ngscopeclient · Feb 13, 2020 · Feb 14, 2020
Showing with 121 additions and 55 deletions.

+121 −55 glscopeclient/WaveformArea_rendering.cpp
diff --git a/glscopeclient/WaveformArea_rendering.cpp b/glscopeclient/WaveformArea_rendering.cpp
@@ -68,84 +68,152 @@ bool WaveformArea::PrepareGeometry()
 		return false;
 
 	//Create the geometry
-	size_t waveform_size = count * 12;	//3 points * 2 triangles * 2 coordinates
-	m_traceBuffer.resize(waveform_size);
 	double radius = 1;
 	double offset = m_channel->GetOffset();
 	m_xoff = (pdat->m_triggerPhase - m_group->m_timeOffset) * m_group->m_pixelsPerPicosecond;
 	double xscale = pdat->m_timescale * m_group->m_pixelsPerPicosecond;
-	bool dbscale = IsFFT();
-	#pragma omp parallel for num_threads(8)
-	for(size_t j=0; j<(count-1); j++)
-	{
-		//Actual X/Y start/end point of the data
-		float xleft = data.GetSampleStart(j) * xscale;
-		float xright = data.GetSampleStart(j+1) * xscale;
-
-		float yleft;
-		float yright;
 
-		//log scale
-		if(dbscale)
+	//Use old code path for FFT traces, for now
+	if(IsFFT())
+	{
+		size_t waveform_size = count * 12;	//3 points * 2 triangles * 2 coordinates
+		m_traceBuffer.resize(waveform_size);
+		m_waveformLength = count;
+		#pragma omp parallel for num_threads(8)
+		for(size_t j=0; j<(count-1); j++)
 		{
+			//Actual X/Y start/end point of the data
+			float xleft = data.GetSampleStart(j) * xscale;
+			float xright = data.GetSampleStart(j+1) * xscale;
+
 			double db1 = 20 * log10(data[j]);
 			double db2 = 20 * log10(data[j+1]);
 
 			db1 = -70 - db1;	//todo: dont hard code plot limit
 			db2 = -70 - db2;
 
-			yleft = DbToYPosition(db1);
-			yright = DbToYPosition(db2);
+			float yleft = DbToYPosition(db1);
+			float yright = DbToYPosition(db2);
+
+			//Find the normal vector (swap x and y components)
+			float dy = xright - xleft;
+			float dx = yright - yleft;
+
+			//Normalize
+			float scale = radius / sqrt(dy*dy + dx*dx);
+			dx = dx * scale;
+			dy = dy * scale;
+
+			//Calculate final coordinates
+			float x1 = xleft - dx;
+			float y1 = yleft - dy;
+
+			float x2 = xleft + dx;
+			float y2 = yleft + dy;
+
+			float x3 = xright + dx;
+			float y3 = yright + dy;
+
+			float x4 = xright - dx;
+			float y4 = yright - dy;
+
+			//and emit the vertexes
+			size_t base = j*12;
+			m_traceBuffer[base+0] = x2;
+			m_traceBuffer[base+1] = y2;
+
+			m_traceBuffer[base+2] = x1;
+			m_traceBuffer[base+3] = y1;
+
+			m_traceBuffer[base+4] = x3;
+			m_traceBuffer[base+5] = y3;
+
+			m_traceBuffer[base+6] = x1;
+			m_traceBuffer[base+7] = y1;
+
+			m_traceBuffer[base+8] = x3;
+			m_traceBuffer[base+9] = y3;
+
+			m_traceBuffer[base+10] = x4;
+			m_traceBuffer[base+11] = y4;
 		}
+	}
 
-		//normal linear scale
-		else
+	else
+	{
+		size_t waveform_size = count * 12;	//3 points * 2 triangles * 2 coordinates
+		m_traceBuffer.resize(waveform_size);
+		m_waveformLength = count;
+
+		for(size_t j=0; j<(count-1); j++)
 		{
-			yleft = m_pixelsPerVolt * (data[j] + offset);
-			yright = m_pixelsPerVolt * (data[j+1] + offset);
-		}
+			float xleft = data.GetSampleStart(j) * xscale;
+			float xright = xleft + 1;
+			if(xscale > 1)
+				xright = xleft + xscale;
+
+			float ymid = m_pixelsPerVolt * (data[j] + offset);
+			float nextymid = m_pixelsPerVolt * (data[j+1] + offset);
+
+			float ybot = std::min(ymid, nextymid) - 1;
+			float ytop = std::max(ymid, nextymid) + 1;
 
