Hello,

There is documentation for GL_ONE_MINUS_SRC_ALPHA on https://www.khronos.org/registry/OpenGL-Refpages/es2.0/xhtml/glBlendFunc.xml​

I am trying to emulate that in C++ code:

vertex_3 white(1.0f, 1.0f, 1.0f);
vertex_3 pc(player_colour[0], player_colour[1], player_colour[2]);
vertex_3 ec(enemy_colour[0], enemy_colour[1], enemy_colour[2]);

vertex_3 final_colour = lin_interp(white, pc, 1 - t_player);
final_colour = lin_interp(final_colour, ec, 1 - t_enemy);

Is this approach correct?

Here is an image. The player colour is yellow, and the enemy colour is blue:

Right, I use 1-t_player and 1-t_enemy as the alpha values during the linear interpolation.

I found another page that basically goes to show that it's just a linear interpolation. Thanks for the link, which confirms it.