From 011cb3e886a87148727288e338e2839c2122fc40 Mon Sep 17 00:00:00 2001
From: Robert Longson <longsonr@gmail.com>
Date: Sat, 14 Aug 2010 20:42:18 -0400
Subject: [PATCH] Bug 584322 - feDisplacementMap seems to be adding an offset.
 r=roc, a=dbaron

---
 content/svg/content/src/nsSVGFilters.cpp | 17 ++++++++++-------
 content/svg/content/src/nsSVGFilters.h   | 16 ++++++++--------
 layout/reftests/svg/filters/reftest.list |  2 ++
 3 files changed, 20 insertions(+), 15 deletions(-)

diff --git a/content/svg/content/src/nsSVGFilters.cpp b/content/svg/content/src/nsSVGFilters.cpp
index 4ace69078da..075dae66354 100644
--- a/content/svg/content/src/nsSVGFilters.cpp
+++ b/content/svg/content/src/nsSVGFilters.cpp
@@ -1068,7 +1068,7 @@ public:
 
   virtual nsXPCClassInfo* GetClassInfo();
 protected:
-  virtual PRBool OperatesOnPremultipledAlpha() { return PR_FALSE; }
+  virtual PRBool OperatesOnPremultipledAlpha(PRInt32) { return PR_FALSE; }
 
   virtual EnumAttributesInfo GetEnumInfo();
   virtual StringAttributesInfo GetStringInfo();
@@ -1695,7 +1695,7 @@ public:
 
   virtual nsXPCClassInfo* GetClassInfo();
 protected:
-  virtual PRBool OperatesOnPremultipledAlpha() { return PR_FALSE; }
+  virtual PRBool OperatesOnPremultipledAlpha(PRInt32) { return PR_FALSE; }
 
   virtual StringAttributesInfo GetStringInfo();
 
@@ -2715,7 +2715,7 @@ public:
   virtual nsXPCClassInfo* GetClassInfo();
 protected:
   virtual PRBool OperatesOnSRGB(nsSVGFilterInstance*,
-                                PRUint32, Image*) { return PR_TRUE; }
+                                PRInt32, Image*) { return PR_TRUE; }
 
   virtual StringAttributesInfo GetStringInfo();
 
@@ -3898,7 +3898,7 @@ public:
 
   virtual nsXPCClassInfo* GetClassInfo();
 protected:
-  virtual PRBool OperatesOnPremultipledAlpha() {
+  virtual PRBool OperatesOnPremultipledAlpha(PRInt32) {
     return !mBooleanAttributes[PRESERVEALPHA].GetAnimValue();
   }
 
@@ -5354,7 +5354,7 @@ private:
 
 protected:
   virtual PRBool OperatesOnSRGB(nsSVGFilterInstance*,
-                                PRUint32, Image*) { return PR_TRUE; }
+                                PRInt32, Image*) { return PR_TRUE; }
 
   virtual nsSVGPreserveAspectRatio *GetPreserveAspectRatio();
   virtual StringAttributesInfo GetStringInfo();
@@ -5689,13 +5689,16 @@ public:
   virtual nsXPCClassInfo* GetClassInfo();
 protected:
   virtual PRBool OperatesOnSRGB(nsSVGFilterInstance* aInstance,
-                                PRUint32 aInput, Image* aImage) {
-    if (aInput == 0 && aImage)
+                                PRInt32 aInput, Image* aImage) {
+    if (aInput == 0)
       return aImage->mColorModel.mColorSpace == ColorModel::SRGB;
 
     return nsSVGFEDisplacementMapElementBase::OperatesOnSRGB(aInstance,
                                                              aInput, aImage);
   }
+  virtual PRBool OperatesOnPremultipledAlpha(PRInt32 aInput) {
+    return !(aInput == 1);
+  }
 
   virtual NumberAttributesInfo GetNumberInfo();
   virtual EnumAttributesInfo GetEnumInfo();
diff --git a/content/svg/content/src/nsSVGFilters.h b/content/svg/content/src/nsSVGFilters.h
index 01460fa82a8..0697d5a2c71 100644
--- a/content/svg/content/src/nsSVGFilters.h
+++ b/content/svg/content/src/nsSVGFilters.h
@@ -119,21 +119,21 @@ protected:
 
 public:
   ColorModel
-  GetInputColorModel(nsSVGFilterInstance* aInstance, PRUint32 aInputIndex,
+  GetInputColorModel(nsSVGFilterInstance* aInstance, PRInt32 aInputIndex,
                      Image* aImage) {
     return ColorModel(
           (OperatesOnSRGB(aInstance, aInputIndex, aImage) ?
              ColorModel::SRGB : ColorModel::LINEAR_RGB),
-          (OperatesOnPremultipledAlpha() ?
+          (OperatesOnPremultipledAlpha(aInputIndex) ?
              ColorModel::PREMULTIPLIED : ColorModel::UNPREMULTIPLIED));
   }
 
   ColorModel
   GetOutputColorModel(nsSVGFilterInstance* aInstance) {
     return ColorModel(
-          (OperatesOnSRGB(aInstance, 0, nsnull) ?
+          (OperatesOnSRGB(aInstance, -1, nsnull) ?
              ColorModel::SRGB : ColorModel::LINEAR_RGB),
-          (OperatesOnPremultipledAlpha() ?
+          (OperatesOnPremultipledAlpha(-1) ?
              ColorModel::PREMULTIPLIED : ColorModel::UNPREMULTIPLIED));
   }
 
@@ -199,13 +199,13 @@ public:
   operator nsISupports*() { return static_cast<nsIContent*>(this); }
   
 protected:
-  virtual PRBool OperatesOnPremultipledAlpha() { return PR_TRUE; }
+  virtual PRBool OperatesOnPremultipledAlpha(PRInt32) { return PR_TRUE; }
 
-  // Called either with aImage non-null, in which case this is
+  // Called either with aInputIndex >=0 in which case this is
   // testing whether the input 'aInputIndex' should be SRGB, or
-  // if aImage is null returns true if the output will be SRGB
+  // if aInputIndex is -1 returns true if the output will be SRGB
   virtual PRBool OperatesOnSRGB(nsSVGFilterInstance* aInstance,
-                                PRUint32 aInputIndex, Image* aImage) {
+                                PRInt32 aInputIndex, Image* aImage) {
     nsIFrame* frame = GetPrimaryFrame();
     if (!frame) return PR_FALSE;
 
diff --git a/layout/reftests/svg/filters/reftest.list b/layout/reftests/svg/filters/reftest.list
index d20cc534530..369628b465f 100644
--- a/layout/reftests/svg/filters/reftest.list
+++ b/layout/reftests/svg/filters/reftest.list
@@ -72,6 +72,8 @@ fails == filter-marked-line-01.svg pass.svg # bug 477704
 == feConvolveMatrix-bias-01.svg feConvolveMatrix-bias-01-ref.svg
 == feConvolveMatrix-order-01.svg feConvolveMatrix-order-01-ref.svg
 
+== feDisplacementMap-alpha-01.svg pass.svg
+
 == feMorphology-radius-negative-01.svg pass.svg
 == feMorphology-radius-negative-02.svg pass.svg
 == feMorphology-radius-zero-01.svg pass.svg