#GIDEROS SET SPRITE OF TEXTURE MANUAL#
We can use SSBO/StructuredBuffer with more per instance data to further specialize the shader without changing the sprites (like manual vertex pulling) but as always, numbers will tell what is better for your application, and finding a balance between draw calls, permutations and shader complexity is paramount! Bonus: post-process bindless trickĪ trick I started using with bindless for post-process shaders is to use the instance id as texture index to be retrieved into the shader! If we can have similar shaders (and many times for pixel art games we CAN), then it is guaranteed that draw calls will be kept at minimum. One draw call RenderDoc truth: 1 draw call for the background, 1 for all those sprites!Īs we can see from this RenderDoc capture we are using an instanced draw call with bindless to render all the sprites on the screen in this demo, even though they are coming from 5 different files!
#GIDEROS SET SPRITE OF TEXTURE CODE#
I also updated the code so you can choose when to disable it and see the problem yourself. Here I highlighted the problem as you can see without that keyword: Non synchronized pixels for missing nonuniformEXT keyword I could see the problem without the keyword only on my integrated AMD card from my AMD 5900HX CPU, not on my Nvidia 2070, but it is great to be aware of these kind of problems. There is an incredibly informative blog post about the nonuniformEXT on Anki 3D blog, as well as the spec itself.Īgain thanks a lot to Christian Forfang to point out the missing keyword. Vec4 color = texture( textures, uv_alpha.xy ) īy simply passing the uint in the instance data we have what we need to render any sprite. Layout (location = 0) out vec4 out_color Layout (location = 1) flat in uint albedo_id The correct shader is this: #if defined FRAGMENT I’ve added a toggle so you can see the problems that could happen when you don’t include that keyword. Thanks to Christian Forfang for the email, I totally forgot about that! NOTE in Vulkan we need an additional keyword to properly sample a texture in the bindless model without incurring in problems, and this is the nonuniformEXT keyword. We can now sample the texture in the fragment program easily. Layout (location = 1) flat out uint out_albedo_id Ĭonst uint vertex_index = gl_VertexID % 6 Layout (location = 1) in vec4 uv_size_offset The sprite shader can be modified to include uints as vertex layout inputs, and pass the a flat uint to the fragment program: #if defined VERTEX In Hydra I have a freelist for all rendering resources, so I can always use the texture index without worrying about index collisions and such.
In this case we use flag1 as the index containing the texture to read. The core of the caching is in sprite_batch.cpp: void SpriteBatch::set( hydra::gfx::PipelineHandle pipeline, hydra::gfx::ResourceListHandle resource_list ) We still need to differentiate shaders that use different constant/structured buffers, but otherwise we can share a common shader! Render states, vertex layouts and shaders are all inside a Pipeline State Object, so the only caching really needed here is: They are in used in descriptor sets, but with bindless we can simply ignore them, because they are passed down as integers into constants. In Vulkan world, render states, shader and vertex layouts are all included into a pipeline. To have an effective Sprite Batch we need to cache some informations in order to know when to group sprites and when not. The ‘set’ method would check if the current texture is differen than the sprite one, and if so then it would submit the accumulated sprites, then cache the sprite texture and start filling the new sprites.Ī good code to check is the one for libGDX sprite batching.Ĭan we do better ? The answer is yes! Sprite Batch: caching We would have something like (pseudocode): for each sprite Normally when batching sprites, we would submit a batch of sprites when any texture would change, an operation that could be reduced by using texture atlases.įor tiles this can be more easily done, but for characters with a lot of complex sprite sheets it is harder. Sprite batching is a way of reducing the number of draw calls (still something to not abuse) by grouping them based on similar properties. In this short article I would like to talk about how easy is to manage sprites, including UI, with the bindless model. Since the Bindless Age has started old algorithms can be implemented in new ways. Sprite batching is one of the fundamental techniques used in almost all pixel art games (that are lovingly back in town after the first era of 3D), and yet I never found any recent documentation. The sprites rendered with 1 draw call using the techniques described in this article.
0 kommentar(er)
