Web/API/EXT float blend

From Get docs


The WebGL API's EXT_float_blend extension allows blending and draw buffers with 32-bit floating-point components.

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

Availability:  This extension is available to both, WebGL1 and WebGL2 contexts. However, to use it, you need to enable the use of 32-bit floating-point draw buffers by  enabling the extension WEBGL_color_buffer_float (for WebGL1) or EXT_color_buffer_float (for WebGL2). Doing so automatically enables EXT_float_blend as well.


With this extension enabled, calling drawArrays() or drawElements() with blending enabled and a draw buffer with 32-bit floating-point components will no longer result in an INVALID_OPERATION error.

Usage notes

On devices that support the EXT_float_blend extension, it is automatically, implicitly, enabled when any one or more of EXT_color_buffer_float, OES_texture_float, or WEBGL_color_buffer_float are enabled. This ensures that content written before EXT_float_blend was exposed by WebGL will function as expected.

Examples

const gl = canvas.getContext('webgl2');

// enable necessary extensions
gl.getExtension('EXT_color_buffer_float');
gl.getExtension('EXT_float_blend');

const tex = gl.createTexture();
gl.bindTexture(gl.TEXTURE_2D, tex);

// use floating point format
gl.texImage2D(gl.TEXTURE_2D, 0, gl.RGBA32F, 1, 1, 0, gl.RGBA, gl.FLOAT, null);

const fb = gl.createFramebuffer();
gl.bindFramebuffer(gl.FRAMEBUFFER, fb);
gl.framebufferTexture2D(gl.FRAMEBUFFER, gl.COLOR_ATTACHMENT0, gl.TEXTURE_2D, tex, 0);

// enable blending
gl.enable(gl.BLEND);

gl.drawArrays(gl.POINTS, 0, 1);
// won't throw gl.INVALID_OPERATION with the extension enabled

Specifications

Specification Status
EXT_float_blend Draft

Browser compatibility

Update compatibility data on GitHub

Desktop Mobile
Chrome Edge Firefox Internet Explorer Opera Safari Android webview Chrome for Android Firefox for Android Opera for Android Safari on iOS Samsung Internet

EXT_float_blend

Experimental'

Chrome

Full support 75

Edge

Full support 79

Firefox

Full support 67

IE

No support No

Opera

No support No

Safari

No support No

WebView Android

No support No

Chrome Android Full support 75

Notes'

Full support 75

Notes'

Notes' Until Chrome 77, this extension was unavailable on several Android devices powered by GLES 3.2. See bug 964208.

Firefox Android

No support No

Opera Android

No support No

Safari iOS

No support No

Samsung Internet Android

No support No

Legend

Full support  
Full support
No support  
No support
Experimental. Expect behavior to change in the future.'
Experimental. Expect behavior to change in the future.
See implementation notes.'
See implementation notes.


See also