Make maxBindingsPerBindGroup 1000 and explain it clearly (gpuweb#4050)

kainino0x · web-flow · commit 24224df8b60c · 2023-04-18T15:22:30.000-07:00
diff --git a/spec/index.bs b/spec/index.bs
@@ -1564,13 +1564,16 @@ A <dfn dfn>supported limits</dfn> object has a value for every limit defined by
         when creating a {{GPUPipelineLayout}}.
 
     <tr><td><dfn>maxBindingsPerBindGroup</dfn>
-        <td>{{GPUSize32}} <td>[=limit class/maximum=] <td>640
+        <td>{{GPUSize32}} <td>[=limit class/maximum=] <td>1000
     <tr class=row-continuation><td colspan=4>
-        The maximum allowed number of {{GPUBindGroupLayoutEntry}}.{{GPUBindGroupLayoutEntry/binding}}
-        values when creating a {{GPUBindGroupLayout}}.
-
-        Note: 640 "ought to be enough for anybody" who is using the default
-        [=exceeds the binding slot limits|binding slot limits=].
+        The number of binding indices available when creating a {{GPUBindGroupLayout}}.
+
+        Note: This limit is normative, but arbitrary.
+        With the default [=exceeds the binding slot limits|binding slot limits=], it is impossible
+        to use 1000 bindings in one bind group, but this allows
+        {{GPUBindGroupLayoutEntry}}.{{GPUBindGroupLayoutEntry/binding}} values up to 999.
+        This limit allows implementations to treat binding space as an array,
+        within reasonable memory space, rather than a sparse map structure.
 
     <tr><td><dfn>maxDynamicUniformBuffersPerPipelineLayout</dfn>
         <td>{{GPUSize32}} <td>[=limit class/maximum=] <td>8
