Fix several issues with radial/axial shadings and tiling patterns.

Previously, we set the base transformation and pattern matrix
directly to the main rendering ctx of the page, however doing this
caused the current transform to be lost. This would cause issues
with things like shear missing so the pattern was misaligned or when
stroke was used the scale of the line width or dash would be wrong.
Instead we should leave the current transform and use setTransfrom
on the pattern so it is applied correctly. For axial and radial shadings I had
to create a temporary canvas to draw the shading so I could in turn
use setTransform.

Fixes: #13325, #6769, #7847, #11018, #11597, #11473

The following already in the corpus are improved:
issue8078-page1
issue1877-page1

src/core/pattern.js

@@ -245,18 +245,17 @@ Shadings.RadialAxial = (function RadialAxialClosure() {
         unreachable(`getPattern type unknown: ${shadingType}`);
       }
 
-      const matrix = this.matrix;
+      return [
-      if (matrix) {
+        "RadialAxial",
-        p0 = Util.applyTransform(p0, matrix);
+        type,
-        p1 = Util.applyTransform(p1, matrix);
+        this.bbox,
-        if (shadingType === ShadingType.RADIAL) {
+        this.colorStops,
-          const scale = Util.singularValueDecompose2dScale(matrix);
+        p0,
-          r0 *= scale[0];
+        p1,
-          r1 *= scale[1];
+        r0,
-        }
+        r1,
-      }
+        this.matrix,
-
+      ];
-      return ["RadialAxial", type, this.bbox, this.colorStops, p0, p1, r0, r1];
     },
   };
 

src/display/canvas.js

@@ -1386,24 +1386,11 @@ const CanvasGraphics = (function CanvasGraphicsClosure() {
       ctx.globalAlpha = this.current.strokeAlpha;
       if (this.contentVisible) {
         if (typeof strokeColor === "object" && strokeColor?.getPattern) {
-          // for patterns, we transform to pattern space, calculate
-          // the pattern, call stroke, and restore to user space
-          ctx.save();
-          // The current transform will be replaced while building the pattern,
-          // but the line width needs to be adjusted by the current transform,
-          // so we must scale it. To properly fix this we should be using a
-          // pattern transform instead (see #10955).
-          const transform = ctx.mozCurrentTransform;
-          const scale = Util.singularValueDecompose2dScale(transform)[0];
-          ctx.strokeStyle = strokeColor.getPattern(ctx, this);
           const lineWidth = this.getSinglePixelWidth();
-          const scaledLineWidth = this.current.lineWidth * scale;
+          ctx.save();
-          if (lineWidth < 0 && -lineWidth >= scaledLineWidth) {
+          ctx.strokeStyle = strokeColor.getPattern(ctx, this);
-            ctx.resetTransform();
+          // Prevent drawing too thin lines by enforcing a minimum line width.
-            ctx.lineWidth = Math.round(this._combinedScaleFactor);
+          ctx.lineWidth = Math.max(lineWidth, this.current.lineWidth);
-          } else {
-            ctx.lineWidth = Math.max(lineWidth, scaledLineWidth);
-          }
           ctx.stroke();
           ctx.restore();
         } else {
@@ -1444,9 +1431,6 @@ const CanvasGraphics = (function CanvasGraphicsClosure() {
 
       if (isPatternFill) {
         ctx.save();
-        if (this.baseTransform) {
-          ctx.setTransform.apply(ctx, this.baseTransform);
-        }
         ctx.fillStyle = fillColor.getPattern(ctx, this);
         needRestore = true;
       }

src/display/pattern_helper.js

@@ -17,6 +17,19 @@ import { FormatError, info, Util } from "../shared/util.js";
 
 const ShadingIRs = {};
 
