I wrote a dice rolling script with 3d rendering, collisions and friction in bash because why not [edit: code available now]

I can easily check for when motion stops, but checking for when any particular face is both parallel to the floor and at the same level can be computationally expensive, particularly in the dice with more sides. What you're suggesting is likely a good idea, but I wouldn't know how to get probabilities without doing what I just mentioned. I'm sure there's an optimization i can do with this that I can't think of rn.

i need to check the corner collisions but when the die start settling and an entire edge comes close to the floor, gravity keeps pulling back on several of them making them bounce back just a tiny bit, not reaching the velocity that gets rounded to zero.

I fixed that on the current version doe!

I forgot to tell you how much I appreciate this meme. heh. thanks!

you make good points

i'm just gonna pastebin it for now but yeah, thanks for the encouragement.

Well, you guys are making some p good points. I'll probably end up sharing it, but'll give it a clean up, try to fix some bugs and improve my comments before posting it publicly. For now whoever really wants it (including you) can just ask and I'll dm it, understanding it will be a hard read and still has bugs.

I changed my mind.

lazy

I fucked that sentence up, but you understand what I mean! ∆<3

Thank you for your inspiration <3

holy shit, I'm so flattered! Thank you for your kind support and encouragement!

It's crazy that it looks okaish right? quaternions, dude. I have implemented them in 3 projects and still have no fucking idea how they work.

Also, you can run it in --quality low if you're struggling with framerate. :)

I didn't have the patience to do it myself bit wanted to see just how complex it would get:

fp32_mul() {
    local a=$1 b=$2
    local sa=$(( (a >> 31) & 1 ))
    local sb=$(( (b >> 31) & 1 ))
    local sign=$((sa ^ sb))

    local ea=$(( (a >> 23) & 0xff ))
    local eb=$(( (b >> 23) & 0xff ))
    local fa=$(( a & 0x7fffff ))
    local fb=$(( b & 0x7fffff ))

    # NaN / infinity / zero handling
    if (( ea == 255 )); then
        if (( fa != 0 )); then
            printf '%08x\n' $((0x7fc00000))
            return
        fi
        if (( eb == 0 && fb == 0 )); then
            printf '%08x\n' $((0x7fc00000))   # inf * 0 = NaN
            return
        fi
        printf '%08x\n' $(((sign << 31) | 0x7f800000))
        return
    fi

    if (( eb == 255 )); then
        if (( fb != 0 )); then
            printf '%08x\n' $((0x7fc00000))
            return
        fi
        if (( ea == 0 && fa == 0 )); then
            printf '%08x\n' $((0x7fc00000))
            return
        fi
        printf '%08x\n' $(((sign << 31) | 0x7f800000))
        return
    fi

    if (( ea == 0 && fa == 0 || eb == 0 && fb == 0 )); then
        printf '%08x\n' $((sign << 31))
        return
    fi

    # Convert subnormals to a normalized significand/exponent.
    # m is a 24-bit significand for normals.
    local ma mb
    if (( ea == 0 )); then
        ma=$fa
        ea=1
        while (( (ma & 0x800000) == 0 )); do
            ma=$((ma << 1))
            ((ea--))
        done
    else
        ma=$((fa | 0x800000))
    fi

    if (( eb == 0 )); then
        mb=$fb
        eb=1
        while (( (mb & 0x800000) == 0 )); do
            mb=$((mb << 1))
            ((eb--))
        done
    else
        mb=$((fb | 0x800000))
    fi

    # Multiply the two 24-bit significands.
    # Product is up to 48 bits.
    local p=$((ma * mb))
    local e=$((ea + eb - 127))

    # Normalize product.
    #
    # ma*mb has binary point after bit 46.  If bit 47 is set,
    # product is [2,4), otherwise [1,2).
    local shift
    if (( p & 0x800000000000 )); then
        shift=24
        ((e++))
    else
        shift=23
    fi

    # Extract 23 fraction bits plus guard/round/sticky information.
    local frac=$(( (p >> shift) & 0x7fffff ))
    local guard=$(( (p >> (shift - 1)) & 1 ))
    local round=$(( (p >> (shift - 2)) & 1 ))
    local sticky=0

    if (( shift >= 3 )); then
        local mask=$(( (1 << (shift - 2)) - 1 ))
        (( (p & mask) != 0 )) && sticky=1
    fi

    # Round-to-nearest, ties-to-even.
    if (( guard && (round || sticky || (frac & 1)) )); then
        ((frac++))
        if (( frac == 0x800000 )); then
            frac=0
            ((e++))
        fi
    fi

    # Overflow -> infinity.
    if (( e >= 255 )); then
        printf '%08x\n' $(((sign << 31) | 0x7f800000))
        return
    fi

    # Normal result.
    if (( e > 0 )); then
        printf '%08x\n' $(((sign << 31) | (e << 23) | frac))
        return
    fi

    # Underflow into the subnormal range.
    #
    # At this point the normalized significand represented by
    # (1.frac) must be shifted right by 1-e positions.
    local mant=$((0x800000 | frac))
    local rshift=$((1 - e))
    local lost=0
    local halfway=0
    local low=0

    if (( rshift >= 25 )); then
        # Everything rounds to zero (unless the exact value is
        # sufficiently close, which it cannot be here).
        mant=0
    else
        low=$((mant & ((1 << rshift) - 1)))
        mant=$((mant >> rshift))

        halfway=$((1 << (rshift - 1)))

        if (( low > halfway || (low == halfway && (mant & 1)) )); then
            ((mant++))
        fi
    fi

    # Rounding a subnormal can produce the smallest normal.
    if (( mant >= 0x800000 )); then
        printf '%08x\n' $(((sign << 31) | (1 << 23)))
    else
        printf '%08x\n' $(((sign << 31) | mant))
    fi
}

hahaha you seem to be familiar with the issues I ran across

Invert the gravity value and then all the dice will be floating point 🫣

yeah, I was trying to stay as pure-bash as possible, but thanks!

Yes, the values are rendered on top of each face with "pixel" maps (ascii art) that have the character of the digit they represent as each pixel. These are later manipulated by the perspective projection.

For example on this d6 you can see the top face has 1s written down (in the shape of a sideways one) and the front one has 4s written down in the shape of a skewed and sideways 4.

In this specific color scheme there's not a lot of contrast between the values, but even in the palettes with better contrast, good readability is something I'm kind of giving up on solving well.

edit: might be clearer here:

here ya go

I'll do a follow up post when I upload

what video hosting service works for you?