I have a fairly short and indeterminate process which needs a quicker-than-standard animation speed. I couldn't find any likely properties, or even anything on the net.
Anyone know?
Thanks!
If you want something specific you could always create your own control that looks like a progress bar and animate as desired.
However, if it's a short process you may want to reconsider the need to display progress or display it in a different way.
Related
I am developing on a linux system using latest (at the moment) SDL2 (2.0.8) + openGL ES 2.0 (GLSL 1.0) eventually targeting a raspberry pi 3 board. I have so far done a few things like drawing text with freetype, drawing lines, text boxes (editable), text lists, waveform boxes (all i need to pass to a function is an array of vertices) and other shapes with glDrawArrays(). Now, there are things that need to be refreshed at, let's say, 10 times per sec and others that need 1 time per second. What would be the best approach to skip re-rendering everything at the rate of 10 times per sec? Because obviously openGL works by drawing everything from scratch on every 'frame'. However i know and you know that other approaches exist that include: rendering on top of the screen you already have or taking a screenshot and rendering on top of it only the fast changing things as well as other solutions. What do you thing would be the best approach to skip re-doing everything before calling SDL_GL_SwapWindow() ? How can i take a screen shot and render it on the invisible buffer then render only the fast changing objects and then call SDL_GL_SwapWindow() ?
This is a screen shot of the app so far drawing basic things
Thanks in advance.
i eventually had to realize that i should not have posted the question in the first place but since this is a place where people learn from others i now feel somewhat nicer :) . So, the thing i had to do was to simply stop clearing the invisible buffer (i will call it that for simplicity) and render on top of it only controls that change. Those that change are updated by covering the area that they take by a rectangle and then draw new stuff on that area. I have already done it and the frame rate just 'exploded'. I do not really think that there is a better approach since the way i do it requires no action at all. All i had to do was to add a few if conditions that selectively rendered or skipped every time the execution reached the point where functions iterate through the controls that have to be drawn on screen and therefore decide what to render and what not. However a well thought set of structures is required for every control instead of declaring and defining endlessly global variables which will only makes things confusing and difficult to maintain.
Regards to all.
I have been looking at Epic Games' Fortnites Website and I am trying to figure out how they achieved the 3D effect on the page:
Epic Games' Fortnite website - scrolled down to 3rd slide
Does any one have any idea how to do it? I would really like something similar to a project I'm working on. I have found Three.js, but I am quite sure that is not the solution they went with.
For these types of questions, i can only recommend to install spector.js and have a look yourself. In short: everything you see is 100% faked.
I mean, that's always the case. In fact, if you want to build something like that, your first question should always be: how much of this can I fake and still get away with that?
In this example, it turns out: everything. Just open the devtools and click through all the assets in the network-tab. You will find these two textures:
looks familiar, right?
So what they appear to be doing is they are using three.js with some custom shaders to handle the translations, the flickering of the lights and the highlighting. These effects are computed using the normal-map and an additional mask-texture which I couldn't quite figure out what it does. But again, if you look at the scene in spector.js you can see the shaders used for every drawcall.
The only thing that is a bit more complex is the little robot-friend in the bottom left corner. But again, it's not 3d as in meshes and so on but rather a set of flat textured quads running a bones-animation thing.
I think that makes it a really great website after all.
Given that epic is building the unreal-engine I would suspect the original renders were done there. And I agree, the lighting looks really amazing :)
It is a simple parallax effect using animated sprite sheets.
Parallax effect is achieved by using several layers of images/video on top of one another in different Z-depth.
You can achieve the moving part by using the mousemove event to track the cursor.
This is really confusing the heck out of me. Take a look at this screenshot:
Sometimes, the GtkFrames in my program look like on the left side, and sometimes they look like on the right side - or even a mix of the two! The program is exactly the same. Just running the same program multiple times yields very different looks of the GtkFrames in the program! How can that be?
It seems that there are two different designs of GtkFrame:
The first one has its label centered at the top of the frame and
smoothly dissolves towards the
bottom so that the frame doesn't completely enclose the GtkFrame's
contents.
The second design has its label left-aligned at the top of the frame
and draws a border around the complete GtkFrame.
The problem is now that GTK+ seems to choose one of the two designs entirely at random. I don't see any pattern in which design I'm going to get. It appears to happen completely at random which is really confusing me.
Can somebody shed a light onto this mystery? What is going on here? Is there a way to force GTK+ to use a certain design?
I'm using GTK+ 2.24.10 with the Adwaita theme on Linux Mint.
I'm working on an app which needs to draw with OpengGL at a refresh rate at least equal to the refresh rate of the monitor. And I need to perform the drawing in a separate thread so that drawing is never locked by intense UI actions.
Actually I'm using a NSOpenGLView in combination with CVDisplayLink and I'm able to achive 60-80FPS without any problem.
Since I need also to display some cocoa controls on top of this view I tried to subclass NSOpenGLView and make it layer-backed, following LayerBackedOpenGLView Apple example.
The result isn't satisfactory and I get a lot of artifacts.
Therefore I've solved the problem using a separate NSWindow to host the cocoa controls and adding this window as a child window of the main window containing the NSOpenGLView.
It works fine and I'm able to get quite the same FPS as the initial implementation.
Since I consider this solution quite like a dirty hack, I'm looking for an alternative and more clean way of achiving what I need.
Few days ago I came across NSOpenGLLayer and I thought that it could be used as a viable solution for my problem.
So finally, after all this preamble, here comes my question:
is it possible to draw to a NSOpenGLLayer from a separate thread using CVDisplayLink callback?.
So far I've tried to implement this but I'm not able to draw from the CVDisplayLink callback. I can only -setNeedsDisplay:TRUE on the NSOpenGLLayer from the CVDisplayLink callback and then perform the drawing in -drawInOpenGLContext:pixelFormat:forLayerTime:displayTime: when it gets automatically called by cocoa. But I suppose that this way I'm drawing from the main thread, isn't it?
After googling for this I've even found this post in which the user claims that under Lion drawing can occur only inside -drawInOpenGLContext:pixelFormat:forLayerTime:displayTime:.
I'm on Snow Leopard at the moment but the app should run flawlessly even on Lion.
Am I missing something?
Yes, it is possible, though not recommend. Call display on the layer from within your CVDisplayLink. This will cause canDrawInContext:... to be called and if it returns YES, drawInContext:... will be called and all this on whatever thread called display. To make the rendered image visible on screen, you have to call [CATransaction flush]. This method has been suggested on the Apple mailing list, though it is not completely problem free (the display method of other view may get called on your background thread as well and not all views support rendering from a background thread).
The recommend way is to make the layer asynchronous and render the OpenGL context on main thread. If you cannot achieve a good framerate that way, since your main thread is busy elsewhere, it is recommend to rather move everything else (pretty much your whole application logic) to other threads (e.g. using Grand Central Dispatch) and only keep user input and drawing code on the main thread. If your window is very big, you may still not get anything better than 30 FPS (one frame ever two screen refreshes), yet that comes from the fact, that CALayer composition seems a rather expensive process and it has been optimized for more or less static layers (e.g. layers containing a picture) and not for layers updating themselves 60 FPS.
E.g. if you are writing a 3D game, you are advised not to mix CALayers with OpenGL content at all. If you need Cocoa UI elements, either keep them separated from your OpenGL content (e.g. split the window horizontally into a part that displays only OpenGL and a part that only displays controls) or draw all controls yourself (which is pretty common for games).
Last but not least, the two window approach is not as exotic as you may think, that's how VLC (the video player) draws its controls over the video image (which is also rendered by OpenGL on Mac).
I'm developing a small j2me game and i want to create a menu for this application. I imagine the menu as a vertical list of items with a cursor on the left or right side that i can move from item to item, something like this menu example but as a main menu.
What elements should i use to obtains such effects? I need only advices or links, i will develope it myself.
Thanks in advance!
import java.util.Vector;
import javax.microedition.lcdui.Canvas;
import javax.microedition.lcdui.Font;
import javax.microedition.lcdui.Graphics;
import javax.microedition.lcdui.Image;
What you plan looks doable. Can't give much links because don't recall any that could help on stuff like you're doing. Actually, most useful link for you will probably be MIDP (JSR 118) API reference - your part is going to be mostly lcdui package, and especially Graphics API.
As for advice, no problem. First thing to note is that there will be more coding and more (much more) testing/debugging than it was in your prior experiment with implicit list. If you can think of some possible deadline / timing requirements that may become a problem - just keep in mind that prior design with implicit list as a fallback. It won't look as fancy but it'll work work safe and correct.
Another important thing is to decide what kind devices you are going to target. For menu like one you are going to develop, it may be rather difficult to get consistent look and feel both at 160x200 basic phone with ITU-T keypad and on 400x600 touchscreen smartphone. Below I am going to assume you'll try to target as wide variety of devices as possible - note the narrower you can get it, the easier it will be to code and test.
When targeting lots of different devices it is helpful to use an emulator that can be configured to simulate various display sizes and resolution, presense or absence of touchscreen input etc. Keep in mind though that emulator alone won't fully simulate real device. To keep your feets on the ground, consider also some regular smoke testing of your application with real device, preferable using over-the-air (OTA) installation.
Here are some particular API tips that I can think of now.
Use Canvas.getGameAction to handle pressed key code - that is likely the most reliable/portable way to figure up/down and select actions for menu.
Use Canvas.hasPointerEvents to figure if there's touch screen support. Users with touch screen devices may get disappointed if it turns out that your fancy menu can't react when they tap on screen.
Use Font.getHeight and Font.stringWidth to figure how much space is occupied by menu item text.
Use Image.getGraphics if you want to draw something over the image object.
As I mentioned, you most likely will do a lot of stuff using lcdui.Graphics API. It's mostly rather simple, but you will probably need to understand somewhat tricky stuff about clipping. Good luck.