I am writing an uwp program, you may treat it as a drawing segments program:
It is only allow to draw segments horizontal or vertical.
a new segment must start at an old segment's vertex, and there are two situation not allowed in this program:
1.overlap.
2.intersection.
Here is my code to judge if two segments are cross over each other，Here is my code :
(I use a for loop to select all of segments I have already created, "line[]" stored all the segments I have already created and "ln" stored a random new segment, it will add the new segment to "line[]" if no erro occurs)
for (int l = 0; l < i - 1; l++)
{
if (ln.getY1() == ln.getY()&&line[l].getX()==line[l].getX1())
{
if(line[l].getX()>=Math.Min(ln.getX(),ln.getX1())&&line[l].getX()<=Math.Max(ln.getX(), ln.getX1())&&ln.getY()>=Math.Min(line[l].getY(),line[l].getY1())&&ln.getY()<= Math.Max(line[l].getY(), line[l].getY1()))
{
sameIslandCount++;
}
}
else if (ln.getX1() == ln.getX()&&line[l].getY()==line[l].getY1())
{
if(ln.getX()>=Math.Min(line[l].getX(),line[l].getX1())&&ln.getX()<=Math.Max(line[l].getX(), line[l].getX1())&&line[l].getY()>=Math.Min(ln.getY(),ln.getY1())&& line[l].getY() <= Math.Max(ln.getY(), ln.getY1()))
{
sameIslandCount++;
}
}
}
but when I test this program, it stuck in this screen:
but if I delete all the equal symbol, the program can run successfully. Can anyone tell me how to improve? sorry about my English, hope you can understand what I mean:p
Related
Good time of the day. I'm doing an assignment which involves writing a program that solves Traveling Salesman Problem in parallel using brute-force method. I managed to write a working version but it was a lot slower than consequential version due to numerous memory allocations at a high rate which I attempted to limit as in a code bellow using buffered channel.
SO probably won't allow to fit all the code into post so, please view definition and methods of data structures on Github: https://github.com/telephrag/tsp_go
This version doesn't work at all.
At the end t will contain empty path and maximum value of uint64 for traveled distance which is set at the beginning.
As could be seen through debugger, salesman with id of 1 is getting node added to its path at sm.Path[1], but once <-t.RouteQueue occurs in the same call to travel() the program stops despite numerous goroutines are supposedly waiting to write to t.RouteQueue at the moment. It's also confirmed through debugger as well that the program never reaches if-block responsible for setting new shortest path in t.
If we create sync.Waitgroup for each for-loop the program will crash on deadlock.
sync.WaitGroup but remove everything related to channel the program would work but do so very slowly. You can get this version at the first commit to main branch of repository above.
Why does the program ends prematurely?
package tsp
func (t *Tsp) Solve() {
sm := NewSalesman(t)
sm.Visit(0) // sets bit corresponding to given node in bitmask
for nextNode := range graph[0] {
t.RouteQueue <- true // book slot in route queue (buffered channel)
go t.travel(sm.Copy(t), nextNode)
}
}
func (t *Tsp) travel(sm *Salesman, node uint64) {
sm.Distance += graph[sm.TailNode()][node] // increase traveled distance
if sm.Distance > t.MinDist { // terminate if traveled distance is bigger than current minimal
<-t.RouteQueue
return
}
sm.Visit(node)
sm.Count++ // increase amount of nodes traveled
sm.Path[sm.Count] = node // add node to path
if sm.Count == t.NodeCount-1 { // stop if t.NodeCount - 1 nodes traveled
sm.Count++
sm.Distance += graph[node][0] // return to zero-node
t.Mu.Lock()
if t.MinDist > sm.Distance { // set new min distance and path if they are shorter
t.MinPath = sm.Path
t.MinDist = sm.Distance
}
t.Mu.Unlock()
}
<-t.RouteQueue // free the slot for routes
for nextNode := range graph[node] {
if !sm.HasVisited(node) {
t.RouteQueue <- true
go t.travel(sm.Copy(t), nextNode)
}
}
}
I am using ltbb to stream from two cameras. ltbb creates two threads(because of two cameras) for simultaneous streaming from two cameras. It makes use of concurrent queues for fetching frames. The following code snippet displays frames:
while (waitKey(20) != 27)
{
//Retrieve frames from each camera capture thread
vector<Mat> iMats(capture_source.size());
for (int i = 0; i < capture_source.size(); i++)
{
Mat frame;
//Pop frame from queue and check if the frame is valid
if (cam.frame_queue[i]->try_pop(frame))
{
//Show frame on Highgui window
// IMats.push_back(frame);
iMats[i] = frame;
imshow(label[i], frame);
}
} // end of for - loop
int x = opencv_tri(iMats);
}
The problem is when I am doing iMats[i] = frame and pass it to other function, It's giving me an error. It works fine when I comment iMats and stop calling opencv_tri(iMats).
Error: Segmentation fault (core dumped)
Link to opencv_tri: opencv_tri.cpp
Can anyone please explain and help me to fix this?
Unfortunatly I can't comment.
I think your vector is empty, therefor you can not access the [i]'th element.
vector<Mat> iMats(capture_source.size());
This creates an empty Vector with capture_source.size() elements.
I did not go through the whole opencv_tri function that you linked, but I spot the possible error.
you have the following
for(int i = 0;i<imats.size();i+=2)
{
...
