From 5916e9f61cd993ce307cca59c648aac7d4fa194c Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Emmanuel=20Beno=C3=AEt?= <tseeker@nocternity.net>
Date: Tue, 21 Nov 2017 15:48:34 +0100
Subject: [PATCH] Sequencer - Right click selection zoom

---
 syncview.cc | 85 ++++++++++++++++++++++++++++++++++++++++++++++++-----
 1 file changed, 77 insertions(+), 8 deletions(-)

diff --git a/syncview.cc b/syncview.cc
index 7059b81..95c5639 100644
--- a/syncview.cc
+++ b/syncview.cc
@@ -21,6 +21,7 @@ struct T_SyncViewImpl_
 	const uint32_t ColHeader{ ImGui::GetColorU32( ImVec4{ .5 , .5 , .5 , .8 } ) };
 	const uint32_t ColHeaderText{ ImGui::GetColorU32( ImVec4{ 0 , 0 , 0 , 1 } ) };
 	const uint32_t ColMain{ ImGui::GetColorU32( ImVec4{ .4 , .4 , .4 , .8 } ) };
+	const uint32_t ColSelection{ ImGui::GetColorU32( ImVec4{ .8 , 1 , .8 , .2 } ) };
 
 	float zoomLevel{ 0.f };
 	float startPos{ 0.f };
@@ -38,8 +39,18 @@ struct T_SyncViewImpl_
 	uint32_t startBar;
 	float startBarPos;
 	float timePerBar;
+	float totalPixels;
+	float startPixel;
+
+	// Zoom area selection
+	bool zoomInProgress{ false };
+	bool justZoomed{ false };
+	float firstZoomPixel;
+	float curZoomPixel;
 };
 
+constexpr float T_SyncViewImpl_::BarWidth;
+
 
 bool T_SyncViewImpl_::display( ) noexcept
 {
@@ -122,14 +133,13 @@ void T_SyncViewImpl_::sequencerWidget( ) noexcept
 	if ( !ItemAdd( bbAll , seqId ) ) {
 		return;
 	}
+	const bool hovered{ ItemHoverable( bbAll , seqId ) };
 	computeMetrics( std::max( 0.f , width - 2.f ) );
 
-	PushID( seqId );
 	BeginGroup( );
-
 	const auto hdrId{ win->GetID( "##header" ) };
 	const auto dspId{ win->GetID( "##display" ) };
-
+	PushID( seqId );
 	if ( ItemAdd( bbHeader , hdrId ) ) {
 		PushID( hdrId );
 		sequencerHeader( bbHeader );
@@ -140,9 +150,53 @@ void T_SyncViewImpl_::sequencerWidget( ) noexcept
 		sequencerBody( bbDisplay );
 		PopID( );
 	}
+	PopID( );
+
+	auto& io( GetIO( ) );
+	if ( hovered && ( io.MouseDown[ 0 ] || io.MouseDown[ 1 ] ) ) {
+		SetActiveID( seqId , win );
+		FocusWindow( win );
+	}
+
+	const bool active( GetCurrentContext( )->ActiveId == seqId );
+	if ( active ) {
+		if ( io.MouseDown[ 0 ] ) {
+			const float p{ io.MousePos.x - bbAll.Min.x + startPixel };
+			auto& sync( Globals::Sync( ) );
+			sync.setTime( p * Globals::Sync( ).duration( ) / totalPixels );
+		}
+		if ( io.MouseDown[ 1 ] ) {
+			const float p{ io.MousePos.x - bbAll.Min.x + startPixel };
+			if ( !zoomInProgress ) {
+				firstZoomPixel = p;
+				zoomInProgress = true;
+			}
+			curZoomPixel = p;
+		} else if ( zoomInProgress ) {
+			zoomInProgress = false;
+			justZoomed = true;
+			const auto zMin{ std::min( firstZoomPixel , curZoomPixel ) } ,
+			      zMax{ std::max( firstZoomPixel , curZoomPixel ) } ,
+			      diff{ zMax - zMin };
+			if ( diff > 4 ) {
+				auto& sync( Globals::Sync( ) );
+				const float u( sync.durationUnits( ) );
+				startPos = zMin * u / totalPixels;
+				if ( ( width - 2.f ) / u >= BarWidth ) {
+					zoomLevel = 0;
+				} else {
+					const auto length{ std::min( u , diff * u / totalPixels ) };
+					const auto ppu{ std::min( ( width - 2 ) / length , BarWidth ) };
+					zoomLevel = ( ppu - BarWidth ) / ( BarWidth - width / u ) + 1;
+				}
+			}
+		}
+		if ( !( io.MouseDown[ 0 ] || io.MouseDown[ 1 ] ) ) {
+			ClearActiveID( );
+		}
+	}
 
