Smoothening tile edges

[User137]

Isn't it out of options to have unique uniforms passed per tile? I am rendering hundreds of tiles on single call. Tessellation is nice idea, but my knowledge on the subject is non existent It might require some higher level graphics card, or high OpenGL version. Also doubling the triangle count might double the rendering time, depending on implementation, graphics card etc. Would be nice to have high compatibility even with the poorest laptops with integrated cards.

I'm not sure if i can use opacity map. Firstly it would have to be massive texture for all tiles on screen at once, and secondly it needs to be changeable at realtime. Current terrain textures are size 256x256 that repeats, and the hexagon is made of 6 triangles connected to the middle vertex. I would guess the resolution of opacity map would have to be at least 6x6 pixels per tile... Well, propably even 512x512 would be enough for that, although the realtime requirement would not be met. 6000x6000 texture or so for whole tilemap would be out of question, but i still haven't set any world sizes in stone.

I think i figured a nice alternative, that i will simply not render those outside triangles, and doing this triangle elimination on the CPU. I could remove 3 or 4 triangles, 3 on straight, 4 on corner. This will let me have really flat surfaces on all 6 sides, and i could make even big circle shapes with no holes in the edges. It will make interesting math for collision with these "half-tiles" though. I can also get rid of all alpha-related special treatment in fragment shader, making rendering even faster.

Oh, there is yet another option... I could add 1 triangle to fill the gap between 2 hexagons. Brilliant...