+let svgElement;
+
+// TODO: remove this when Firefox ESR supports DOMMatrix.
+function createMatrix(matrix) {
+  if (typeof DOMMatrix !== "undefined") {
+    return new DOMMatrix(matrix);
+  }
+  if (!svgElement) {
+    svgElement = document.createElementNS("http://www.w3.org/2000/svg", "svg");
+  }
+  return svgElement.createSVGMatrix(matrix);
+}
+
 function applyBoundingBox(ctx, bbox) {
   if (!bbox || typeof Path2D === "undefined") {
     return;
@@ -37,21 +50,57 @@ ShadingIRs.RadialAxial = {
     const p1 = raw[5];
     const r0 = raw[6];
     const r1 = raw[7];
+    const matrix = raw[8];
+
     return {
-      getPattern: function RadialAxial_getPattern(ctx) {
+      getPattern: function RadialAxial_getPattern(ctx, owner, shadingFill) {
-        applyBoundingBox(ctx, bbox);
+        const tmpCanvas = owner.cachedCanvases.getCanvas(
+          "pattern",
+          ctx.canvas.width,
+          ctx.canvas.height,
+          true
+        );
+
+        const tmpCtx = tmpCanvas.context;
+        tmpCtx.clearRect(0, 0, tmpCtx.canvas.width, tmpCtx.canvas.height);
+        tmpCtx.beginPath();
+        tmpCtx.rect(0, 0, tmpCtx.canvas.width, tmpCtx.canvas.height);
+
+        if (!shadingFill) {
+          tmpCtx.setTransform.apply(tmpCtx, owner.baseTransform);
+          if (matrix) {
+            tmpCtx.transform.apply(tmpCtx, matrix);
+          }
+        } else {
+          tmpCtx.setTransform.apply(tmpCtx, ctx.mozCurrentTransform);
+        }
+        applyBoundingBox(tmpCtx, bbox);
+
         let grad;
         if (type === "axial") {
-          grad = ctx.createLinearGradient(p0[0], p0[1], p1[0], p1[1]);
+          grad = tmpCtx.createLinearGradient(p0[0], p0[1], p1[0], p1[1]);
         } else if (type === "radial") {
-          grad = ctx.createRadialGradient(p0[0], p0[1], r0, p1[0], p1[1], r1);
+          grad = tmpCtx.createRadialGradient(
+            p0[0],
+            p0[1],
+            r0,
+            p1[0],
+            p1[1],
+            r1
+          );
         }
 
         for (let i = 0, ii = colorStops.length; i < ii; ++i) {
           const c = colorStops[i];
           grad.addColorStop(c[0], c[1]);
         }
-        return grad;
+
+        tmpCtx.fillStyle = grad;
+        tmpCtx.fill();
+
+        const pattern = ctx.createPattern(tmpCanvas.canvas, "repeat");
+        pattern.setTransform(createMatrix(ctx.mozCurrentTransformInverse));
+        return pattern;
       },
     };
   },
@@ -505,19 +554,17 @@ const TilingPattern = (function TilingPatternClosure() {
 
       graphics.transform(dimx.scale, 0, 0, dimy.scale, 0, 0);
 
-      // transform coordinates to pattern space
-      graphics.transform(1, 0, 0, 1, -x0, -y0);
-
       this.clipBbox(graphics, bbox, x0, y0, x1, y1);
 
+      graphics.baseTransform = graphics.ctx.mozCurrentTransform.slice();
+
       graphics.executeOperatorList(operatorList);
 
-      this.ctx.transform(1, 0, 0, 1, x0, y0);
+      return {
-
+        canvas: tmpCanvas.canvas,
-      // Rescale canvas so that the ctx.createPattern call generates a pattern
+        scaleX: dimx.scale,
-      // with the desired size.
+        scaleY: dimy.scale,
-      this.ctx.scale(1 / dimx.scale, 1 / dimy.scale);
+      };
-      return tmpCanvas.canvas;
     },
 
     getSizeAndScale: function TilingPattern_getSizeAndScale(
@@ -579,15 +626,34 @@ const TilingPattern = (function TilingPatternClosure() {
       }
     },
 
-    getPattern: function TilingPattern_getPattern(ctx, owner) {
+    getPattern: function TilingPattern_getPattern(ctx, owner, shadingFill) {
       ctx = this.ctx;
       // PDF spec 8.7.2 NOTE 1: pattern's matrix is relative to initial matrix.
-      ctx.setTransform.apply(ctx, this.baseTransform);
+      let matrix = ctx.mozCurrentTransformInverse;
-      ctx.transform.apply(ctx, this.matrix);
+      if (!shadingFill) {
+        matrix = Util.transform(matrix, owner.baseTransform);
+        if (this.matrix) {
+          matrix = Util.transform(matrix, this.matrix);
+        }
+      }
 
       const temporaryPatternCanvas = this.createPatternCanvas(owner);
 
