EXT_disjoint_timer_query extension
Limited availability
This feature is not Baseline because it does not work in some of the most widely-used browsers.
TheEXT_disjoint_timer_query extension is part of theWebGL 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 theWebGLRenderingContext.getExtension() method. For more information, see alsoUsing Extensions in theWebGL tutorial.
Note:This extension should be available inWebGL1 contexts only.EXT_disjoint_timer_query_webgl2 is available inWebGL 2 contexts.
In WebGL 2, the OpenGL methodgetQueryObject() is renamed toWebGL2RenderingContext.getQueryParameter.In WebGL 2, other queries (such as occlusion queries and primitive queries) are possible usingWebGLQuery objects.
Types
This extension exposes a new type:
GLuint64EXTUnsigned 64-bit integer number.
Constants
This extension exposes seven new constants.
ext.QUERY_COUNTER_BITS_EXTA
GLintindicating the number of bits used to hold the query result for the given target.ext.CURRENT_QUERY_EXTA
WebGLQueryobject, which is the currently active query for the given target.ext.QUERY_RESULT_EXTA
GLuint64EXTcontaining the query result.ext.QUERY_RESULT_AVAILABLE_EXTA
GLbooleanindicating whether or not a query result is available.ext.TIME_ELAPSED_EXTElapsed time (in nanoseconds).
ext.TIMESTAMP_EXTThe current time.
ext.GPU_DISJOINT_EXTA
GLbooleanindicating 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
trueif a given object is a validWebGLQuery.ext.beginQueryEXT()The timer starts when all commands prior to
beginQueryEXThave been fully executed.ext.endQueryEXT()The timer stops when all commands prior to
endQueryEXThave 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 |