[Gambas-user] gb3: gb.opengl will not render alpha channel of 2D texture

[Laurent Carlier]

Le Samedi 30 Juillet 2011 00:19:41, Kevin Fishburne a écrit :
> I've been researching this for hours and nothing I try works. The image
> used for the texture has an alpha channel, but it is displayed as black
> instead of transparent. I'm starting to think that the line:
> 
> Gl.TexImage2D(t1)
> 
> isn't passing the presence of an alpha channel to OpenGL, but that's
> just a guess. Normally you specify the image format there, but those
> parameters aren't supported yet in the gb3 implementation.
> 
> The project is attached. You can move the little wizard around with the
> ASDW keys and rotate with the QE keys. Any help appreciated...I'm going
> crazy and am calling it quits for the night

This is what i do in the sdl component to get alpha blending:

glEnable(GL_BLEND);
glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA);

So it should be in gambas3 code:

Gl.Enable(Gl.GL_BLEND)
Gl.BlendFunc(Gl.GL_SRC_ALPHA, Gl.GL_ONE_MINUS_SRC_ALPHA)

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