OpenGL Texture to SDL_Surface

[dandymcgee]

If it's loaded in as an OpenGL tex where do you expect to magically find all of that information to construct an SDL_Surface?

I have no idea what your even talking about here, what I meant to say was you would be getting rid of information that can be usefull such as the dimensions of the image you've loaded and its color dept.

I believe he was implying he never had access to an SDL_Surface in the first place. If he does then there shouldn't have ever been any problem storing it somewhere (other than the extra memory).

[N64vSNES]

If it's loaded in as an OpenGL tex where do you expect to magically find all of that information to construct an SDL_Surface?

I have no idea what your even talking about here, what I meant to say was you would be getting rid of information that can be usefull such as the dimensions of the image you've loaded and its color dept.

I believe he was implying he never had access to an SDL_Surface in the first place. If he does then there shouldn't have ever been any problem storing it somewhere (other than the extra memory).

OK I think we're on the same page now

[RandomDever]

Alright first of all let me say the problem is solved I'm just going to include an SDL_Surface in my texture struct.
As for the mentioning of using SDL and OpenGL rendering at the same time, that was not my intention at all.
I just wanted to be able to modify the texture like applying a clip ( which is easier in SDL ).
And BTW I use SDL_image to load the textures so all I have to do is copy the SDL_Surface pointer.
However even though the problem which was listed in this topic is still valid and I would like to have a conversion rather than having an SDL_Surface in every texture there is a new problem.
OpenGL is returning 0 as the texture ID for a 128 by 128 .png and is refusing to draw it.
Does anyone have any idea why?

[RandomDever]

I still need someone to help me fix the texture ID problem because it's a HUGE speed bump.

[qpHalcy0n]

You should contact me on that. I posted a solution for ya. OpenGL will facilitate for you all of the information you need to retrieve the texture, load it into an SDL_Surface or what have you.
It would be difficult to say why the load fails without code, there's a couple reasons it would.

[Zer0XoL]

i found a function here that works awesomely

in "krumm"s post:
http://www.gamedev.net/community/forums ... _id=184477

might be of interest

[Ginto8]

i found a function here that works awesomely

in "krumm"s post:
http://www.gamedev.net/community/forums ... _id=184477

might be of interest

that's the other way around

[Zer0XoL]

i found a function here that works awesomely

in "krumm"s post:
http://www.gamedev.net/community/forums ... _id=184477

might be of interest

that's the other way around

oh :P, well i hope someone of interest sees it

[RandomDever]

Here's my draw function:

Code: Select all

   glEnable( GL_TEXTURE_2D );
	glEnable( GL_BLEND );
	glBlendFunc( GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA );
	glTranslatef( x + ( w / 2 ), y + ( h / 2 ), 0 );

	glColor4f( 1, 1, 1, alpha );

	glScalef( scale, scale, scale );
	glRotatef( rotation, 0, 0, 1.0 );

	glBindTexture( GL_TEXTURE_2D, id );

	glBegin( GL_QUADS );

	glTexCoord2i( 0, 0 );
	glVertex3f( -w / 2, -h / 2, 0 );

	glTexCoord2i( 1, 0 );
	glVertex3f( w / 2, -h / 2, 0 );

	glTexCoord2i( 1, 1 );
	glVertex3f( w / 2, h / 2, 0 );

	glTexCoord2i( 0, 1 );
	glVertex3f( -w / 2, h / 2, 0 );

	glEnd();
	glDisable( GL_TEXTURE_2D );
	glDisable( GL_BLEND );

The texture will not draw on the quad.

[qpHalcy0n]

If indeed your handle is zero, then you have not generated a texture handle or the img load (glTexImagexxxx) was passed an invalid parameter. This will result in a failure to apply the texture.

It's also possible that your blend mode does not agree with your pixel format. You need to have a valid format with some form of packed alpha in that.