Add Xorg composition support to kdm

KDM composition can be enabled in the control center
When enabled, it provides seamless composited logins to Trinity sessions
It also gets rid of the remaining artifacts in the themed kdm login screen


git-svn-id: svn://anonsvn.kde.org/home/kde/branches/trinity/kdebase@1246834 283d02a7-25f6-0310-bc7c-ecb5cbfe19da

1 files changed, 42 insertions, 9 deletions

diff --git a/kdm/kfrontend/themer/kdmpixmap.cpp b/kdm/kfrontend/themer/kdmpixmap.cpp
index af64714b8..436483c48 100644
--- a/kdm/kfrontend/themer/kdmpixmap.cpp
+++ b/kdm/kfrontend/themer/kdmpixmap.cpp
@@ -37,6 +37,8 @@
 #include <tqpixmap.h>
 #include <tqimage.h>
 
+extern bool argb_visual_available;
+
 KdmPixmap::KdmPixmap( KdmItem *parent, const TQDomNode &node, const char *name )
     : KdmItem( parent, node, name )
 {
@@ -47,6 +49,7 @@ KdmPixmap::KdmPixmap( KdmItem *parent, const TQDomNode &node, const char *name )
 	pixmap.normal.alpha = 0.0;
 	pixmap.active.present = false;
 	pixmap.prelight.present = false;
+	bool true_transparency = false;
 
 	// Read PIXMAP ID
 	// it rarely happens that a pixmap can be a button too!
@@ -66,13 +69,20 @@ KdmPixmap::KdmPixmap( KdmItem *parent, const TQDomNode &node, const char *name )
 			pixmap.normal.alpha = el.attribute( "alpha", "1.0" ).toFloat();
 
 			if (el.attribute( "file", "" ) == "@@@KDMBACKGROUND@@@") {
-				// Use the preset KDM background...
-				KStandardDirs *m_pDirs = KGlobal::dirs();
-				KSimpleConfig *config = new KSimpleConfig( TQFile::decodeName( _backgroundCfg ) );
-				config->setGroup("Desktop0");
-				pixmap.normal.fullpath = m_pDirs->findResource("wallpaper", config->readPathEntry("Wallpaper"));
-				// TODO: Detect when there is no wallpaper and use the background settings instead
-				delete config;
+				if ((_compositor.isEmpty()) || (!argb_visual_available)) {
+					// Software blend only (no compositing support)
+					// Use the preset KDM background...
+					KStandardDirs *m_pDirs = KGlobal::dirs();
+					KSimpleConfig *config = new KSimpleConfig( TQFile::decodeName( _backgroundCfg ) );
+					config->setGroup("Desktop0");
+					pixmap.normal.fullpath = m_pDirs->findResource("wallpaper", config->readPathEntry("Wallpaper"));
+					// TODO: Detect when there is no wallpaper and use the background settings instead
+					delete config;
+				}
+				else {
+					true_transparency = true;
+					pixmap.normal.alpha = 0.0;
+				}
 			}
 
 		} else if (tagName == "active") {
@@ -189,7 +199,6 @@ KdmPixmap::drawContents( TQPainter *p, const TQRect &r )
 	kdDebug() << "draw " << id << " " << pClass->pixmap.isNull() << endl;
  
 	if (pClass->pixmap.isNull()) {
-	        
 	        if (pClass->fullpath.isEmpty())	// if neither is set, we're empty
 			return;
 		
@@ -246,7 +255,7 @@ KdmPixmap::drawContents( TQPainter *p, const TQRect &r )
 		  if (haveTint || haveAlpha)
                   {
 			scaledImage = pClass->pixmap.convertToImage();
-                        // enforce rgba values for the later
+                        // enforce rgba values for the latter
                         scaledImage = scaledImage.convertDepth( 32 );
                   }
 		  else
@@ -275,7 +284,31 @@ KdmPixmap::drawContents( TQPainter *p, const TQRect &r )
 					ls[x] = tqRgba( r, g, b, a );
 				}
 			}
+		}
+		if ((_compositor.isEmpty()) || (!argb_visual_available)) {
+			// Software blend only (no compositing support)
+		}
+		else {
+			// We have a compositor!
+			// Apply the alpha in the same manner as above, exept we are now
+			// using the hardware blending engine for all painting
+			scaledImage = pClass->readyPixmap;
+			scaledImage = scaledImage.convertDepth( 32 );
+			int w = scaledImage.width();
+			int h = scaledImage.height();
 
+			for (int y = 0; y < h; ++y) {
+				QRgb *ls = (QRgb *)scaledImage.scanLine( y );
+				for (int x = 0; x < w; ++x) {
+					QRgb l = ls[x];
+					float alpha_adjust = (tqAlpha( l )/256.0);
+					int r = int( tqRed( l ) * alpha_adjust );
+					int g = int( tqGreen( l ) * alpha_adjust );
+					int b = int( tqBlue( l ) * alpha_adjust );
+					int a = int( tqAlpha( l ) * 1 );
+					ls[x] = tqRgba( r, g, b, a );
+				}
+			}
 		}
 
 		if (!scaledImage.isNull()) {