D3D11 - Bitmap Font Rendering

Do you create a buffer for each quad or are you using a buffer to hold multiple quads? (the text you wrote to me indicates that you create a buffer for each quad so just want to clear that up)

You should discard the content of the old buffer when you are filling it again with new data, you could create a quad data that contains all of the transformed vertex data and then just copy that into the vertex buffer for rendering. You would need a new VB if you change font or scaling size offcourse, and even that is fixable with instanced rendering.

I've has font problem several days ago and i decided to use Direct2D shared surface. It is not perfect but it works well.

Your approach should be fast enough, i use it for my entire gui draw which is rebuilt each frame.

Please report back if you manage to make it work. Tell me if you are somehow able to predict how much space will rendered text take, I cannot find out how to do it.

I just do the naive thing with 2D and it seems quite fast. Even on older hardware I could throw tens of thousands of them around like it was nothing.

I pre-fill a static 16 bit index buffer and create a dynamic vertex buffer for my sprites. I create the sprite geometry each frame and do some basic sorting and batching. It's pretty easy to batch large amounts of the sprites into a single draw call. Buffers for it are created once up front and destroyed only at the end.

Since the index buffer was 16 bit, I capped the number of sprites at 10922 per draw call.

(10922 * 4) * sizeof(Vertex2D)... which was 32. So 1398016 bytes for the vertex buffer. About 1.4mb.

I completely did not understand clashie... :) Are you able to change the text during runtime efficiently?

A thanks for the recommendations. Looks like I'm off to implement nice batching then. I thought so, I was just befuddled at what a difference it makes, the little bit of text would cause such tremendous slowdowns.

@NightCreature83: I was creating a buffer for every quad. So that's quite a few reuses per frame for a few lines of text :)

Its the number of buffers here that are the problem, you are usually better of creating a fewer vertex buffers and having a few large ones than really small ones, the CPU overhead will cost more on the small buffers than on the large ones.

I completely did not understand clashie... :) Are you able to change the text during runtime efficiently?

Yes, my font is just packed into a texture. I wrote a tool that generates bitmap fonts and it also creates the glyph data I need alongside the actual texture.

So when I pass a character, it's indexes to an array with information for drawing it so I have the character's bounds, texture coordinates and whatever else I needed.