7 replies to this topic

[Lucky808]

Hi all,

 

I'm having trouble to get z-buffer to work properly on my isometric tile map. (using glOrthof() projection)

I've created and bound a depth buffer and enabled it. however during rendering, it only seems to work properly when my player character is walking behind other objects on the map. however, whenever the character gets in front of an object, the overlapping part between character and object does show up, meaning the entire object gets rendered and my character gets cut off from where the overlapping starts.

I'm stuck with this problem for 3 days and couldn't figure out why. any help is much appreciated!

 

 

[Seabolt]

Have you enabled depth testing?

[Lucky808]

Yes I have.

 

here is how I initialized openGL. do you see any issues with them:

 

 

if (!depthRenderbuffer){

glGenRenderbuffersOES(1, &depthRenderbuffer);

glBindRenderbufferOES(GL_RENDERBUFFER_OES, depthRenderbuffer);

glRenderbufferStorageOES(GL_RENDERBUFFER_OES, GL_DEPTH_COMPONENT24_OES, framebufferWidth, framebufferHeight);

glFramebufferRenderbufferOES(GL_FRAMEBUFFER_OES, GL_DEPTH_ATTACHMENT_OES, GL_RENDERBUFFER_OES, depthRenderbuffer);

}

 

 

glViewport(0, 0, rect.size.width , rect.size.height);

    

 

glMatrixMode(GL_PROJECTION);

glLoadIdentity();

 

glOrthof(0, rect.size.width, 0, rect.size.height, -1024, 1024);

 

glMatrixMode(GL_MODELVIEW);

glLoadIdentity();

 

 

glClearColor(0.0f, 0.0f, 0.0f, 1.0f);

glClearDepthf(1.0f);

glEnable(GL_DEPTH_TEST);

glDepthMask(GL_TRUE);

glDepthFunc(GL_LEQUAL);

glHint(GL_PERSPECTIVE_CORRECTION_HINT, GL_NICEST);

 

glEnable(GL_ALPHA_TEST);

glAlphaFunc(GL_GREATER, 0);

 

glEnableClientState(GL_VERTEX_ARRAY);

glEnableClientState(GL_COLOR_ARRAY);

glEnable(GL_TEXTURE_2D);

glEnableClientState(GL_TEXTURE_COORD_ARRAY);

glEnable(GL_BLEND);

 

glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);

 

Thanks.

[Seabolt]

That setup looks fine enough to me. Have you been error checking? In OpenGL it's glGetError(), I'm not sure if there is an equivalent on OpenGL ES.

[Lucky808]

I tried glGetError() and got an error code 1280, which is GL_INVALID_ENUM. my understanding is that this code can be ignored, right?

[Seabolt]

No way, that essentially means you're passing an invalid parameter to a function and it has no idea how to handle it. So instead, it does nothing.

[Lucky808]

i got it to work. it turned out that i had assigned the wrong z-values to tiles. how stupid of me.

thanks for the help though.

[Seabolt]

No problem!