Question before I dive deeper into converting my current rendering system to openGL. I heard that textures needed to be in base2 sizes in order to be stored for rendering. Is this true?
My application is very tight on memory, but most of the bitmaps are not a perfect square. Does storing non-base 2 textures waste extra memory?
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I'm learning OpenGL on my own atm and I have a question about texturing a surface:
I can create a simple polygon like this:
CODE:......
Then I load all of that info into the approriate buffers and draw it to the screen with a call to:
CODE:..
My question:
I'm looking for a good example of how to take an image and texture it to the surface.
For some reason my code here (this is the entire thing) doesnt actually render anything besides a red screen..
can anyone tell me why?
CODE:.................
I've googled around everywhere, but cannot find much for rendering strings to textures and then displaying that texture on a quad on the screen. Can someone provide a run-down on the process or provide good resources that describe how? Is rendering strings to textures even the best method for displaying text in an Android OpenGL ES app?
Okay, so LabelMaker interferes with alpha blending, the texture (created from a PNG with a transparent background) now has a solid black background, rather than a transparent background. If I comment out all the LabelMaker-related code, it works fine.
UPDATE:
Nevermind. I took a look at the code to find that LabelMaker was disabling blending after drawing the labels.
I can't seem to get GLUtils.texImage2D to use my full RGBA (A=my alpha component).
I've tried doing setEGLConfigChooser(8, 8, 8, 8, 0, 0); getHolder().setFormat(PixelFormat.RGBA_8888);
I've tried converting the source image (.png in ARGB) to RGBA.. which works ok for the ordering of data before texImage2D, but when it draws, it draws yellow where it should be "transparent white"... which suggests it's diminishing the "B"(blue) component instead of the A(alpha) component. But the same thing happens when I just use the orignal ARGB data instead ("B" diminishes instead of "A", leaving yellow).
In Android OpenGL ES, I want to be able to switch textures for a given Rectangle. I have one rect and I put two textures, depending on different conditions. I just want to switch between textures.
I followed this code to create the textures: http://blog.poweredbytoast.com/loading-opengl-textures-in-android but it seems that this is only for one texture.
If I use only one texture, it renders fine, but then I don't know how to tell the rect to use another texture (same rect, different texture). Do I do something like "setTexture" with the ID that is generated in loadTextures()? Do I have to have an array with texture names (numbers) that I then change .. I just don't get it..
I need to enlarge(Zoom) Textures when I hold&drag at the corners.
I am using glOrtho() to setup ModelView.
CODE:.............
I am able to do hit-test and detect corners of the images(Textures) on the screen.
Now I need to enlarge(zoom) the image(texture). I have offset values, means how far I moved on the screen in X,Y directions.
If I need to use glScalef(), it will accept values in percentage(I think). How can I map the offset values to this percentage value.
or is there any other way to zoom(ie by enlarging the background polygon vertices, so that the mapped texture will automatically get zoomed) ? In this method, I am fixing the polygon sides at time of Surface Creation.
Good pattern for loading textures in an Android Java & OpenGL ES app.
My first concern is determining how many texture names to allocate and how I can efficiently go about doing this prior to rendering my vertices.
My second concern is in loading the textures, I have to infer the texture to be loaded based on my game data. This means I'll be playing around with strings, which I understand is something I really shouldn't be doing in my GL thread.
Overall I understand what's happening when loading textures, I just want to get the best lifecycle out of it. Are there any other things I should be considering?
I've noticed that OpenGLContext is removed from 1.5. Everybody says that GLSurfaceView should be used instead. Does this mean that there is no way to render OpenGL graphics into a regular View?
View 4 Replies View RelatedI'm writing a game engine.
I have a little example (see http://qrcode.kaywa.com/img.php?s=8&d=http://rokonandroid.com/rd.apk), that seems to work fine on every device except Droid / Milestone.
It displays a blue screen (due to glClearColor being set to blue), and nothing more.
I have tried with/without textures, and with/without VBOs. Yet still all blue screens on Droid.
What is unique about Droid and how it handles OpenGL, and why is it doing this?
I have a texture-mapped cube based in part on the Kube API demo and the Textured Cube example from anddev.org, It is working fine using bitmaps loaded from R.drawable.. what I need to do now is to make the texture for each face dynamic (using Bitmaps created in code). I'm having trouble understanding how to change the textures on the fly and I'm hoping someone can point me in the right direction.What would I need to change in this code to allow an existing texture to be replaced (eg. a new Bitmap would be passed in instead of loading the resource, but when I try this the texture remains unchanged).
