arrow visibility fix

stepmania/src/ArrowEffects.cpp

@@ -20,7 +20,10 @@ static float GetNoteFieldHeight( PlayerNumber pn )
 	return SCREEN_HEIGHT + fabsf(GAMESTATE->m_CurrentPlayerOptions[pn].m_fPerspectiveTilt)*200;
 }
 
-float ArrowGetYOffset( PlayerNumber pn, int iCol, float fNoteBeat )
+/* For visibility testing: if iAbsolute is -1, then all random modifiers must return
+ * the minimal possible offset; if +1, they must return the maximum possible offset.
+ * When actually rendering, iAbsolute is 0. */
+float ArrowGetYOffset( PlayerNumber pn, int iCol, float fNoteBeat, int iAbsolute )
 {
 	float fYOffset = 0;
 
@@ -83,14 +86,22 @@ float ArrowGetYOffset( PlayerNumber pn, int iCol, float fNoteBeat )
 		fYOffset +=	fAccels[PlayerOptions::ACCEL_BOOMERANG] * (fYOffset * SCALE( fYOffset, 0.f, SCREEN_HEIGHT, 1.5f, 0.5f )- fYOffset);
 
 	float fScrollSpeed = GAMESTATE->m_CurrentPlayerOptions[pn].m_fScrollSpeed;
-	if ( GAMESTATE->m_CurrentPlayerOptions[pn].m_fRandomSpeed > 1.0f )
+	if( GAMESTATE->m_CurrentPlayerOptions[pn].m_fRandomSpeed > 1.0f )
 	{
 		int seed = GAMESTATE->m_iRoundSeed + ( BeatToNoteRow( fNoteBeat ) << 8 ) + (iCol * 100);
-		float soRandom = RandomFloat( seed );
+		float fRandom;
+		switch( iAbsolute )
+		{
+		case 0: fRandom = RandomFloat( seed ); break;
+		case -1: fRandom = 1.0f; break; /* highest scroll speed = lowest visibility */
+		case +1: fRandom = 0.0f; break;
+		default: FAIL_M( ssprintf("%i",iAbsolute) );
+		};
+
 		fScrollSpeed *=
-							SCALE( soRandom,
-								   0.0f, 1.0f,
-								   1.0f, GAMESTATE->m_CurrentPlayerOptions[pn].m_fRandomSpeed ); // min. scale shold be defined as a constatnt somewhere
+				SCALE( fRandom,
+						0.0f, 1.0f,
+						1.0f, GAMESTATE->m_CurrentPlayerOptions[pn].m_fRandomSpeed ); // min. scale shold be defined as a constatnt somewhere
 	}	
 
 

stepmania/src/ArrowEffects.h

@@ -11,7 +11,7 @@
 //	fYOffset is a vertical position in pixels relative to the center.
 //	(positive if has not yet been stepped on, negative if has already passed).
 //	The ArrowEffect and ScrollSpeed is applied in this stage.
-float ArrowGetYOffset( PlayerNumber pn, int iCol, float fNoteBeat );
+float ArrowGetYOffset( PlayerNumber pn, int iCol, float fNoteBeat, int iAbsolute = 0 );
 
 /* Actual display position, with reverse and post-reverse-effects factored in
  * (fYOffset -> YPos). */

stepmania/src/NoteField.cpp

@@ -354,7 +354,7 @@ float FindFirstDisplayedBeat( PlayerNumber pn, int iFirstPixelToDraw )
 
 	while( fFirstBeatToDraw < GAMESTATE->m_fSongBeat )
 	{
-		float fYOffset = ArrowGetYOffset(pn, 0, fFirstBeatToDraw);
+		float fYOffset = ArrowGetYOffset( pn, 0, fFirstBeatToDraw, -1 );
 		if( fYOffset < iFirstPixelToDraw )	// off screen
 			fFirstBeatToDraw += 0.1f;	// move toward fSongBeat
 		else	// on screen
@@ -378,7 +378,7 @@ float FindLastDisplayedBeat( PlayerNumber pn, int iLastPixelToDraw )
 
 	for( int i=0; i<NUM_ITERATIONS; i++ )
 	{
-		float fYOffset = ArrowGetYOffset( pn, 0, fLastBeatToDraw );
+		float fYOffset = ArrowGetYOffset( pn, 0, fLastBeatToDraw, +1 );
 
 		if( fYOffset > iLastPixelToDraw )	// off screen
 			fLastBeatToDraw -= fSearchDistance;