-		//Find the normal vector (swap x and y components
-		float dy = xright - xleft;
-		float dx = yright - yleft;
+			float x1 = xleft;
+			float y1 = ybot;
 
-		//Normalize
-		float scale = radius / sqrt(dy*dy + dx*dx);
-		dx = dx * scale;
-		dy = dy * scale;
+			float x2 = xright;
+			float y2 = ybot;
 
-		//Calculate final coordinates
-		float x1 = xleft - dx;
-		float y1 = yleft - dy;
+			float x3 = xright;
+			float y3 = ytop;
 
-		float x2 = xleft + dx;
-		float y2 = yleft + dy;
+			float x4 = xleft;
+			float y4 = ytop;
 
-		float x3 = xright + dx;
-		float y3 = yright + dy;
+			/*
+				If we stop here, we just get ugly looking boxes when zoomed in.
 
-		float x4 = xright - dx;
-		float y4 = yright - dy;
+				At higher zooms, we need to move the corners a bit.
+				Find the average of our starting Y coordinates and the previous box's end,
+				then move both to that point.
+			 */
+			if( (xscale > 1) && (j > 0) )
+			{
+				size_t oldbase = (j-1)*12;
+
+				float oldtop = m_traceBuffer[oldbase + 9];
+				float oldbot = m_traceBuffer[oldbase + 1];
+
+				y4 = (oldtop + ytop) / 2;
+				y1 = (oldbot + ybot) / 2;
+
+				//Patch up the old points
+				m_traceBuffer[oldbase + 5] = y4;
+				m_traceBuffer[oldbase + 9] = y4;
 
-		//and emit the vertexes
-		size_t base = j*12;
-		m_traceBuffer[base+0] = x2;
-		m_traceBuffer[base+1] = y2;
+				m_traceBuffer[oldbase + 1] = y1;
+			}
+
+			//and emit the vertexes
+			size_t base = j*12;
+			m_traceBuffer[base+0] = x2;
+			m_traceBuffer[base+1] = y2;
 
-		m_traceBuffer[base+2] = x1;
-		m_traceBuffer[base+3] = y1;
+			m_traceBuffer[base+2] = x1;
+			m_traceBuffer[base+3] = y1;
 
-		m_traceBuffer[base+4] = x3;
-		m_traceBuffer[base+5] = y3;
+			m_traceBuffer[base+4] = x3;
+			m_traceBuffer[base+5] = y3;
 
-		m_traceBuffer[base+6] = x1;
-		m_traceBuffer[base+7] = y1;
+			m_traceBuffer[base+6] = x1;
+			m_traceBuffer[base+7] = y1;
 
-		m_traceBuffer[base+8] = x3;
-		m_traceBuffer[base+9] = y3;
+			m_traceBuffer[base+8] = x3;
+			m_traceBuffer[base+9] = y3;
 
-		m_traceBuffer[base+10] = x4;
-		m_traceBuffer[base+11] = y4;
+			m_traceBuffer[base+10] = x4;
+			m_traceBuffer[base+11] = y4;
+		}
 	}
 
 	double dt = GetTime() - start;
@@ -154,16 +222,14 @@ bool WaveformArea::PrepareGeometry()
 
 	//Download waveform data
 	m_traceVBOs[0]->Bind();
-	glBufferData(GL_ARRAY_BUFFER, 0, NULL, GL_DYNAMIC_DRAW);
-	glBufferData(GL_ARRAY_BUFFER, sizeof(float) * m_traceBuffer.size(), &m_traceBuffer[0], GL_DYNAMIC_DRAW);
+	glInvalidateBufferData(GL_ARRAY_BUFFER);
+	glBufferData(GL_ARRAY_BUFFER, sizeof(float) * m_traceBuffer.size(), &m_traceBuffer[0], GL_STREAM_DRAW);
 
 	//Configure vertex array settings
 	m_traceVAOs[0]->Bind();
 	m_waveformProgram.EnableVertexArray("vert");
 	m_waveformProgram.SetVertexAttribPointer("vert", 2, 0);
 
-	m_waveformLength = count;
-
 	dt = GetTime() - start;
 	m_downloadTime += dt;