使用 SWT 进行快速像素绘图？
我正在寻找一种快速、简单的方法来在 SWT 画布中绘制任意颜色的像素。 到目前为止，我正在使用类似的东西：
// initialization:
GC gc = new GC(canvas);
// inside the drawing loop:
Color cc = new Color(display, r, g, b);
gc.setForeground(cc);
gc.drawPoint(x, y);
cc.dispose();
这非常慢。 用像素填充 300x300 画布大约需要一秒半的时间。 我可以在屏幕外创建一个图像，在其中设置像素，然后绘制图像。 这会更快，但我特别想要在画布上逐像素绘制图像的渐进绘画效果。
I'm looking for a fast and easy way to plot arbitrarily colored pixels in an SWT Canvas.
So far I'm using something like that:
// initialization:
GC gc = new GC(canvas);
// inside the drawing loop:
Color cc = new Color(display, r, g, b);
gc.setForeground(cc);
gc.drawPoint(x, y);
cc.dispose();
This is horribly horribly slow. it takes about a second and a half to fill a 300x300 canvas with pixels.
I could create an image off-screen, set the pixels in it and then draw the image. This will be faster but I specifically want the gradual painting effect of plotting the image pixel by pixel on the canvas.
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创建一个 BufferedImage 对象：
在绘图循环中设置像素：
最后显示缓冲图像：
如果您发现 setRGB() 慢，您可以直接访问位图数据：
然后
Create a BufferedImage object:
inside the drawing loop set your pixels:
and finally display the buffered image:
If you find setRGB() slow, you can access the bitmap data directly:
and later
我敢打赌，影响性能的是分配和释放 90,000 个 Color 对象。 请记住，在 SWT 中，每个
Color对象都会分配本机资源，这就是您必须dispose()它的原因。 这意味着每次分配和处置Color对象时，都必须在 JVM 和本机代码之间来回转换。您可以在 300x300 像素循环中缓存
Color实例，然后在循环后处理这些对象吗？ 您需要一个有点智能的缓存，它只能容纳最多这么多的对象，然后将处理其中的一些条目，但这应该会大大加快速度。I bet that what is killing performance is allocating and releasing 90,000
Colorobjects. Remember, in SWT, eachColorobject allocates native resources, which is why you have todispose()it. This means each time you allocate and dispose aColorobject, you have to transition from the JVM to native code and back.Can you cache your
Colorinstances while in the 300x300 pixel loop and then dispose of the objects after your loop? You'd need a somewhat intelligent cache that only holds a maximum of so many objects, and after that will dispose of some of its entries, but this should speed things up greatly.您可以绘制多个屏幕外图像，逐渐填充 300x300 区域。 这样您就可以控制图像显示的速度。
You could draw several offscreen images where you gradually fill the 300x300 area. This way you can control how fast the image should appear.