Wednesday 11 December 2019

Gym in the Winter

It's cold in the UK at the minute, but I've rediscovered long johns. I used to wear them all the time when we lived aboard (in fact I used to put on more clothes than I took off for bed), but it's been a couple of years since I've felt the need.

They're lovely and warm, and my feet are warm more often than not these days, but going to the gym is becoming an issue. Quite apart from the looks I get from other people in the changing room when I get ready for my workout, the problem of getting dressed afterwards is a pain.

The thing is that I go not only to work out but to spend time in the steam room so when I do get ready, I change into trunks and shorts. When I finish my workout, I remove everything except the trunks, have a shower and then get hot and sweaty.

But when I get back, I shower and get changed and have to put on loads of layers without any of them getting any wetter then they got on my cycle to the gym, which is no mean feat! I've finally figured out the way to do it though. Once I've got my undies on I get my shoes, socks, long johns and trousers all in place beside me. Dry one foot thoroughly put on one sock, then long johns on one leg (the socks help stop the long johns disappearing up my leg while I cycle), then my trousers on the same leg. After the long johns and strides are put on, the remaining "leg" is bunched in my lap to keep dry. Finally, my shoe goes on, and my foot goes to the floor. Then the other foot is lifted and dried, and the same process is repeated for that leg, what a faff! But it does save the bottom half of my clothes from getting even wetter than usual!

Every once in a while I go to Yoga afterwards, and that process involves having a pair of shorts put on betwixt the undies and the long johns (no one wants to see long johns on underneath shorts at Yoga, I'd look like some geriatric superhero).

I'm not sure why I wrote this, except it tickles me.

Tuesday 26 November 2019

VueJS Pagination

I've written about pagination before, and it's something I'm interested in so when the chance came to write a component that dealt with it at work I jumped at the chance. Rather than using any of the other techniques I've used in the past, this component was using VueJS, and I knew I'd get some data via a message bus. The data was in the form of an object with just three numbers: the current page selected, the total number of items and the number of items for display on each page.

The total number of items could range from one to many; the number of pages could also be massive depending upon the page size selected by the user.

As well as wanting to display a sensible number of page numbers to the user, I also wanted to decorate the pagination. The decoration needed to have the ability to jump three pages back and forth as well as a quick way of navigating to the first and last page.

So I did what I usually do and fired up JSFiddle to work up a quick prototype and came up with this. I've not included the message bus, but I'm instead using values within the data of the component. While I know it's not good form to alter the data within the component; I'm doing so here for illustration purposes.

Logic splits between the markup and the JS, but I quite like that for some reason.

HTML
<div id="app">
    <ol v-if="totalPages > 0" 
        aria-label="Pagination navigation">
        <li v-on:click="paginationOptions.page = 1" 
            aria-label="Go to the first page" 
            title="Go to the first page"
            v-bind:class="{
                'disabled': paginationOptions.page === 1
            }">
            <div class="content">&larr;</div>
        </li>
        <li v-if="totalPages > 3 && paginationOptions.page - 2 >= 1" 
            v-on:click="paginationOptions.page = (paginationOptions.page - 3 < 1) ? 1 : paginationOptions.page - 3" 
            aria-label="Jump three pages backward" 
            title="Jump three pages backward"><div class="content"></div></li>
        <li v-for="page in pages" 
            v-bind:key="page" 
            v-on:click="paginationOptions.page = page" 
            v-bind:aria-label="(page === paginationOptions.page) ? 'Current page, page ' + page : 'Go to page ' + page" 
            v-bind:aria-current="page === paginationOptions.page" 
            v-bind:title="(page === paginationOptions.page) ? 'Current page, page ' + page : 'Go to page ' + page"
            v-bind:class="{
                'active': page === paginationOptions.page
            }">
            <div class="content">{{page}}</div>
            <span v-if="page === paginationOptions.page" 
                  style="display: none">(current)</span>
        </li>
        <li v-if="totalPages > 3 && paginationOptions.page + 2 <= totalPages" 
            v-on:click="paginationOptions.page = (paginationOptions.page + 3 <= totalPages) ? paginationOptions.page + 3 : totalPages" 
            aria-label="Jump three pages forward" 
            title="Jump three pages forward"><div class="content"></div></li>
        <li v-on:click="paginationOptions.page = totalPages" 
            aria-label="Go to the last page" 
            title="Go to the last page"
            v-bind:class="{
                'disabled': paginationOptions.page === totalPages
            }">
            <div class="content">&rarr;</div>
        </li>
    </ol>
</div>
JS
new Vue({
    el: "#app",
    data: {
        paginationOptions: {
            page: 2,
            total: 55,
            pageSize: 10
        }
    },
    computed: {
        totalPages() {
            return Math.ceil(this.paginationOptions.total / this.paginationOptions.pageSize);
        },
        pages: function () {
            const returnArray = [];
            if(this.paginationOptions.page === 1){
                for(i = 1, count = 0; i <= this.totalPages && count < 3; i++, count++){
                    returnArray.push(i)
                }
            } else {
                if(this.paginationOptions.page === this.totalPages){
                    for(let i = this.totalPages, count = 0; i >= 1 && count < 3; i--, count++){
                        returnArray.push(i)
                    }
                    returnArray.reverse();
                } else {
                    returnArray.push(this.paginationOptions.page);
                    if(this.paginationOptions.page < this.totalPages){
                        returnArray.push(this.paginationOptions.page + 1)
                    }
                    if(this.paginationOptions.page >= 1){
                        returnArray.unshift(this.paginationOptions.page - 1)
                    }
                }
            }
            return returnArray;
        },
    }
});
SCSS
#app{
    margin: 1em;
}
ol {
    display: flex;
    align-items: center;
    justify-content: flex-end;
    margin: 0;
    padding: 0;
    list-style-type: none;
    width: 100%;
    text-align: right;
    li{
        display: inline-block;
        &.disabled {
            cursor: not-allowed;
        }
        .content {
            text-decoration: none;
            font-weight: bold;
            background-color: #fff;
            color: #7f8c8d;
            display: flex;
            align-items: center;
            justify-content: center;
            width: 40px;
            height: 40px;
            margin: 0 3px;
            border: 1px solid #e5e5e5;
        }
        &.active {
            .content {
                border-color: #2c3e50;
                background-color: #2c3e50;
                color: #fff;
                text-decoration: none;
            }
        }
    }
}

