I am reading the documentation for wxScrolled, and came across wxScrolled.SetScale(). There is no documentation for it, and calling it seems to have no effect. What does it do?
If it matters, I am using wxPython 4.1.0.
In context:
I am writing my own widget subclassing wxScrolled. It displays a graph, and I want my user to be able to zoom in and out of the graph. Can I use safely use wxScrolled.SetScale() and GetScaleX()/GetScaleY() to store zoom ratio information?
The scale values will be forwarded to wxDC::SetUserScale(), when DoPrepareDC() was called (i.e. you should see their effect if you do your own drawing by overriding wxScrolled< T >::OnDraw()).
Probable causes for not having any effect:
you don't do any drawing;
custom drawing is done by directly handling wxEVT_PAINT and not calling DoPrepareDC() explicitly.
Related
Is there any way to build an image map with qml (qt quick) components directly without importing html code?And I want to it's coordinates be same as html imagemap's coordinates(I dont want to recalculate my image map coords).
and
my shape is rectangular.tnx
No, there is no way. MouseAreas are always rectangular.
You would need to provide a some kind of collision detection function, to check whether your click happened inside of your object, described by the coordinates.
For this you can implement any of the algorithmns out there, in a way, that it supports your coordinate format. The right choice depends on the characteristics of your objects, like:
Is it a circle?
Is it a regular shape?
Is it convex?
Is it concave?
There are many good pages on collision detection, though a performant implementation might be tricky - especially in QtQuicks JS, so you probably want to do it in C++.
Another shot you might take, is dropping your coordinates, and produce masks that can be used with the solution provided here: https://stackoverflow.com/a/38177820/2056452 (coming from an official example)
I'm using Animate CC 2015 and publishing to Canvas.
Can anyone tell me how to apply a tint to an object on my timeline?
The object has been placed there manually and has an instance name. I simply want to change it from white to red using code that runs in the first frame.
On a related note, do you know of a good JS language reference for Animate CC? I always seem to end up on Actionscript references or the CreateJS site which doesn't cater well for stuff that is created manually on the timeline.
Cheers
Have you applied a tint already in Animate? Filters in Canvas are particularly expensive, so by default, Animate will cache items that have filters applied. You have a few options:
Every frame, cache the symbol again. This can be very expensive, but it will work.
Instead of transitioning a single filter, cross-fade between a filtered and non-filtered object. This looks very similar (especially with a tint), and has no performance concerns.
As for JavaScript reference, what exactly are you looking for? Mozilla's MDN reference tends to be the goto place for our team when it comes to raw JavaScript. https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference
Cheers.
I have some quads that have a texture with transparency and some objects behind these quads. However, these don't seem to be shown. I know it's something about GL_BLEND but I can't manage to make the objects behind show.
I've tried with:
glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA);
glEnable(GL_BLEND);
but still not working. What I basically have is:
// I paint the object
draw_ac3d_file([actualObject getCurrentObject3d]);
// I paint the quad
paintQuadWithAlphaTexture();
There are two common scenarios that create this situation, and it is difficult to tell which one your program is doing, if either at all.
Draw Order
First, make sure you are drawing your objects in the correct order. You must draw from back-to-front or else the models will not be blended properly.
http://www.opengl.org/wiki/Transparency_Sorting
note as Arne Bergene Fossaa pointed out, front-to-back is the proper way to render objects that are not transparent from a performance stand point. Because of this, most renderers first draw all the models that have no transparency front-to-back, and then they go back and render all models that have transparency back-to-front. This is covered in most 3D-graphic texts out there.
back-to-front
front-to-back
image credit to Geoff Leach at RMIT University
Lighting
The second most common issue is improper use of lighting. Normally in this case if you were using the fixed-function pipeline, people would advise you to simply call glDisable(GL_LIGHTING);
Now this should work (if it is the cause at all) but what if you want lighting? Then you would either have to employ custom shaders or set up proper material settings for the models.
A discussion of using the material properties can be found at http://www.opengl.org/discussion_boards/ubbthreads.php?ubb=showflat&Number=285889
So I want to have a view (NSView, NSOpenGLView, something CG related?) which basically displays a map. Such as:
http://dump.tanaris4.com/map.png
Obviously that looks horrible, but I did it using an NSView, and it draws SO slow. Clearly not designed for this.
I just need to allow users to click on the individual (x,y) coordinates to make changes, and zoom into a certain area (to see it better).
Should I go the OpenGL route? And if so - any suggestions as to how to get started? (I was able to follow the guide to draw a triangle, so that's good).
I did find this post on zooming in an NSView: How to implement zoom/scale in a Cocoa AppKit-application
My concern is if I'm drawing over 6000 coordinates and the lines connecting them, this isn't efficient at all.
I don't think using OpenGL would be of any good here. The problem does not seem to be the actual painting, but rather the rendering strategy. You would need a scene graph of some kind to dynamically handle level of detail and culling.
Qt has all this packaged in a nice class class QGraphicsScene (see http://doc.qt.nokia.com/latest/qgraphicsscene.html for reference, and http://doc.qt.nokia.com/main-snapshot/demos-chip.html for an example).
Some basic concepts you should consider using:
http://en.wikipedia.org/wiki/Scene_graph
http://en.wikipedia.org/wiki/Quadtree
http://en.wikipedia.org/wiki/Level_of_detail
Try using core graphics for this, really there is so much that could be done. Watch the video Practical Drawing for iOS Developers from WWDC 2011 and it should give an over view of what can be done with CG.
I believe even CoreGraphics will suffice for what you want to achieve, and that should work under a UIView if you draw the rectangle of your view completely under the DrawRect method of your UIView (you must overload this method). Please see the UIView Class Reference. I have a mobile application that logs points on the UIMapKit, kind of like Nike+, and it certainly works well for massive amounts of points/line segments. There is no reason why this simple approach cannot work for you as well.
I am using UIImagePickerController for selecting images from the photo library. But I am getting a message on the console saying "Using two-stage rotation animation. To use the smoother single-stage animation, this application must remove two-stage method implementations."
What is this due to ?
Thanks
Several people appear to be having the same problem. None of these links provide a solution (as far as I can tell), so this post is intended just as a starting point for more searching. I have made it CW.
stackoverflow: Single-Stage vs Two-Stage Animation for iPhone Apps
cocoabuilder: how to change to the smoother single stage animation
stackoverflow: tabbarcontroller and navigationcontrollers in landscape mode
Apple support: 11186784
That normally means you have implemented one of:
willAnimateFirstHalfOfRotationToInterfaceOrientation:duration:
willAnimateSecondHalfOfRotationFromInterfaceOrientation:duration:
on one of your view controllers, even if they are empty. This is neither wrong nor deprecated, the message just say it could possibly done better if you moved your implementation to: willAnimateRotationToInterfaceOrientation:duration: