How shall I create buffers for several attributes specific for my pass

[stavenko]

Hello!

I am trying to create my own rendering pass. Main purpose of this pass is to render tile-map, using predefined texture for tiles. This is the main idea, how, i believe, this task shall be accomplished:

• 1. Vertex shader shall receive simple point attributes, which shall have following info:
  • center of tile in the world. (vec3)
  • offset of tile piece on the provided texture (uvec2)
  • size of tile on the texture (uvec2)
• 2. Geometry shader shall produce desired tile with center from vertex shader and with size, controlled by uniform variable. And pass offset and slice size to fragment shader then. (for example, I create six triangles with shared point in the center of the tile -- hex tile);
• 3. Fragment shader shall retreive desired texture piece and put it on the framebuffer.

To accomplish this, somewhere internally in the deep of my code, I prepare three arrays:

• Vec [x, y, z, x, y z....] with size = amount_of_tiles * 3 * size_of_float
• Vec [x,y, x, y, ...] with size = amount_of_tiles * 2 * size_of_u32
• Vec [w, h, w, h, ...] with size = amount_of_tiles * 2 * size_of_u32
  And try to create all three buffers with call

factory
      .create_buffer_immutable(
        &tile_coords_array, // Vec<f32> or Vec<u32>
        buffer::Role::Vertex, 
        Bind::empty()
      )

And then each apply call I do

effect.clear()

and then binding those buffers with:

    effect.data.vertex_bufs.push(vb.raw().clone()); // vec3
    effect.data.vertex_bufs.push(ob.raw().clone()); // uvec2
    effect.data.vertex_bufs.push(sb.raw().clone()); // uvec2

As a result I can see perfecly aligned tiles(so position attribute is passed to shader corretly), but it seems that other attributes are not passed at all.

I build effect with:

    effect 
      .geom(VERT_SHADER, GEOM_SHADER, FRAG_SHADER)
      .with_primitive_type(Primitive::PointList)
      .with_texture("tileSheet")
      .with_raw_constant_buffer(
        "TileMapArguments",
        mem::size_of::<<TileMapArguments as Uniform>::Std140>(),
        1
        )
      .with_raw_vertex_buffer(
        TileMapAttributes::ATTRIBUTES, 
        TileMapAttributes::size() as ElemStride,
        0)
      .with_blended_output("color", ColorMask::all(), blend::ALPHA, None)
      .build()

So I want to clear this out:

1. Which way shall I create and organise my buffers. Shall I interleave them? Shall I make binding somehow else?
2. Which way is it better to create effect? Shall I discover what is a Separate trait?
3. How do I create PosColorTex(or PosColor, or whatever) instances? How to make array of them?

[fhaynes]

My apologies @stavenko. Do you still need assistance with this?

[fhaynes]

@stavenko Feel free to join Discord or post here: https://community.amethyst-engine.org/c/other-help if you still need this answered.

[stavenko]

@fhaynes, no problem. I figured out how to do that using rendering passes. If anyone needs assistance - feel free to contact me.