1 // Copyright 2016 Paul Hänsch
3 // This file is part of Confetti.
5 // Confetti is free software: you can redistribute it and/or modify
6 // it under the terms of the GNU Affero General Public License as published by
7 // the Free Software Foundation, either version 3 of the License, or
8 // (at your option) any later version.
10 // Confetti is distributed in the hope that it will be useful,
11 // but WITHOUT ANY WARRANTY; without even the implied warranty of
12 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
13 // GNU Affero General Public License for more details.
15 // You should have received a copy of the GNU Affero General Public License
16 // along with Confetti. If not, see <http://www.gnu.org/licenses/>.
19 dbg = document.getElementById("jsdebug")
20 canvas = document.getElementById("canvas")
21 data=document.getElementById("image_serialize")
23 image = canvas.getContext("2d")
27 // start and current coordinates of a draw
28 // serves for tracking, whether path ends close to its beginning
36 if ( c == "#FFF" ) image.lineWidth = 32
37 else image.lineWidth = 4
38 data.value += " stroke " + c + " stroke-width " + image.lineWidth
44 if ( body.clientWidth >= 800 ){
45 return Math.floor(cscaleW * (x - canvas.offsetLeft))
47 return Math.floor(cscaleW * (x - canvas.offsetLeft + window.pageXOffset))
51 if ( body.clientWidth >= 800 ){
52 return Math.floor(cscaleH * (y - canvas.offsetTop))
54 return Math.floor(cscaleH * (y - canvas.offsetTop + window.pageYOffset))
60 cux=relX(x), cuy=relY(y)
62 image.lineTo( cux, cuy )
65 image_serialize += " " + cux + "," + cuy
69 function drawstart(x, y) {
72 cscaleW = canvas.width / canvas.clientWidth
73 cscaleH = canvas.height / canvas.clientHeight
75 stx=relX(x), sty=relY(y)
78 draw(x, y) // why must this not use relative Coords ???
80 image_serialize = " polyline"
85 // if path ends close to beginning ( < 50 px); then close path and fill
86 if ( mouse == 1 && Math.sqrt( Math.pow(stx - cux, 2) + Math.pow(sty - cuy, 2)) <= 50 && c !== "#FFF" ){
87 image.lineTo( stx, sty )
90 image.globalAlpha = .5
94 image_serialize += " " + stx + "," + sty
95 data.value += " fill " + c + "8" + image_serialize
96 } else if (mouse == 1) {
97 data.value += " fill #0000 " + image_serialize
99 dbg.innerHTML = " stx: " + stx + " cux: " + cux + " sty: " + sty + " cuy: " + cuy
106 window.addEventListener( 'mouseup', function() { drawstop() } )
107 canvas.addEventListener( 'mousedown', function(e) { drawstart(e.clientX, e.clientY) } )
108 canvas.addEventListener( 'mousemove', function(e) { draw(e.clientX, e.clientY) } )
110 window.addEventListener( 'touchend', function() { drawstop() } )
111 canvas.addEventListener( 'touchstart', function(e) { drawstart(e.touches[0].clientX, e.touches[0].clientY) } )
112 canvas.addEventListener( 'touchmove', function(e) { e.preventDefault(); draw(e.touches[0].clientX, e.touches[0].clientY) } )