Finished implementation of MidiPlayer. Yay!

git-svn-id: file:///srv/svn/repos/haiku/trunk/current@8064 a95241bf-73f2-0310-859d-f6bbb57e9c96

src/apps/midiplayer/ScopeView.cpp

@@ -20,23 +20,77 @@
  * DEALINGS IN THE SOFTWARE.
  */
 
+#include <Synth.h>
+#include <Window.h>
+
 #include "ScopeView.h"
 
 //------------------------------------------------------------------------------
 
 ScopeView::ScopeView()
-	: BView(BRect(0, 0, 127, 47), NULL, B_FOLLOW_LEFT | B_FOLLOW_TOP,
-	        B_WILL_DRAW | B_PULSE_NEEDED)
+	: BView(BRect(0, 0, 127, 63), NULL, B_FOLLOW_LEFT | B_FOLLOW_TOP,
+	        B_WILL_DRAW)
 {
 	SetViewColor(0, 0, 0);
+
 	enabled = true;
 	haveFile = false;
+	
+	sampleCount = (int32) Bounds().Width();
+	leftSamples = new int16[sampleCount];
+	rightSamples = new int16[sampleCount];
 }
 
 //------------------------------------------------------------------------------
 
 ScopeView::~ScopeView()
 {
+	delete[] leftSamples;
+	delete[] rightSamples;
+}
+
+//------------------------------------------------------------------------------
+
+void ScopeView::AttachedToWindow()
+{
+	finished = false;
+	threadId = spawn_thread(_Thread, "ScopeThread", B_NORMAL_PRIORITY, this);
+	if (threadId >= B_OK)
+	{
+		resume_thread(threadId);
+	}
+}
+
+//------------------------------------------------------------------------------
+
+void ScopeView::DetachedFromWindow()
+{
+	if (threadId >= B_OK)
+	{
+		finished = true;
+		status_t exitValue;
+		wait_for_thread(threadId, &exitValue);
+	}
+}
+
+//------------------------------------------------------------------------------
+
+void ScopeView::Draw(BRect updateRect)
+{
+	super::Draw(updateRect);
+
+	if (!haveFile)
+	{
+		DrawNoFile();
+	}
+	else if (!enabled)
+	{
+		DrawDisabled();
+	}
+	else 
+	{
+		DrawPlaying();
+	}
 }
 
 //------------------------------------------------------------------------------
@@ -54,3 +108,94 @@ void ScopeView::SetHaveFile(bool flag)
 }
 
 //------------------------------------------------------------------------------
+
+int32 ScopeView::_Thread(void* data)
+{
+	return ((ScopeView*) data)->Thread();
+}
+
+//------------------------------------------------------------------------------
+
+int32 ScopeView::Thread()
+{
+	// Because Pulse() was too slow, I created a thread that tells the 
+	// ScopeView to repaint itself. Note that we need to call LockLooper
+	// with a timeout, otherwise we'll deadlock in DetachedFromWindow().
+
+	while (!finished)
+	{
+		if (enabled && haveFile)
+		{
+			if (LockLooperWithTimeout(50000) == B_OK)
+			{
+				Invalidate();
+				UnlockLooper();
+			}
+		}
+		snooze(50000);
+	}
+	return 0;
+}
+
+//------------------------------------------------------------------------------
+
+void ScopeView::DrawNoFile()
+{
+	const char* string = "Drop MIDI file here";
+
+	font_height height;
+	GetFontHeight(&height);
+
+	float strWidth = StringWidth(string);
+	float strHeight = height.ascent + height.descent;
+
+	float x = (Bounds().Width() - strWidth)/2;
+	float y = height.ascent + (Bounds().Height() - strHeight)/2;
+
+	SetHighColor(255, 255, 255);
+	SetLowColor(ViewColor());
+	SetDrawingMode(B_OP_OVER);
+
+	DrawString(string, BPoint(x, y));
+}
+
+//------------------------------------------------------------------------------
+
+void ScopeView::DrawDisabled()
+{
+	SetHighColor(64, 64, 64);
+
+	StrokeLine(
+		BPoint(0, Bounds().Height() / 2), 
+		BPoint(Bounds().Width(), Bounds().Height() / 2));
+}
+
+//------------------------------------------------------------------------------
+
+void ScopeView::DrawPlaying()
+{
+	int32 width = (int32) Bounds().Width();
+	int32 height = (int32) Bounds().Height();
+
+	// Scope drawing magic based on code by Michael Pfeiffer.
+	
+	int32 size = be_synth->GetAudio(leftSamples, rightSamples, sampleCount);
+	if (size > 0)
+	{
+		SetHighColor(255, 0, 130);
+		SetLowColor(0, 130, 0);
+		#define N 16
+		int32 x, y, sx = 0, f = (height << N) / 65535, dy = height / 2;
+		for (int32 i = 0; i < width; i++)
+		{
+			x = sx / width;
+			y = ((leftSamples[x] * f) >> N) + dy;
+			FillRect(BRect(i, y, i, y));
+			y = ((rightSamples[x] * f) >> N) + dy;
+			FillRect(BRect(i, y, i, y), B_SOLID_LOW);
+			sx += size;
+		}
+	}
+}
+
+//------------------------------------------------------------------------------