Merge pull request #3506 from brendandahl/base-transform

Paint patterns relative to content base transformation.

src/canvas.js

@@ -407,6 +407,10 @@ var CanvasGraphics = (function CanvasGraphicsClosure() {
     this.imageLayer = imageLayer;
     this.groupStack = [];
     this.processingType3 = null;
+    // Patterns are painted relative to the initial page/form transform, see pdf
+    // spec 8.7.2 NOTE 1.
+    this.baseTransform = null;
+    this.baseTransformStack = [];
     if (canvasCtx) {
       addContextCurrentTransform(canvasCtx);
     }
@@ -509,6 +513,7 @@ var CanvasGraphics = (function CanvasGraphicsClosure() {
       }
 
       var transform = viewport.transform;
+      this.baseTransform = transform.slice();
       this.ctx.save();
       this.ctx.transform.apply(this.ctx, transform);
 
@@ -1318,7 +1323,7 @@ var CanvasGraphics = (function CanvasGraphicsClosure() {
           color = base.getRgb(args, 0);
         }
         var pattern = new TilingPattern(IR, color, this.ctx, this.objs,
-                                        this.commonObjs);
+                                        this.commonObjs, this.baseTransform);
       } else if (IR[0] == 'RadialAxial' || IR[0] == 'Dummy') {
         var pattern = Pattern.shadingFromIR(IR);
       } else {
@@ -1453,10 +1458,13 @@ var CanvasGraphics = (function CanvasGraphicsClosure() {
                                                                         bbox) {
       this.save();
       this.current.paintFormXObjectDepth++;
+      this.baseTransformStack.push(this.baseTransform);
 
       if (matrix && isArray(matrix) && 6 == matrix.length)
         this.transform.apply(this, matrix);
 
+      this.baseTransform = this.ctx.mozCurrentTransform;
+
       if (bbox && isArray(bbox) && 4 == bbox.length) {
         var width = bbox[2] - bbox[0];
         var height = bbox[3] - bbox[1];
@@ -1473,6 +1481,7 @@ var CanvasGraphics = (function CanvasGraphicsClosure() {
         // some pdf don't close all restores inside object
         // closing those for them
       } while (this.current.paintFormXObjectDepth >= depth);
+      this.baseTransform = this.baseTransformStack.pop();
     },
 
     beginGroup: function CanvasGraphics_beginGroup(group) {

src/pattern.js

@@ -271,7 +271,7 @@ var TilingPattern = (function TilingPatternClosure() {
 
   var MAX_PATTERN_SIZE = 8192;
 
-  function TilingPattern(IR, color, ctx, objs, commonObjs) {
+  function TilingPattern(IR, color, ctx, objs, commonObjs, baseTransform) {
     this.name = IR[1][0].name;
     this.operatorList = IR[2];
     this.matrix = IR[3] || [1, 0, 0, 1, 0, 0];
@@ -283,7 +283,7 @@ var TilingPattern = (function TilingPatternClosure() {
     this.color = color;
     this.objs = objs;
     this.commonObjs = commonObjs;
-    this.curMatrix = ctx.mozCurrentTransform;
+    this.baseTransform = baseTransform;
     this.type = 'Pattern';
     this.ctx = ctx;
   }
@@ -328,7 +328,8 @@ var TilingPattern = (function TilingPatternClosure() {
 
       // Obtain scale from matrix and current transformation matrix.
       var matrixScale = Util.singularValueDecompose2dScale(this.matrix);
-      var curMatrixScale = Util.singularValueDecompose2dScale(this.curMatrix);
+      var curMatrixScale = Util.singularValueDecompose2dScale(
+                             this.baseTransform);
       var combinedScale = [matrixScale[0] * curMatrixScale[0],
                            matrixScale[1] * curMatrixScale[1]];
 
@@ -412,7 +413,7 @@ var TilingPattern = (function TilingPatternClosure() {
       this.createPatternCanvas(temporaryPatternCanvas);
 
       var ctx = this.ctx;
-      ctx.setTransform.apply(ctx, this.curMatrix);
+      ctx.setTransform.apply(ctx, this.baseTransform);
       ctx.transform.apply(ctx, this.matrix);
       this.scaleToContext();
 

test/test_manifest.json

@@ -943,6 +943,13 @@
       "type": "eq",
       "about": "Rotated transparency group with blend mode."
     },
+    { "id": "issue3458.pdf",
+      "file": "pdfs/issue3458.pdf",
+      "md5": "dab8bd3ad1acfc8dc82a8381a3c8ff94",
+      "rounds": 1,
+      "type": "eq",
+      "about": "Pattern with current transform different than base transform."
+    },
     {  "id": "issue2462",
       "file": "pdfs/issue2462.pdf",
       "md5": "d4e3dddfdd35464c71cf0310bff29b42",