Friday 27 September 2019

The Tea Set

The Tea Set recently released their latest album Back in Time for Tea, and I thought I'd have a play with one of their old logos. I spent ages working out the SCSS mixin, but I'm pleased with the result.

This is the mixin and its usage:

$main-duration: 10s;
$base-percentage: 3%;

@mixin animate_movement($initial, $id, $main-duration, $delay, $duration) {
    $animation-name: unique-id() !global;
    @keyframes #{$animation-name} {
    
        0%, 
        #{$delay * $base-percentage} {
            transform: $initial;
        }
    
        #{($delay + $duration) * $base-percentage}, 
        100% {
            transform: translate(0px, 0px);
        }
    }
    ##{$id} {
        transform: $initial;
        animation: $animation-name  $main-duration linear infinite alternate;
    }
}

@keyframes scale-in-top {
    0% {
        transform: scale(0);
        transform-origin: 50% 0%;
        opacity: 1;
    }
    100% {
        transform: scale(3);
        transform-origin: 50% 0%;
        opacity: 1;
    }
}


.icon-holder {
    text-align: center;
    margin-top: 1em;
    svg {
        animation: scale-in-top 0.5s cubic-bezier(0.250, 0.460, 0.450, 0.940) both;
    }
    @include animate_movement(translateY(-88px), TheTeaSet, $main-duration, 1, 5);
    @include animate_movement(translateX(-16px), tHe, $main-duration, 9, 3);
    @include animate_movement(translateX(-32px), thE, $main-duration, 6, 6);
    @include animate_movement(translateX(-16px), tEa, $main-duration, 15, 3);
    @include animate_movement(translateX(-32px), teA, $main-duration, 12, 6);
    @include animate_movement(translateX(32px), Set, $main-duration, 18, 6);
    @include animate_movement(translateX(16px), sEt, $main-duration, 21, 3);
}

Monday 23 September 2019

She said, he thought

This has been rattling around in my head for a while so I thought I'd best get it written. It's basically the reason why I shouldn't try relaxation.

She said, “Breath in,” then waited for my huge inhalation to finish and paused for a beat before saying, “breath out”. Again she waited for my chest to shrink, then my belly to implode, before again saying, “Breath in”, waiting while I inhaled and again pausing for a beat before telling me to exhale.

This repeated for about half a dozen times before she said, “Breath normally”. I did as I was told, but noted that my breathing was much deeper and slower than before.

She said, “Empty your mind”. Nice idea but utterly impossible. Or maybe not even a nice idea… where would I be without the whirling maelstrom of chaos rolling around in my head?

She said, “Imagine you’re walking through the grass...” So I did and wondered what the weather was like.

