The text becomes blurry if I use a non whole number for the position of the string. Any ideas what is causing this and how to correct it?
this->pSpriteBatch->Begin();
this->pSpriteFont->DrawString(this->pSpriteBatch, szTempMessage, XMFLOAT2(x, y), color);
this->pSpriteBatch->End();
I'm calling it with only the position and color parameters.
SpriteBatch renders using CommonStates::LinearClamp by default, so it will be blurry if you rendering to a sub-pixel location. You can try using another filtering mode by overriding it with Begin:
// create an instance of CommonStates as pStates
pSpriteBatch->Begin(SpriteSortMode_Deferred,
nullptr /*use default blend state */,
pStates->AnisotropicClamp());
pSpriteFont->DrawString(...);
pSpriteBatch->End();
See if that improves your results.
Related
I am using Unity 5 and I started to make a menu scene. When I made the canvas, all of values under the Rect Transform component are locked and it says "some values driven by Canvas." The only thing I can change is the z position when using the gizmo in the editor. I can't reset the position or anything. Why is this happening?
This means that the canvas's canvas component has it's render mode set to Screen space - overlay. This forces it to be the size of the screen. Change it to World Space and it will allow you to resize it and move it around.
Changing the Render mode is not an ideal solution; neither is Overlay mode the reason why this is happening at all. World Space is just a render mode that changes the way your whole UI behaves and would mean a whole different set up and a whole lot more work just to get a child UI object to move independently.
Here is the description of what World Space is for from the Unity site:
In this render mode, the Canvas will behave as any other object in the
scene. The size of the Canvas can be set manually using its Rect
Transform, and UI elements will render in front of or behind other
objects in the scene based on 3D placement. This is useful for UIs
that are meant to be a part of the world. This is also known as a
“diegetic interface”.
The Rect Transform usually gets locked because it is a child of another Canvas Object which controls its Transforms. The way to fix this is to overwrite it by adding a “Layout Element” component to it. From there you can configure it to work the way you like and it can have transforms independent of the Parent UI Object.
For full details, see this Unity support page: https://support.unity3d.com/hc/en-us/articles/115000179163-How-to-overwrite-Width-and-Height-values-that-are-driven-by-a-Layout-Group-in-runtime-
Canvas is depend on game tab in your window panel.
Adjust panel by use of close tab or resize panel or doc game panel.
It will help you make default 800 X 600 canvas.
Recently I am writting game editor in my project. I want to implement a editor which has four viewport like 3ds max or other 3D software.
So, how to use opengles2 to render context on multi-window?
You can usually have multiple views with each having its own frame buffer. In this case all you need to do is bind the correct frame buffer before drawing to each of the views. You might also need to have different contexts for each view and setting them as current before drawing (also before binding the frame buffer). If you need multiple contexts you will need to find a way to share resources between them though.
Another approach is having a single view and simply using glViewport to draw to different parts. In this case you need to set glViewport for a specific part, setting ortho or frustum (if view segments are of different size) and that is it. For instance if you split the view with buffer having dimensions bWidth and bHeight into 4 equal rectangles and you want to refresh the top right:
glViewport(bWidth*.5f, .0f, bWidth*.5f, bWidth*.5f);
glOrthof(.0f, bWidth*.5f, bHeight*.5f, .0f, .1, 1.0); //same for each in this case
//do all the drawing
and when you are finished with all you want to update just present the frame buffer.
I have an app, its a small game using opengles with GLKit.
No im wondering how it works when i want to draw text on
my screen (if it is possible).
How can i do it?
i draw all of my game objects using images (wrapped in some kind
of sprite). its possible to scale, to move, and to rotate.
everything works fine.
but finding out how it works to print text on that glkview
gets me deep inside of problems ^^
I dont want to use uiimages cause i also dont know how
to present uiimages on a glkview.
There are a number of ways to do what you want:
1) Have an image with all the text glyphs you need in it. For example, if your application is in English, you'd have the 26 uppercase and 26 lowercase letters in the image. Upload that texture to the GPU and use the proper texture coordinates or glSubTexImage2d() to pull out the glyphs you need. (It's not clear to me if this is what you meant by not wanting a UIImage. It doesn't have to be a UIImage, though that's probably easiest.)
2) Every time you need to display text, draw it on the CPU on the fly, and upload the entire word, phrase, or sentence as a texture. You could create a CGBitmapContext and use Core Graphics to draw text to it. Then upload it using glTexImage2D().
