add calc interval bars to notefield, add lua access to beatbars too

Themes/Til Death/BGAnimations/_chartpreview.lua

@@ -126,7 +126,13 @@ local t = Def.ActorFrame {
 			else
 				self:LoadDummyNoteData()
 			end
-		end
+		end,
+		CalcInfoOnMessageCommand = function(self)
+			self:show_interval_bars(true)
+		end,
+		CalcInfoOffMessageCommand = function(self)
+			self:show_interval_bars(false)
+		end,
 	},
 
 	Def.Quad {

Themes/_fallback/metrics.ini

@@ -668,6 +668,7 @@ ShowBeatBars=false
 FadeBeforeTargetsPercent=0
 FadeFailTime=1.5
 #
+CalcBarAlpha=0.6
 BarMeasureAlpha=1
 Bar4thAlpha=1
 Bar8thAlpha=1

src/Etterna/Actor/Gameplay/NoteField.cpp

@@ -32,6 +32,7 @@ static ThemeMetric<bool> SHOW_BEAT_BARS("NoteField", "ShowBeatBars");
 static ThemeMetric<float> FADE_BEFORE_TARGETS_PERCENT(
   "NoteField",
   "FadeBeforeTargetsPercent");
+static ThemeMetric<float> CALC_BAR_ALPHA("NoteField", "CalcBarAlpha");
 static ThemeMetric<float> BAR_MEASURE_ALPHA("NoteField", "BarMeasureAlpha");
 static ThemeMetric<float> BAR_4TH_ALPHA("NoteField", "Bar4thAlpha");
 static ThemeMetric<float> BAR_8TH_ALPHA("NoteField", "Bar8thAlpha");
@@ -450,6 +451,32 @@ NoteField::DrawBeatBar(const float fBeat, BeatBarType type, int iMeasureIndex)
 	m_sprBeatBars.Draw();
 }
 
+void
+NoteField::DrawCalcIntervalBar(const float fBeat)
+{
+	const auto fYOffset = ArrowEffects::GetYOffset(m_pPlayerState, 0, fBeat);
+	const auto fYPos =
+	  ArrowEffects::GetYPos(0, fYOffset, m_fYReverseOffsetPixels);
+
+	const float fAlpha = CALC_BAR_ALPHA;
+	const int iState = 0;
+
+	const auto fWidth = GetWidth();
+	const auto fFrameWidth = m_sprBeatBars.GetUnzoomedWidth();
+
+	m_sprBeatBars.SetX(0);
+	m_sprBeatBars.SetY(fYPos);
+	m_sprBeatBars.SetDiffuse(RageColor(1, 1, 1, fAlpha));
+	m_sprBeatBars.SetState(iState);
+	m_sprBeatBars.SetCustomTextureRect(
+	  RectF(0,
+			SCALE(iState, 0.f, 4.f, 0.f, 1.f),
+			fWidth / fFrameWidth,
+			SCALE(iState + 1, 0.f, 4.f, 0.f, 1.f)));
+	m_sprBeatBars.SetZoomX(fWidth / m_sprBeatBars.GetUnzoomedWidth());
+	m_sprBeatBars.Draw();
+}
+
 void
 NoteField::DrawBoard(int iDrawDistanceAfterTargetsPixels,
 					 int iDrawDistanceBeforeTargetsPixels)
@@ -751,7 +778,7 @@ NoteField::DrawPrimitives()
 
 	unsigned i = 0;
 	// Draw beat bars
-	if (SHOW_BEAT_BARS && pTiming != nullptr) {
+	if ((SHOW_BEAT_BARS || showBeatBars) && pTiming != nullptr) {
 		const auto& tSigs = *segs[SEGMENT_TIME_SIG];
 		auto iMeasureIndex = 0;
 		for (i = 0; i < tSigs.size(); i++) {
@@ -791,6 +818,26 @@ NoteField::DrawPrimitives()
 			}
 		}
 	}
+	if (showCalcBars && pTiming != nullptr) {
+		const auto intervalSize =
+		  0.5F * GAMESTATE->m_SongOptions.GetCurrent().m_fMusicRate;
+
+		const auto firstIntervalStart =
+		  pTiming->GetElapsedTimeFromBeat(m_pNoteData->GetFirstBeat());
+		const auto visibleSecondStart =
+		  GAMESTATE->m_Position.m_fMusicSecondsVisible;
+		const auto visibleSecondEnd =
+		  pTiming->GetElapsedTimeFromBeat(m_FieldRenderArgs.last_beat);
+
+		const auto distanceThroughInterval =
+		  fmodf(visibleSecondStart - firstIntervalStart, intervalSize);
+		const auto realStart = visibleSecondStart - distanceThroughInterval;
+		for (auto timePos = realStart; timePos <= visibleSecondEnd;
+			 timePos += intervalSize) {
+			const auto fBeat = pTiming->GetBeatFromElapsedTime(timePos);
+			DrawCalcIntervalBar(fBeat);
+		}
+	}
 
 	// Optimization is very important here because there are so many arrows to
 	// draw. Draw the arrows in order of column. This minimizes texture switches
@@ -1076,6 +1123,18 @@ class LunaNoteField : public Luna<NoteField>
 		return 1;
 	}
 
+	static int show_beat_bars(T* p, lua_State* L)
+	{
+		p->SetShowBeatBars(BArg(1));
+		COMMON_RETURN_SELF;
+	}
+
+	static int show_interval_bars(T* p, lua_State* L)
+	{
+		p->SetShowIntervalBars(BArg(1));
+		COMMON_RETURN_SELF;
+	}
+
 	LunaNoteField()
 	{
 		ADD_METHOD(set_step_callback);
@@ -1087,6 +1146,8 @@ class LunaNoteField : public Luna<NoteField>
 		ADD_METHOD(did_tap_note);
 		ADD_METHOD(did_hold_note);
 		ADD_METHOD(get_column_actors);
+		ADD_METHOD(show_beat_bars);
+		ADD_METHOD(show_interval_bars);
 	}
 };
 

src/Etterna/Actor/Gameplay/NoteField.h

@@ -52,6 +52,9 @@ class NoteField : public ActorFrame
 
 	void PushSelf(lua_State* L) override;
 
+	void SetShowBeatBars(bool b) { showBeatBars = b; }
+	void SetShowIntervalBars(bool b) { showCalcBars = b; }
+
 	// Allows the theme to modify the parameters to Step, SetPressed,
 	// DidTapNote, and DidHoldNote before they pass on to the ghost arrows or
 	// receptors. -Kyz
@@ -86,6 +89,7 @@ class NoteField : public ActorFrame
 		quarter_beat
 	};
 	void DrawBeatBar(float fBeat, BeatBarType type, int iMeasureIndex);
+	void DrawCalcIntervalBar(const float fBeat);
 	void DrawMarkerBar(int fBeat);
 	void DrawAreaHighlight(int iStartBeat, int iEndBeat);
 	void set_text_measure_number_for_draw(float beat,
@@ -112,6 +116,8 @@ class NoteField : public ActorFrame
 	int m_iDrawDistanceAfterTargetsPixels;	// this should be a negative number
 	int m_iDrawDistanceBeforeTargetsPixels; // this should be a positive number
 	float m_fYReverseOffsetPixels;
+	bool showCalcBars = false;
+	bool showBeatBars = false;
 
 	// This exists so that the board can be drawn underneath combo/judge. -Kyz
 	bool m_drawing_board_primitive;