index.html
1 |
<html>
|
---|---|
2 |
<head>
|
3 |
<script>
|
4 |
/* eslint no-console:0 consistent-return:0 */
|
5 |
"use strict";
|
6 |
|
7 |
var vertexShaderSource = `
|
8 |
// this will receive data from a buffer
|
9 |
attribute vec4 a_position;
|
10 |
|
11 |
void main() {
|
12 |
|
13 |
// shader must set the special variable gl_Position
|
14 |
gl_Position = a_position;
|
15 |
}
|
16 |
`;
|
17 |
|
18 |
var fragmentShaderSource = `
|
19 |
// set precision, this is needed as fragment shaders don't have default precision
|
20 |
precision mediump float;
|
21 |
|
22 |
void main() {
|
23 |
// shader must set the special variable gl_FragColor
|
24 |
gl_FragColor = vec4(0, 0, 0, 1); // black
|
25 |
}
|
26 |
`;
|
27 |
|
28 |
function createShader(gl, type, source)
|
29 |
{
|
30 |
var shader = gl.createShader(type);
|
31 |
gl.shaderSource(shader, source);
|
32 |
gl.compileShader(shader);
|
33 |
var success = gl.getShaderParameter(shader, gl.COMPILE_STATUS);
|
34 |
if (success)
|
35 |
{
|
36 |
return shader;
|
37 |
}
|
38 |
|
39 |
console.log(gl.getShaderInfoLog(shader));
|
40 |
gl.deleteShader(shader);
|
41 |
}
|
42 |
|
43 |
function createProgram(gl, vertexShader, fragmentShader)
|
44 |
{
|
45 |
var program = gl.createProgram();
|
46 |
gl.attachShader(program, vertexShader);
|
47 |
gl.attachShader(program, fragmentShader);
|
48 |
gl.linkProgram(program);
|
49 |
var success = gl.getProgramParameter(program, gl.LINK_STATUS);
|
50 |
if (success)
|
51 |
{
|
52 |
return program;
|
53 |
}
|
54 |
|
55 |
console.log(gl.getProgramInfoLog(program));
|
56 |
gl.deleteProgram(program);
|
57 |
}
|
58 |
|
59 |
var gl;
|
60 |
var canvas;
|
61 |
var program;
|
62 |
var positionAttributeLocation;
|
63 |
var positionBuffer;
|
64 |
|
65 |
function oneTimeInitGL(canvasSelector)
|
66 |
{
|
67 |
// get WebGL context
|
68 |
canvas = document.querySelector(canvasSelector);
|
69 |
gl = canvas.getContext("webgl", {antialias: false});
|
70 |
if (!gl)
|
71 |
{
|
72 |
return;
|
73 |
}
|
74 |
|
75 |
var vertexShader = createShader(gl, gl.VERTEX_SHADER, vertexShaderSource);
|
76 |
var fragmentShader = createShader(gl, gl.FRAGMENT_SHADER, fragmentShaderSource);
|
77 |
|
78 |
// set the two shaders into a program
|
79 |
program = createProgram(gl, vertexShader, fragmentShader);
|
80 |
|
81 |
// look up where the vertex data will be assigned
|
82 |
positionAttributeLocation = gl.getAttribLocation(program, "a_position");
|
83 |
|
84 |
// create buffer
|
85 |
positionBuffer = gl.createBuffer();
|
86 |
}
|
87 |
|
88 |
function clear()
|
89 |
{
|
90 |
// init viewport to convert clip space to pixels
|
91 |
gl.viewport(0, 0, gl.canvas.width, gl.canvas.height);
|
92 |
|
93 |
gl.clearColor(0, 0, 0, 0);
|
94 |
gl.clear(gl.COLOR_BUFFER_BIT);
|
95 |
}
|
96 |
|
97 |
function drawLinesWithTriangles(vertices)
|
98 |
{
|
99 |
// bind it to ARRAY_BUFFER
|
100 |
gl.bindBuffer(gl.ARRAY_BUFFER, positionBuffer);
|
101 |
|
102 |
var linesNum = vertices.length / 4;
|
103 |
var pos = new Float32Array(linesNum * 12);
|
104 |
for (var i = 0; i < linesNum; i++)
|
105 |
{
|
106 |
var j = i * 4;
|
107 |