View 5 Replies View RelatedHow do I track the memory used by OpenGL textures in Android? I understand the texture memory is on the Video RAM, but do they get swapped in with the RAM? If I call glGenTextures and do not call glDeleteTextures, how does it impact the memory usage of my current process?
View 1 Replies View RelatedSo I'm doing some simple 2D stuff with OpenGL on Android and found the performance to be very, very poor. To give you an example, I made an app with a full screen LSurfaceView. I loaded a 512x1024 texture (containing a 480x854 image), set up an orthogonal 2D matrix, and set it to draw a 480x854 pixel quad with that texture, using vertex and texture arrays. Lighting, dither, blending, etc. is disabled.
I would expect this to run at 60fps without problem, but that simple operation already drags the frame drawing time to 19ms/frame. If I add some more small textured quads around the screen, the drawing time goes up to 22/24ms. If I enable blending it balloons to 28/30ms. This is testing on a Motorola Milestone, running 2.0.1. Is this normal? Am I doing something wrong or is it just a common problem in Android?
I ran into a rather strange problem with my OpenGL game. While most textures look good, five or six are not drawn on Droid, and I don't see anything special about these images/models. For example, my HUD is made of 4 elements. The upper part is drawn correctly, while the lower part appears as white rectangles. The code used for loading and drawing these models and textures is exactly the same. Textures are 32-bit TGAs in both cases, POT dimensions, in - nodpi, inScaled==false, using GLSurfaceView to rule out configuration issues. No problems on G1 and Hero (and of course on emulator). And I don't have the Droid, so I can't just try whatever comes to my mind. Asked users to send me logs - no errors, all models and images appear to load normally.
View 2 Replies View RelatedI'm using GLSurfaceView for one of my applications and I've encountered a problem. It seems I can only create textures when in onSurfaceChanged, after that glGenTextures only returns 0. I've tried without glGenTextures and keeping track of texture indices myself, but the textures generated just turn up white. Is it only possible to load these types of resources in onSurfaceChanged (and possible onSurfaceCreated)? Or am I missing something?
View 2 Replies View RelatedIn Android OpenGL ES, I want to be able to switch textures for a given Rectangle. I have one rect and I put two textures, depending on different conditions. I just want to switch between textures.
I followed this code to create the textures: link text
and they render fine, but then I don't know how to tell the given rect to use another texture. Do I do something like "setTexture" with the ID that is generated in loadTextures() ? Do I have to have an array with texture names (numbers) that I then change .. I just don't get it..
I have just began opengl programming in android and i am fairly new to opengl as well. I've been using nehe's opengl tutorials as well as insanitydesign's android ports.I successfully managed to create a cube with a single texture mapped to all its 6 faces. I even mapped multiple textures to different faces of the cube.But the way I did it was to create 6 faces seperately, have 6 seperate index and texture buffers and then using glBindTexture() with the selected texture for each face and then calling glDrawElements. Isn't there an efficient way around this. Should i use a cube map texture instead of a GL_TEXTURE_2D?
View 4 Replies View RelatedI have troubles with OpenGL textures on Motorola Milestone with 2.1 firmware. Each call to glGenTextures fails with error GL_INVALID_OPERATION and sets the id with random numbers. The exact same application works on G1 without any error.
View 1 Replies View RelatedI'm creating an opengl es application and I would like to be able to dynamically create the text of my buttons etc.
The 2 obvious reasons for that are:
-to be modular (changing the text quickly without using photoshop)
-to be able to add languages later down the line
give me the basic steps/functions to:
create textures form text load custom fonts to display text textures with the chosen custom font indicate if I can use this for loading Kanji ?
Running into REALLY interesting problems with OpenGL ES. Basically when I start my program in 1.5 or 1.6 emulator, it works just fine but on HTC Hero 1.5 it does not. The problem is that the vertices are not being rendered but the gl.glClear() command is working just fine. I followed in with the debugger and it does go into the rendering function and such but still not rendering the vertices...
Here is the code in PasteBin (easier to read: http://pastebin.com/m706686e6 )
And here is the same thing pasted here:
CODE:............
Also I got my projection set in 2D ortho projection to match screen coordinates so that's why scale to 50,50 to actually make a bit bigger. I've tried using glDrawElements and glDrawArrays and nothing on the actual phone but works perfectly fine on the actual emulator. Any ideas where I might be going wrong? Why is the actual phone not rendering the vertices like the emulator is?
