Android：GLES 2.0打破三星S2？

Question

I have some very simple shader code that is failing on the S2 and only the S2.

precision highp float;
varying vec4 v_colour;
uniform mat4 proj_cam;
uniform mat4 trans;
attribute vec4 vp; //vertex xyz from buffer.
attribute vec4 vc; //vertex colour, from buffer. Standard 32bit value.
void main()
{
  v_colour = vc;
  gl_Position = proj_cam * (trans * vp);
};

precision mediump float;
varying vec4 v_colour;
void main()
{
    gl_FragColor = v_colour;
}

On the S2 this fails to render any output. If I remove the colour part of the pipe line or remove the separate view and model matrices and combine them it works. Even worse, with the same shader code only using one matrix that works I then add the "uniform mat4 trans;" line but don't use it that is enough for the rendering to fail. GL output's no errors. I'm doing this in Java, I may recode it all in C/C++ to see if that works but I don't think it will.

This code works on other phones including my old 2.2 ZT-180 tablet!

I may add that some games fail badly on my S2, others work fine.

I've been coding GLES 2.0 for a few years now and this phone has me stumped. I've resorted to shouting at it! ;)

Answer 1

And I have finally found MY bug, I was using 'glBindAttribLocation' incorrectly.

In using my old C/C++ GLES 2.0 code I've written over the years as reference I had failed to notice that I had been calling glBindAttribLocation before linking the shader. Has to be done after compiling but before linking.

After going through my code line by line and reading the docs for each function I found this. Just goes to show, even an experienced coder can slip up. :)

Would have been nice to have. Had an error from GL Question is, why did it work on the other phones I tried it?.......

Answer 2

Have you checked your AndroidManifest.xml? I have met a similar situation and fix it by using declaration below

<uses-feature android:glEsVersion="0x00020000"/>

And please make sure it's not

android:glEsVersion="2" //Wrong