|
108 |
var x1 = vertices[j];
|
109 |
var y1 = vertices[j + 1];
|
110 |
var x2 = vertices[j + 2];
|
111 |
var y2 = vertices[j + 3];
|
112 |
|
113 |
j = i * 12;
|
114 |
pos[j] = xtogl(x1, canvas);
|
115 |
pos[j + 1] = ytogl(y1, canvas);
|
116 |
pos[j + 2] = xtogl(x1 + 1, canvas);
|
117 |
pos[j + 3] = ytogl(y1 + 1, canvas);
|
118 |
pos[j + 4] = xtogl(x2, canvas);
|
119 |
pos[j + 5] = ytogl(y2, canvas);
|
120 |
pos[j + 6] = xtogl(x2, canvas);
|
121 |
pos[j + 7] = ytogl(y2, canvas);
|
122 |
pos[j + 8] = xtogl(x2 + 1, canvas);
|
123 |
pos[j + 9] = ytogl(y2 + 1, canvas);
|
124 |
pos[j + 10] = xtogl(x1 + 1, canvas);
|
125 |
pos[j + 11] = ytogl(y1 + 1, canvas);
|
126 |
}
|
127 |
|
128 |
gl.bufferData(gl.ARRAY_BUFFER, pos, gl.STATIC_DRAW);
|
129 |
|
130 |
// which program (with assigned shaders) to use
|
131 |
gl.useProgram(program);
|
132 |
|
133 |
// enable the attribute
|
134 |
gl.enableVertexAttribArray(positionAttributeLocation);
|
135 |
|
136 |
// set up the attribute how to get data out of positionBuffer (ARRAY_BUFFER)
|
137 |
var size = 2; // 2 components per iteration
|
138 |
var type = gl.FLOAT; // the data is 32bit floats
|
139 |
var normalize = false; // don't normalize the data
|
140 |
var stride = 0; // 0 = move forward size * sizeof(type) each iteration to get the next position
|
141 |
var offset = 0; // start at the beginning of the buffer
|
142 |
gl.vertexAttribPointer(positionAttributeLocation, size, type, normalize, stride, offset);
|
143 |
|
144 |
// draw
|
145 |
var primitiveType = gl.TRIANGLES;
|
146 |
var offset = 0;
|
147 |
var count = 6 * linesNum;
|
148 |
gl.drawArrays(primitiveType, offset, count);
|
149 |
}
|
150 |
|
151 |
function drawLinesWithLines(vertices)
|
152 |
{
|
153 |
// bind it to ARRAY_BUFFER
|
154 |
gl.bindBuffer(gl.ARRAY_BUFFER, positionBuffer);
|
155 |
|
156 |
var positions = [
|
157 |
xtogl(20, canvas), ytogl(20, canvas),
|
158 |
xtogl(100, canvas), ytogl(20, canvas)
|
159 |
];
|
160 |
gl.bufferData(gl.ARRAY_BUFFER, new Float32Array(positions), gl.STATIC_DRAW);
|
161 |
|
162 |
// which program to use
|
163 |
gl.useProgram(program);
|
164 |
|
165 |
// enable the attribute
|
166 |
gl.enableVertexAttribArray(positionAttributeLocation);
|
167 |
|
168 |
// set up the attribute how to get data out of positionBuffer (ARRAY_BUFFER)
|
169 |
var size = 2; // 2 components per iteration
|
170 |
var type = gl.FLOAT; // the data is 32bit floats
|
171 |
var normalize = false; // don't normalize the data
|
172 |
var stride = 0; // 0 = move forward size * sizeof(type) each iteration to get the next position
|
173 |
var offset = 0; // start at the beginning of the buffer
|
174 |
gl.vertexAttribPointer(
|
175 |
positionAttributeLocation, size, type, normalize, stride, offset);
|
176 |
|
177 |
// draw
|
178 |
var primitiveType = gl.LINES;
|
179 |
var offset = 0;
|
180 |
var count = 2;
|
181 |
gl.drawArrays(primitiveType, offset, count);
|
182 |
}
|
183 |
|
184 |
function drawRectanglesWithTriangles(vertices)
|
185 |
{
|
186 |
// bind it to ARRAY_BUFFER
|
187 |
gl.bindBuffer(gl.ARRAY_BUFFER, positionBuffer);
|
188 |
|
189 |
