varying lifebar amounts for HowToPlay screen

stepmania/src/LifeMeterBar.cpp

@@ -707,3 +707,15 @@ void LifeStream::DrawPrimitives()
 
 }
 */
+
+void LifeMeterBar::FillForHowToPlay(int NumPerfects, int NumMisses)
+{
+	m_iProgressiveLifebar = 0;  // disable progressive lifebar
+
+	float AmountForPerfect	= NumPerfects * m_fLifeDifficulty * 0.008f;
+	float AmountForMiss		= NumMisses / m_fLifeDifficulty * 0.08f;
+
+	m_fLifePercentage = AmountForMiss - AmountForPerfect;
+	CLAMP( m_fLifePercentage, 0.0f, 1.0f );
+	AfterLifeChanged();
+}

stepmania/src/LifeMeterBar.h

@@ -38,6 +38,8 @@ public:
 	virtual bool FailedEarlier();
 
 	void UpdateNonstopLifebar(int cleared, int total, int ProgressiveLifebarDifficulty);
+	void FillForHowToPlay(int NumPerfects, int NumMisses);
+	// this function is solely for HowToPlay
 
 private:
 	void ResetBarVelocity();

stepmania/src/ScreenHowToPlay.cpp

@@ -46,7 +46,9 @@ ScreenHowToPlay::ScreenHowToPlay() : ScreenAttract("ScreenHowToPlay")
 	m_LifeMeterBar.SetXY( 480, 40 );
 	// we need to be a little lower than half if we want to hit
 	// zero with the actual miss steps. cheat.
-	m_LifeMeterBar.ChangeLife(TNS_MISS);
+//	m_LifeMeterBar.ChangeLife(TNS_MISS);
+	// nicer fix :P  it depends on difficulty
+	m_LifeMeterBar.FillForHowToPlay(4, 6);
 
 	// Display random character+pad
 	if( GAMESTATE->m_pCharacters.size() )