I have three different classes. Each class is responsible for drawing a specific thing using ncurses.
I must draw all the three things at once. One of the classes is responsible for a board, and the other two classes draws something inside the board.
I got it to work, but the problem is that whenever I use clear, it clears the board and the other two things; I want the board to stay and never get erased. I want to clear the drawing that only the specific class is responsible for.
For example, let's say I have a board, and I have a person class and a dog class. When I call the draw method in the person class, it draws me the person inside the board, but whenever I move it to a different point, it draws a new person, but it never clears the old person.
Same thing with the dog unless I use the clear method from the curses.h but it erases and clears everything including the board and the dog.
However, I only want to erase the person and not everything. Is there any built-in method to use from ncurses other than clear or erase, or anything that clears the whole screen?
As Ivan Rubinson suggested in the comments, the usual approach is to clear everything then redraw everything every frame/repaint.
According to the documentation, clear() should clear the whole screen:
The clear(), erase(), wclear() and werase() functions clear every position in the current or specified window.
The clear() and wclear() functions also achieve the same effect as calling clearok(), so that the window is cleared completely on the next call to wrefresh() for the window and is redrawn in its entirety.
Your main loop / drawing code should look something like this (pseudocode):
clear(); // clear everything
// redraw everything
for(auto& widget : drawables)
{
widget.draw();
}
// display
refresh();
You can do this by creating a window for each of the objects, and removing them when they're done. That way, you need only clear the window that you're removing, refresh it and then delete it.
That is, use newwin, waddstr, wrefresh, wclear and delwin rather than addstr, refresh and clear.
Related
i've tried to make a project, but i can't draw a sprite as i want. I mean that everything works when i just draw a sprite, but it stop working when i am trying to draw the sprite by clicking left mouse button. There's code i tried:
if(zdarzenie.type == Event::MouseButtonPressed && zdarzenie.mouseButton.button == Mouse::Left)
{
pocisk.setPosition(10, 10);
oknoAplikacji.draw(pocisk);
}
Btw, I am writing in Polish as if it would change something.
And yes, i have everything good besides that.
(and i am using 2.4.1 version of SFML)
I don't know what you are doing now because you didn't provide enough of your code and I actually don't understand your if statement but, it can just be :
if (sf::Mouse::isButtonPressed(sf::Mouse::Left))
{
sprite.setPosition(sf::Mouse::getPosition());
renderTarget.draw(sprite);
}
By the way I strongly suggest that you do not use the draw function here but organize your code to have a draw method called in a render loop, because depending on where your code is in your program, the sprite could be drawn for only one frame and then erased since it's not updated.
From what I understand in your code in Polish, you have the right code to do what you want, but the problem comes from the fact that you draw the sprite only once.
The draw method is called every frame and it will erase everything on screen and then redraw them. Doing it only once, like in your code, will only draw it a single time then delete it the very next frame.
At that point multiple solution can be used. If its a GameObject clicking can activate the object to then draw it or a simple bool could be used has a switch in your draw to make it appear.
Recently, I attempt to obtain the rectangle by function GetClipBox in OnDraw(CDC*pDC), having a glance at implements simply.
void CObjView::OnDraw(CDC* pDC)
{
CRect expose;
int retVal = pDC->GetClipBox(&expose);
}
As situation I expect, it works fine in almost time. But in several times, the object expose is empty, what it means is that the function GetClipBox isn't able to get rectangle. To make it correct, you can browse pictures in following section.
In picture one, There is a grid one created in parent window two. The object expose can be obtained accurately by GetClipBox. In picture two, Nonetheless, the object expose is empty when grid is fully covered parent window. Actually, the grid is zoom in bigger than parent window.
Hence, Can someone provide a scenario to solve this situation.
Best regards for everyone who can provide assistance to me.
I add some nodes that move around the screen. at some point, when I press a button (MenuItemImage), I need to change layer (not scene). So, I try to remove all moving nodes' PhysicBody from the PhysicWorld and then, remove nodes themselves. It works usually, but sometimes, I get crash from inside of PhysicsBody::update function. at that point, this refers moving object PhysicBody. and, it seems parent is NULL. But, I try all PhysicBody from the World. So, after I remove, they should not be drawn (I guess this is causing the problem)
It is too obvious that there are some concurrency problem. but, I don't want to touch cocos2d-x dispatcher. so, what is the proper way to remove a PhysicBody and node from the world.
now, I call removeFromWorld() for PhysicBody and removeChildren for Cocos2d node. Even, I put some delay between these two operation, I still get crash sometimes.
