Posted by slava_jazz on Mar 22, 2012; 1:59pm
URL: https://forum.jogamp.org/blank-screen-by-shader-render-tp3848071p3848575.html

Thanks, Wade Walker,  
after size fixing the  "glDrawArray" works correct for both cases (data pre-loaded into gpu and on-fly loaded from heap). Additional I was found that  "gl2.glEnableVertexAttribArray(a_vertex);" have to be called for both cases as well.

Big step forward, but "glDrawElements" still does not work, your nice diagnostic function checkGLError(gl2,"glDrawElements"); keep silence...
would you please look what there can be wrong:

        int count = Triangle.INDICES.length;
        gl2.glEnable(GL2.GL_VERTEX_ARRAY);
        checkGLError(gl2,"glEnable");
        gl2.glDrawElements(GL2.GL_TRIANGLES, count, GL2.GL_UNSIGNED_SHORT, 0);
        checkGLError(gl2,"glDrawElements");