Mat imgATest = imats[i];
Mat imgBTest = imats[i+1];
when i is in imats.size()-1 it will try to access:
Mat imgBTest = imats[i+1];
This is an out of bounds. since i+1 is imats.size()
You have to loop up to imats.size()-1
for(int i = 0;i<imats.size()-1;i+=2)
{
this way it will not try to access the wrong value
I have the thread where the worker object is running infinite cycle. Here I have the following code that I would like it to read coordinates from list and place QGraphicsEllipseItem on these coordinates. The list can be updated by another thread, so I protect it by mutex. But sometimes the size of list may grow up so I would like to create new QGraphicsEllipse items for it if needed.
int meter_to_pixel_ratio = 20;
int x_pixel, y_pixel;
int i;
forever {
visualizationDataMutex->lock();
while(ellipseList->count()<visualizationData->count())
{
qDebug() << "Creating new visual item...";
ellipseList->append(new QGraphicsEllipseItem(0.0, 0.0, 10.0, 10.0));
ellipseList->last()->setVisible(false);
visualizationScene->addItem(ellipseList->last());
}
for(i=0; i<visualizationData->count(); i++)
{
x_pixel = meter_to_pixel_ratio*visualizationData->at(i)->x();
y_pixel = meter_to_pixel_ratio*visualizationData->at(i)->y();
ellipseList->at(i)->setPos(x_pixel, y_pixel);
ellipseList->at(i)->setBrush(QBrush(*visualizationColor->at(i)));
if(!ellipseList->at(i)->isVisible()) ellipseList->at(i)->setVisible(true);
}
visualizationDataMutex->unlock();
// repaint scene
visualizationScene->update();
QThread::msleep(100);
}
The problem I have is, that when I try to run the program I´ll obtain a runtime error. Tried to qDebug() the ellipseList->count() and seems to have the exactly same number of elements as needed (as visualizationData->count()). When commented these three lines:
//ellipseList->at(i)->setPos(x_pixel, y_pixel);
//ellipseList->at(i)->setBrush(QBrush(*visualizationColor->at(i)));
//if(!ellipseList->at(i)->isVisible()) ellipseList->at(i)->setVisible(true);
program can run without crashing. I do not understand why is this happening since there is no other function working with QGraphicsView/QGraphicsScene. (QGraphicsView was added from Qt Designer environment into mainwindow).
consider the code
for(i = 0; i < 5; i++)
{
if(control.Exists)
{
mouse.Click(button);
}
}
In this, control is a popup window. for the first time of execution, control.Exists = true and for the second time it is false though the control is present. Why is that so? How to make it to be true?
Thanks in advance.
Programs often draw another copy of a control, it looks identical to the eye but it is different. Hence the second time around the loop control refers to the old version of the control but it is no longer present.
Your code is likely to be equivalent to
for(i = 0; i < 5; i++)
{
if(top.middle.control.Exists)
{
mouse.Click(top.middle.button);
}
}
There may be more levels in the UI Control hierarchy but three is enough for the explaination here.
The normal fix is to find the new copy of the control before using it. So change the code to be
for(i = 0; i < 5; i++)
{
top.middle.Find();
if(top.middle.control.Exists)
{
mouse.Click(top.middle.button);
}
}
If that does not work, because middle is also not available, then use top.Find();.
To learn more about which controls are available or not, try code like this and observe which parts of the screen are highlighted with blue boxes.
for(i = 0; i < 5; i++)
{
top.DrawHighLight();
top.middle.DrawHighLight();
top.middle.control.DrawHighLight();
if(top.middle.control.Exists)
{
mouse.Click(top.middle.button);
}
}
Use TryFind() instead, and set the searchTimeout.
You can use Inspect/UISpy to check the RuntimeId of the control. I think it's kind of controls' version described in AdrianHHH's reply.
But, what confuses me most is that I can use the found control in the first time, in the following loops, Although my application is restarted.
I want to use custom fonts in my j2me application. so I created a png file contains all needed glyph and an array of glyphs width and another for glyphs offset in PNG file.
Now, I want to render a text in my app using above font within a gameCanvas class. but when I use the following code, rendering text in real device is very slow.
Note: the text is coded(for some purposes) to bytes and stored in this.text variable. 242=[space],241=[\n] and 243=[\r].
int textIndex = 0;
while(textIndex < this.text.length)
{
int index = this.text[textIndex] & 0xFF;
if(index > 243)
{
continue;
}
else if(index == 242) lineLeft += 3;
else if(index == 241 || index == 243)
{
top += font.getHeight();
lineLeft = 0;
continue;
}
else
{
lineLeft += widths[index];
if(lineLeft <= getWidth())
lineLeft = 0;
int left = starts[index];
int charWidth = widths[index];
try{
bg.drawRegion(font, left, 0, charWidth, font.getHeight(), 0, lineLeft, top, Graphics.LEFT|Graphics.TOP);
}catch(Exception ee)
{
}
}
textIndex++;
}
Can anyone help me to improve performance and speed in my code?
At end sorry for my bad English and thanks in advanced.:)
Edit: I changed line
bg.drawRegion(font, left, 0, charWidth, font.getHeight(), 0, lineLeft, top, Graphics.LEFT|Graphics.TOP);
To:
bg.clipRect(left, top, charWidth, font.getHeight());
bg.drawImage(font, lineLeft - left, top,0)
bg.setClip(0, 0, getWidth(), getHeight());
but there was no difference in speed!!
any help please!!
Can anyone plz help me to improve my app?
text will appear after 2-3 seconds in real device by this code, I want reduce this time to milliseconds. this is very important for me.
Can I use threads? If yes, How?
I can't sure why your code's performance is not good in real device.
But, how about refer some well known open source J2ME libraries to check it's text drawing implementation for example, LWUIT.
http://java.net/projects/lwuit/sources/svn/content/LWUIT_1_5/UI/src/com/sun/lwuit/CustomFont.java?rev=1628
You can find from the above link it's font drawing implementation. It uses drawImage rather than drawRegion.
I would advice you to look into this library. The implementation is quite good and makes use of industry standard design patters ( Flyweight pattern, predominantly) and robust.