[ScreenDebugOverlay] Added BackgroundColor metric.

Docs/Changelog_sm5.txt

@@ -4,9 +4,9 @@ The StepMania 5 Changelog covers all post-sm-ssc changes. For a list of changes
 from StepMania 4 alpha 5 to sm-ssc v1.2.5, see Changelog_sm-ssc.txt.
 ________________________________________________________________________________
 
-================================================================================
-StepMania 5.0 alpha 3 | 20120711
---------------------------------------------------------------------------------
+2012/07/26
+----------
+* [ScreenDebugOverlay] Added BackgroundColor metric. [AJ]
 
 2012/07/19
 ----------
@@ -17,6 +17,10 @@ StepMania 5.0 alpha 3 | 20120711
 ----------
 * [SongManager] Fix a bug where DVNO wouldn't always be gold. [AJ]
 
+================================================================================
+StepMania 5.0 alpha 3 | 20120711
+--------------------------------------------------------------------------------
+
 2012/07/11
 ----------
 * [ScreenEditMenu] Don't use "Blank" in the description for blank steps;

Themes/_fallback/metrics.ini

@@ -1504,6 +1504,8 @@ ShowCreditDisplay=false
 Class="ScreenDebugOverlay"
 Fallback="Screen"
 
+BackgroundColor=color("0,0,0,0.5")
+
 LineOnColor=color("1,1,1,1")
 LineOffColor=color("0.6,0.6,0.6,1")
 LineStartY=SCREEN_TOP+50

src/ScreenDebugOverlay.cpp

@@ -37,6 +37,7 @@ static float g_fImageScaleCurrent = 1;
 static float g_fImageScaleDestination = 1;
 
 // DebugLine theming
+static const ThemeMetric<RageColor>	BACKGROUND_COLOR	("ScreenDebugOverlay", "BackgroundColor");
 static const ThemeMetric<RageColor>	LINE_ON_COLOR	("ScreenDebugOverlay", "LineOnColor");
 static const ThemeMetric<RageColor>	LINE_OFF_COLOR	("ScreenDebugOverlay", "LineOffColor");
 static const ThemeMetric<float>		LINE_START_Y	("ScreenDebugOverlay", "LineStartY");
@@ -238,7 +239,7 @@ void ScreenDebugOverlay::Init()
 	m_bForcedHidden = false;
 
 	m_Quad.StretchTo( RectF( 0, 0, SCREEN_WIDTH, SCREEN_HEIGHT ) );
-	m_Quad.SetDiffuse( RageColor(0, 0, 0, 0.5f) );
+	m_Quad.SetDiffuse( BACKGROUND_COLOR );
 	this->AddChild( &m_Quad );
 
 	// if you're going to add user commands, make sure to have the overrides