-      return ctx.createPattern(temporaryPatternCanvas, "repeat");
+      let domMatrix = createMatrix(matrix);
+      // Rescale and so that the ctx.createPattern call generates a pattern with
+      // the desired size.
+      domMatrix = domMatrix.scale(
+        1 / temporaryPatternCanvas.scaleX,
+        1 / temporaryPatternCanvas.scaleY
+      );
+
+      const pattern = ctx.createPattern(
+        temporaryPatternCanvas.canvas,
+        "repeat"
+      );
+      pattern.setTransform(domMatrix);
+
+      return pattern;
     },
   };
 

test/pdfs/.gitignore

@@ -42,6 +42,7 @@
 !issue7406.pdf
 !issue7426.pdf
 !issue7439.pdf
+!issue7847_radial.pdf
 !issue7446.pdf
 !issue7492.pdf
 !issue7544.pdf
@@ -101,6 +102,7 @@
 !issue11242_reduced.pdf
 !issue11279.pdf
 !issue11362.pdf
+!issue13325_reduced.pdf
 !issue11578_reduced.pdf
 !issue11651.pdf
 !issue11878.pdf
@@ -296,6 +298,7 @@
 !bug1028735.pdf
 !bug1046314.pdf
 !bug1065245.pdf
+!issue6769.pdf
 !bug1151216.pdf
 !bug1175962.pdf
 !bug1020226.pdf
@@ -365,6 +368,7 @@
 !issue5481.pdf
 !issue5567.pdf
 !issue5701.pdf
+!issue6769_no_matrix.pdf
 !issue12007_reduced.pdf
 !issue5896.pdf
 !issue6010_1.pdf
@@ -378,6 +382,7 @@
 !issue13271.pdf
 !issue6298.pdf
 !issue6889.pdf
+!issue11473.pdf
 !bug1001080.pdf
 !bug1671312_reduced.pdf
 !bug1671312_ArialNarrow.pdf

test/pdfs/issue6769.pdf

@@ -0,0 +1,114 @@
+%PDF-1.5
+%âãÏÓ
+1 0 obj 
+<<
+/Kids [2 0 R]
+/Type /Pages
+/Count 1
+>>
+endobj 
+2 0 obj 
+<<
+/Resources 3 0 R
+/Type /Page
+/Parent 1 0 R
+/Contents 4 0 R
+/MediaBox [0 0 100 100]
+/Group 
+<<
+/CS /DeviceRGB
+/I true
+/Type /Group
+/S /Transparency
+>>
+>>
+endobj 
+3 0 obj 
+<<
+/ExtGState 
+<<
+/a0 
+<<
+/CA 1
+/ca 1
+>>
+>>
+/Pattern 
+<<
+/p5 5 0 R
+>>
+>>
+endobj 
+5 0 obj 
+<<
+/PatternType 2
+/Type /Pattern
+/Shading 
+<<
+/Coords [0 0 0 0 0 100]
+/Extend [true true]
+/Function 6 0 R
+/ShadingType 3
+/Domain [0 1]
+/ColorSpace /DeviceRGB
+>>
+/Matrix [1 0 0 -1 0 10]
+>>
+endobj 
+4 0 obj 
+<<
+/Length 77
+>>
+stream
+q
+/Pattern CS /p5 SCN /a0 gs
+0.3 0 0 0.1 0 0 cm
+50 w
+100 100 m
+300 700 l
+S
+Q
+
+endstream 
+endobj 
+6 0 obj 
+<<
+/FunctionType 2
+/N 1
+/C1 [0 1 0]
+/C0 [0 0 1]
+/Domain [0 1]
+>>
+endobj 
+7 0 obj 
+<<
+/Type /Catalog
+/Pages 1 0 R
+>>
+endobj 
+8 0 obj 
+<<
+/Creator (cairo 1.13.1 \(http://cairographics.org\))
+/Producer (cairo 1.13.1 \(http://cairographics.org\))
+>>
+endobj xref
+0 9
+0000000000 65535 f 
+0000000015 00000 n 
+0000000074 00000 n 
+0000000247 00000 n 
+0000000542 00000 n 
+0000000337 00000 n 
+0000000672 00000 n 
+0000000754 00000 n 
+0000000805 00000 n 
+trailer
+
+<<
+/Info 8 0 R
+/Root 7 0 R
+/Size 9
+>>
+startxref
+934
+%%EOF

