combine src1 * src2

Multiplies src1 and src2 together. The result will be darker than either input.
将源1和源2的元素相乘。结果会比单独输出任何一个都要暗

combine src1 + src2

Adds src1 and src2 together. The result will be lighter than either input.
将将源1和源2的元素相加。结果会比单独输出任何一个都要亮

combine src1 - src2

Subtracts src2 from src1.
源1 减去 源2

combine src1 +- src2

Adds src1 to src2, then subtracts 0.5 (a signed add).
先相加，然后减去0.5（添加了一个符号）

combine src1 lerp (src2) src3

Interpolates between src3 and src1, using the alpha of src2. Note that the interpolation is opposite direction: src1 is used when alpha is one, and src3 is used when alpha is zero.
使用源2的透明度通道值在源3和源1中进行差值，注意差值是反向的：当透明度值是1是使用源1，透明度为0时使用源3

combine src1 * src2 + src3

Multiplies src1 with the alpha component of src2, then adds src3.
源1和源2的透明度相乘，然后加上源3

combine src1 * src2 +- src3

Multiplies src1 with the alpha component of src2, then does a signed add with src3.
源1和源2的透明度相乘，然后和源3做符号加

combine src1 * src2 - src3

Multiplies src1 with the alpha component of src2, then subtracts src3.
源1和源2的透明度相乘，然后和源3相减

All the src properties can be either one of previous, constant, primary or texture.

所有源属性都可以是previous, constant, primary or texture其中的一个。

• Previous is the the result of the previous SetTexture.
  上一次SetTexture的结果
• Primary is the color from the lighting calculation or the vertex color if it is bound.
  来自光照计算的颜色或是当它绑定时的顶点颜色
• Texture is the color of the texture specified by [_TextureName] in the SetTexture (see above).
  在SetTexture中被定义的纹理的颜色
• Constant is the color specified in ConstantColor.
  被ConstantColor定义的颜色

Modifiers 解释：

• The formulas specified above can optionally be followed by the keywords Double or Quad to make the resulting color 2x or 4x as bright.
  上述的公式都均能通过关键字 Double 或是 Quad 将最终颜色调高亮度2倍或4倍。
• All the src properties, except lerp argument, can optionally be preceded by one - to make the resulting color negated.
  所有的src属性，除了差值参数都能被标记一个-符号来使最终颜色反相。
• All the src properties can be followed by alpha to take only the alpha channel.
  所有src属性能通过跟随 alpha 标签来表示只取用alpha通道。