4 replies to this topic

[MA-Mestre]

I use P-Buffer to reach a RTT as stated in certain some docs on nvidia developer center. No probs appear thru the implementation, but... ohhh, always the new texture appears inverted like bmp's format do. :dry: Any idea ?

Thanks.

[ravuya]

Inverted colour-wise, or inverted as in upside-down?

[MA-Mestre]

upside down



Draw into p-buufer:

glBegin (GL_TRIANGLES);
glVertex3f (0.0f,5.0f,-15.0f);
glVertex3f (5.0f,-5.0f,-15.0f);
glVertex3f (-5.0f,-5.0f,-15.0f);
glEnd ();



Draw into Front Buffer

glEnable (GL_TEXTURE_2D);
glBindTexture(GL_TEXTURE_2D, rtt.GetTexture());
glBegin(GL_TRIANGLE_STRIP);
glTexCoord2f(1.0f, 1.0f); glVertex3f(-5.0f,5.0f,-15.0f);
glTexCoord2f(1.0f, 0.0f); glVertex3f(-5.0f,-5.0f,-15.0f);
glTexCoord2f(0.0f, 1.0f); glVertex3f(5.0f,5.0f,-15.0f);
glTexCoord2f(0.0f, 0.0f); glVertex3f(5.0f,-5.0f,-15.0f);
glEnd();
glDisable(GL_TEXTURE_2D);

As u will see, the TexCoords are changed to show the texture correctly. Otherwise the texture appears upside-down.

[Reedbeta]

This is the natural way that textures work in OpenGL....their coordinate system has (0,0) on the bottom left and (1,1) on the top right. It is like a standard Cartesian coordinate system.

[MA-Mestre]

Thanks :wub: