From e756452c40b39fc0fc7ea15b446b88c6c8736c90 Mon Sep 17 00:00:00 2001
From: Andrzej Hunt <andrzej.hunt@collabora.com>
Date: Tue, 10 Jun 2014 17:15:49 +0100
Subject: [PATCH] Add base value to set alpha channel for 32 bit colourspaces.

Currently the alpha channel is completely ignored by basebmp.
However this results in completely "transparent" output, meaning
the client has to manually overwrite the alpha channel -- instead
we now set it automatically when writing colourdata.

Unfortunately this doesn't quite work -- it seems that drawing
a non-opaque bitmap/image on top of the existing bitmap can
erase the alpha channel information (i.e. these areas will
once again be transparent -- for example document borders seem
to have a transition effect overlayed onto them): presumably
there is some method that bypasses our RGBMaskSetter (probably
some form of direct manipulation of raw values?).
manipulation in basebmp

Change-Id: Ia4be6a748cc30191a4422121f9ec347d9198b225
---
 include/basebmp/rgbmaskpixelformats.hxx | 10 ++++++++++
 1 file changed, 10 insertions(+)

diff --git a/include/basebmp/rgbmaskpixelformats.hxx b/include/basebmp/rgbmaskpixelformats.hxx
index d1d9b8464e49..696f35aac846 100644
--- a/include/basebmp/rgbmaskpixelformats.hxx
+++ b/include/basebmp/rgbmaskpixelformats.hxx
@@ -148,6 +148,7 @@ template< typename     PixelType,
 
 template< typename     PixelType,
           typename     ColorType,
+          unsigned int BaseValue,
           unsigned int RedMask,
           unsigned int GreenMask,
           unsigned int BlueMask,
@@ -174,6 +175,7 @@ template< typename     PixelType,
         const typename base_type::unsigned_pixel_type blue (c.getBlue());
 
         typename base_type::unsigned_pixel_type res(
+            BaseValue |
             (shiftLeft(red,
                        base_type::red_shift-8*
                        (signed)sizeof(typename base_type::component_type)+
@@ -194,6 +196,7 @@ template< typename     PixelType,
 
 
 template< typename     PixelType,
+          unsigned int BaseValue,
           unsigned int RedMask,
           unsigned int GreenMask,
           unsigned int BlueMask,
@@ -209,6 +212,7 @@ template< typename     PixelType,
                           SwapBytes>            getter_type;
     typedef RGBMaskSetter<pixel_type,
                           Color,
+                          BaseValue,
                           RedMask,
                           GreenMask,
                           BlueMask,
@@ -256,6 +260,7 @@ template< typename     PixelType,
 // 16bpp MSB RGB
 typedef PixelFormatTraitsTemplate_RGBMask<
     sal_uInt16,
+    0,
     0xF800,
     0x07E0,
     0x001F,
@@ -266,6 +271,7 @@ BASEBMP_SPECIALIZE_ACCESSORTRAITS(PixelFormatTraits_RGB16_565_MSB::getter_type,
 // 16bpp LSB RGB
 typedef PixelFormatTraitsTemplate_RGBMask<
     sal_uInt16,
+    0,
     0xF800,
     0x07E0,
     0x001F,
@@ -286,6 +292,7 @@ BASEBMP_SPECIALIZE_ACCESSORTRAITS(PixelFormatTraits_RGB16_565_LSB::getter_type,
 
 typedef PixelFormatTraitsTemplate_RGBMask<
     sal_uInt32,
+    0xFF000000,
     0x00FF0000,
     0x0000FF00,
     0x000000FF,
@@ -297,6 +304,7 @@ BASEBMP_SPECIALIZE_ACCESSORTRAITS(PixelFormatTraits_BGRX32_8888::getter_type,
 
 typedef PixelFormatTraitsTemplate_RGBMask<
     sal_uInt32,
+    0xFF000000,
     0x00FF0000,
     0x0000FF00,
     0x000000FF,
@@ -308,6 +316,7 @@ BASEBMP_SPECIALIZE_ACCESSORTRAITS(PixelFormatTraits_XRGB32_8888::getter_type,
 
 typedef PixelFormatTraitsTemplate_RGBMask<
     sal_uInt32,
+    0x000000FF,
     0xFF000000,
     0x00FF0000,
     0x0000FF00,
@@ -317,6 +326,7 @@ BASEBMP_SPECIALIZE_ACCESSORTRAITS(PixelFormatTraits_XBGR32_8888::getter_type,
 
 typedef PixelFormatTraitsTemplate_RGBMask<
     sal_uInt32,
+    0x000000FF,
     0xFF000000,
     0x00FF0000,
     0x0000FF00,