“It’s a warm and sunny day and you’re barefoot” Okay, I can live with that. I can live with it as long as there’s no dog shit on the grass… I guess there isn’t or this wouldn’t be relaxing… trying to avoid stepping in shit and then going for a Burton and landing on my arse would be a pain, especially if I managed to land in the shite.

“You step from the grass onto the sand by the sea.” Ah, bugger. It’s the grass like pampas grass, isn’t it? The stuff on dunes which is sharp as anything and likely to lacerate my feet, still, thankfully I’m in the sand now. Let’s hope there’s no dog shit or broken glass or some slimy seaweed in the sand now. That’d be just my luck, wouldn’t it? Perhaps I could slide on the seaweed and then manage to land in dogshit… and broken glass! When did I have my last Tetanus injection again?

“You step into the warm sea.” Where is this? It’s not local if the sea is warm… are there jellyfish or sea urchins here? Do I need sunscreen? She said it was warm before… I’ll get a burnt head!

“You see a rock standing in the sea.” A rock? How big is the rock? Are we looking at a pebble here or something more substantial? Am I gonna have to avoid it with my bare feet, as well as avoiding the jellyfish and sea urchins? It’s warm though, isn’t it? I’m sure she said it was warm… happen it’s Australia where everything is trying to kill you! There could be sharks or a manta ray - I’ll end up getting stuck on the tail of the manta ray, bleeding and then the sharks will come and I’ll be buggered! All while being covered in dog shit with a broken bottle stuck out my back!

“You climb the roc.k” Ah, it’s not a pebble, it’s a bit bigger! Wonder how big? Am I gonna be climbing for a while? I do hope not: I’m not as young as I once was and I’m not sure my belly will allow for any major climbing elegance… perhaps it’s the South China seas and the rock is like the island where Goldfinger had his super, secret weapon? That was huge though wasn’t it? I’ll be climbing all bloody day!

“You sit on the top of the rock.” OK, guess it’s not that big… something like that lass was marooned on when the sharks started circling… are the sharks here now, did I manage to cut my feet on the razor grass or broken glass, or are they attracted by dog shit in the water? Also, rocks aren’t all that comfortable, this is gonna kill my arse after a while. Am I even gonna be here a while, should I ask if I can put my hat on?

Monday 29 July 2019

Been a busy boy

I've just had a busy old weekend and managed to get my digital counter working with CSS animations. I have been wanting to do this for ages but haven't had the time to research the technique correctly. It's here, and I'm quite pleased with the result despite it taking a shed load of tweaking to get right.

I've also caught up some on updated p5 implementations from WireFrame, and I've added three projects to the site hosted by GitHub, all to do with mazes. The first uses an algorithm to generate a maze, and I got lost in the C implementation but found a set of videos from The Coding Train that went through the steps required. I've pretty much stolen them but made them a little more ES6y. The second draws the view of a character navigating a maze, and I'm impressed with the cheating in terms of the images used to illustrate the perspective required. The third and final one also cheats by using images to build up a semi-3D illustration of a landscape and was lots of fun (you can navigate using the arrow keys)!

Friday 31 May 2019

rgba2rgb

I had a lovely little challenge a couple of days ago which, in conjunction with my invite to the First Alpha Testing of Empire of Code, got me excited. It led me to generate the following chunk of code:

const rgba2rgb = rgba => "#" + rgba.match(/.{1,2}/g)
                             .map((c, i, a) => (i !== a.length -1) 
                                 ? parseInt(c, 16) 
                                 : parseInt(c, 16) / 255)
                             .map((c, i, a) => (i !== a.length -1) 
                                 ? ~~((1 - a[3]) * 255 + a[3] * c) 
                                 : null)
                             .reverse()
                             .slice(1)
                             .reverse()
                             .map(c => c.toString(16))
                             .join("");

We needed to convert an RGBA colour to RGB, with the assumption that the original colour was atop a white background. The maths and colour theory are a little confusing, and I went through any number of iterations. The result made me feel a bit smug though as it is teeny - I'm guessing it could be improved though.

Have at it!