3) Get the individual glyphs out of the fonts and draw directly using the bezier curves that make up the glyphs. This allows for 3D extrusion, too. However, this option is the most time consuming to code and probably least performant. It also involves dealing with the many small problems that fonts have (like degenerate segments, and incorrect winding orders). IF you want to go down this path, I think maybe Core Text can help.
There are at least two clean ways to do this, depending on your requirements.
While documentation advises against compositing over a CAEAGLLayer (GLKView), it works quite well, at least in recent iOS versions, when transparent content is layered on top of the CAEAGLLayer. For example, try dropping a UITextView, with opaque set to false and a clear background color, on top of a GLKView in your Storyboard in Interface Builder in the Apple GLKit template or your app. In my test on an iPhone 5, frame rendering time remained around 1ms, even while scrolling in the text view. If your text needs are static, or you don't want the user to interact with the text, use CATextLayer as a child layer of your EAGLLayer instead of a view.
The second approach is to render the text into a texture. You can then composite the text onto your view by disabling the depth buffer and rendering the texture on a full screen rectangle. Look at UIGraphicsBeginImageContextWithOptions to see how to render to an offscreen image with Quartz. UIGraphicsGetImageFromCurrentImageContext allows you to retrieve the UIImage to use as a texture.
Please see this thread for details.
To summarize, given the following circumstances:
gl = canvas.getContext('experimental-webgl');
gl.clearColor(0, 0, 0, 1);
gl.colorMask(1, 1, 1, 0);
gl.blendFunc(gl.SRC_ALPHA, gl.ONE_MINUS_SRC_ALPHA);
gl.enable(gl.BLEND);
...and a standard render loop:
function doRender() {
gl.clear(gl.COLOR_BUFFER_BIT | gl.DEPTH_BUFFER_BIT);
// render stuff, and request another frame
requestAnimationFrame(doRender);
}
...then I would like to know what the expected output should theoretically be.
In actuality, I'm seeing that the first frame renders as if there were no color mask, and the second (and subsequent) frames render the entire canvas opaque white.
Note that it doesn't matter what the alpha level is set to: the second frame is always immediately, completely white (including areas that were not rendered to), even if the rendered alpha values are extremely low.
The Question: what is the expected result of the above operations on the first, second, and subsequent frames? Also, is what I am experiencing the expected result, or due to some bug in the GL driver or WebGL implementation? And finally, if it is the expected result, why? What is actually happening on the video card to produce this result?
System details: Chrome / Firefox (both) on a MacBook Pro / GeForce 320M / Snow Leopard.
WebGL automatically clears the drawing buffer on each frame unless you tell it not to
try
gl = canvas.getContext('experimental-webgl', {
preserveDrawingBuffer: true
});
That's potentially slower than letting it clear though since it might have to make a copy of the drawing buffer each frame to preserve it so it has a copy to composite with the rest of the page while you draw new stuff into it. So, it's probably better to call gl.clear inside your render loop. Of course if the effect you were going for was to continually blend stuff into the drawing buffer then you either need to tell it to be preserved like the example above or you need to draw into a texture or renderbuffer using a framebuffer and then render that to the drawing buffer.
I have some rather simple code drawing some text into a CGContext. Here is an excerpt (slightly edited).
CGContextSelectFont(context, "Helvetica", 1.5, kCGEncodingMacRoman);
CGContextShowTextAtPoint(context, xpos, ypos, "Hello", 5);
The text renders ok. For some unknown reason, however, the font changes to a smaller size after I click in the view containing the context. Also when I resize the window containing the view the font returns to original size. What is the reason for this?
1.5 points is mighty tiny to begin with. Assuming no other scaling is in effect, that will be one whole pixel and a blurry pixel above it on the screen.
You're probably seeing a bug that I ran into myself: On entry into drawRect:, the current context's text matrix was not the identity matrix. In my case, I saw it contain a scale by 13 on both axes, plus a translation. (Possibly left over from drawing the title bar.) I filed this in Radar as #10585106, in case you want to file your own and cite it.
The solution is to set the text matrix back to the identity transform before trying to draw text.
Once you do that, you'll find that your text will be exactly as tiny as you asked for it to be. You should change your font size to something more reasonable; Core Text contains a function to get the system fonts (from which you can get their sizes), and AppKit's NSFont class contains methods for the same purpose.