Optimize timeline drawing to avoid fully overlapped message sends and pack times

Previously, EPs were not drawn if they didn't paint any new pixels (which is
often the case when zoomed far out, many small EPs can correspond to the same
pixel). This generalizes that optimization to message send ticks and pack times.

Change-Id: Idfbf97328fb2590c51b47937b6add904f6d8bad1

Author: rbuch

src/projections/Tools/Timeline/EntryMethodObject.java

@@ -763,10 +763,11 @@ public boolean isDisplayed() {
 	}
 
 
-	public int paintMe(Graphics2D g2d, int actualDisplayWidth, int maxFilledX){
+	public boolean paintMe(Graphics2D g2d, int actualDisplayWidth, MainPanel.MaxFilledX maxFilledX){
+		boolean paintedEP = false;
 		// If it is hidden, we may not display it
 		if(!isDisplayed()){
-			return -1;
+			return paintedEP;
 		}
 
 		int leftCoord = data.timeToScreenPixel(beginTime, actualDisplayWidth);
@@ -798,7 +799,9 @@ public int paintMe(Graphics2D g2d, int actualDisplayWidth, int maxFilledX){
 		}
 
 		// Only draw this EMO if it covers some pixel that hasn't been filled yet
-		if (right > maxFilledX) {
+		if (right > maxFilledX.ep) {
+			maxFilledX.ep = right;
+			paintedEP = true;
 
 			// Determine the base color
 			Paint c = determineColor();
@@ -878,7 +881,10 @@ public int paintMe(Graphics2D g2d, int actualDisplayWidth, int maxFilledX){
 					// Compute the end pixel coordinate relative to the containing panel
 					int packEndCoordX = data.timeToScreenPixelRight(packEndTime);
 
-					g2d.fillRect(packBeginCoordX, topCoord+verticalInset+rectHeight, (packEndCoordX-packBeginCoordX+1), data.messagePackHeight());
+					if (packEndCoordX > maxFilledX.pack) {
+						maxFilledX.pack = packEndCoordX;
+						g2d.fillRect(packBeginCoordX, topCoord + verticalInset + rectHeight, (packEndCoordX - packBeginCoordX + 1), data.messagePackHeight());
+					}
 
 				}
 			}
@@ -898,13 +904,15 @@ public int paintMe(Graphics2D g2d, int actualDisplayWidth, int maxFilledX){
 				{
 					// Compute the pixel coordinate relative to the containing panel
 					int msgCoordX = data.timeToScreenPixel(msgtime);
-
-					g2d.drawLine(msgCoordX, topCoord+verticalInset+rectHeight, msgCoordX, topCoord+verticalInset+rectHeight+data.messageSendHeight());
+					if (msgCoordX > maxFilledX.msg) {
+						maxFilledX.msg = msgCoordX;
+						g2d.drawLine(msgCoordX, topCoord + verticalInset + rectHeight, msgCoordX, topCoord + verticalInset + rectHeight + data.messageSendHeight());
+					}
 				}
 			}
 		}
 
-		return right;
+		return paintedEP;
 	}
 
 

src/projections/Tools/Timeline/MainPanel.java

@@ -210,6 +210,18 @@ public void paintInParallel(Graphics g){
 
 	}
 
+	/**
+	 * Stores the maximum x coordinates of what has been drawn so far to avoid unnecessary overlapped drawing
+	 */
+	public class MaxFilledX {
+		public int ep, pack, msg;
+
+		public MaxFilledX() {
+			ep = 0;
+			pack = 0;
+			msg = 0;
+		}
+	}
 	/**
 	 * Paint the desired clipped region for this component 
 	 * 
@@ -234,13 +246,14 @@ public long paintAll(Graphics2D g){
 
 			if(l != null){ // FIXME: this shouldn't be here but is to fix a race condition with reloading ranges once something is displayed
 				Iterator<EntryMethodObject> iter = l.iterator(leftClipTime, rightClipTime);
-				int maxFilledX = 0; // Tracks maximum x index of filled pixels for this PE, used to optimize away
-				                    // drawing of multiple overlapping single pixel entry methods
+
+				// Saves the furthest right position EPs and msg lines have been drawn in
+				// order to optimize performance by only drawing when new pixels will be colored in
+				MaxFilledX maxFilledX = new MaxFilledX();
+
 				while(iter.hasNext()){
 					EntryMethodObject o = iter.next();
-					int emoMaxFilledX = o.paintMe((Graphics2D) g, getWidth(), maxFilledX);
-					if (emoMaxFilledX > maxFilledX) {
-						maxFilledX = emoMaxFilledX;
+					if(o.paintMe((Graphics2D) g, getWidth(), maxFilledX)) {
 						count1++;
 					}
 				}