EDIT

So I clocked that the above wasn't quite as brilliant as I thought so I've updated it after simplifying it:

const rgba2rgb = function(rgba){ 
 const coloursAsBase16 = rgba.match(/.{1,2}/g);
    console.log("coloursAsBase16", coloursAsBase16);
    const coloursAsBase10 = coloursAsBase16.map(function(c, i, a){ 
     if(i !== a.length - 1){
         return parseInt(c, 16) // Value between 1 - 255
        }else{
         return parseInt(c, 16) / 255 // Value between 0 - 1
        }
    });
    console.log("coloursAsBase10", coloursAsBase10);
    const coloursWithAlpha = coloursAsBase10.reduce(function(t, c, i, a){
     if(i !== a.length - 1){
         return t.concat([parseInt(((1 - a[3]) * 255 + a[3] * c), 10)]);
        }else{
         return t;
        }
    }, [])
    console.log("coloursWithAlpha", coloursWithAlpha);
    const coloursChangedToBase16 = coloursWithAlpha.map(function(c){
     return c.toString(16)
    });
    console.log("coloursChangedToBase16", coloursChangedToBase16);
 return "#" + coloursChangedToBase16.join("");
}

Which led to this one-liner:

const rgba2rgb = rgba => "#" + rgba.match(/.{1,2}/g)
    .map((c, i, a) => (i !== a.length - 1) 
        ? parseInt(c, 16) 
        : parseInt(c, 16) / 255)
    .reduce((t, c, i, a) => (i !== a.length - 1) 
        ? t.concat([parseInt(((1 - a[3]) * 255 + a[3] * c), 10)]) 
        : t, [])
    .map(c => c.toString(16))
    .join("");

Wednesday 8 May 2019

lodash _.sortBy

I needed to order an array of objects in an arbitrary fashion, using strings which make sense to the business but aren't necessarily orderable otherwise. Unfortunately I had to support IE11, so couldn't do fancy JS. Thankfully I had access to lodash. Anyway, I came up with this:

var statuses = ["one", "two", "three", "four"];

var complexObj = {
    dataset: [
        {
            label: "two"
        },
        {
            label: "four"
        },
        {
            label: "three"
        },
        {
            label: "one"
        },
    ]
};

console.table(complexObj.dataset)

complexObj.dataset = _.sortBy(complexObj.dataset, function(n) {
  return _.indexOf(statuses, n.label);
});

console.table(complexObj.dataset)

Which worked a treat, once I'd clocked I need to return the sorted array rather than merely sort it.

Sunday 5 May 2019

Op Art with p5

My Dad and I both love Op art, and he recently forwarded an email from Tumblr with this link. It piqued my interest as I'm playing with p5 an awful lot at the minute in my spare time as you'll see from previous posts.

So I got to it but clocked that there might be an issue in terms of masking the squares which make up the image. A little judicious playing with Gimp meant that I knew the graphic would be made up of multiple squares. The squares either started with a black or yellow background and they changed after a delay. To get around the issue of masking, I opted to use createGraphics() and then embed that graphic in the main body of the image using the image() function. I ended up making a simple error though, but Stack Overflow came to my rescue, and I'm quite pleased with the result:

The code, which is also up on GitHub and as a single file on JSFiddle:

class Tile {

    constructor(p5, x, y, dimension, row, delay) {
        this.p5 = p5;
        this.x = x;
        this.y = y;
        this.dimension = dimension;
        this.delay = delay;
        this.onFirst = row % 2;
        this.on = p5.color(255, 184, 0);
        this.off = p5.color(26, 17, 16);
        this.diameter = Math.sqrt(Math.pow(dimension, 2) * 2)
        this.pg = p5.createGraphics(dimension, dimension)
        this.pg.noStroke();
    }

    update() {
        if (this.delay === 0) {
            if (this.diameter < 0) {
                this.diameter = Math.sqrt(Math.pow(this.dimension, 2) * 2);
                this.onFirst = !this.onFirst;
                this.delay = 120;
            }
            else {
                this.diameter -= 1;
            }
        } else {
            this.delay -= 1;
        }
        return this.draw();
    }

    draw() {
        this.pg.fill(this.onFirst ? this.off : this.on);
        this.pg.rect(0, 0, this.dimension, this.dimension);
        this.pg.fill(this.onFirst ? this.on : this.off);
        this.pg.circle(this.dimension / 2, this.dimension / 2, this.diameter);
        return this.pg;
    }
}

new p5(p5 => {

    const rows = 14;
    const columns = 14;
    const dimension = 40;
    const framerate = 20;
    const tiles = [];
    const delay = 30;

    p5.setup = () => {
        p5.createCanvas(columns * dimension, rows * dimension);
        for (let row = 0; row < rows; row++) {
            for (let column = 0; column < columns; column++) {
                tiles.push(new Tile(
                    p5,
                    column * dimension,
                    row * dimension,
                    dimension,
                    row,
                    column % 2 ? ((rows - row) * 5) + 80 : row * 5
                ));
            }
        }
    };

    p5.draw = () => {
        p5.background(200);
        tiles.forEach((tile) => {
            p5.image(tile.update(), tile.x, tile.y);
        });
    };
});

Wednesday 24 April 2019

JS Comma Operator

A mate at work asked me a question about checking things in JS. He had a case where if an object had a property he needed to check for 3 conditions, one of which was if the properties value matched a given value. If it didn't have the property then he needed just needed to check 2 conditions. He wasn't overly keen on wrapping the two conditions within a further if statement and asked if I knew of a way of combining them all into one if statement, I must admit I knew that there was one but I couldn't think of it for the life of me...

