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EXT_disjoint_timer_query extension

files/en-us/web/api/ext_disjoint_timer_query/index.md

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{{APIRef("WebGL")}}

The EXT_disjoint_timer_query extension is part of the WebGL API and provides a way to measure the duration of a set of GL commands, without stalling the rendering pipeline.

WebGL extensions are available using the {{domxref("WebGLRenderingContext.getExtension()")}} method. For more information, see also Using Extensions in the WebGL tutorial.

[!NOTE] This extension should be available in {{domxref("WebGLRenderingContext", "WebGL1", "", 1)}} contexts only. {{domxref("EXT_disjoint_timer_query_webgl2")}} is available in {{domxref("WebGL2RenderingContext", "WebGL 2", "", 1)}} contexts.

In WebGL 2, the OpenGL method getQueryObject() is renamed to {{domxref("WebGL2RenderingContext.getQueryParameter")}}. In WebGL 2, other queries (such as occlusion queries and primitive queries) are possible using {{domxref("WebGLQuery")}} objects.

Types

This extension exposes a new type:

  • GLuint64EXT
    • : Unsigned 64-bit integer number.

Constants

This extension exposes seven new constants.

  • ext.QUERY_COUNTER_BITS_EXT
    • : A {{domxref("WebGL_API/Types", "GLint")}} indicating the number of bits used to hold the query result for the given target.
  • ext.CURRENT_QUERY_EXT
    • : A {{domxref("WebGLQuery")}} object, which is the currently active query for the given target.
  • ext.QUERY_RESULT_EXT
    • : A {{domxref("WebGL_API/Types", "GLuint64EXT")}} containing the query result.
  • ext.QUERY_RESULT_AVAILABLE_EXT
    • : A {{domxref("WebGL_API/Types", "GLboolean")}} indicating whether or not a query result is available.
  • ext.TIME_ELAPSED_EXT
    • : Elapsed time (in nanoseconds).
  • ext.TIMESTAMP_EXT
    • : The current time.
  • ext.GPU_DISJOINT_EXT
    • : A {{domxref("WebGL_API/Types", "GLboolean")}} indicating whether or not the GPU performed any disjoint operation.

Instance methods

This extension exposes eight new methods.

  • {{domxref("EXT_disjoint_timer_query.createQueryEXT()", "ext.createQueryEXT()")}}
    • : Creates a new {{domxref("WebGLQuery")}}.
  • {{domxref("EXT_disjoint_timer_query.deleteQueryEXT()", "ext.deleteQueryEXT()")}}
    • : Deletes a given {{domxref("WebGLQuery")}}.
  • {{domxref("EXT_disjoint_timer_query.isQueryEXT()", "ext.isQueryEXT()")}}
    • : Returns true if a given object is a valid {{domxref("WebGLQuery")}}.
  • {{domxref("EXT_disjoint_timer_query.beginQueryEXT()", "ext.beginQueryEXT()")}}
    • : The timer starts when all commands prior to beginQueryEXT have been fully executed.
  • {{domxref("EXT_disjoint_timer_query.endQueryEXT()", "ext.endQueryEXT()")}}
    • : The timer stops when all commands prior to endQueryEXT have been fully executed.
  • {{domxref("EXT_disjoint_timer_query.queryCounterEXT()", "ext.queryCounterEXT()")}}
    • : Records the current time into the corresponding query object.
  • {{domxref("EXT_disjoint_timer_query.getQueryEXT()", "ext.getQueryEXT()")}}
    • : Returns information about a query target.
  • {{domxref("EXT_disjoint_timer_query.getQueryObjectEXT()", "ext.getQueryObjectEXT()")}}
    • : Return the state of a query object.

Examples

js
const ext = gl.getExtension("EXT_disjoint_timer_query");

Specifications

{{Specifications}}

Browser compatibility

{{Compat}}

See also

  • {{domxref("WebGLRenderingContext.getExtension()")}}