I'm having great difficulty getting basic textures to work in an OpenGL ES app on my Droid (2.1-update1). I trying to render a simple textured quad - four vertices, two faces, with normals and texture coords. When rendered, the texture is garbled and full of static, similar to TV noise. Here's a pic showing the original texture map image, and then a screencap from my droid of the rendered textured quad. The basic colors are there, but obviously the texture isn't being read or applied correctly.
View 1 Replies View RelatedSingle Threaded OpenGL game ! (check bottom, you can download and use the helper class) Lighting disabled ! Depth Buffer disabled ! Culling enabled ! Textures disabled !
Just 176 integers (x,y values only) making 88 vertexes along with 132 index numbers making "44 triangles only"
Framerates I get is
with GL_BLENDING disabled - 145 fps approx only! enabled - 110 fps approx only!
I have the screenshot of exact code in the draw function here.. just 2 damn lines ! I have hidden only the comments.. click here to see it http://prasna991.googlepages.com/drawframe.png
variable details in the 2 lines of code =========================== ipts = 176 elements (only x and y for each vertex) totallinetriangles * 3 = 176 lineindexes = 132 elements - type "short"
Here is the screenshot of output drawing and how it will look like http://prasna991.googlepages.com/screen.png
OpenGL single threaded Initialization Helper ================================ Here is my OpenGL helper class.. makes the OpenGL initialization for newbies a cakewalk http://prasna991.googlepages.com/OpenGLHelperclass.txt
I tested by rendering on the touch event only.. frame rate drops only when u touch and drag and here I have just tested by tapping and releasing gently on the emulator and on the device
Is this the device limitations ? So graphics is actually a lot lot lot slower than on iPhone ?
I would like to be able to use the OpenGL API from both Java and C (via NDK).
In Java, there is a GL object passed, which has all GL methods on it.
In C, you just talk to the native library.
In a single onDrawFrame callback (for which Java is passed a GL), can I use methods on the GL object, and also call NDK methods which access the openGL library?
In other words, is the GL object just a wrapper for the same instance of the native library?
I would like to find the dimensions of an ImageView to use to scale a Bitmap, prior to to calling view.setImageBitmap. ImageView.getWidth and ImageView.getHeight return 0 if no image has been set. (Presumably because the ImageView has not yet been measured?). Is there anyway to determine the dimensions of the ImageView prior to setting the Bitmap?
View 1 Replies View RelatedI have a image in drawable folder and i need to get dimensions of that image.
i tried BitmapFactory,getHeight etc but it is rerunning me null.
I'm trying to develop a little game, with 2D Graphics. I want my "gaming board" to be at a specific position on my screen, so that I can display in-game informations above and below the box. But since there is beginning to be a lot of Android phones out there, I was thinking about getting "dynamic" values so that I can adapt my font size to every device.
My game is not in full screen (but it could be, it's no big deal), but in a window with no title bar.
I'm using an extension of the default SurfaceView class, implementing SurfaceHolder.Callback. I tried writing the following method :
CODE:................
But the values returned are zeroes.
(even if it means changing display strategy) ?
Which are the default dimension of the Home wallpaper/background for the various Android screen configurations (small, normal and large screens with low, medium and high density)?
Are 9-patch PNG files supported for the wallpaper? Should I be using these instead?
I found a method in API level 5 that gives you the minimum size of the wallpaper, but I would like to support previous versions of Android as well.
My Android app uses a GLSurfaceView so that I can draw to screen directly from native code. As part of the app, I invoke the Android softKeyboard when necessary to receive input. I then feed the input to the native app via JNI. All this works well.. Now, the problem is that I need to know the dimensions of the soft keyboard or any other Input Method windows that are displayed so that I can pan, scroll the native application correctly.
View 4 Replies View RelatedI found that it is possible to set dimensions of my interface elements in XML layouts using DIPs as in following fragment : "android:layout_width="10dip" But all Java interface takes integer as arguments and there is no way to specify dimensions in DIPs. What is the correct way to calculate this? I figured that I have to use property density of DisplayMetrics class but is this a correct way ? May I rely on that formula:
pixels * DisplayMetrics.density = dip
The Android Developer guidance on Creating a Custom Dialog specifies a layout that starts:
code:........
If I use this code I get a dialog that sits in the centre of the screen with about 40 pixels of the underlying view visible on each side.
What exactly does "fill_parent" mean (for the width and height)?