART_BOARD_WIDTH / 2) - rect.x,
             (ART_BOARD_HEIGHT / 2) - rect.y);
-        } else if (isVector(actualFormat)) {
+
+        if (!skipSnapshot) {
+            performSnapshot(this.props.undoSnapshot, Formats.BITMAP);
+        }
+    }
+    handleUpdateVector (skipSnapshot) {
         const guideLayers = hideGuideLayers(true /* includeRaster */);
 
         // Export at 0.5x
@@ -212,10 +245,9 @@ class PaintEditor extends React.Component {
         paper.project.activeLayer.applyMatrix = true;
 
         showGuideLayers(guideLayers);
-        }
 
         if (!skipSnapshot) {
-            performSnapshot(this.props.undoSnapshot, actualFormat);
+            performSnapshot(this.props.undoSnapshot, Formats.VECTOR);
         }
     }
     handleUndo () {

src/helper/bit-tools/select-tool.js

@@ -1,8 +1,8 @@
 import paper from '@scratch/paper';
 import Modes from '../../lib/modes';
 
-import {createCanvas, getRaster} from '../layer';
+import {getRaster} from '../layer';
-import {fillRect, scaleBitmap} from '../bitmap';
+import {commitSelectionToBitmap} from '../bitmap';
 
 import BoundingBoxTool from '../selection-tools/bounding-box-tool';
 import NudgeTool from '../selection-tools/nudge-tool';
@@ -117,57 +117,10 @@ class SelectTool extends paper.Tool {
     commitSelection () {
         if (!this.selection || !this.selection.parent) return;
 
-        this.maybeApplyScaleToCanvas(this.selection);
+        commitSelectionToBitmap(this.selection, getRaster());
-        this.commitArbitraryTransformation(this.selection);
+        this.selection.remove();
-        this.onUpdateImage();
-    }
-    maybeApplyScaleToCanvas (item) {
-        if (!item.matrix.isInvertible()) {
-            item.remove();
-            return;
-        }
-
-        // context.drawImage will anti-alias the image if both width and height are reduced.
-        // However, it will preserve pixel colors if only one or the other is reduced, and
-        // imageSmoothingEnabled is set to false. Therefore, we can avoid aliasing by scaling
-        // down images in a 2 step process.
-        const decomposed = item.matrix.decompose(); // Decomposition order: translate, rotate, scale, skew
-        if (Math.abs(decomposed.scaling.x) < 1 && Math.abs(decomposed.scaling.y) < 1 &&
-                decomposed.scaling.x !== 0 && decomposed.scaling.y !== 0) {
-            item.canvas = scaleBitmap(item.canvas, decomposed.scaling);
-            if (item.data && item.data.expanded) {
-                item.data.expanded.canvas = scaleBitmap(item.data.expanded.canvas, decomposed.scaling);
-            }
-            // Remove the scale from the item's matrix
-            item.matrix.append(
-                new paper.Matrix().scale(new paper.Point(1 / decomposed.scaling.x, 1 / decomposed.scaling.y)));
-        }
-    }
-    commitArbitraryTransformation (item) {
-        // Create a canvas to perform masking
-        const tmpCanvas = createCanvas();
-        const context = tmpCanvas.getContext('2d');
-        // Draw mask
-        const rect = new paper.Shape.Rectangle(new paper.Point(), item.size);
-        rect.matrix = item.matrix;
-        fillRect(rect, context);
-        rect.remove();
-        context.globalCompositeOperation = 'source-in';
-
-        // Draw image onto mask
-        const m = item.matrix;
-        context.transform(m.a, m.b, m.c, m.d, m.tx, m.ty);
-        let canvas = item.canvas;
-        if (item.data && item.data.expanded) {
-            canvas = item.data.expanded.canvas;
-        }
-        context.transform(1, 0, 0, 1, -canvas.width / 2, -canvas.height / 2);
-        context.drawImage(canvas, 0, 0);
-
-        // Draw temp canvas onto raster layer
-        getRaster().drawImage(tmpCanvas, new paper.Point());
-        item.remove();
         this.selection = null;
+        this.onUpdateImage();
     }
     deactivateTool () {
         this.commitSelection();

src/helper/bitmap.js

@@ -653,7 +653,78 @@ const scaleBitmap = function (canvas, scale) {
     return tmpCanvas;
 };
 
