Ok, basically what I am doing right now is using a 1D Texture as a HeightMap Texture for a 2D object (terrain, water, lava, etc.) and, using a vertex shader, the position of the vertices at the top are modified based on this 1D Texture.
I have it working right now with a 1D Texture but anytime I want to change the heightMap I have to use glTexImage1D and glTexSubImage1D while for the other Bitmaps I am using allegro functions.
It is Not Crucial for me to find this solution since I got it working as I've explained above but I was just wondering if there was another way or if there was some state I had to establish before al_create_bitmap to accomplish a 1D Texture. It feels kind of awkward accessing all textures from their respective ALLEGRO_BITMAP using al_get_opengl_texture(bmp) but not being able to follow the same habit for these 1D Textures.
But what you are saying makes sense but I don't have that much experience with allegro 5, so here is another question:
What it is the performance advantage using a 1D Texture over using a 2D Texture with size (2^x, 1)?