How to mix opacity of textures (taken from images) according to a runtime value?

[Predator106]

I'm trying to draw a day sky (blue) and during the evening, I want to slowly blend in another image/texture which is the dusk (orangish blue).

How can I do this? People mentioned using mix() and lerp (which is a HLSL term). I want to adjust my opacity as it blends in, as the time changes.

[danikaze]

use the sf::Sprite::setColor(sf::Color(255, 255, 255, alpha)) to do it

Just control the alpha value interpolating it according to the desired time

[Predator106]

doesn't this set my sprite to be white?

[gyscos]

The sprite's "color" is only a filter, that is multiplied with its texture.

[masskiller]

Alternatively you could use a shader for it, but it's pretty much overkill for something that simple.