 	EndGroup( );
-	PopID( );
 }
 
 void T_SyncViewImpl_::computeMetrics(
@@ -152,7 +206,7 @@ void T_SyncViewImpl_::computeMetrics(
 	const uint32_t units{ sync.durationUnits( ) };
 	zoomLevel = ImSaturate( zoomLevel );
 	const float zoom1Pixels{ std::max( units * BarWidth , innerWidth ) };
-	const float totalPixels{ zoomLevel * ( zoom1Pixels - innerWidth ) + innerWidth };
+	totalPixels = zoomLevel * ( zoom1Pixels - innerWidth ) + innerWidth;
 	const uint32_t totalBars{ [=](){
 			const float b{ std::max( std::min( totalPixels / BarWidth , float( units ) ) , 1.f ) };
 			const float mod{ fmod( b , 1.f ) };
@@ -169,14 +223,18 @@ void T_SyncViewImpl_::computeMetrics(
 		const float spp{ startPos * totalPixels / units };
 		const float epp{ endPos * totalPixels / units };
 		if ( absCursorPos < spp || absCursorPos > epp ) {
-			startPos = std::max( 0.f , sync.time( ) / uSize - unitsPerBar * .5f );
+			if ( justZoomed ) {
+				followTime = false;
+			} else {
+				startPos = std::max( 0.f , sync.time( ) / uSize - unitsPerBar * .5f );
+			}
 		}
 	}
 	const float unadjustedStartPixel{ totalPixels * startPos / units };
 	if ( unadjustedStartPixel + innerWidth > totalPixels ) {
 		startPos = std::max( 0.f , totalPixels - innerWidth );
 	}
-	const float startPixel{ totalPixels * startPos / units };
+	startPixel = totalPixels * startPos / units;
 	startBar = [=](){
 			const float b{ startPixel * totalBars / totalPixels };
 			const float mod{ fmod( b , 1.f ) };
@@ -185,9 +243,10 @@ void T_SyncViewImpl_::computeMetrics(
 	startBarPos = startBar * barWidth - startPixel;
 	cursorPos = absCursorPos - startPixel;
 	timePerBar = unitsPerBar * sync.durationUnitSize( );
-	printf( "Z: %f; P@zl1: %f; Pt: %f; Bt: %d; U/B: %f; Bw: %f; Sp: %f; Sb: %d, SbP: %f\n" , zoomLevel , zoom1Pixels , totalPixels , totalBars , unitsPerBar , barWidth , startPixel , startBar , startBarPos );
 	assert( startBarPos <= 0 );
 	assert( totalPixels >= innerWidth );
+
+	justZoomed = false;
 }
 
 void T_SyncViewImpl_::sequencerHeader(
@@ -241,6 +300,16 @@ void T_SyncViewImpl_::sequencerBody(
 
 	dl->AddRectFilled( inner.Min , inner.Max , ColMain );
 	dl->AddRect( bb.Min , bb.Max , ColFrame );
+	if ( zoomInProgress ) {
+		const float z0{ ImClamp( firstZoomPixel - startPixel + inner.Min.x , inner.Min.x , inner.Max.x ) } ,
+			      z1{ ImClamp( curZoomPixel - startPixel + bb.Min.x , inner.Min.x , inner.Max.x ) };
+		const float zMin{ std::min( z0 , z1 ) } , zMax{ std::max( z0 , z1 ) };
+		if ( zMin != zMax ) {
+			dl->AddRectFilled( ImVec2{ zMin , inner.Min.y } ,
+					ImVec2{ zMax , inner.Max.y } ,
+					ColSelection );
+		}
+	}
 
 	auto pos{ startBarPos };
 	auto bar{ startBar };