[fpc-pascal] OpenGL ES bitmap drawing

[Felipe Monteiro de Carvalho]

On Fri, Nov 25, 2011 at 7:00 PM, Jeppe Græsdal Johansen
<jjohan07 at student.aau.dk> wrote:
> Are you sure width and height are powers of two here?
>
> And shouldn't you be calling glDrawArrays at line 158 instead of line 148?

I fixed the pixel format missmatch, made width=height=128 and changed
glDrawArrays like you proposed but still no change.

On Sat, Nov 26, 2011 at 3:06 PM, Reimar Grabowski <reimgrab at web.de> wrote:
> It looks like you are using lit geometry, any reason for that?

What is lit geometry? Google didn't help me here.

I just want to draw a 2D image which fills the entire screen. I don't
want any 3D at all. Only 1 texture which covers the entire screen.

The worse part here is that with the power of two limitation it seams
that I will have a lot of problems, because with this limitation I
can't match correctly the screen format. Usually the screens are 2x3
in proporsions, but power of two allows only 1x2 from what I
understand.

> Why do you enable blending after drawing and at all?
> Why do you set up your matrices after drawing? (See Jeppes remark about glDrawArrays)
> Why do you enable texturing after drawing? (You only loose the first frame as for the next it will be enabled, but it is strange nonetheless)

No idea about any of this ... I copied the code from a tutorial,
probably the guy wasn't vey good in OpenGL.

> You said there is a pixel format mismatch. AFAIR your texture should be white if something is wrong with it, but I am not 100% sure in case of a format mismatch.

I already fixed the missmatch.

> Disable blending, texturing, lighting and face culling and just draw a colored quad to check if your matrix setup in combination with placement of the quad in the world is correct.
> Reenable face culling and check.
> Reenable texturing and check (fix your pixel format mismatch before that).
> Reenable lighting if needed.
> Reenable blending if needed.
> Be generous with glGetError calls see
> http://www.khronos.org/opengles/documentation/opengles1_0/html/glGetError.html.

ok, thanks, I'll try that (as soon as figure out how to do that)

-- 
Felipe Monteiro de Carvalho