test/pdfs/issue6769_no_matrix.pdf

@@ -0,0 +1,114 @@
+%PDF-1.5
+%âãÏÓ
+1 0 obj 
+<<
+/Kids [2 0 R]
+/Type /Pages
+/Count 1
+>>
+endobj 
+2 0 obj 
+<<
+/Resources 3 0 R
+/Type /Page
+/Parent 1 0 R
+/Contents 4 0 R
+/MediaBox [0 0 100 100]
+/Group 
+<<
+/CS /DeviceRGB
+/I true
+/Type /Group
+/S /Transparency
+>>
+>>
+endobj 
+3 0 obj 
+<<
+/ExtGState 
+<<
+/a0 
+<<
+/CA 1
+/ca 1
+>>
+>>
+/Pattern 
+<<
+/p5 5 0 R
+>>
+>>
+endobj 
+5 0 obj 
+<<
+/PatternType 2
+/Type /Pattern
+/Shading 
+<<
+/Coords [0 0 0 0 0 100]
+/Extend [true true]
+/Function 6 0 R
+/ShadingType 3
+/Domain [0 1]
+/ColorSpace /DeviceRGB
+>>
+/Matrix [2  0 0 2  0 0]
+>>
+endobj 
+4 0 obj 
+<<
+/Length 77
+>>
+stream
+q
+/Pattern CS /p5 SCN /a0 gs
+0.3 0 0 0.1 0 0 cm
+50 w
+100 100 m
+300 700 l
+S
+Q
+
+endstream 
+endobj 
+6 0 obj 
+<<
+/FunctionType 2
+/N 1
+/C1 [0 1 0]
+/C0 [0 0 1]
+/Domain [0 1]
+>>
+endobj 
+7 0 obj 
+<<
+/Type /Catalog
+/Pages 1 0 R
+>>
+endobj 
+8 0 obj 
+<<
+/Creator (cairo 1.13.1 \(http://cairographics.org\))
+/Producer (cairo 1.13.1 \(http://cairographics.org\))
+>>
+endobj xref
+0 9
+0000000000 65535 f 
+0000000015 00000 n 
+0000000074 00000 n 
+0000000247 00000 n 
+0000000542 00000 n 
+0000000337 00000 n 
+0000000672 00000 n 
+0000000754 00000 n 
+0000000805 00000 n 
+trailer
+
+<<
+/Info 8 0 R
+/Root 7 0 R
+/Size 9
+>>
+startxref
+934
+%%EOF

