DreaMana

材料: BitmapData, Timer
2009/05/08 Update: 增加副本拷贝功能（BitmapData 重用）


In computer graphics, a sprite (also known by other names; see Synonyms below) is a two-dimensional image or animation that is integrated into a larger scene.
计算机图形学中，“精灵”(Sprite)是指整合在大场景中的一个二维图像或动画。

Sprites were originally invented as a method of quickly compositing several images together in two-dimensional video games using special hardware. As computer performance improved, this optimization became unnecessary and the term evolved to refer specifically to the two dimensional images themselves that were integrated into a scene. That is, figures generated by either custom hardware or by software alone were all referred to as sprites. As three-dimensional graphics became more prevalent, the term was used to describe a technique whereby flat images are seamlessly integrated into complicated three-dimensional scenes.
“精灵”起初是为了在特殊硬件环境的电子游戏中快速将若干图像混合在一起而发明的。随着计算机性能的提升，这种优化方法变得不必要了，而这个术语已演变成特指整合于场景中的二维图像本身。即不论是定制硬件还是单独软件生成的图形都被称为“精灵”。随着三维图形越来越流行，此术语被用来描述将平面图像无缝整合于复杂三维场景的技术。

More often sprite now refers to a partially transparent two dimensional animation that is mapped onto a special plane in a three dimensional scene. Unlike a texture map, the sprite plane is always perpendicular to the axis emanating from the camera. The image can be scaled to simulate perspective, it can be rotated two dimensionally, it can overlap other objects and be occluded, but it can only be viewed from the same angle. This rendering method is also referred to as billboarding.
现在更多地将映射到三维场景中特定平面的部分透明的二维动画称作“精灵”。不同于纹理映射，精灵平面总是垂直于摄像机的轴。这图像可以缩放到模拟视角，可以二维旋转，可以与其他对象重叠并封闭，但只能在同一角度被看到。这种绘制方法也被称为告示板技术(billboarding)。

From Wikipedia, the free encyclopedia
来自维基百科——自由的百科全书