Fix off-by-one error in an accelerated compositor path

tannerhelland · Aug 18, 2016 · 79174ce · 79174ce
1 parent d706b65
commit 79174ce
Showing 1 changed file with 7 additions and 2 deletions.
diff --git a/Classes/pdPixelBlender.cls b/Classes/pdPixelBlender.cls
@@ -118,7 +118,7 @@ Friend Sub BlendDIBs(ByRef topDIB As pdDIB, ByRef bottomDIB As pdDIB, ByVal blen
         End Select
 
         'Composited results will have been placed inside the temporary top DIB copy.  Apply the final blend now!
-        If applyFinalBlend Then m_topDIBCopy.AlphaBlendToDCEx bottomDIB.GetDIBDC, xOffsetBottom, yOffsetBottom, finalX - initX, finalY - initY, 0, 0, finalX - initX, finalY - initY, alphaModifier * 255
+        If applyFinalBlend Then m_topDIBCopy.AlphaBlendToDCEx bottomDIB.GetDIBDC, xOffsetBottom, yOffsetBottom, finalX - initX + 1, finalY - initY + 1, 0, 0, finalX - initX + 1, finalY - initY + 1, alphaModifier * 255
 
         'That's all there is to it!
 
@@ -558,7 +558,12 @@ Private Sub ApplyBlendMode_Generic(ByRef topDIB As pdDIB, ByRef bottomDIB As pdD
                         newR = topR * bottomR
                         newG = topG * bottomG
                         newB = topB * bottomB
-
+
+                    Case BL_SCREEN
+                        newR = 1 - (1 - bottomR) * (1 - topR)
+                        newG = 1 - (1 - bottomG) * (1 - topG)
+                        newB = 1 - (1 - bottomB) * (1 - topB)
+
                     Case Else
                         newR = topR
                         newG = topG