does the glBlendFunc only defines the operation of blending when it is enabled? or it also do the blending?
i mean… who is doing the blending calculation?
thanks!
https://www.khronos.org/opengl/wiki/Blending
https://www.khronos.org/registry/OpenGL-Refpages/gl4/html/glBlendFunc.xhtml
initially disabled, you have to enable bleding first with glEnable(GL_BLEND);
… your graphics card, maybe ?!
in general, blending says what has to be done the incoming fragment color (source color) and the color stored in the framebuffer (destination color)
glBlendFunc(GL_ONE, GL_ZERO); // which is the default setting
… that means:
resulting color = (source color x 1) + (destination color * 0) = source color
https://www.khronos.org/registry/OpenGL-Refpages/gl4/html/glBlendEquation.xhtml
… sets the operation that has to be performed on both scaled colors, by default “+” or GL_FUNC_ADD