remove support for BITMASK in vcl backends

Rather use a proper alpha channel if we need transparency.

This is another small step towards merged alpha in our vcl
layer.

I suspect the intent in a lot of this code was to save memory.
Which have been a thing way back then, but these days our
backends mostly end up doing a copy-and-convert to a real
alpha channel anyway, so the existing code is actually
now a pessimisation.

Change-Id: I4a2bcbb2f76b841f05bc00580f364492829c69de
Reviewed-on: https://gerrit.libreoffice.org/c/core/+/114808
Tested-by: Jenkins
Reviewed-by: Noel Grandin <noel.grandin@collabora.co.uk>

2 files changed, 7 insertions, 15 deletions

diff --git a/include/vcl/salgtype.hxx b/include/vcl/salgtype.hxx
index 1ab62fbdb6c7..a6559d68da23 100644
--- a/include/vcl/salgtype.hxx
+++ b/include/vcl/salgtype.hxx
@@ -28,7 +28,6 @@
 enum class DeviceFormat {
                             NONE = -1,
                             DEFAULT = 0,
-                            BITMASK = 1,
 #ifdef IOS
                             GRAYSCALE = 8
 #endif
diff --git a/include/vcl/virdev.hxx b/include/vcl/virdev.hxx
index 55a4a7f5ddcb..459660eb71cd 100644
--- a/include/vcl/virdev.hxx
+++ b/include/vcl/virdev.hxx
@@ -82,13 +82,11 @@ protected:
 
         @param eFormat
         Device format of the generated virtual device. Use DeviceFormat::DEFAULT here, to
-        indicate: take default screen depth. Only DeviceFormat::BITMASK
-        is the other possibility to denote a binary mask.
+        indicate: take default screen depth.
 
         @param eAlphaFormat
         Device format of the generated virtual device. Use DeviceFormat::DEFAULT here, to
-        indicate: take default screen depth. Only DeviceFormat::BITMASK
-        is the other possibility to denote a binary mask.
+        indicate: take default screen depth.
 
         @param eOutDevType
         This real virtual output device type.
@@ -102,13 +100,11 @@ public:
 
         @param eFormat
         Device format of the generated virtual device. Use DeviceFormat::DEFAULT here, to
-        indicate: take default screen depth. Only DeviceFormat::BITMASK
-        is the other possibility to denote a binary mask.
+        indicate: take default screen depth.
 
         @param eAlphaFormat
         Device format of the generated virtual device. Use DeviceFormat::DEFAULT here, to
-        indicate: take default screen depth. Only DeviceFormat::BITMASK
-        is the other possibility to denote a binary mask.
+        indicate: take default screen depth.
      */
     explicit VirtualDevice(DeviceFormat eFormat = DeviceFormat::DEFAULT, DeviceFormat eAlphaFormat = DeviceFormat::NONE)
         : VirtualDevice(nullptr, eFormat, eAlphaFormat, OUTDEV_VIRDEV) {}
@@ -120,8 +116,7 @@ public:
 
         @param eFormat
         Device format of the generated virtual device. Use DeviceFormat::DEFAULT here, to
-        indicate: take default screen depth. Only DeviceFormat::BITMASK
-        is the other possibility to denote a binary mask.
+        indicate: take default screen depth.
      */
     explicit VirtualDevice(const OutputDevice& rCompDev,
                            DeviceFormat eFormat = DeviceFormat::DEFAULT)
@@ -134,13 +129,11 @@ public:
 
         @param eFormat
         Device format of the generated virtual device. Use DeviceFormat::DEFAULT here, to
-        indicate: take default screen depth. Only DeviceFormat::BITMASK
-        is the other possibility to denote a binary mask.
+        indicate: take default screen depth.
 
         @param eAlphaFormat
         Device format of the generated virtual device. Use DeviceFormat::DEFAULT here, to
-        indicate: take default screen depth. Only DeviceFormat::BITMASK
-        is the other possibility to denote a binary mask.
+        indicate: take default screen depth.
      */
     explicit VirtualDevice(const OutputDevice& rCompDev,
                            DeviceFormat eFormat, DeviceFormat eAlphaFormat)