glBindTexture Problem with OpenGL ES on iPhone

I'm new to OpenGL, and am having a curious problem with my textures - looking for a nudge in the right direction.

I have an app which uses a Render to texture technique for accomplishing a certain effect - it's working marvelously. I draw to an offscreen buffer every time I need to, and am able to use this as a texture in my render loop.

This texture is only updated when necessary - it's drawn to the screen as is most frames.

I have some toolbars which are also drawn using OpenGL, on top of this surface using a texture atlas, and using blending.

I have recently begun 开发者_如何学Pythontrying to incorporate a particle system into the app, but whenever I try to render my particle system graphics, I "lose" my texture that I've rendered in the first step - ie it's contents disappear.

I have traced this to the call to glBindTexture that binds the texture of the particles.

EDIT: I can reproduce this in my simple toolbar drawing routine, code below. This is a crude routine that animates toolbar graphics on and off screen.

When I uncomment the first two lines in drawToolBar(), my rendered in memory texture disappears, ie the drawarrays call in my render loop renders nothing to the screen. Through testing, I have determined that the glBidTexture call is what triggers this. (For example, I can render colored quads over my texture, just not textured ones)

However, everything is fine if I allow drawToolbar() to run as below - the only difference is that the eventual call to drawTools() is wrapped in glPush/Pop, and is translated.

Note that the toolbar rendering always works - there is some unintended side effect, consequence, or bug issue going on here, which causes my background texture to disappear.

Any ideas are welcome - this is driving me nuts.

The code:

void drawTools()
{   
//*Texture Coordinate Stuff Snipped*//

glBindTexture(GL_TEXTURE_2D, _buttontexture);

glEnable(GL_TEXTURE_2D);

glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
glEnableClientState(GL_TEXTURE_COORD_ARRAY);

glVertexPointer  (2, GL_FLOAT, 0,bottomToolQuads);
glTexCoordPointer(2, GL_FLOAT, 0,texc);

glDrawArrays(GL_TRIANGLE_STRIP, 0, 4);
glDrawArrays(GL_TRIANGLE_STRIP, 4, 4);
glDrawArrays(GL_TRIANGLE_STRIP, 8, 4);
glDrawArrays(GL_TRIANGLE_STRIP, 12, 4);
glDrawArrays(GL_TRIANGLE_STRIP, 16, 4);
glDrawArrays(GL_TRIANGLE_STRIP, 20, 4);

glDisable(GL_TEXTURE_2D);

}

void drawToolBar()

{

//drawTools();
//return;

if(_toolbarState ==0)
{
    drawTools();
}
else if(_toolbarState == 2)//hiding
{
    _toolbarVisiblePct -= TOOLINC;

    if(_toolbarVisiblePct <= 0.0)
    {
        _toolbarState = 1;
        _toolbarVisiblePct = 0.0;
    }
    else
    {
        glPushMatrix();
        glTranslatef(0.0, -(1-_toolbarVisiblePct) * 50, 0);
        drawTools();
        glPopMatrix();
    }
}
else if(_toolbarState == 3) //showing
{
    _toolbarVisiblePct += TOOLINC;
    if(_toolbarVisiblePct >= 1.0)
    {
        _toolbarState = 0;
        _toolbarVisiblePct = 1.0;
        drawTools();
    }
    else
    {
        glPushMatrix();
        glTranslatef(0.0, -(1-_toolbarVisiblePct) * 50, 0);
        drawTools();
        glPopMatrix();

    }
}   

}

Looks like you're disabling texture rendering at the end of the drawTools method. OpenGL is a state machine, if you disable a state it will stay disabled until you enable it again.