Fix interpolation of effects

6f02d6fc made relevant effects respect the smooth property of the layer,
but made a few mistakes in the interpolation binding:

- It got the order of the ternary operator branches wrong: Nearest was
  used when smooth was true, when it should have been Linear.
- It uses the smooth property of the layer, which is automatically set
  by QGfxSourceProxy::updatePolish() as a result of setting its
  interpolation.
- It also used the smooth property of the rootItem, which is the
  overlay itself, and not the source item. It would make more sense to
  base it on the smooth property of the source item, since all
  Item-derived types have this.

Somehow (and luckily) this didn't result in any visible issues.

Task-number: QTBUG-67382
Change-Id: I264579505b4195f5d19e1869e7e579d75bf97d5d
Reviewed-by: Andy Nichols <andy.nichols@qt.io>

7 files changed, 7 insertions, 14 deletions

diff --git a/src/effects/BrightnessContrast.qml b/src/effects/BrightnessContrast.qml
index a95872c..85b38bb 100644
--- a/src/effects/BrightnessContrast.qml
+++ b/src/effects/BrightnessContrast.qml
@@ -167,8 +167,7 @@ Item {
     SourceProxy {
         id: sourceProxy
         input: rootItem.source
-        interpolation: rootItem.smooth || (rootItem.layer.enabled && rootItem.layer.smooth)
-            ? SourceProxy.NearestInterpolation :  SourceProxy.LinearInterpolation
+        interpolation: input && input.smooth ? SourceProxy.LinearInterpolation : SourceProxy.NearestInterpolation
     }
 
     ShaderEffectSource {
diff --git a/src/effects/ColorOverlay.qml b/src/effects/ColorOverlay.qml
index b2cdaa0..f348541 100644
--- a/src/effects/ColorOverlay.qml
+++ b/src/effects/ColorOverlay.qml
@@ -123,8 +123,7 @@ Item {
     SourceProxy {
         id: sourceProxy
         input: rootItem.source
-        interpolation: rootItem.smooth || (rootItem.layer.enabled && rootItem.layer.smooth)
-            ? SourceProxy.NearestInterpolation :  SourceProxy.LinearInterpolation
+        interpolation: input && input.smooth ? SourceProxy.LinearInterpolation : SourceProxy.NearestInterpolation
     }
 
     ShaderEffectSource {
diff --git a/src/effects/Colorize.qml b/src/effects/Colorize.qml
index 501111f..42f1796 100644
--- a/src/effects/Colorize.qml
+++ b/src/effects/Colorize.qml
@@ -210,8 +210,7 @@ Item {
     SourceProxy {
         id: sourceProxy
         input: rootItem.source
-        interpolation: rootItem.smooth || (rootItem.layer.enabled && rootItem.layer.smooth)
-            ? SourceProxy.NearestInterpolation :  SourceProxy.LinearInterpolation
+        interpolation: input && input.smooth ? SourceProxy.LinearInterpolation : SourceProxy.NearestInterpolation
     }
 
     ShaderEffectSource {
diff --git a/src/effects/Desaturate.qml b/src/effects/Desaturate.qml
index 3347e2f..e56de55 100644
--- a/src/effects/Desaturate.qml
+++ b/src/effects/Desaturate.qml
@@ -122,8 +122,7 @@ Item {
     SourceProxy {
         id: sourceProxy
         input: rootItem.source
-        interpolation: rootItem.smooth || (rootItem.layer.enabled && rootItem.layer.smooth)
-            ? SourceProxy.NearestInterpolation :  SourceProxy.LinearInterpolation
+        interpolation: input && input.smooth ? SourceProxy.LinearInterpolation : SourceProxy.NearestInterpolation
     }
 
     ShaderEffectSource {
diff --git a/src/effects/GammaAdjust.qml b/src/effects/GammaAdjust.qml
index e4e39e5..2c3edbb 100644
--- a/src/effects/GammaAdjust.qml
+++ b/src/effects/GammaAdjust.qml
@@ -159,8 +159,7 @@ luminance = pow(original_luminance, 1.0 / gamma); // The luminance is assumed to
     SourceProxy {
         id: sourceProxy
         input: rootItem.source
-        interpolation: rootItem.smooth || (rootItem.layer.enabled && rootItem.layer.smooth)
-            ? SourceProxy.NearestInterpolation :  SourceProxy.LinearInterpolation
+        interpolation: input && input.smooth ? SourceProxy.LinearInterpolation : SourceProxy.NearestInterpolation
     }
 
     ShaderEffectSource {
diff --git a/src/effects/HueSaturation.qml b/src/effects/HueSaturation.qml
index 526f474..eb13dcb 100644
--- a/src/effects/HueSaturation.qml
+++ b/src/effects/HueSaturation.qml
@@ -199,8 +199,7 @@ Item {
     SourceProxy {
         id: sourceProxy
         input: rootItem.source
-        interpolation: rootItem.smooth || (rootItem.layer.enabled && rootItem.layer.smooth)
-            ? SourceProxy.NearestInterpolation :  SourceProxy.LinearInterpolation
+        interpolation: input && input.smooth ? SourceProxy.LinearInterpolation : SourceProxy.NearestInterpolation
     }
 
     ShaderEffectSource {
diff --git a/src/effects/LevelAdjust.qml b/src/effects/LevelAdjust.qml
index 004c798..b98faca 100644
--- a/src/effects/LevelAdjust.qml
+++ b/src/effects/LevelAdjust.qml
@@ -408,8 +408,7 @@ Item {
     SourceProxy {
         id: sourceProxy
         input: rootItem.source
-        interpolation: rootItem.smooth || (rootItem.layer.enabled && rootItem.layer.smooth)
-            ? SourceProxy.NearestInterpolation :  SourceProxy.LinearInterpolation
+        interpolation: input && input.smooth ? SourceProxy.LinearInterpolation : SourceProxy.NearestInterpolation
     }
 
     ShaderEffectSource {