Custom vertex declaration for use in 2D?

Graphics
1

Dear all,

I am at a bit of a loss concerning how to pass data to a custom pixel shader when drawing sprites from a sprite batch.

I am drawing a 2D tile-based landscape and would like to additionally pass information on the height of the tile for later use. In 3D, I would use a custom vertex declaration and store the needed information in, e.g., an additional texture coordinate. However, I do not know how to access the vertex declaration when using the SpriteBatch.Draw() method.

Here is the (default) VertexShaderOutput I am using right now:

struct VertexShaderOutput
{
	float4 Position		: SV_POSITION;
	float4 Color		: COLOR0;
	float2 TexCoord	: TEXCOORD0;
};

Now, is there a way to use a custom vertex declaration instead?

Alternatively, I could use an additional Texture2D object to pass height information. then I would also need to pass the tile position so that I can relate the height information to the correct tile.

So I am pretty much stuck at the moment, even though I am sure I am overlooking something fundamental. Any help (or alternative approach) would be highly appreciated.

Thanks!

2

It seems using SpriteSortMode.Immediate() seems to allow me to pass changing values of global variables for each draw call. However, I have the feeling this is a hack …

3

If you want to use something other than a VertexPositionColorTexture decleration then you can’t use SpriteBatch since it uses only that declaration to create and batch coloured textured quadrilaterals.

You can check out Primitives Tutorials - RB Whitaker's Wiki for a tutorial on how to draw geometry without using SpriteBatch.

4

Thanks, this explained a lot!

5

If you want to draw simple quads you can use the quadrenderer from this sample:

At least it’s a good headstart I think

6

Cool project, I will check it out!