var positions = [
|
190 |
xtogl(20, canvas), ytogl(30, canvas),
|
191 |
xtogl(20, canvas), ytogl(30 + 30, canvas),
|
192 |
xtogl(100, canvas), ytogl(30, canvas),
|
193 |
xtogl(100, canvas), ytogl(30, canvas),
|
194 |
xtogl(100, canvas), ytogl(30 + 30, canvas),
|
195 |
xtogl(20, canvas), ytogl(30 + 30, canvas)
|
196 |
|
197 |
];
|
198 |
gl.bufferData(gl.ARRAY_BUFFER, new Float32Array(positions), gl.STATIC_DRAW);
|
199 |
|
200 |
// which program to use
|
201 |
gl.useProgram(program);
|
202 |
|
203 |
// enable the attribute
|
204 |
gl.enableVertexAttribArray(positionAttributeLocation);
|
205 |
|
206 |
// set up the attribute how to get data out of positionBuffer (ARRAY_BUFFER)
|
207 |
var size = 2; // 2 components per iteration
|
208 |
var type = gl.FLOAT; // the data is 32bit floats
|
209 |
var normalize = false; // don't normalize the data
|
210 |
var stride = 0; // 0 = move forward size * sizeof(type) each iteration to get the next position
|
211 |
var offset = 0; // start at the beginning of the buffer
|
212 |
gl.vertexAttribPointer(
|
213 |
positionAttributeLocation, size, type, normalize, stride, offset);
|
214 |
|
215 |
// draw
|
216 |
var primitiveType = gl.TRIANGLES;
|
217 |
var offset = 0;
|
218 |
var count = 6;
|
219 |
gl.drawArrays(primitiveType, offset, count);
|
220 |
}
|
221 |
|
222 |
// convert x from pixel to clip space
|
223 |
function xtogl(x, canvas)
|
224 |
{
|
225 |
var dx = 2 / canvas.width;
|
226 |
return (x - (canvas.width / 2)) * dx;
|
227 |
}
|
228 |
|
229 |
// convert y from pixel to clip space
|
230 |
function ytogl(y, canvas)
|
231 |
{
|
232 |
var dy = 2 / canvas.height;
|
233 |
return ((canvas.height - y) - (canvas.height / 2)) * dy;
|
234 |
}
|
235 |
|
236 |
function drawLines2DLineTo(lines, screenCtx, ctx, offcanvas)
|
237 |
{
|
238 |
var linesCount = lines.length / 4;
|
239 |
for (var i = 0; i < linesCount; i++)
|
240 |
{
|
241 |
var curLine = i * 4;
|
242 |
ctx.beginPath();
|
243 |
ctx.moveTo(lines[curLine], lines[curLine + 1]);
|
244 |
ctx.lineTo(lines[curLine + 2], lines[curLine + 3]);
|
245 |
ctx.closePath();
|
246 |
ctx.stroke();
|
247 |
}
|
248 |
|
249 |
screenCtx.drawImage(offcanvas, 0, 0);
|
250 |
}
|
251 |
|
252 |
function drawLines2DPixels(lines, screenCtx, ctx, offcanvas)
|
253 |
{
|
254 |
var linesCount = lines.length / 4;
|
255 |
for (var m = 0; m < linesCount; m++)
|
256 |
{
|
257 |
var curLine = m * 4;
|
258 |
var x1 = lines[curLine];
|
259 |
var y1 = lines[curLine + 1];
|
260 |
var x2 = lines[curLine + 2];
|
261 |
var y2 = lines[curLine + 3];
|
262 |
|
263 |
var image = ctx.createImageData(1, 1);
|
264 |
var imageData = image.data;
|
265 |
|
266 |
for (var i = 0; i < 4; i += 4)
|
267 |
{
|
268 |
imageData[i] = 0;
|
269 |
imageData[i + 1] = 0;
|
270 |
imageData[i + 2] = 0;
|
271 |
imageData[i + 3] = 255;
|
272 |
}
|
273 |
|
274 |
var lineWidth = x2 - x1 + 1;
|
275 |
var lineHeight = y2 - y1 + 1;
|
276 |
// Create a line image
|
277 |
var screenImage = ctx.createImageData(lineWidth, lineHeight);
|
278 |
var data = screenImage.data;
|
279 |
var length = 4 * lineWidth * lineHeight;
|
280 |
|
281 |
