B4A Library OpenGL library

alfcen · Aug 6, 2011

Hello Andrew

Perhaps it is next to impossible, nevertheless, is there any means of saving a glsv View to a bitmap, thus to an output stream and a file?

I do not screw up my expectations to too high altitudes, though.

Cheers
Robert

agraham · Aug 6, 2011

Try GL1.glReadPixelBitmap.

alfcen · Aug 7, 2011

Thanks a lot, Andrew, that was the right hint!
Sorry, if I bothered, just didn't find it in the jungle of functions in Help.

Smee · Aug 9, 2011

:sign0188::sign0087:

You guys are truly awesome. I have just read thru the previous 11 pages and got a headache.
Thanks for your work Andrew on creating the library and thanks to all the others for the encouragement to Andrew.

There will be a demand for this stuff.

I have been researching for 2 days on page flip software or how it could be integrated. It is however beyond my skill set. I am hoping that someone here could develop an example from which i could learn.

I have found this
[Moof:Bar]: Implementing iBooks page curling using a conical deformation algorithm

And there is code here to do the page turning but i am unable to do the translation from the programming language

https://github.com/harism/android_page_curl

there are also a load of examples of page turning examples on youtube

Once again ppl well done on your work, and i hope we are able to see a port of page flipping code

:sign0188:

ZJP · Aug 17, 2011

Great tutos : Per-Erik Bergman | Jayway Team Blog - Sharing Experience

alwaysbusy · Sep 8, 2011

New Initialize for transparent backgound

Hi agraham,

Is it possible to add an new Initialize (Initialize3?)

This one should make the background transparent. (order of gl commands seems to be important)

B4X:

glview.setEGLConfigChooser(8,8,8,8,16,0);

glview.setRenderer(new MyRenderer(this));
glview.getHolder().setFormat([B]PixelFormat.TRANSLUCENT[/B]);

[B]glview.setZOrderOnTop(true)[/B];

Thanks in advance!

agraham · Sep 8, 2011

This is what Initialize2 does

B4X:

public void Initialize2(BA ba, int RenderMode, String EventName, int depthSize, int stencilSize)
{
   super.Initialize(ba, EventName);
   ((GLSurfaceView)getObject()).setEGLConfigChooser(8, 8, 8, 8, depthSize, stencilSize);
   ((GLSurfaceView)getObject()).getHolder( ).setFormat( PixelFormat.RGBA_8888 );
   ((GLSurfaceView)getObject()).setRenderer(new myRenderer(this, EventName));
   setRenderMode(RenderMode);
}

According to the docs for PixelFormat.TRANSLUCENT it "chooses a format that supports translucency (many alpha bits) " which PixelFormat.RGBA_8888 does and is probably the one that would be chosen anyway.

Why do you need setZOrderOnTop?

alwaysbusy · Sep 9, 2011

Thanks agraham,

Works like a charm. I thought setZOrderOnTop(true) was needed to make it transparent (according to some websites, but it looks like they were having the same problem as me).

In my code the GLSurfaceView always was under the panel. But, when I add the GLSurfaceView first and then the panel, it works great.

Mikie · Sep 9, 2011

OpenGL vs OpenGL2

What is the difference between OpenGL1.7 and OpenGL2_1.0? Should we have both of them installed?

agraham · Sep 9, 2011

Mikie said:
What is the difference between OpenGL1.7 and OpenGL2_1.0? Should we have both of them installed?

One implements OpenGL1.1 and the other implements OpenGL2. They are quite different. 3D with OpenGL | Android Developers

Kamac · Sep 9, 2011

If someone would make a bigger tut on this with B4A, i would be greateful, because it's hard to translate Java code

scrat · Oct 24, 2011

Hello agraham

I try your very well opengl 1.7 library.
The library works well on Arm platform but on android X86 the texture color is reverted (red are bleu)

It is possible to expose the "format" parameter in gltexImage2d to be set either GL_RGB(A) or GL_BGR(A)

Thanks

Ps: sorry my english is bad

agraham · Oct 25, 2011

Neither the GL_BGR nor the GL_BGRA constants are defined in the Android OpenGL library so I have no idea what values you would use. If you can guess the values you could try using my Reflection library to invoke it but I guess that Android might not support it. If you get a "not found" error then one or more of the args may not be of Int type. To make sure assign them from an Int variable.

B4X:

Dim Obj1 As Reflector
Dim args(6) As Object
Dim types(6) As String
args(0) = target 
args(1) = level 
args(2) = bmpinternalformat 
args(3) = myBitmap  
args(4) = bmptype 
args(5) = border 
types(0) = "I"   
types(1) = "I"   
types(2) = "I"   
types(3) = "android.graphics.Bitmap"
types(4) = "I"   
types(5) = "I"   
Obj1.RunStaticMethod("android.opengl.GLUtils", "texImage2D", args, types)

You could also try the PixelsABGRtoARGB method in my Jpeg library to swap the R and B values.

B4X:

Dim jpg As Jpeg
jpg.SetPixelsFromBmp(bmp)
jpg.PixelsABGRtoARGB
bmp = jpg.GetBmpFromPixels

NeoTechni · Nov 8, 2011

So my 2D app is running a bit slow and I'd like to switch to OpenGL to speed it up.

My requirements are as follows:
-Use of a custom font file (I'm sure OpenGL allows this)
-Use of the Webview control, while allowing images with transparency
-Use of PNG and GIF textures with transparency (8 bit in PNG's case, 1 bit in GIF's)
-Drawing primitives (Rectangles, lines, and maybe pie segments?)

Are these possible?

Jim · Nov 18, 2011

Just want to throw out a mega thank you for this library!

grobi71 · Jan 16, 2012

transparent background

Hallo agraham,

thank you for your hard work. i have a little problem:

i use opengl lib 1.7 and want to set the color around the Object to transparent

gl.glClearColor(r,g,b,A) set the backgroundcolor but without Alpha if i set

gl.glClearColor(0,0,0,0) the background is set to black not transparent
gl.glClearColor(0,0,0,1) the background is also black

do you have any suggestions ?

best regards
Harald (Grobi71)

agraham · Jan 16, 2012

See posts #107 and #108. Initialize2 worked for alwaysbusy.

scrat · Jan 16, 2012

Hello

@Agraham
With new version of android x86 (ICS version 1/1/2012) color is now correct Blue and Red are not swapped. sorry for the inconvenience

I found a problem : gltranslatex as no effect (x,y,z are integer)
gltranslatef work fine with integer or float

@grobi71
No problem with alphachanel and initialize() and texture for me.

grobi71 · Jan 16, 2012

Background transparent

Hallo agraham,

i used your test app. Now i changed Initialize to Initialize2 as
Dim glsv As GLSurfaceView

glsv.Initialize2(glsv.RENDERMODE_WHEN_DIRTY, "glsv", 16, 0)

Sub glsv_Draw(gl As GL1)
If GLSurfaceChanged=True Then
GLMaterial_Reload(obj1.Material,gl)
GLSurfaceChanged=False
End If
gl.glClearColor(1,1,1,0)
gl.glClear(Bit.Or(gl.GL_COLOR_BUFFER_BIT, gl.GL_DEPTH_BUFFER_BIT))
' cube - textured
gl.glLoadIdentity : gl.glScalef(0.5,0.5,0.5)
gl.glTranslatef(0.0,0.0,distZ)
gl.glRotatef(rotX,1,0,0) : gl.glRotatef(rotY,0,1,0)
GLObject_Draw(obj1,gl)
End Sub

with the same effect

@scrat Do you have a simple example ?

rgds
Harald (Grobi71)

scrat · Jan 16, 2012

Attached a small exemple

Line 70 you can change gl.glColor4f(1,1,1,1) to gl.glColor4f(1,1,1,0.2) and see

B4A Library OpenGL library

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