Benchmark: alpha false - MeasureThat.net

HTML Preparation code:

<div style="width: 830; height: 200; background-color: red;"> <canvas id="canvas1" width="400" height="400"></canvas> <canvas id="canvas2" width="400" height="400"></canvas> </div> <style> canvas { border: 1px solid black; } </style>

Script Preparation code:

var can = document.getElementById('canvas1');
var ctx = can.getContext('2d');
ctx.fillRect(50,50,50,50);
ctx.clearRect(0,0,400,400);

var can2 = document.getElementById('canvas2');
var ctx2 = can2.getContext('2d', {alpha: false} );
ctx2.fillRect(50,50,50,50);
ctx2.clearRect(0,0,400,400);

Tests:

false
ctx2.fillStyle = 'rgba(255, 255, 255, 0.3)'; ctx2.fillRect(0,0,400,400);
true
ctx.fillStyle = 'rgba(255, 255, 255, 0.3)'; ctx.fillRect(0,0,400,400);

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
false
true

Fastest: N/A

Slowest: N/A

Latest run results:

Run details: (Test run date: one year ago)

User agent: Mozilla/5.0 (iPhone; CPU iPhone OS 18_3_2 like Mac OS X) AppleWebKit/605.1.15 (KHTML, like Gecko) Version/18.3.1 Mobile/15E148 Safari/604.1

Browser/OS: Mobile Safari 18 on iOS 18.3.2

View result in a separate tab

Test name	Executions per second
false	1501215.0 Ops/sec
true	1553935.4 Ops/sec

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

LLMs can make mistakes. Check important info.

Let's break down the provided benchmark and explain what's being tested.

**Benchmark Overview**

The MeasureThat.net benchmark tests two different approaches to rendering semi-transparent rectangles using the `Canvas` API in JavaScript.

**Script Preparation Code**

The script preparation code sets up two canvases, `can1` and `can2`, using the HTML preparation code. It then clears the contents of both canvases and draws a black rectangle on each one. For `can2`, it also passes an options object to the `getContext()` method with the `alpha` property set to `false`.

**Html Preparation Code**

The HTML preparation code defines two canvases, `canvas1` and `canvas2`, within a container div.

**Individual Test Cases**

There are two test cases:

1. "false": This test case sets the `alpha` value of the canvas context to `true` when drawing the semi-transparent rectangle using `fillStyle = 'rgba(255, 255, 255, 0.3)'`. It then draws a semi-transparent white rectangle on both canvases.
2. "true": This test case sets the `alpha` value of the canvas context to `false` when drawing the semi-transparent rectangle using `fillStyle = 'rgba(255, 255, 255, 0.3)'`. It then draws a semi-transparent white rectangle on both canvases.

**Comparison**

The benchmark is comparing two approaches:

1. **`alpha: true`**: This approach uses the `alpha` property of the canvas context to control transparency. When `alpha` is set to `true`, the canvas will render semi-transparent rectangles using the specified alpha value.
2. **`alpha: false`**: This approach does not use the `alpha` property and instead relies on the browser's default behavior for rendering semi-transparent rectangles. When `alpha` is set to `false`, the canvas will render solid white rectangles.

**Pros and Cons**

1. **`alpha: true`**:
	* Pros:
		+ More control over transparency
		+ Can be used in more complex graphics scenarios
	* Cons:
		+ May require additional JavaScript code to handle alpha channel calculations
2. **`alpha: false`**:
	* Pros:
		+ Simpler and faster execution
		+ Less overhead due to no need for explicit alpha channel calculations
	* Cons:
		+ Less control over transparency
		+ May not perform as well in complex graphics scenarios

**Library Usage**

The benchmark uses the `Canvas` API, which is a built-in JavaScript API. The `getContext()` method with an options object is used to specify the alpha value.

**Special JS Features or Syntax**

None mentioned.

**Other Alternatives**

There are other approaches for rendering semi-transparent rectangles in JavaScript, such as:

1. Using WebGL (Web Graphics Library) instead of Canvas
2. Employing a library like Pixi.js or React Canvas for more complex graphics scenarios
3. Utilizing a framework like Three.js for 3D graphics and alpha channel management

These alternatives may offer different trade-offs between performance, complexity, and control over transparency.

Related benchmarks:

alpha false (version: 0)

Comparing performance of: false vs true

Created: 8 years ago by: Guest

Jump to the latest result

false

true

Suite status: <idle, ready to run>

Fastest: N/A

Slowest: N/A

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