GL_LINEAR

I am trying to use fragment shaders to convert 2x2 image to 2x4 image which is basically I am trying to convert an image to double sized vertical only (not horizontal, atleast not yet)

Even though I have specified the texture parameters as GL_LINEAR for min and mag I am getting the final image sampled as GL_NEAREST.

I am not using any mipmaps

eg on how the double vertical should be sampled is as below

Original 2x2 Image

| a | b |

| c | d |

Final 2x4 image should look like

| a | b |

| ac | bd |

| c | d |

| c~ | d~ |

but the final 2x4 image looks like (which is wrong and I believe its doing GL_NEAREST)

| a | b |

| a | b |

| c | d |

| c | d |

Let me know what I am doing wrong, apart from setting the GL_LINEAR is there anything else I am missing.

Appreciate your reply.

thx
Chidu

Can you show us a piece of code? Texture setup part would be interesting.