B4A Library OpenGL 2.0 library

Erel · May 20, 2011

Thank you

The documentation is online: Basic4android - OpenGL2

NeoTechni · May 20, 2011

I get a blank screen on my device, Xperia Play

i get, Testing Queue event, and 60 frames shown

agraham · May 21, 2011

That's correct. Didn't you read

does little more than test the device OpenGL capability and initialise a drawing surface

The demo is an empty version of the OpenGL 1.0 demo.

NeoTechni · May 23, 2011

Ah, expected it to what the first one did. my bad.

NeoTechni · May 26, 2011

Could you find the API needed to poll the states of hardware buttons?
We cant make realtime games using just the keypress event...

agraham · May 26, 2011

I don't see that the question has anything to do with OpenGL.

OpenGl has no API to interact with other views.

GDO · Feb 27, 2013

glBufferData (target As Int, size As Int, data As java.nio.Buffer, usage As Int)

Hello,

Could you please tell me how to define data as java.nio.Buffer ?

Thank you

agraham · Mar 4, 2013

I know nothing about OpenGL but I exposed as much of Android's OpenGL capability as I could in the OpenGL and OpenGL2 libraries in the hope that someone with OpenGL experience could help me get them working properly. This happened with the OpenGL library, thanks to Jim Brown and others. Unfortunately however in the twenty months since no-one, until now, has shown any interest in using this library. Either that or it's working perfectly well for them!

In this library glBufferData, glBufferSubData, glCompressedTexImage2D and glCompressedTexSubImage2D all want a java.nio.Buffer. Buffer is the superclass of a set of typed buffers, ByteBuffer, IntBuffer, FloatBuffer etc.

Some of the OpenGL methods require a specific type of buffer and in this case I have made the method I exposed accept the required type of array and converted the array to a buffer of the required type.

I think that the reason the calls above specify the base Buffer type of parameter is that they can then accept various types of typed buffers depending on the required use, about which I could not find any information. I left these methods exposed using the Buffer type in the hope that an OpenGL expert would tell me what is required for these methods and I could then provide variations of the methods that accept arrays of the required types.

GDO · Mar 4, 2013

Hi,
An array of GL_FLOAT (FLOAT) will be a good beginning.
Could you, please ?

GDO · Mar 4, 2013

an array of FLOAT.

agraham · Mar 6, 2013

Version 1.1 now posted replaces glBufferData() and glBufferSubData with glBufferDataF, glBufferSubDataF, glBufferDataI, and glBufferSubDataI. The methods suffixed "F" accept a float array of data and the methods suffixed "I" accept an int array.

GDO · Mar 7, 2013

Hi,
Thanks for the new version.
I am trying to use Opengl es 2 but it seems to me that something is wrong with glVertexAttribPointer.

You define it like that : glVertexAttribPointer (
indx As Int,
size As Int,
normalized As Boolean,
stride As Int,
ptr() As Float)

but it should be (I think) like that :void glVertexAttribPointer(
GLuint index,
GLint size,
GLenum type,
GLboolean normalized,
GLsizei stride,
const GLvoid * pointer);

GLenum type is missing and
const GLvoid * pointer (often 0) is not possible with ptr() As Float

Am I right ?

Thank you for your help.

agraham · Mar 7, 2013

The Android definition of glVertexAttribPointer is

Code: Copy

public void  glVertexAttribPointer(int indx, int size, int type, boolean normalized, int stride, Buffer ptr)

Because Basic4android cannot cope with buffers I implemented it to accept a float array and pass a FloatBuffer

Code: Copy

   public void glVertexAttribPointer(int indx, int size, boolean normalized, int stride, float[] ptr)
   {
      ByteBuffer pbb = ByteBuffer.allocateDirect(ptr.length * 4);
      pbb.order(ByteOrder.nativeOrder());
      FloatBuffer pfb = pbb.asFloatBuffer();
      pfb.put(ptr);
      pfb.position(0);
      GLES20.glVertexAttribPointer(indx, size, GL_FLOAT, false, 0, pfb);
   }

It looks like passing "false" rather passing the normalised argument is a bug.

As Java doesn't allow pointer manipulation you can't pass 0 like in C. You could try either Null or a zero length array.

GDO · Mar 7, 2013

Hello,
It seems to me that "int offset" is defined, too :
Added in API level 9
public static void glVertexAttribPointer (int indx, int size, int type, boolean normalized, int stride, int offset)

For now, nothing is working, for me, with "Buffer ptr" :

in API level 8
public static void glVertexAttribPointer (int indx, int size, int type, boolean normalized, int stride, Buffer ptr)

Could you change/add glVertexAttribPointer with "int offset", please.

agraham · Mar 7, 2013

In version 1.2 now posted the previous version of glVertexAttribPointer is corrected and named glVertexAttribPointerF

Code: Copy

public void glVertexAttribPointerF(int indx, int size, boolean normalized, int stride, float[] ptr)
   {
      ByteBuffer pbb = ByteBuffer.allocateDirect(ptr.length * 4);
      pbb.order(ByteOrder.nativeOrder());
      FloatBuffer pfb = pbb.asFloatBuffer();
      pfb.put(ptr);
      pfb.position(0);
      GLES20.glVertexAttribPointer(indx, size, GL_FLOAT, normalized, stride, pfb);
   }

A new glVertexAttribPointer method is added.

Code: Copy

public void glVertexAttribPointer(int indx, int size, int type, boolean normalized, int stride, int offset)
   {
      GLES20.glVertexAttribPointer(indx, size, type, normalized, stride, offset);
   }

GDO · Mar 8, 2013

Thank you for the change.

There is a problem with buffer :

main_v7 (java line: 317)
java.lang.IllegalArgumentException: remaining() < size

at android.opengl.GLES20.glBufferData(Native Method)
at anywheresoftware.b4a.agraham.opengl2.GLWrapper2.glBufferDataF(GLWrapper2.java:470)

at gdo.opengl2.main._v7(main.java:317)
at gdo.opengl2.main._glsv_surfacecreated(main.java:477)
at java.lang.reflect.Method.invokeNative(Native Method)
at java.lang.reflect.Method.invoke(Method.java:507)
at anywheresoftware.b4a.BA.raiseEvent2(BA.java:167)
at anywheresoftware.b4a.BA.raiseEvent2(BA.java:155)
at anywheresoftware.b4a.BA.raiseEvent(BA.java:151)
at anywheresoftware.b4a.agraham.opengl2.GLWrapper2$GLSurfaceViewWrapper2$myRenderer.onSurfaceCreated(GLWrapper2.java:1668)
at android.opengl.GLSurfaceView$GLThread.guardedRun(GLSurfaceView.java:1348)
at android.opengl.GLSurfaceView$GLThread.run(GLSurfaceView.java:1118)
java.lang.IllegalArgumentException: remaining() < size

java.lang.RuntimeException: Can't create handler inside thread that has not called Looper.prepare()

at android.os.Handler.<init>(Handler.java:121)
at android.app.Dialog.<init>(Dialog.java:101)
at android.app.AlertDialog.<init>(AlertDialog.java:63)
at android.app.AlertDialog.<init>(AlertDialog.java:59)
at android.app.AlertDialog$Builder.create(AlertDialog.java:786)
at anywheresoftware.b4a.BA.raiseEvent2(BA.java:204)
at anywheresoftware.b4a.BA.raiseEvent2(BA.java:155)
at anywheresoftware.b4a.BA.raiseEvent(BA.java:151)
at anywheresoftware.b4a.agraham.opengl2.GLWrapper2$GLSurfaceViewWrapper2$myRenderer.onSurfaceCreated(GLWrapper2.java:1668)
at android.opengl.GLSurfaceView$GLThread.guardedRun(GLSurfaceView.java:1348)
at android.opengl.GLSurfaceView$GLThread.run(GLSurfaceView.java:1118)
** Activity (main) Pause, UserClosed = true **

Thanks

agraham · Mar 8, 2013

What value are you passing in for size? I supect it is a byte count and needs to be data.length * 4.

GDO · Mar 8, 2013

It's : gl.GL_FLOAT * 3*3

gl.glBufferDataF(gl.GL_ARRAY_BUFFER, gl.GL_FLOAT * 3*3, triVertices, gl.GL_STATIC_DRAW)

where triVertices is Dim triVertices(9) As Float

GDO · Mar 8, 2013

ooops !

gl.GL_FLOAT is not correct !

I change it by 4.

Sorry.

B4A Library OpenGL 2.0 library

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