<canvas id='master' width='100' height='100'></canvas>master<br><br><canvas id='pid' width='100' height='100'></canvas>pid1<br><br><canvas id='di' width='100' height='100'></canvas>di1<br><br><canvas id='pid2' width='100' height='100'></canvas>pid2<br><br><canvas id='di2' width='100' height='100'></canvas>di2var master = document.getElementById('master');var masterctx = master.getContext('2d');var pid = document.getElementById('pid').getContext('2d');var di = document.getElementById('di').getContext('2d');var pid2 = document.getElementById('pid2').getContext('2d');var di2 = document.getElementById('di2').getContext('2d');masterctx.fillRect(0,0,50,50);masterctx.fillStyle = "red";masterctx.fillRect(50,50,100,100);var imgData = masterctx.getImageData(0,0,100,100);var imgDatas = masterctx.getImageData(25,0,50,100);di.drawImage(master,0,0);pid.putImageData(imgData,0,0);di2.drawImage(master,25,0,50,100,25,0,50,100);pid2.putImageData(imgDatas,25,0);--enable-precise-memory-info flag.
| Test case name | Result |
|---|---|
| DrawImage whole master into di canvas | |
| PutImageData whole master into pid canvas | |
| DrawImage half master into di2 canvas | |
| PutImageData half master into pid2 canvas |
| Test name | Executions per second |
|---|---|
| DrawImage whole master into di canvas | 271356.2 Ops/sec |
| PutImageData whole master into pid canvas | 24757.6 Ops/sec |
| DrawImage half master into di2 canvas | 293920.6 Ops/sec |
| PutImageData half master into pid2 canvas | 24470.7 Ops/sec |
Let's dive into the world of JavaScript benchmarks!
The provided benchmark measures the performance difference between two approaches: DrawImage and PutImageData. We'll break down each test case, explore the options being compared, and discuss their pros and cons.
Test Case 1: DrawImage whole master into di canvas
di.drawImage(master,0,0);
In this test case, the entire canvas (master) is drawn onto another canvas (di) using DrawImage. The browser has to create a new image from scratch for each execution.
Pros:
Cons:
Test Case 2: PutImageData whole master into pid canvas
pid.putImageData(imgData,0,0);
In this test case, the entire canvas (master) is stored as image data (imgData) and then drawn onto another canvas (pid). This approach stores the image data once and reuses it.
Pros:
Cons:
Test Case 3: DrawImage half master into di2 canvas
di2.drawImage(master,25,0,50,100,25,0,50,100);
In this test case, a portion of the original canvas (master) is drawn onto another canvas (di2). This approach can be faster than storing the entire image data.
Pros:
Cons:
Test Case 4: PutImageData half master into pid2 canvas
pid2.putImageData(imgDatas,25,0);
In this test case, a portion of the original image data (imgDatas) is drawn onto another canvas (pid2). This approach can be faster than drawing the entire image using DrawImage.
Pros:
Cons:
Library:
The ImageBitmap API is used in some test cases, but it's not explicitly mentioned in the benchmark definition. However, given the context, it's likely that ImageBitmap is being used behind the scenes to store and manipulate image data.
Special JS feature:
There doesn't appear to be any special JavaScript features or syntax used in this benchmark. The focus is on comparing the performance of two approaches (DrawImage and PutImageData) rather than showcasing advanced JavaScript features.
Alternatives:
Other alternatives for drawing images onto canvases include:
CanvasRenderingContext2D.drawImage(): This method draws an image directly from a URL, not requiring explicit image data.WebGL or other 3D graphics APIs: These APIs provide more advanced rendering capabilities and may offer better performance in certain situations.Keep in mind that the choice of approach depends on the specific requirements of your application. Drawing images onto canvases can be optimized for different scenarios, so it's essential to consider factors like performance, memory usage, and ease of use when selecting an approach.
