[PDF] Fix shader fallback mapping when clipped

src/pdf/SkPDFShader.cpp

Index: src/pdf/SkPDFShader.cpp
diff --git a/src/pdf/SkPDFShader.cpp b/src/pdf/SkPDFShader.cpp
index 20df873cbd14b7ba60a7a252cab2d499cf3518e9..54528ce38b245ab16dd7ae158bd2989d26a465e5 100644
--- a/src/pdf/SkPDFShader.cpp
+++ b/src/pdf/SkPDFShader.cpp
@@ -1219,6 +1219,15 @@ SkPDFShader::State::State(const SkShader& shader, const SkMatrix& canvasTransfor
             //  * shade the whole area
             //  * use the result as a bitmap shader
 
+            // bbox is in device space. While that's exactly what we want for sizing our bitmap,
+            // we need to map it into shader space for adjustments (to match
+            // SkPDFImageShader::Create's behavior).
+            SkRect shaderRect = SkRect::Make(bbox);

[robertphillips, 2015/02/12 21:12:59]

inverse_transform_bbox ?

[f(malita), 2015/02/12 21:28:33]

Done.

+            if (!inverseTransformBBox(canvasTransform, &shaderRect)) {
+                fImage.reset();
+                return;
+            }
+
             // Clamp the bitmap size to about 1M pixels
             static const SkScalar kMaxBitmapArea = 1024 * 1024;
             SkScalar bitmapArea = rasterScale * bbox.width() * rasterScale * bbox.height();
@@ -1228,8 +1237,8 @@ SkPDFShader::State::State(const SkShader& shader, const SkMatrix& canvasTransfor
 
             SkISize size = SkISize::Make(SkScalarRoundToInt(rasterScale * bbox.width()),
                                          SkScalarRoundToInt(rasterScale * bbox.height()));
-            SkSize scale = SkSize::Make(SkIntToScalar(size.width()) / SkIntToScalar(bbox.width()),
-                                        SkIntToScalar(size.height()) / SkIntToScalar(bbox.height()));
+            SkSize scale = SkSize::Make(SkIntToScalar(size.width()) / shaderRect.width(),
+                                        SkIntToScalar(size.height()) / shaderRect.height());
 
             fImage.allocN32Pixels(size.width(), size.height());
             fImage.eraseColor(SK_ColorTRANSPARENT);
@@ -1239,10 +1248,10 @@ SkPDFShader::State::State(const SkShader& shader, const SkMatrix& canvasTransfor
 
             SkCanvas canvas(fImage);
             canvas.scale(scale.width(), scale.height());
-            canvas.translate(-SkIntToScalar(bbox.x()), -SkIntToScalar(bbox.y()));
+            canvas.translate(-shaderRect.x(), -shaderRect.y());
             canvas.drawPaint(p);
 
-            fShaderTransform.setTranslate(SkIntToScalar(bbox.x()), SkIntToScalar(bbox.y()));
+            fShaderTransform.setTranslate(shaderRect.x(), shaderRect.y());
             fShaderTransform.preScale(1 / scale.width(), 1 / scale.height());
         } else {
             SkASSERT(matrix.isIdentity());