In case it's not obvious, faster DMA and larger buffer/texture capacity vs. float32. Many applications benefit hugely from having floating point data but certainly do not need float32's range and precision - for those, half/float16 is a great choice.
On 29 July 2015 at 23:48, Sebastian Markbåge <[email protected]> wrote: > IIRC, OpenGL ES 3.0 (and therefore WebGL 2.0) requires full float texture > support and full float32 operations in GLSL and hardware. Is there > significant gains to use half floats on modern hardware or do they > effectively end up on that same path as float32s? > > My question becomes, is this a problem that will go away anyway or will it > be long lived? > > If there are performance gains to be had even for the most modern > hardware, then I think we should be able to push this through. > > > On Fri, Nov 21, 2014 at 12:52 AM, Florian Bösch <[email protected]> wrote: > >> Typed arrays today are specified with support for Float32Array, >> Float32Array. >> >> A useful additional data type would be Float16Array. It's useful because >> GPUs (particularly mobiles) have support for it, and because VRAM and >> bandwidth limits are a legitimate concern (particularly for mobiles). >> >> GPU support for it appears in the following forms: >> >> - Desktop OpenGL ARB_half_float_pixel: support for half-float textures >> - Desktop OpenGL ARB_half_float_vertex: support for half-float vertex >> data >> - Desktop OpenGL 2.1 core specification, extended support in 3.0 >> - Mobile OES_texture_float: support for half-float textures >> - Mobile OES_vertex_half_float: support for half-float vertex data >> - Mobile EXT_color_buffer_half_float: support to render to half-float >> render targets >> - Mobile OpenGL ES 3.0 core specification. >> - WebGL OES_texture_half_float: support for half-float textures >> - WebGL OES_texture_half_float_linear: support for half-float texture >> linear filtering >> - WebGL EXT_color_buffer_half_float: support for half-float render >> targets >> - WebGL 2.0 core specification >> >> These types are defined per IEEE 753-2008 >> >> - binary16, common: half >> - binary32, common: single >> - binary64, common: double >> >> It is possible today to service half-float data types trough JS, by >> performing the conversion in JS. The code for this is however rather >> complex and it's difficult to implement all of IEEE 753-2008 correctly (my >> version doesn't support rounding quite correctly >> http://codeflow.org/experiment/half-float/main.js). It may also be >> unnecessarily slow. Convenience is also an issuebecause JS can't override >> the array access [] operator to do the job. >> >> I'd like to propose adding Float16Array to the typed array specification. >> If JS accesses arrays like these, appropriate conversion is applied (as is >> the case for any other non JS-native numerical type) >> >> _______________________________________________ >> es-discuss mailing list >> [email protected] >> https://mail.mozilla.org/listinfo/es-discuss >> >> > > _______________________________________________ > es-discuss mailing list > [email protected] > https://mail.mozilla.org/listinfo/es-discuss > >
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