image - Algorithm for change specific color of when rendering

Question

Given that I have a texture file generated from a font bitmap builder like this:

Now I load it into my program. Then, I want to write my text with different colors rather than black such as blue, pink, ... from that original texture file.

What trick or algorithm should I use?

Any one can help me, please

Thank you very much.

Answer 1

如果您可以访问具有透明度的白色版本，则可以使用硬件顶点混合来获得所需的任何颜色，但正如我所说，文本必须是白色的。在软件循环中执行它是可能的，但只能使用蛮力。即使您使用库，它也只会扫描每个像素，转换它，然后重新编写它......这很慢。所以使用硬件顶点着色。