@rygorous

Abstraction maker, abstraction breaker. @rygorous@mastodon.gamedev.place he/him

fgiesen.wordpress.com
Joined December 2009
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Fabian Giesen (@[email protected])

13.4K Posts, 75 Following, 4.35K Followers · Abstraction maker, abstraction breaker. FUN FACT: things I prefix with FUN FACT are sometimes fun and sometimes factual, but very rarely both.

mastodon.gamedev.place
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This is comparable to slightly less amount of work than just converting regular (u)int32 to float is!
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New blog post: "UNORM and SNORM to float, hardware edition" fgiesen.wordpress.com/2024/1…

UNORM and SNORM to float, hardware edition

I mentioned in a previous post that doing exact UNORM or SNORM conversions to float in hardware was not particularly expensive, but didn’t go into detail how. Let’s rectify that! (If yo…

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We just released Oodle 2.9.13. Significantly increased BC7 encoding speed (about 20-25% encode time reduction for non-RDO on typical content, 25-30% encode time reduction for RDO) at slightly increased quality. Also several bug fixes and experimental WASM 64-bit support.
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New blog post: "Exact UNORM8 to float" fgiesen.wordpress.com/2024/1… a satisfying solution to a problem that, quite possibly, nobody has

Exact UNORM8 to float

GPUs support UNORM formats that represent a number inside [0,1] as an 8-bit unsigned integer. In exact arithmetic, the conversion to a floating-point number is straightforward: take the integer and…

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New blog post: "BC7 optimal solid-color blocks" fgiesen.wordpress.com/2024/1… clearing out my "I should write this up" queue, this technique is from... *checks git logs* May 2017. Oh my. (I have quite the backlog.)

BC7 optimal solid-color blocks

That’s right, it’s another texture compression blog post! I’ll keep it short. By “solid-color block”, I mean a 4×4 block of pixels that all have the same color. A…

fgiesen.wordpress.com
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New blog post: "Why those particular integer multiplies?" fgiesen.wordpress.com/2024/1… some explanation and some speculation on the integer SIMD multiplies offered in x86, along with some history

Why those particular integer multiplies?

The x86 instruction set has a somewhat peculiar set of SIMD integer multiply operations, and Intel’s particular implementation of several of these operations in their headline core designs ha…

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New blog post: "Inserting a 0 bit in the middle of a value" fgiesen.wordpress.com/2024/1… I guess it's 2-for-1 bit hacks week.

Inserting a 0 bit in the middle of a value

This one originally came up for me in Oodle Texture’s BC7 decoder. In the BC7 format, each pixel within a 4×4 block can choose from a limited set of between 4 to 16 colors (ignoring some…

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New blog post: "Zero or sign extend" fgiesen.wordpress.com/2024/1…

Zero or sign extend

A while back I had to deal with a bit-packed format that contained a list of integer values encoded in one of a pre-defined sets of bit widths, where both the allowed bit widths and the signed-ness…

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