gdiplus: Add a stub for GdipSetImageAttributesThreshold.

dlls/gdiplus/gdiplus.spec

@@ -529,7 +529,7 @@
 @ stdcall GdipSetImageAttributesOutputChannel(ptr long long long)
 @ stdcall GdipSetImageAttributesOutputChannelColorProfile(ptr long long ptr)
 @ stdcall GdipSetImageAttributesRemapTable(ptr long long long ptr)
-@ stub GdipSetImageAttributesThreshold
+@ stdcall GdipSetImageAttributesThreshold(ptr long long long)
 @ stub GdipSetImageAttributesToIdentity
 @ stdcall GdipSetImageAttributesWrapMode(ptr long long long)
 @ stdcall GdipSetImagePalette(ptr ptr)

dlls/gdiplus/imageattributes.c

@@ -158,3 +158,14 @@ GpStatus WINGDIPAPI GdipSetImageAttributesRemapTable(GpImageAttributes *imageAtt
 
     return NotImplemented;
 }
+
+GpStatus WINGDIPAPI GdipSetImageAttributesThreshold(GpImageAttributes *imageAttr,
+    ColorAdjustType type, BOOL enableFlag, REAL threshold)
+{
+    static int calls;
+
+    if(!(calls++))
+        FIXME("not implemented\n");
+
+    return NotImplemented;
+}