With scanline rendering coloring in all the polygons, our teapot looks like this.

在所有多边形中都使用扫描线渲染着色，我们的茶壶看起来像这样。

The job of the scanline algorithm is to fill in the pixels between the two intersections.

扫描线算法的工作是填充两个交叉点之间的像素。

Let’s jump to the first pixel that scanline rendering needs to fill in.

让我们跳到扫描线渲染需要填充的第一个像素。

Now that they’re in order, we can use scanline rendering to fill each polygon, one at a time.

现在它们是有序的，我们可以使用扫描线渲染来填充每个多边形，一次一个。

The scanline algorithm starts by reading the three points that make up the polygon, and finding the lowest and highest Y values.

扫描线算法首先读取构成多边形的三个点，然后找到最低和最高 Y 值。

When we’re filling this in, using scanline rendering, we can look up what color to use at every pixel according to a texture image saved in memory.

当我们填充它时，使用扫描线渲染，我们可以根据保存在内存中的纹理图像查找每个像素使用什么颜色。

But importantly, it’s the same type of calculations being performed over and over and over again for many millions of polygons – scanline filling, antialiasing, lighting, and texturing.

但重要的是，它是对数百万个多边形一遍又一遍地执行相同类型的计算——扫描线填充、抗锯齿、照明和纹理。

In this case, that’s A. It follows the same logic as the scanline algorithm, but instead of coloring in pixels, it checks the distance of the polygon versus what’s recorded in its Z-Buffer.

在这种情况下，它是 A。它遵循与扫描线算法相同的逻辑，但它不是以像素为单位着色，而是检查多边形的距离与其 Z 缓冲区中记录的距离。

This completed Z-buffer is used in conjunction with a fancier version of scanline rendering that not only tests for line intersection, but also does a lookup to see if that pixel will even be visible in the final scene.

这个完整的 Z 缓冲区与更高级版本的扫描线渲染结合使用，它不仅测试线相交，而且还进行查找以查看该像素在最终场景中是否可见。