javascript - Html5 canvas size to print size -



have 1 small issue though have searched blogs, articles, , stackoverflow questions there still small confusion thought put question.
need adjust canvas printing, how can ? maximum limit printing 6.50' x 15.75' (inches), size can vary in range. if not wrong dpi irrespective of screens (they more useful printing devices) on working how can dominate size on canvas? e.g.

6.50 * 72 = 468 px 15.75 * 72 = 1134 px

or 6.50 * 96 = 624 px 15.75 *96 = 1512 px

or 6.50 * 300 = 1950 px 15.75 * 300 = 4725 px

my work area canvas cannot exceeded more 703px x 391px; need adjust canvas size exact required printing? or missing something? scale factor considered drawing in confined region , printing on various sizes. suggestions or links grateful.

thanks

ps: using fabricjs canvas stuff.

fabric js helps in providing zoom factor.

you can define canvas big need, limit respecting aspect ratio of print size.

let's want print 6 x 15 inch sheet.

you define canvas in aspect ration of 6/15 2/5.

700px x 280px fit aspect ratio , canvas size limit.

you work on canvas , when time export graphic file can:

define final size

6 x 15 inch @ 300dpi = 1800 x 4500 pixels.

find ratio between canvas , final canvas:

4500 / 700 = 6.428

you can do

canvas.todataurl({ multiplier: 6.428 }) , should obtain file of right size.


Comments

Post a Comment

Popular posts from this blog

angular - Ionic slides - dynamically add slides before and after -

hi i'm using ngfor create set of 3 slides while starting in middle i'm guaranteed able slide left or right on start. when slide right can simple listen reachedend , push slide array i'm looping. but have problem adding slide beginning. if same above , use e.g. array.unshift() or spread add item beginning, view think it's on position 0 , snaps view new slide. the code below work animates slide change index 1. slide = [0,1,2] //example loop slidechanged(event) { if(this.slides.isbeginning()){ this.slide = [this.slide[0]-1, ...this.slide]; this.slides.update(); this.slides.slideto(1) } } <ion-slides [initialslide]="1" (ionslidedidchange)="slidechanged($event)"> <ion-slide *ngfor="let item of slide"> <h1>slide {{item}}</h1> </ion-slide> </ion-slides> any appreciated! you can using ionslidenextend , ionslideprevend events slides . please
Read more

minify - Minimizing css files -

i want know how css files can minimized. currently, using external sites css minifier compress css files. however, after removing whitespaces, comments, etc, file sizes reduced 10-15%. how frameworks bootstrap manage make minimized versions kilobytes. as example, css is: body { background-color: #ff0; } the reduction goes 28 bytes 22 bytes other css files have lot more characters still smaller this. actually minifying code means it's remove thing code white space characters new line characters comments block delimiters it reduces amount of code has transferred on web , speed site load fastly.but unreadable format.
Read more

Add a dynamic header in angular 2 http provider -

i have http interceptor built via tutorial https://scotch.io/@kashyapmukkamala/using-http-interceptor-with-angular2 the problem need have dynamic header changes automatically once changes 'mode' in app. service able tell interceptor change header, or have interceptor pull header (which string)from service each request. able throwing away patch method, call http.patch('new header string') set header string. call in service controls 'mode' setting. wondering if there way interceptor pull recent value service each request or if can add method http provider via interceptor? i've tried call service in interceptor each request returns undefined. because creating new instance of service or copying value before service fired , loaded/changed data. i don't want pass header string every http provider call because defeats purpose of having interceptor, id able set once changes or have provider fetch service before makes request. tl;dr : need add autom
Read more