test/pdfs/issue7847_radial.pdf

@@ -0,0 +1,130 @@
+%PDF-1.3
+%ÿÿÿÿ
+6 0 obj
+<<
+/FunctionType 2
+/Domain [0 1]
+/C0 [1 1 0]
+/C1 [0 0.5019607843137255 0]
+/N 1
+>>
+endobj
+7 0 obj
+<<
+/FunctionType 2
+/Domain [0 1]
+/C0 [0 0.5019607843137255 0]
+/C1 [1 1 1]
+/N 1
+>>
+endobj
+8 0 obj
+<<
+/FunctionType 3
+/Domain [0 1]
+/Functions [6 0 R 7 0 R]
+/Bounds [0.5]
+/Encode [0 1 0 1]
+>>
+endobj
+9 0 obj
+<<
+/ShadingType 3
+/ColorSpace /DeviceRGB
+/Coords [0.5 0.5 0 0.5 0.5 0.5]
+/Function 8 0 R
+/Extend [true true]
+>>
+endobj
+10 0 obj
+<<
+/Type /Pattern
+/PatternType 2
+/Shading 9 0 R
+/Matrix [440 0 0 -200 20 220]
+>>
+endobj
+11 0 obj
+<<
+/Type /ExtGState
+/ca 1
+>>
+endobj
+5 0 obj
+<<
+/Type /Page
+/Parent 1 0 R
+/MediaBox [0 0 480 240]
+/Contents 3 0 R
+/Resources 4 0 R
+>>
+endobj
+4 0 obj
+<<
+/ProcSet [/PDF /Text /ImageB /ImageC /ImageI]
+/Pattern <<
+/Sh1 10 0 R
+>>
+/ExtGState <<
+/Gs1 11 0 R
+>>
+>>
+endobj
+3 0 obj
+<<
+/Length 66
+>>
+stream
+1 0 0 -1 0 240 cm
+20 20 440 200 re
+/Pattern cs
+/Sh1 scn
+/Gs1 gs
+f
+
+endstream
+endobj
+12 0 obj
+<<
+/Producer (PDFKit)
+/Creator (PDFKit)
+/CreationDate (D:20161124005340Z)
+>>
+endobj
+2 0 obj
+<<
+/Type /Catalog
+/Pages 1 0 R
+>>
+endobj
+1 0 obj
+<<
+/Type /Pages
+/Count 1
+/Kids [5 0 R]
+>>
+endobj
+xref
+0 13
+0000000000 65535 f 
+0000001071 00000 n 
+0000001022 00000 n 
+0000000813 00000 n 
+0000000690 00000 n 
+0000000586 00000 n 
+0000000015 00000 n 
+0000000112 00000 n 
+0000000209 00000 n 
+0000000317 00000 n 
+0000000444 00000 n 
+0000000541 00000 n 
+0000000929 00000 n 
+trailer
+<<
+/Size 13
+/Root 2 0 R
+/Info 12 0 R
+>>
+startxref
+1128
+%%EOF

test/test_manifest.json

@@ -485,6 +485,12 @@
        "lastPage": 2,
        "type": "load"
     },
+    {  "id": "issue7847_radial",
+       "file": "pdfs/issue7847_radial.pdf",
+       "md5": "59dc206ec5dd6e6f701943e4694e4147",
+       "rounds": 1,
+       "type": "eq"
+    },
     {  "id": "rotation",
        "file": "pdfs/rotation.pdf",
        "md5": "4fb25ada00ce7528569d9791c14decf5",
@@ -637,6 +643,12 @@
        "rounds": 1,
        "type": "eq"
     },
+    {  "id": "issue6769_no_matrix",
+       "file": "pdfs/issue6769_no_matrix.pdf",
+       "md5": "f88806137fb4592975052ff3508d7b1e",
+       "rounds": 1,
+       "type": "eq"
+    },
     {  "id": "unix01",
        "file": "pdfs/unix01.pdf",
        "md5": "2742999f0bf9b9c035dbb0736096e220",
@@ -2552,6 +2564,12 @@
        "rounds": 1,
        "type": "eq"
     },
+    {  "id": "issue6769",
+       "file": "pdfs/issue6769.pdf",
+       "md5": "724b94d6bd1e8010403328446d0ab061",
+       "rounds": 1,
+       "type": "eq"
+    },
     {  "id": "issue4304",
        "file": "pdfs/issue4304.pdf",
        "md5": "1b1205bf0d7c1ad22a154b60da8e694d",
@@ -3976,6 +3994,12 @@
       "link": true,
       "type": "eq"
     },
+    {  "id": "issue11473",
+       "file": "pdfs/issue11473.pdf",
+       "md5": "c530851b0523c81784ab4ea3115a7c67",
+       "rounds": 1,
+       "type": "eq"
+    },
     {  "id": "bug1140761",
        "file": "pdfs/bug1140761.pdf",
        "md5": "b74eced7634d4f248dc6265f8225d432",
@@ -4392,6 +4416,12 @@
        "type": "eq",
        "about": "Support for CMap GBKp-EUC-H"
     },
+    {  "id": "issue13325_reduced",
+       "file": "pdfs/issue13325_reduced.pdf",
+       "md5": "a9311230d2e3388070711be8748a1aa0",
+       "rounds": 1,
+       "type": "eq"
+    },
     {  "id": "issue2829",
       "file": "pdfs/issue2829.pdf",
       "md5": "f32b28cf8792f6ccc470446bfbb38584",