# Shadowmapping on iphone 3GS ? **URL:** \ **Category:** PowerVR Insider\ **Created:** [September 29, 2009, 11:56pm UTC](https://forums.imgtec.com/t/shadowmapping-on-iphone-3gs/493 "2009-09-29T23:56:04Z")\ **Posts on this page:** 6\ **Page:** 1
**Author:** ![nicolasbol](https://avatars.discourse-cdn.com/v4/letter/n/ad7895/32.png) [@nicolasbol](https://forums.imgtec.com/u/nicolasbol)\ **Post date:** [September 29, 2009, 11:56pm UTC](https://forums.imgtec.com/t/shadowmapping-on-iphone-3gs/493/1 "2009-09-29T23:56:04Z")
Hi guys, I’ve having the hardest time porting my shadow map tutorial to iPhone: The framebuffer creation fails whatever I tried so far:      GLenum status;            glGenFramebuffers(1, &shadowFBOId);      glBindFramebuffer(GL\_FRAMEBUFFER,shadowFBOId);                  glGenTextures(1, &colorTextureId);      glBindTexture(GL\_TEXTURE\_2D, colorTextureId);      glTexParameteri(GL\_TEXTURE\_2D, GL\_TEXTURE\_WRAP\_S, GL\_CLAMP\_TO\_EDGE);      glTexParameteri(GL\_TEXTURE\_2D, GL\_TEXTURE\_WRAP\_T, GL\_CLAMP\_TO\_EDGE);      glTexParameterf(GL\_TEXTURE\_2D, GL\_TEXTURE\_MAG\_FILTER, GL\_NEAREST);      glTexParameterf(GL\_TEXTURE\_2D, GL\_TEXTURE\_MIN\_FILTER, GL\_NEAREST);      glTexImage2D(GL\_TEXTURE\_2D, 0, GL\_RGBA, renderWidth, renderHeight, 0, GL\_RGBA, GL\_UNSIGNED\_BYTE, NULL);      glFramebufferTexture2D(GL\_FRAMEBUFFER, GL\_COLOR\_ATTACHMENT0,GL\_TEXTURE\_2D, colorTextureId, 0);                  glGenTextures(1, &shadowMapTextureId);      glBindTexture(GL\_TEXTURE\_2D, shadowMapTextureId);      glTexParameteri(GL\_TEXTURE\_2D, GL\_TEXTURE\_WRAP\_S, GL\_CLAMP\_TO\_EDGE);      glTexParameteri(GL\_TEXTURE\_2D, GL\_TEXTURE\_WRAP\_T, GL\_CLAMP\_TO\_EDGE);      glTexParameterf(GL\_TEXTURE\_2D, GL\_TEXTURE\_MAG\_FILTER, GL\_NEAREST);      glTexParameterf(GL\_TEXTURE\_2D, GL\_TEXTURE\_MIN\_FILTER, GL\_NEAREST);      glTexImage2D( GL\_TEXTURE\_2D, 0, GL\_DEPTH\_COMPONENT, renderWidth, renderHeight, 0, GL\_DEPTH\_COMPONENT16, GL\_UNSIGNED\_SHORT, NULL);      glFramebufferTexture2D(GL\_FRAMEBUFFER,GL\_DEPTH\_ATTACHMENT,GL\_TEXTURE\_2D,shadowMapTextureId,0 );                  status = glCheckFramebufferStatus(GL\_FRAMEBUFFER);             I’ve tried to use a renderBuffer for the depth attachment and it is working fine:       GLuint depthRenderbuffer;       glGenRenderbuffers(1, &depthRenderbuffer);       glBindRenderbuffer(GL\_RENDERBUFFER, depthRenderbuffer);       glRenderbufferStorage(GL\_RENDERBUFFER, GL\_DEPTH\_COMPONENT16, renderWidth, renderHeight);       glFramebufferRenderbuffer(GL\_FRAMEBUFFER, GL\_DEPTH\_ATTACHMENT, GL\_RENDERBUFFER, depthRenderbuffer);      So I think there is an issue in my glTexImage2D for the depth buffer. Anyone has a clue ? ---
**Author:** ![nicolasbol](https://avatars.discourse-cdn.com/v4/letter/n/ad7895/32.png) [@nicolasbol](https://forums.imgtec.com/u/nicolasbol)\ **Post date:** [September 29, 2009, 11:58pm UTC](https://forums.imgtec.com/t/shadowmapping-on-iphone-3gs/493/2 "2009-09-29T23:58:54Z")
By the way, the error I get in status is GL\_FRAMEBUFFER\_INCOMPLETE\_ATTACHMENT ---
**Author:** ![nicolasbol](https://avatars.discourse-cdn.com/v4/letter/n/ad7895/32.png) [@nicolasbol](https://forums.imgtec.com/u/nicolasbol)\ **Post date:** [September 30, 2009, 4:49am UTC](https://forums.imgtec.com/t/shadowmapping-on-iphone-3gs/493/3 "2009-09-30T04:49:28Z")
Just checked out the SDK 2.5, iphone version doesn’t have the training course 29: ShadowMapping ☹ ! Any plan to update it ? ---
**Author:** ![xmas](https://avatars.discourse-cdn.com/v4/letter/x/958977/32.png) [@xmas](https://forums.imgtec.com/u/xmas)\ **Post date:** [September 30, 2009, 12:10pm UTC](https://forums.imgtec.com/t/shadowmapping-on-iphone-3gs/493/4 "2009-09-30T12:10:59Z")
Depth textures are an extension (GL\_OES\_depth\_texture) to OpenGL ES 2.0 and are currently not supported on the iPhone. Always check the extension string before using non-core functionality. You could try other shadow map approaches (object ID, encode depth to RGBA texture), though. Xmas2009-09-30 14:16:26 ---
**Author:** ![nicolasbol](https://avatars.discourse-cdn.com/v4/letter/n/ad7895/32.png) [@nicolasbol](https://forums.imgtec.com/u/nicolasbol)\ **Post date:** [October 4, 2009, 6:20am UTC](https://forums.imgtec.com/t/shadowmapping-on-iphone-3gs/493/5 "2009-10-04T06:20:28Z")
Thanks XMas. I’m packing the depth value in a RGBA (32bits) texture for now and I’m pretty happy with the result (only that I am still looking for an artist so I won’t have to borrow John C’s georgous Hellknight): ![](http://fabiensanglard.net/dEngine/shadowMapping.png) I don’t think I need so much precision (plus I’m starting to consum a lot of bandwidth) so I’m now trying to render to a 16 bits texture:GL\_RGBA4 or GL\_RGB565 none of them are working, I am not sure where to look to check if they are supported.nicolasbol2009-10-04 08:31:07 ---
**Author:** ![xmas](https://avatars.discourse-cdn.com/v4/letter/x/958977/32.png) [@xmas](https://forums.imgtec.com/u/xmas)\ **Post date:** [October 5, 2009, 7:18am UTC](https://forums.imgtec.com/t/shadowmapping-on-iphone-3gs/493/6 "2009-10-05T07:18:31Z")
The sized formats GL\_RGBA4 and GL\_RGB565 are for renderbuffer creation, not for textures. OpenGL ES does not support sized internal texture formats. If you want to use 16-bit textures, just use GL\_UNSIGNED\_SHORT\_5\_6\_5 or GL\_UNSIGNED\_SHORT\_4\_4\_4\_4 as type argument to glTexImage2D. Both RGBA4444 and RGB565 textures should be supported as rendertargets.