// Fill a line image with the given stroke color
|
282 |
data[0] = 0;
|
283 |
data[1] = 0;
|
284 |
data[2] = 0;
|
285 |
data[3] = 255;
|
286 |
|
287 |
var pos = 4;
|
288 |
var seqLen = 4;
|
289 |
while (pos < length)
|
290 |
{
|
291 |
data.copyWithin(pos, 0, seqLen);
|
292 |
// increment position by the length of the current segment
|
293 |
pos += seqLen;
|
294 |
// double the length of the next segment
|
295 |
seqLen <<= 1;
|
296 |
}
|
297 |
|
298 |
ctx.putImageData(screenImage, x1, y1);
|
299 |
}
|
300 |
|
301 |
screenCtx.drawImage(offcanvas, 0, 0);
|
302 |
}
|
303 |
|
304 |
var two;
|
305 |
|
306 |
function initTwo()
|
307 |
{
|
308 |
// var elem = document.getElementById('two_container');
|
309 |
// var params = {width: 1280, height: 720, type: Two.Types.webgl};
|
310 |
// two = new Two(params).appendTo(elem);
|
311 |
}
|
312 |
|
313 |
function drawLinesWithTwo(lines)
|
314 |
{
|
315 |
var linesCount = lines.length / 4;
|
316 |
for (var m = 0; m < linesCount; m++)
|
317 |
{
|
318 |
var curLine = m * 4;
|
319 |
var x1 = lines[curLine];
|
320 |
var y1 = lines[curLine + 1];
|
321 |
var x2 = lines[curLine + 2];
|
322 |
var y2 = lines[curLine + 3];
|
323 |
two.makeLine(x1, y1, x2, y2);
|
324 |
}
|
325 |
|
326 |
two.update();
|
327 |
}
|
328 |
|
329 |
function createOffscreenCanvas()
|
330 |
{
|
331 |
var isChrome = navigator.userAgent.toLowerCase().indexOf('chrome') > -1;
|
332 |
|
333 |
/**
|
334 |
* The off screen canvas to be used to make batch drawing.
|
335 |
*
|
336 |
* Canvas created with document.createElement is very slow in Chrome, use OffscreenCanvas instead.
|
337 |
* Chrome version 79 is known to have drawing issues with OffscreenCanvas, see #4473.
|
338 |
*/
|
339 |
var offcanvas;
|
340 |
if (isChrome && typeof OffscreenCanvas != "undefined")
|
341 |
{
|
342 |
offcanvas = new OffscreenCanvas(1280, 720);
|
343 |
}
|
344 |
else
|
345 |
{
|
346 |
offcanvas = document.createElement('canvas');
|
347 |
offcanvas.width = 1280;
|
348 |
offcanvas.height = 720;
|
349 |
}
|
350 |
|
351 |
return offcanvas;
|
352 |
}
|
353 |
|
354 |
|
355 |
function main(iterations, linesPerIteration)
|
356 |
{
|
357 |
var offcanvas2 = createOffscreenCanvas();
|
358 |
var offcanvas3 = createOffscreenCanvas();
|
359 |
|
360 |
var canvas2 = document.querySelector("#mycanvas2");
|
361 |
var screenCtx2 = canvas2.getContext("2d");
|
362 |
var ctx2 = offcanvas2.getContext("2d");
|
363 |
screenCtx2.imageSmoothingEnabled = false;
|
364 |
ctx2.imageSmoothingEnabled = false;
|
365 |
|
366 |
var canvas3 = document.querySelector("#mycanvas3");
|
367 |
var screenCtx3 = canvas3.getContext("2d");
|
368 |
var ctx3 = offcanvas3.getContext("2d");
|
369 |
screenCtx3.imageSmoothingEnabled = false;
|
370 |
ctx3.imageSmoothingEnabled = false;
|
371 |
|
372 |
oneTimeInitGL("#mycanvas");
|
373 |
initTwo();
|
374 |
|
375 |
var res = [];
|
376 |
var headers = ["Number of lines", "Web GL", "2D lineTo", "2D pixel"];
|
377 |
res.push(headers);
|
378 |
|
379 |
for (var j = 1; j <= iterations; j++)
|
380 |
{
|
381 |
var oneRes = [];
|
382 |
oneRes.push(linesPerIteration * j);
|
383 |
