Re: [Boost-users] gil and OpenGL

Subject: Re: [Boost-users] gil and OpenGL
From: Ruben Lopez (r.lopez_at_[hidden])
Date: 2010-01-12 04:05:41

Kenny Riddile wrote:
> Kenny Riddile wrote:
>>
>> I do this to load GIL images as OpenGL textures and it works fine for 
>> me:
>>
>> reinterpret_cast<const char*>( 
>> interleaved_view_get_raw_data(imageView) )
>
> Also, I've noticed that OpenGL interprets the image data upside down, 
> so I flip it prior to calling glTexImage2D using flipped_up_down_view. 
> Flipping the image data seems to be common practice when loading 
> OpenGL textures based on what I've read online.
You can flip the image, but it is more efficient to flip the texture 
coordinates on Y (or T) axis. If you have a lot of texture coordinates, 
you can set a texture matrix (glMatrixMode(GL_TEXTURE)) that flips them 
on hardware.