WebGL2RenderingContext.beginQuery()

This is an experimental technology
Check the Browser compatibility table carefully before using this in production.

The WebGL2RenderingContext.beginQuery() method of the WebGL 2 API starts an asynchronous query. The target parameter indicates which kind of query to begin.

Syntax

void gl.beginQuery(target, query);

Parameters

target
A GLenum specifying the target of the query. Possible values:
  • gl.ANY_SAMPLES_PASSED: Specifies an occlusion query: these queries detect whether an object is visible (whether the scoped drawing commands pass the depth test and if so, how many samples pass).
  • gl.ANY_SAMPLES_PASSED_CONSERVATIVE: Same as above above, but less accurate and faster version.
  • gl.TRANSFORM_FEEDBACK_PRIMITIVES_WRITTEN: Number of primitives that are written to transform feedback buffers.
query
A WebGLQuery object for which to start the querying.

Return value

None.

Examples

var query = gl.createQuery();
gl.beginQuery(gl.ANY_SAMPLES_PASSED, query);

// ...

Specifications

Specification Status Comment
WebGL 2.0
The definition of 'beginQuery' in that specification.		 Editor's Draft Initial definition.
OpenGL ES 3.0
The definition of 'glBeginQuery' in that specification.		 Standard Man page of the (similar) OpenGL API.

Browser compatibility

Update compatibility data on GitHub
DesktopMobile
ChromeEdgeFirefoxInternet ExplorerOperaSafariAndroid webviewChrome for AndroidFirefox for AndroidOpera for AndroidSafari on iOSSamsung Internet
beginQueryChrome Full support 56Edge No support NoFirefox Full support 51IE No support NoOpera Full support 43Safari No support NoWebView Android Full support 58Chrome Android Full support 58Firefox Android Full support 51Opera Android Full support 43Safari iOS No support NoSamsung Internet Android Full support 7.0

Legend

Full support  
Full support
No support  
No support

See also

Related Topics
  1. WebGL API
  2. WebGL2RenderingContext
  3. Methods
    1. beginQuery()
    2. beginTransformFeedback()
    3. bindBufferBase()
    4. bindBufferRange()
    5. bindSampler()
    6. bindTransformFeedback()
    7. bindVertexArray()
    8. blitFramebuffer()
    9. clearBuffer[fiuv]()
    10. clientWaitSync()
    11. compressedTexSubImage3D()
    12. copyBufferSubData()
    13. copyTexSubImage3D()
    14. createQuery()
    15. createSampler()
    16. createTransformFeedback()
    17. createVertexArray()
    18. deleteQuery()
    19. deleteSampler()
    20. deleteSync()
    21. deleteTransformFeedback()
    22. deleteVertexArray()
    23. drawArraysInstanced()
    24. drawBuffers()
    25. drawElementsInstanced()
    26. drawRangeElements()
    27. endQuery()
    28. endTransformFeedback()
    29. fenceSync()
    30. framebufferTextureLayer()
    31. getActiveUniformBlockName()
    32. getActiveUniformBlockParameter()
    33. getActiveUniforms()
    34. getBufferSubData()
    35. getFragDataLocation()
    36. getIndexedParameter()
    37. getInternalformatParameter()
    38. getQuery()
    39. getQueryParameter()
    40. getSamplerParameter()
    41. getSyncParameter()
    42. getTransformFeedbackVarying()
    43. getUniformBlockIndex()
    44. getUniformIndices()
    45. invalidateFramebuffer()
    46. invalidateSubFramebuffer()
    47. isQuery()
    48. isSampler()
    49. isSync()
    50. isTransformFeedback()
    51. isVertexArray()
    52. pauseTransformFeedback()
    53. readBuffer()
    54. renderbufferStorageMultisample()
    55. resumeTransformFeedback()
    56. samplerParameter[if]()
    57. texImage3D()
    58. texStorage2D()
    59. texStorage3D()
    60. texSubImage3D()
    61. transformFeedbackVaryings()
    62. uniform[1234][uif][v]()
    63. uniformBlockBinding()
    64. uniformMatrix[234]x[234]fv()
    65. vertexAttribDivisor()
    66. vertexAttribI4[u]i[v]()
    67. vertexAttribIPointer()
    68. waitSync()
  4. Inheritance:
    1. WebGLRenderingContext
  5. Related pages for WebGL
    1. ANGLE_instanced_arrays
    2. EXT_blend_minmax
    3. EXT_color_buffer_half_float
    4. EXT_disjoint_timer_query
    5. EXT_frag_depth
    6. EXT_sRGB
    7. EXT_shader_texture_lod
    8. EXT_texture_filter_anisotropic
    9. OES_element_index_uint
    10. OES_standard_derivatives
    11. OES_texture_float
    12. OES_texture_float_linear
    13. OES_texture_half_float
    14. OES_texture_half_float_linear
    15. OES_vertex_array_object
    16. WEBGL_color_buffer_float
    17. WEBGL_compressed_texture_atc
    18. WEBGL_compressed_texture_etc1
    19. WEBGL_compressed_texture_pvrtc
    20. WEBGL_compressed_texture_s3tc
    21. WEBGL_compressed_texture_s3tc_srgb
    22. WEBGL_debug_renderer_info
    23. WEBGL_debug_shaders
    24. WEBGL_depth_texture
    25. WEBGL_draw_buffers
    26. WEBGL_lose_context
    27. WebGLActiveInfo
    28. WebGLBuffer
    29. WebGLContextEvent
    30. WebGLFramebuffer
    31. WebGLObject
    32. WebGLProgram
    33. WebGLQuery
    34. WebGLRenderbuffer
    35. WebGLRenderingContext
    36. WebGLSampler
    37. WebGLShader
    38. WebGLShaderPrecisionFormat
    39. WebGLSync
    40. WebGLTexture
    41. WebGLTransformFeedback
    42. WebGLUniformLocation
    43. WebGLVertexArrayObject