var lines = [];
|
384 |
for (var i = 0; i < (linesPerIteration * j); i++)
|
385 |
{
|
386 |
var x1 = Math.round(1280 * Math.random());
|
387 |
var x2 = Math.round(1280 * Math.random());
|
388 |
if (x1 > x2)
|
389 |
{
|
390 |
var x = x2;
|
391 |
x2 = x1;
|
392 |
x1 = x;
|
393 |
}
|
394 |
|
395 |
var y1 = Math.round(720 * Math.random());
|
396 |
var y2 = Math.round(720 * Math.random());
|
397 |
if (y1 > y2)
|
398 |
{
|
399 |
var y = y2;
|
400 |
y2 = y1;
|
401 |
y1 = y;
|
402 |
}
|
403 |
|
404 |
var dir = Math.random();
|
405 |
if (dir <= 0.5)
|
406 |
{
|
407 |
// horizontal
|
408 |
y2 = y1;
|
409 |
} else
|
410 |
{
|
411 |
// vertical
|
412 |
x2 = x1;
|
413 |
}
|
414 |
|
415 |
lines.push(x1);
|
416 |
lines.push(y1);
|
417 |
lines.push(x2);
|
418 |
lines.push(y2);
|
419 |
}
|
420 |
|
421 |
var t1 = window.performance.now();
|
422 |
drawLinesWithTriangles(lines);
|
423 |
var t2 = window.performance.now();
|
424 |
console.log("WebGL took " + (t2 - t1) + " ms");
|
425 |
oneRes.push(t2 - t1);
|
426 |
// drawLinesWithLines();
|
427 |
// drawRectanglesWithTriangles();
|
428 |
|
429 |
t1 = window.performance.now();
|
430 |
drawLines2DLineTo(lines, screenCtx2, ctx2, offcanvas2);
|
431 |
t2 = window.performance.now();
|
432 |
console.log("2D lineTo took " + (t2 - t1) + " ms");
|
433 |
oneRes.push(t2 - t1);
|
434 |
|
435 |
t1 = window.performance.now();
|
436 |
drawLines2DPixels(lines, screenCtx3, ctx3, offcanvas3);
|
437 |
t2 = window.performance.now();
|
438 |
console.log("2D pixels took " + (t2 - t1) + " ms");
|
439 |
oneRes.push(t2 - t1);
|
440 |
|
441 |
//t1 = window.performance.now();
|
442 |
//drawLinesWithTwo(lines);
|
443 |
//t2 = window.performance.now();
|
444 |
//console.log("Two took " + (t2 - t1) + " ms");
|
445 |
//oneRes.push(t2 - t1);
|
446 |
|
447 |
res.push(oneRes);
|
448 |
}
|
449 |
|
450 |
var results = document.querySelector("#results");
|
451 |
var tbl = document.createElement('table');
|
452 |
tbl.style.width = '100%';
|
453 |
tbl.setAttribute('border', '1');
|
454 |
var tbdy = document.createElement('tbody');
|
455 |
for (var i = 0; i < res[0].length; i++)
|
456 |
{
|
457 |
var tr = document.createElement('tr');
|
458 |
for (var j = 0; j < res.length; j++)
|
459 |
{
|
460 |
var td = document.createElement('td');
|
461 |
td.appendChild(document.createTextNode("" + res[j][i]))
|
462 |
tr.appendChild(td)
|
463 |
}
|
464 |
tbdy.appendChild(tr);
|
465 |
}
|
466 |
tbl.appendChild(tbdy);
|
467 |
results.appendChild(tbl)
|
468 |
}
|
469 |
</script>
|
470 |
</head>
|
471 |
|
472 |
<body onload="main(10, 2000);"> |
473 |
<div>Two.js:</div> |
474 |
<div id="two_container"></div> |
475 |
<div>Web GL:</div> |
476 |
<canvas id="mycanvas" width="1280" height="720" style="width:1280px; height: 720px"></canvas> |
477 |
<div>2D lineTo:</div> |
478 |
<canvas id="mycanvas2" width="1280" height="720" style="width:1280px; height: 720px"></canvas> |
479 |
<div>2D pixel:</div> |
480 |
<canvas id="mycanvas3" width="1280" height="720" style="width:1280px; height: 720px"></canvas> |
481 |
<div id="results">Results</div> |
482 |
</body>
|
483 |
</html>
|