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
Desktop | Mobile | |||||||||||
---|---|---|---|---|---|---|---|---|---|---|---|---|
EXT_float_blend | 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
| 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.