Benchmark: Canvas Pixel vs Fill rect 1px

HTML Preparation code:

<canvas id="c" width="800" height="300"></canvas>

Script Preparation code:

$c = document.getElementById('c');
$ctx = $c.getContext('2d');
$ctx.clearRect(0, 0, 800, 300);
$px = $ctx.createImageData(250, 100);
$pxls = [];
for (var i=0; i<25000; ++i) $pxls.push({
   x: Math.random() * 800 << 0,
   y: Math.random() * 300 << 0,
   r: Math.random() * 255 << 0,
   g: Math.random() * 255 << 0,
   b: Math.random() * 255 << 0,
   a: Math.random() * 128 << 0 + 128
});
$i = 0;

Tests:

fillRect/concat
for (var i=250;i--;){ for(var j=100;j--;){ var px = $pxls[i*j] $ctx.fillStyle = 'rgba(' + px.r + ',' + px.g + ',' + px.b + ',' + (px.a / 255) + ')'; $ctx.fillRect(px.x, px.y, 1, 1); } }
1×1 Image Data
for (var i=0; i<25000; ++i){ var px=$pxls[i], d=$px.data[i]; d[0] = px.r; d[1] = px.g; d[2] = px.b; d[3] = px.a; } $ctx.putImageData($px, 500,500);

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
fillRect/concat
1×1 Image Data

Fastest: N/A

Slowest: N/A

Latest run results:

Run details: (Test run date: 7 months ago)

User agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/140.0.0.0 Safari/537.36 Edg/140.0.0.0

Browser/OS: Chrome 140 on Windows

View result in a separate tab

Test name	Executions per second
fillRect/concat	77.4 Ops/sec
1×1 Image Data	81.3 Ops/sec

Autogenerated LLM Summary (model llama3.2:3b, generated one year ago):

LLMs can make mistakes. Check important info.

I'll break down the provided benchmark and explain what's being tested, compared options, pros and cons of each approach, and other considerations.

**Benchmark Overview**

The provided benchmark compares two approaches to drawing 25000 pixel values on a canvas: `fillRect/concat` and using image data (`1×1 Image Data`). Both methods are used to draw pixels at specific coordinates with varying red, green, blue (RGB), and alpha (RGBA) values.

**Test Case Analysis**

### 1. "Canvas Pixel vs Fill rect 1px"

This test case is comparing the performance of two approaches:

a. `fillRect/concat`: This approach uses the `fillStyle` property to set the fill color for each pixel, followed by a call to `fillRect()` with the x, y, width, and height of the pixel.

b. Using image data (`1×1 Image Data`): In this approach, an image is created using `createImageData()`, where each pixel's color value is stored in an array. The image data is then used with `putImageData()` to draw the pixels on the canvas.

**Pros and Cons of Each Approach**

**a. `fillRect/concat`:**

Pros:

* Simple and straightforward implementation
* Easy to understand for beginners

Cons:

* Potential performance issues due to repeated calls to `fillStyle` and `fillRect()`
* Can be slower for large numbers of pixels

**b. Using image data (`1×1 Image Data`):**

Pros:

* More efficient, as the browser can use hardware acceleration
* Less repeated function calls, reducing overhead

Cons:

* Requires more complex implementation, including creating an image and accessing its pixel data
* May require additional memory allocation for the image data array

**Other Considerations**

* Both approaches are using JavaScript to interact with the canvas element. The choice of approach may depend on the specific requirements of the application.
* Using image data can be beneficial for performance-critical applications, as it allows the browser to use hardware acceleration.

**Library and Special JS Features Used**

* No libraries are explicitly mentioned in the benchmark definition or test cases.
* There is no use of special JavaScript features like Web Workers, async/await, or Promises. However, some browsers may optimize certain operations for Chrome (e.g., `putImageData()`).

**Alternatives to the Benchmark**

Other alternatives to compare these two approaches could include:

* Using a graphics API like WebGL
* Implementing a custom pixel shader using shaders
* Comparing performance using other graphics libraries or frameworks

However, the provided benchmark is a good starting point for comparing the performance of these two approaches in JavaScript.

Related benchmarks:

Canvas Pixel vs Fill rect 1px (version: 0)

Comparing performance of: fillRect/concat vs 1×1 Image Data

Created: 5 years ago by: Guest

Jump to the latest result

fillRect/concat

1×1 Image Data

Suite status: <idle, ready to run>

Fastest: N/A

Slowest: N/A

Autogenerated LLM Summary (model llama3.2:3b, generated one year ago):