I am fairly new to VTK and I really enjoy using it.
Now, I want to interact with multiple objects independently. For example, if I have 5 objects in a render window, I want to only move, rotate and interact with the one selected object; whilst the rest of the 4 objects stay where it is.
At the moment, the camera is doing the magic and as I rotate the independent object, other objects move at the same time and I don't want that to happen.
I also want to store all the objects in memory.
I intend to use C++.
This is my sort of class structure...
class ScreenObjects
{
vtkActor (LinkedList); // I intend on using a linkedlist to store all the actors
public:
ScreenObjects(); // Constructor. Initializes vtkActor to null.
void readSTLFile(); // Reads the STL File
bool setObject(); // Sets current object, so you can only interact with the selected object
}
I am missing quite a lot of functions and detail in my class, as I don't know what else to include that would be of use. I was also thinking of joining two objects together, but again, I don't know how to incorporate that in my class; any information on that would be appreciated.
Would really appreciate it if I could be given ideas. This is something of big interest to me and it would really mean a lot to me, and I mean this deep down from my heart.
First of all you should read some tutorials and presentations like this one for example:
http://www.cs.rpi.edu/~cutler/classes/visualization/F10/lectures/03_interaction.pdf
I say that cause it looks like you're currently just moving the camera.
Then you should look into the VTK examples. They are very helpful for all VTK classes.
Especially for your problem have a look at:
http://www.vtk.org/Wiki/VTK/Examples/Cxx/Interaction/Picking
Basicly you have to create a vtkRenderWindowInteractor derived class to get the mouse events (onMouseDown,onMouseUp,onMouseMove,...).
And a vtkPropPicker to shoot a ray from your mouse position into the 3D view and get the vtkActor.
Now you can store onMouseDown inside your vtkRenderWindowInteractor derived class the vtkActor you'd like to move and the currentMouse position. When the user release the mouse (onMouseUp) just get the new mouse position and use the difference of the onMouseDown/onMouseUp positions to modify the vtkActor position.
I'm making an endless running game in which users dodge obstacles, and I'm working on producing the obstacles right now. The plan I had where I'm spawning these obstacles is as follows:
obstacle->setPosition(CCPointMake(this->getContentSize().width, this->getContentSize().height*.75));
obstacle->setScale(.5);
this->addChild(obstacle);
_obstacles->addObject(obstacle);
obstacle->runAction(CCMoveBy::create(2.0, CCPointMake(-(this->getContentSize().width + obstacle->getContentSize().width/2), 0)));
obstacle->removeFromParent();
I set the position, set it's scale, add it to the scene, run an action on it so that it moves across the screen from right to left, add it to an array called _obstacles to be used elsewhere, and then I remove it from the scene so as to save memory. However, the problem is that once I try implement this, the obstacle doesn't show up at all as if it's nowhere to be seen. When I don't call obstacle->removeFromParent() it shows up and performs the action. What am I doing wrong here? If I don't call removeFromParent(), what do I call? Is there a problem in my code not related to removeFromParent()?
The reason that obstacle doesn't apeear at all is that it is removed as it start moving. You just have to create a sequence of move action and function call with obstacle as parameter and than remove this obstacle in that function , so that obstacle will be removed after moving out of screen.
CCCallFuncN *myCallFunc = CCCallFuncN::create(this, callfuncN_selector(CLASS_NAME::removeObstacles));
obstacle->runAction(CCSequence::create(CCMoveBy::create(2.0, CCPointMake(-(this->getContentSize().width + obstacle->getContentSize().width/2), 0)),myCallFunc,NULL));
Method to remove obstacle from array and from parent view
void CLASS_NAME::removeObstacles(CCObject* pSender){
// Type cast pSender to obstacle type e.g if obstacle is of CCSprite type.
CCSprite *tempObstacle = (CCSprite *)pSender;
_obstacle.pop_back(tempObstacle);
tempObstacle->removeFromParent();
}
Don't forget to replace CLASS_NAME by your class name
I would need more info on what removeFromParent is doing and how you use _obstacles
I'm taking a guess on how the parent is structured. I would guess that it has a list of children and when the parent is updated/render, it calls those functions for its children. If removeFromParent removes the object from its parent list, then that would explain why it is not being render or used in the scene. If you have a setup like this, then you should only call removeFromParent before destroying the parent object