+/**
+ * Given a raster, take the scale on the transform and apply it to the raster's canvas, then remove
+ * the scale from the item's transform matrix. Do this only if scale.x or scale.y is less than 1.
+ * @param {paper.Raster} item raster to change
+ */
+const maybeApplyScaleToCanvas_ = function (item) {
+    if (!item.matrix.isInvertible()) {
+        item.remove();
+        return;
+    }
+
+    // context.drawImage will anti-alias the image if both width and height are reduced.
+    // However, it will preserve pixel colors if only one or the other is reduced, and
+    // imageSmoothingEnabled is set to false. Therefore, we can avoid aliasing by scaling
+    // down images in a 2 step process.
+    const decomposed = item.matrix.decompose(); // Decomposition order: translate, rotate, scale, skew
+    if (Math.abs(decomposed.scaling.x) < 1 && Math.abs(decomposed.scaling.y) < 1 &&
+            decomposed.scaling.x !== 0 && decomposed.scaling.y !== 0) {
+        item.canvas = scaleBitmap(item.canvas, decomposed.scaling);
+        if (item.data && item.data.expanded) {
+            item.data.expanded.canvas = scaleBitmap(item.data.expanded.canvas, decomposed.scaling);
+        }
+        // Remove the scale from the item's matrix
+        item.matrix.append(
+            new paper.Matrix().scale(new paper.Point(1 / decomposed.scaling.x, 1 / decomposed.scaling.y)));
+    }
+};
+
+/**
+ * Given a raster, apply its transformation matrix to its canvas. Call maybeApplyScaleToCanvas_ first
+ * to avoid introducing anti-aliasing to scaled-down rasters.
+ * @param {paper.Raster} item raster to resolve transform of
+ * @param {paper.Raster} destination raster to draw selection to
+ */
+const commitArbitraryTransformation_ = function (item, destination) {
+    // Create a canvas to perform masking
+    const tmpCanvas = createCanvas();
+    const context = tmpCanvas.getContext('2d');
+    // Draw mask
+    const rect = new paper.Shape.Rectangle(new paper.Point(), item.size);
+    rect.matrix = item.matrix;
+    fillRect(rect, context);
+    rect.remove();
+    context.globalCompositeOperation = 'source-in';
+
+    // Draw image onto mask
+    const m = item.matrix;
+    context.transform(m.a, m.b, m.c, m.d, m.tx, m.ty);
+    let canvas = item.canvas;
+    if (item.data && item.data.expanded) {
+        canvas = item.data.expanded.canvas;
+    }
+    context.transform(1, 0, 0, 1, -canvas.width / 2, -canvas.height / 2);
+    context.drawImage(canvas, 0, 0);
+
+    // Draw temp canvas onto raster layer
+    destination.drawImage(tmpCanvas, new paper.Point());
+};
+
+/**
+ * Given a raster item, take its transform matrix and apply it to its canvas. Try to avoid
+ * introducing anti-aliasing.
+ * @param {paper.Raster} selection raster to resolve transform of
+ * @param {paper.Raster} bitmap raster to draw selection to
+ */
+const commitSelectionToBitmap = function (selection, bitmap) {
+    maybeApplyScaleToCanvas_(selection);
+    commitArbitraryTransformation_(selection, bitmap);
+};
+
 export {
+    commitSelectionToBitmap,
     convertToBitmap,
     convertToVector,
     fillRect,

src/helper/undo.js

@@ -2,6 +2,7 @@
 // modifed from https://github.com/memononen/stylii
 import paper from '@scratch/paper';
 import {hideGuideLayers, showGuideLayers, getRaster} from '../helper/layer';
+import {getSelectedLeafItems} from '../helper/selection';
 import Formats from '../lib/format';
 import {isVector, isBitmap} from '../lib/format';
 import log from '../log/log';
@@ -23,7 +24,7 @@ const performSnapshot = function (dispatchPerformSnapshot, format) {
     showGuideLayers(guideLayers);
 };
 
-const _restore = function (entry, setSelectedItems, onUpdateImage) {
+const _restore = function (entry, setSelectedItems, onUpdateImage, isBitmapMode) {
     for (let i = paper.project.layers.length - 1; i >= 0; i--) {
         const layer = paper.project.layers[i];
         if (!layer.data.isBackgroundGuideLayer) {
@@ -32,20 +33,41 @@ const _restore = function (entry, setSelectedItems, onUpdateImage) {
         }
     }
     paper.project.importJSON(entry.json);
-
     setSelectedItems();
-    getRaster().onLoad = function () {
+
+    // Ensure that all rasters are loaded before updating storage with new image data.
+    const rastersThatNeedToLoad = [];
+    const onLoad = () => {
+        if (!getRaster().loaded) return;
+        for (const raster of rastersThatNeedToLoad) {
+            if (!raster.loaded) return;
+        }
         onUpdateImage(true /* skipSnapshot */);
     };
-    if (getRaster().loaded) {
+
-        getRaster().onLoad();
+    // Bitmap mode should have at most 1 selected item
+    if (isBitmapMode) {
+        const selectedItems = getSelectedLeafItems();
+        if (selectedItems.length === 1 && selectedItems[0] instanceof paper.Raster) {
+            rastersThatNeedToLoad.push(selectedItems[0]);
+            if (selectedItems[0].data && selectedItems[0].data.expanded instanceof paper.Raster) {
+                rastersThatNeedToLoad.push(selectedItems[0].data.expanded);
+            }
+        }
+    }
+
+    getRaster().onLoad = onLoad;
+    if (getRaster().loaded) getRaster().onLoad();
+    for (const raster of rastersThatNeedToLoad) {
+        raster.onLoad = onLoad;
+        if (raster.loaded) raster.onLoad();
     }
 };
 
 const performUndo = function (undoState, dispatchPerformUndo, setSelectedItems, onUpdateImage) {
     if (undoState.pointer > 0) {
         const state = undoState.stack[undoState.pointer - 1];
-        _restore(state, setSelectedItems, onUpdateImage);
+        _restore(state, setSelectedItems, onUpdateImage, isBitmap(state.paintEditorFormat));
         const format = isVector(state.paintEditorFormat) ? Formats.VECTOR_SKIP_CONVERT :
             isBitmap(state.paintEditorFormat) ? Formats.BITMAP_SKIP_CONVERT : null;
         dispatchPerformUndo(format);
@@ -56,7 +78,7 @@ const performUndo = function (undoState, dispatchPerformUndo, setSelectedItems,
 const performRedo = function (undoState, dispatchPerformRedo, setSelectedItems, onUpdateImage) {
     if (undoState.pointer >= 0 && undoState.pointer < undoState.stack.length - 1) {
         const state = undoState.stack[undoState.pointer + 1];
-        _restore(state, setSelectedItems, onUpdateImage);
+        _restore(state, setSelectedItems, onUpdateImage, isBitmap(state.paintEditorFormat));
         const format = isVector(state.paintEditorFormat) ? Formats.VECTOR_SKIP_CONVERT :
             isBitmap(state.paintEditorFormat) ? Formats.BITMAP_SKIP_CONVERT : null;
         dispatchPerformRedo(format);