As in a particularly nasty case of athletes foot, it itched at me overnight, then I started to remember a rather obscure feature of JS which it seems it borrowed from C, the Comma Operator. In order to check that it would do what he needed to do, I wrote this simple JSFiddle:

let a;

if(true && true && a === 1, a){
  alert("First: a === 1");
}

a = 1;

if(true && true && a === 1, a){
  alert("Second: a === 1");
}

It's rather obscure though, so I'm a little concerned about using it with production code, as discussed on StackOverflow.

Saturday 6 April 2019

p5-INVADER

You might've seen previous posts on my conversion of Python to p5 from Wireframe magazine, and this has been by far the hardest one I've tried as it involved lots and lots of looping through arrays. Arrays not only of the elements which make up the characters, such as shots and shields but also through the matrix which I use to generate the images of the shots and shields. Using a matrix or multi-dimensional array in this way is an approach I'm thinking of adapting for the Digital Counter as it allows a visual representation of the character within an array and so makes tweaking the characters more accessible.

If you check through the history of the repo, you'll see that I went through many different methods of calculating whether or not a shot simply grazed a shield or whether it had a substantial impact, resulting in an explosion. I did this eventually by allowing the shot to have a hit point value which incremented each time it chewed a pixel from the shield; when that hit point reached a critical level, then the shot exploded and eroded a far greater chunk from the shield.

To save resources each shot is removed from an array when it drops too far beneath the stage, and each shield removed when it is empty. I guess I should also close the processing when there are no more shields, but this does pretty much what I wanted and seems to mimic the original Python implementation closely enough. If not you're welcome to branch and tweak it.

Monday 1 April 2019

grid-area in VueJS

As you can probably tell from recent posts, I'm making extensive use of CSS grid layouts... I'm also having to support IE11 while doing so, oh joy. The thing is I like the grid-area approach to defining where things should go within the layout, and I write it in the following way:

{
  ...
  grid-area: grid-row-start / grid-column-start / grid-row-end / grid-column-end;
  ...
}

Which is cool, but it took me ages to figure out why it wasn't working... even though it was simple enough to get it working in IE11 too where I replaced it with four declarations:

{
  ...
  grid-row: grid-row-start;
  grid-row-span: (grid-row-end - grid-row-start);
  grid-column: grid-column-start;
  grid-column-span: (grid-column-end - grid-column-start);
  ...
}

I was left though with it still not working as expected until I clocked that Vue was replacing grid-row-end and grid-column-end with auto. I then clocked that the JS syntax is slightly different in that the final two values can also use spans like this:

{
  ...
  grid-area: grid-row-start / grid-column-start / span (grid-row-end - grid-row-start) / span (grid-column-end - grid-column-start);
  ...
}


Setting it as four integers was not working, setting it as integers prefixed with span was working in Vue where the final two integers were getting replaced with auto - so I replaced all instances with width and depth spans and updated my script accordingly, the required output is now:

{
  ...
  grid-area: grid-row-start / grid-column-start / span width / span depth;
  ...
}


Combined with the specificity required for IE11 we then have the following:

{
  ...
  grid-row: grid-row-start;
  grid-row-span: width;
  grid-column: grid-column-start;
  grid-column-span: depth;
  grid-area: grid-row-start / grid-column-start / span width / span depth;
  ...
}

Which, when converted to a method function, results in this:

placeElement: function (x, y, width, depth) {
    return {
        gridRow: x,
        gridRowSpan: width,
        gridColumn: y,
        gridColumnSpan: depth,
        gridArea: [x, y, "span " + width, "span " + depth].join(" / "),
    };
}

Not brilliant to look at but Vue will auto prefix the individual values so that gridRow becomes -ms-grid-row etc. for IE11 and won't bother outputting anything other than the grid-area for Chrome et al.

It also seems cleaner in that we have the four arguments and it looks more natural and logical somehow to define how many rows and columns the element should span.

Along with that, returning an object means we can then add to it in subsequent functions.