@@ -849,6 +859,166 @@ A [=device=] has the following internal slots:
### Limits ### {#limits}
+Each
limit is a numeric limit on the usage of WebGPU on a device.
+Each [=adapter=] has a set of supported limits, and [=devices=] are created
+with specific limits in place. The device limits are enforced regardless of the
+adapter's limits, and default to a strictly-specified [=limit/baseline=].
+
+One limit value may be
better than another.
+For each limit, "better" is defined.
+
+Note:
+Setting "better" limits may not necessarily be desirable.
+While they enable strictly more programs to be valid, they may have a performance impact.
+Because of this, and to improve portability across devices and implementations,
+applications should generally request the "worst" limits that work for their content.
+
+Each limit also has a
baseline value.
+Every [=adapter=] is guaranteed to support the baseline value or [=limit/better=].
+The baseline value is also the default value for the limit in {{GPULimits}} if
+a better limit is not specified.
+
+
+
+ | {{GPULimitName}} | Type | [=limit/Better=] | [=limit/Baseline=]
+ |
|---|
+
+ | "maxBindGroups"
+ | {{GPUSize32}} | Higher | 4
+ |
|
+ The maximum number of {{GPUBindGroupLayout|GPUBindGroupLayouts}}
+ allowed in {{GPUPipelineLayoutDescriptor/bindGroupLayouts}}
+ when creating a {{GPUPipelineLayout}}.
+
+ |
| "maxDynamicUniformBuffersPerPipelineLayout"
+ | {{GPUSize32}} | Higher | 8
+ |
|
+ The maximum number of {{GPUBindGroupLayoutDescriptor/entries}} for which:
+
+ - {{GPUBindGroupLayoutEntry/type}} is {{GPUBindingType/"uniform-buffer"}}, and
+ - {{GPUBindGroupLayoutEntry/hasDynamicOffset}} is `true`,
+
+ across all {{GPUPipelineLayoutDescriptor/bindGroupLayouts}}
+ when creating a {{GPUPipelineLayout}}.
+
+ |
| "maxDynamicStorageBuffersPerPipelineLayout"
+ | {{GPUSize32}} | Higher | 4
+ |
|
+ The maximum number of {{GPUBindGroupLayoutDescriptor/entries}} for which:
+
+ - {{GPUBindGroupLayoutEntry/type}} is {{GPUBindingType/"storage-buffer"}}, and
+ - {{GPUBindGroupLayoutEntry/hasDynamicOffset}} is `true`,
+
+ across all {{GPUPipelineLayoutDescriptor/bindGroupLayouts}}
+ when creating a {{GPUPipelineLayout}}.
+
+ |
| "maxSampledTexturesPerShaderStage"
+ | {{GPUSize32}} | Higher | 16
+ |
|
+ For each possible {{GPUShaderStage}} `stage`,
+ the maximum number of {{GPUBindGroupLayoutDescriptor/entries}} for which:
+
+ - {{GPUBindGroupLayoutEntry/type}} is {{GPUBindingType/"sampled-texture"}} or
+ {{GPUBindingType/"multisampled-texture"}}, and
+ - {{GPUBindGroupLayoutEntry/visibility}} includes `stage`,
+
+ across all {{GPUPipelineLayoutDescriptor/bindGroupLayouts}}
+ when creating a {{GPUPipelineLayout}}.
+
+ |
| "maxSamplersPerShaderStage"
+ | {{GPUSize32}} | Higher | 16
+ |
|
+ For each possible {{GPUShaderStage}} `stage`,
+ the maximum number of {{GPUBindGroupLayoutDescriptor/entries}} for which:
+
+ - {{GPUBindGroupLayoutEntry/type}} is {{GPUBindingType/"sampler"}} or {{GPUBindingType/"comparison-sampler"}}, and
+ - {{GPUBindGroupLayoutEntry/visibility}} includes `stage`,
+
+ across all {{GPUPipelineLayoutDescriptor/bindGroupLayouts}}
+ when creating a {{GPUPipelineLayout}}.
