docs: Fixed buffers (#1780)

Author: aleksanderkatan

apps/typegpu-docs/src/content/docs/fundamentals/buffers.mdx

@@ -332,3 +332,82 @@ const indexBuffer = root
 
 ```
 
+## Binding buffers
+
+To use a buffer in a shader, it needs to be bound using a bind group.
+There are two approaches provided by TypeGPU.
+
+### Manual binding
+
+The default option is to create bind group layouts and bind your buffers via bind groups.
+Read more in the chapter dedicated to [bind groups](/TypeGPU/fundamentals/bind-groups).
+
+```ts twoslash
+import tgpu from 'typegpu';
+import * as d from 'typegpu/data';
+
+const root = await tgpu.init();
+// ---cut---
+const pointsBuffer = root
+  .createBuffer(d.arrayOf(d.vec2i, 100))
+  .$usage('storage');
+
+const bindGroupLayout = tgpu.bindGroupLayout({
+  points: { storage: d.arrayOf(d.vec2i, 100), access: 'mutable' },
+});
+
+const bindGroup = root
+  .createBindGroup(bindGroupLayout, { points: pointsBuffer });
+
+const mainCompute = tgpu['~unstable'].computeFn({
+  in: { gid: d.builtin.globalInvocationId },
+  workgroupSize: [1],
+})((input) => {
+  // Access and modify the bound buffer via the layout
+  bindGroupLayout.$.points[input.gid[0]] = d.vec2i(1, 2);
+});
+
+const pipeline = root['~unstable']
+  .withCompute(mainCompute)
+  .createPipeline();
+
+pipeline
+  .with(bindGroupLayout, bindGroup)
+  .dispatchWorkgroups(100);
+```
+
+### Using fixed resources
+
+For scenarios where buffers remain consistent across multiple compute or render operations,
+TypeGPU offers fixed resources that appear bindless from a code perspective.
+Fixed buffers are created using dedicated root methods.
+
+| WGSL type                  | TypeGPU constructor     |
+|----------------------------|-------------------------|
+| `var<uniform>`             | `root.createUniform()`  |
+| `var<storage, read>`       | `root.createReadonly()` |
+| `var<storage, read_write>` | `root.createMutable()`  |
+
+```ts twoslash
+import tgpu from 'typegpu';
+import * as d from 'typegpu/data';
+
+const root = await tgpu.init();
+// ---cut---
+const pointsBuffer = root.createMutable(d.arrayOf(d.vec2i, 100));
+
+const mainCompute = tgpu['~unstable'].computeFn({
+  in: { gid: d.builtin.globalInvocationId },
+  workgroupSize: [1],
+})((input) => {
+  // Access and modify the fixed buffer directly
+  pointsBuffer.$[input.gid[0]] = d.vec2i();
+});
+
+const pipeline = root['~unstable'].withCompute(mainCompute).createPipeline();
+pipeline.dispatchWorkgroups(100);
+```
+
+TypeGPU automatically generates a "catch-all" bind group and populates it with the fixed resources.
+
+You can also use [`resolveWithContext`](/TypeGPU/fundamentals/resolve/#resolvewithcontext) to access the automatically generated bind group and layout containing your fixed resources.