The WebGLRenderingContext.pixelStorei()
method of the WebGL API specifies the pixel storage modes.
WebGLRenderingContext.pixelStorei()
Syntax
pixelStorei(pname, param)
Parameters
Return value
None.
Pixel storage parameters
Parameter name (for pname ) |
Description | Type | Default value | Allowed values (for param ) |
Specified in |
---|---|---|---|---|---|
gl.PACK_ALIGNMENT |
Packing of pixel data into memory | GLint |
4 | 1, 2, 4, 8 | OpenGL ES 2.0 |
gl.UNPACK_ALIGNMENT |
Unpacking of pixel data from memory. | GLint |
4 | 1, 2, 4, 8 | OpenGL ES 2.0 |
gl.UNPACK_FLIP_Y_WEBGL |
Flips the source data along its vertical axis if true. | GLboolean |
false | true, false | WebGL |
gl.UNPACK_PREMULTIPLY_ALPHA_WEBGL |
Multiplies the alpha channel into the other color channels | GLboolean |
false | true, false | WebGL |
gl.UNPACK_COLORSPACE_CONVERSION_WEBGL |
Default color space conversion or no color space conversion. | GLenum |
gl.BROWSER_DEFAULT_WEBGL |
gl.BROWSER_DEFAULT_WEBGL , gl.NONE |
WebGL |
When using a WebGL 2 context, the following values are available additionally:
Constant | Description | Type | Default value | Allowed values (for param ) |
Specified in |
---|---|---|---|---|---|
gl.PACK_ROW_LENGTH |
Number of pixels in a row. | GLint |
0 | 0 to Infinity |
OpenGL ES 3.0 |
gl.PACK_SKIP_PIXELS |
Number of pixel locations skipped before the first pixel is written into memory. | GLint |
0 | 0 to Infinity |
OpenGL ES 3.0 |
gl.PACK_SKIP_ROWS |
Number of rows of pixel locations skipped before the first pixel is written into memory | GLint |
0 | 0 to Infinity |
OpenGL ES 3.0 |
gl.UNPACK_ROW_LENGTH |
Number of pixels in a row. | GLint |
0 | 0 to Infinity |
OpenGL ES 3.0 |
gl.UNPACK_IMAGE_HEIGHT |
Image height used for reading pixel data from memory | GLint |
0 | 0 to Infinity |
OpenGL ES 3.0 |
gl.UNPACK_SKIP_PIXELS |
Number of pixel images skipped before the first pixel is read from memory | GLint |
0 | 0 to Infinity |
OpenGL ES 3.0 |
gl.UNPACK_SKIP_ROWS |
Number of rows of pixel locations skipped before the first pixel is read from memory | GLint |
0 | 0 to Infinity |
OpenGL ES 3.0 |
gl.UNPACK_SKIP_IMAGES |
Number of pixel images skipped before the first pixel is read from memory | GLint |
0 | 0 to Infinity |
OpenGL ES 3.0 |
Examples
Setting the pixel storage mode affects the WebGLRenderingContext.readPixels()
operations, as well as unpacking of textures with the WebGLRenderingContext.texImage2D()
and WebGLRenderingContext.texSubImage2D()
methods.
var tex = gl.createTexture(); gl.bindTexture(gl.TEXTURE_2D, tex); gl.pixelStorei(gl.PACK_ALIGNMENT, 4);
To check the values for packing and unpacking of pixel data, you can query the same pixel storage parameters with WebGLRenderingContext.getParameter()
.
gl.getParameter(gl.PACK_ALIGNMENT); gl.getParameter(gl.UNPACK_ALIGNMENT);
Specifications
Specification |
---|
WebGL Specification # 5.14.3 |
WebGL Specification # PIXEL_STORAGE_PARAMETERS |
WebGL 2.0 Specification # 3.7.2 |
Browser compatibility
Desktop | Mobile | |||||||||||
---|---|---|---|---|---|---|---|---|---|---|---|---|
Chrome | Edge | Firefox | Internet Explorer | Opera | Safari | WebView Android | Chrome Android | Firefox for Android | Opera Android | Safari on IOS | Samsung Internet | |
pixelStorei |
9
|
12
|
4
|
11
|
12
|
5.1
|
4.4.3
|
25
|
4
|
12
|
8
|
1.5
|
WebGL2 |
56
|
79
|
51
|
No
|
43
|
No
|
58
|
58
|
51
|
43
|
No
|
7.0
|
See also
© 2005–2021 MDN contributors.
Licensed under the Creative Commons Attribution-ShareAlike License v2.5 or later.
https://developer.mozilla.org/en-US/docs/Web/API/WebGLRenderingContext/pixelStorei