+
+ |
| "maxStorageBuffersPerShaderStage"
+ | {{GPUSize32}} | Higher | 4
+ |
|
+ For each possible {{GPUShaderStage}} `stage`,
+ the maximum number of {{GPUBindGroupLayoutDescriptor/entries}} for which:
+
+ - {{GPUBindGroupLayoutEntry/type}} is {{GPUBindingType/"storage-buffer"}}, and
+ - {{GPUBindGroupLayoutEntry/visibility}} includes `stage`,
+
+ across all {{GPUPipelineLayoutDescriptor/bindGroupLayouts}}
+ when creating a {{GPUPipelineLayout}}.
+
+ |
| "maxStorageTexturesPerShaderStage"
+ | {{GPUSize32}} | Higher | 4
+ |
|
+ For each possible {{GPUShaderStage}} `stage`,
+ the maximum number of {{GPUBindGroupLayoutDescriptor/entries}} for which:
+
+ - {{GPUBindGroupLayoutEntry/type}} is {{GPUBindingType/"readonly-storage-texture"}} or
+ {{GPUBindingType/"writeonly-storage-texture"}}, and
+ - {{GPUBindGroupLayoutEntry/visibility}} includes `stage`,
+
+ across all {{GPUPipelineLayoutDescriptor/bindGroupLayouts}}
+ when creating a {{GPUPipelineLayout}}.
+
+ |
| "maxUniformBuffersPerShaderStage"
+ | {{GPUSize32}} | Higher | 12
+ |
|
+ For each possible {{GPUShaderStage}} `stage`,
+ the maximum number of {{GPUBindGroupLayoutDescriptor/entries}} for which:
+
+ - {{GPUBindGroupLayoutEntry/type}} is {{GPUBindingType/uniform-buffer}}, and
+ - {{GPUBindGroupLayoutEntry/visibility}} includes `stage`,
+
+ across all {{GPUPipelineLayoutDescriptor/bindGroupLayouts}}
+ when creating a {{GPUPipelineLayout}}.
+
+ |
| "maxUniformBufferBindingSize"
+ | {{GPUSize32}} | Higher | 16384
+ |
|
+ The maximum {{GPUBufferBinding}}.{{GPUBufferBinding/size}} for bindings
+ of type {{GPUBindingType/uniform-buffer}}.
+ |
+
+####
GPULimitName #### {#gpulimitname}
+
+A {{GPULimitName}} identifies a particular [=limit=].
+It is used to query the supported limits on a {{GPUAdapter}}.
+
+
+
+####
GPULimits #### {#gpulimits}
+
+{{GPULimits}} describes the limits with which a device should be created.
+See {{GPUDeviceDescriptor/limits|GPUDeviceDescriptor.limits}}.
+
+
+
### Extensions ### {#extensions}
@@ -1013,7 +1183,9 @@ To get a {{GPUAdapter}}, use {{GPU/requestAdapter()}}.
interface GPUAdapter {
readonly attribute DOMString name;
readonly attribute FrozenArray
extensions;
- //readonly attribute GPULimits limits; Don't expose higher limits for now.
+
+ boolean supportsLimit(GPULimitName name, double value);
+ double getLimit(GPULimitName name);
Promise requestDevice(optional GPUDeviceDescriptor descriptor = {});
};
@@ -1043,6 +1215,40 @@ interface GPUAdapter {
{{GPUAdapter}} has the following methods:
+ : supportsLimit(name, value)
+ ::
+ Queries whether a [=limit=] is supported by the adapter.
+
+
+ **Called on:** {{GPUAdapter}} |this|.
+
+ **Arguments:**
+
+ |name|: Name of the limit to query.
+ |value|: Limit value to query for support.
+
+
+ Return `true` if
+ |this|.{{GPUAdapter/[[adapter]]}}.{{adapter/[[limits]]}}[|name|]
+ is [=limit/better=] or equal to |value|. Otherwise, return `false`.
+
+ **Called on:** {{GPUAdapter}} |this|.
+
+ **Arguments:**
+
+ |name|: Name of the limit to query.
+
+
+ Return the value of
+ |this|.{{GPUAdapter/[[adapter]]}}.{{adapter/[[limits]]}}[|name|].
+