Tweaks to ink annotation for smoothness.

Patch from "andyhan2000" to make the ink annotations smoother.

3 files changed, 80 insertions, 16 deletions

diff --git a/android/src/com/artifex/mupdfdemo/MuPDFReaderView.java b/android/src/com/artifex/mupdfdemo/MuPDFReaderView.java
index 3a1b708a..9cab70b7 100644
--- a/android/src/com/artifex/mupdfdemo/MuPDFReaderView.java
+++ b/android/src/com/artifex/mupdfdemo/MuPDFReaderView.java
@@ -96,13 +96,7 @@ public class MuPDFReaderView extends ReaderView {
 
 	@Override
 	public boolean onDown(MotionEvent e) {
-		switch (mMode) {
-		case Drawing:
-			MuPDFView pageView = (MuPDFView)getDisplayedView();
-			if (pageView != null)
-				pageView.startDraw(e.getX(), e.getY());
-			break;
-		}
+
 		return super.onDown(e);
 	}
 
@@ -119,10 +113,6 @@ public class MuPDFReaderView extends ReaderView {
 			if (pageView != null)
 				pageView.selectText(e1.getX(), e1.getY(), e2.getX(), e2.getY());
 			return true;
-		case Drawing:
-			if (pageView != null)
-				pageView.continueDraw(e2.getX(), e2.getY());
-			return true;
 		default:
 			return true;
 		}
@@ -148,12 +138,69 @@ public class MuPDFReaderView extends ReaderView {
 	}
 
 	public boolean onTouchEvent(MotionEvent event) {
-		if ((event.getAction() & event.ACTION_MASK) == MotionEvent.ACTION_DOWN)
+
+		if ( mMode == Mode.Drawing )
+		{
+			float x = event.getX();
+			float y = event.getY();
+			switch (event.getAction())
+			{
+				case MotionEvent.ACTION_DOWN:
+					touch_start(x, y);
+					break;
+				case MotionEvent.ACTION_MOVE:
+					touch_move(x, y);
+					break;
+				case MotionEvent.ACTION_UP:
+					touch_up();
+					break;
+			}
+		}
+
+		if ((event.getAction() & event.getActionMasked()) == MotionEvent.ACTION_DOWN)
+		{
 			tapDisabled = false;
+		}
 
 		return super.onTouchEvent(event);
 	}
 
+	private float mX, mY;
+
+	private static final float TOUCH_TOLERANCE = 2;
+
+	private void touch_start(float x, float y) {
+
+		MuPDFView pageView = (MuPDFView)getDisplayedView();
+		if (pageView != null)
+		{
+			pageView.startDraw(x, y);
+		}
+		mX = x;
+		mY = y;
+	}
+
+	private void touch_move(float x, float y) {
+
+		float dx = Math.abs(x - mX);
+		float dy = Math.abs(y - mY);
+		if (dx >= TOUCH_TOLERANCE || dy >= TOUCH_TOLERANCE)
+		{
+			MuPDFView pageView = (MuPDFView)getDisplayedView();
+			if (pageView != null)
+			{
+				pageView.continueDraw(x, y);
+			}
+			mX = x;
+			mY = y;
+		}
+	}
+
+	private void touch_up() {
+
+		// NOOP
+	}
+
 	protected void onChildSetup(int i, View v) {
 		if (SearchTaskResult.get() != null
 				&& SearchTaskResult.get().pageNumber == i)
diff --git a/android/src/com/artifex/mupdfdemo/PageView.java b/android/src/com/artifex/mupdfdemo/PageView.java
index 14d6b729..200821dd 100644
--- a/android/src/com/artifex/mupdfdemo/PageView.java
+++ b/android/src/com/artifex/mupdfdemo/PageView.java
@@ -364,16 +364,30 @@ public abstract class PageView extends ViewGroup {
 							if (arc.size() >= 2) {
 								Iterator<PointF> iit = arc.iterator();
 								p = iit.next();
-								path.moveTo(p.x*scale, p.y*scale);
+								float mX = p.x * scale;
+								float mY = p.y * scale;
+								path.moveTo(mX, mY);
 								while (iit.hasNext()) {
 									p = iit.next();
-									path.lineTo(p.x*scale, p.y*scale);
+									float x = p.x * scale;
+									float y = p.y * scale;
+									path.quadTo(mX, mY, (x + mX) / 2, (y + mY) / 2);
+									mX = x;
+									mY = y;
 								}
+								path.lineTo(mX, mY);
 							}
 						}
+
+						paint.setAntiAlias(true);
+						paint.setDither(true);
+						paint.setStrokeJoin(Paint.Join.ROUND);
+						paint.setStrokeCap(Paint.Cap.ROUND);
+
 						paint.setStyle(Paint.Style.STROKE);
-						paint.setStrokeWidth(INK_THICKNESS*scale);
+						paint.setStrokeWidth(INK_THICKNESS * scale);
 						paint.setColor(INK_COLOR);
+
 						canvas.drawPath(path, paint);
 					}
 				}
diff --git a/pdf/pdf_annot.c b/pdf/pdf_annot.c
index ad89725b..37c89902 100644
--- a/pdf/pdf_annot.c
+++ b/pdf/pdf_annot.c
@@ -1141,6 +1141,7 @@ pdf_set_ink_obj_appearance(pdf_document *doc, pdf_obj *annot)
 
 		for (i = 0; i < n; i ++)
 		{
+			fz_point pt_last;
 			pdf_obj *arc = pdf_array_get(list, i);
 			m = pdf_array_len(arc);
 
@@ -1163,8 +1164,10 @@ pdf_set_ink_obj_appearance(pdf_document *doc, pdf_obj *annot)
 				if (j == 0)
 					fz_moveto(ctx, path, pt.x, pt.y);
 				else
-					fz_lineto(ctx, path, pt.x, pt.y);
+					fz_curvetov(ctx, path, pt_last.x, pt_last.y, (pt.x + pt_last.x) / 2, (pt.y + pt_last.y) / 2);
+				pt_last = pt;
 			}
+			fz_lineto(ctx, path, pt_last.x, pt_last.y);
 		}
 
 		fz_stroke_path(dev, path, stroke, &fz_identity, cs, color, 1.0f);