Thanks for the responses.
To TreKing : I quite clearly explained that the drawing area was where I
needed to optimise. You can see that I trace the time taken here and this
is where I can say that, on the emulator, it takes 18 seconds.
to lbendlin : Thank you for the advice, I will do some further tests to see
if this will affect the processing time.
On Friday, 18 May 2012 02:16:47 UTC+2, lbendlin wrote:
>
> No need to worry about the screen pixels relative to your waypoints. The
> overlay manager handles that for you, and only renders the part that is on
> screen. Load all the points.
>
> On Thursday, May 17, 2012 12:19:33 PM UTC-4, Simon Giddings wrote:
>>
>> I am developing a maps application which will display a user defined
>> driving itinerary.
>> I obtain the driving directions from the Directions Web Service and parse
>> the json response in a separate thread.
>>
>> I then hand the resulting itinerary object to my custom overlay for
>> display.
>> Before appending the overlay to the maps overlay list, I decode the
>> polyline strings to obtain the coordinates.
>>
>> My drawing code obtains the projection object and draws out the line -
>> this is taking 18 seconds ! ! !
>> Here is my code :
>>
>> @Override
>> public void draw(Canvas cv, MapView view, boolean shadow)
>> {
>> GeoCoordsE6 point = null; // utility class holding a geopoint
>> and a point class with a method to handle projection manipulation
>> int iScreenWidth = view.getWidth();
>> int iScreenHeight = view.getHeight();
>> Paint paintLine = null;new Paint();
>>
>> if(shadow)
>> {
>> super.draw(cv, view, shadow);
>> return;
>> }
>>
>> long lStartMs = android.os.SystemClock.uptimeMillis();
>>
>> paintLine = new Paint();
>> paintLine.setColor(m_iLineClr);
>> paintLine.setAntiAlias(true);
>> paintLine.setStyle(Paint.Style.FILL_AND_STROKE);
>> paintLine.setStrokeJoin(Paint.Join.ROUND);
>> paintLine.setStrokeCap(Paint.Cap.ROUND);
>> paintLine.setStrokeWidth(4);
>>
>> // get the projection to work with
>> Projection pj = view.getProjection();
>>
>> // get the first lat/lng position
>> point = m_ItinLine.item(0);
>> // convert the coorinates to screen pixels
>> point.ResolvePosition(pj);
>> // store the start position
>> m_ptStart.x = point.m_pt.x;
>> m_ptStart.y = point.m_pt.y;
>>
>> // now walk through the array list
>> for(int i = 1; i < m_ItinLine.count(); i++)
>> {
>> point = m_ItinLine.item(i);
>> point.ResolvePosition(pj);
>> m_ptEnd.x = point.m_pt.x;
>> m_ptEnd.y = point.m_pt.y;
>>
>> if(m_ptStart.x < 0 && m_ptEnd.x < 0 || // to the left
>> m_ptStart.y < 0 && m_ptEnd.y < 0 || // above the
>> top
>> m_ptStart.x > iScreenWidth && m_ptEnd.x >
>> iScreenWidth || // to the right
>> m_ptStart.y > iScreenHeight && m_ptEnd.y >
>> iScreenHeight) // below the bottom
>> {
>> // ignore the drawing
>> }
>> else if(m_ptStart.x == m_ptEnd.x && m_ptStart.y == m_ptEnd.y)
>> continue;
>> else
>> {
>> cv.drawLine(m_ptStart.x, m_ptStart.y, m_ptEnd.x,
>> m_ptEnd.y, paintLine);
>> }
>>
>> m_ptStart.x = m_ptEnd.x;
>> m_ptStart.y = m_ptEnd.y;
>> }
>>
>> long lEndMs = android.os.SystemClock.uptimeMillis();
>> Log.d("ItineraryOverlay", "Drawing took " + (lEndMs - lStartMs) +
>> "ms");
>>
>> super.draw(cv, view, shadow);
>> }
>>
>> Knowing that a number of people have done similar tasks, can anyone
>> advise me as to how to improve the performance ?
>> Should I be building a path object and fill it with ALL of the points ?
>>
>>
>>
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