EXT_disjoint_timer_query extension

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 WebGLRenderingContext.getExtension() method. For more information, see also Using Extensions in the WebGL tutorial.

Note: This extension should be available in WebGL1 contexts only. EXT_disjoint_timer_query_webgl2 is available in WebGL 2 contexts .

In WebGL 2, the WebGLRenderingContext.getQueryObject was renamed to WebGL2RenderingContext.getQueryParameter. In WebGL 2, other queries (such as occlusion queries and primitive queries) are possible using 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 GLint indicating the number of bits used to hold the query result for the given target.
ext.CURRENT_QUERY_EXT: A WebGLQuery object, which is the currently active query for the given target.
ext.QUERY_RESULT_EXT: A GLuint64EXT containing the query result.
ext.QUERY_RESULT_AVAILABLE_EXT: A 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 GLboolean indicating whether or not the GPU performed any disjoint operation.

Instance methods

This extension exposes eight new methods.

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

Examples

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

Specifications

Specification
WebGL EXT_disjoint_timer_query Extension Specification

Browser compatibility

BCD tables only load in the browser