async texture load causes flickering during initial frames

[KarateSnoopy]

Might be something I'm doing wrong but when I load the simple example I see a quick single flicker, and later after I move my mouse cursor over the dialog I see flicker.

I debugged it down to draw() internally creates an AsyncTexturePtr if its not yet cached based on if mMouseFocus is true or not. I fixed it by adding a loadTex() API to widget and doing basically:

void Widget::loadTex(SDL_Renderer* renderer)
{
    for (auto child : mChildren)
        if (child->visible())
            child->loadTex(renderer);
}

void Window::loadTex(SDL_Renderer* renderer)
{
    for (int i = 0; i < 2; i++)
    {
        bool mMouseFocusTemp = (i==0) ? true : false;
        int id = (mMouseFocusTemp ? 0x1 : 0);
        auto atx = std::find_if(_txs.begin(), _txs.end(), [id](AsyncTexturePtr p) { return p->id == id; });
        if (atx == _txs.end())
        {
            AsyncTexturePtr newtx = std::make_shared<AsyncTexture>(id);
            newtx->load(this, 0, 0, mMouseFocusTemp);
            _txs.push_back(newtx);
        }
    }

    Widget::loadTex(renderer);
}

Then calling this at startup.
This avoids any runtime flickering.
No idea if I'm on the right track to solving this, but fyi in case any one hits this.

[dalerank]

Thanks,will check up it

[Artem Kuskis]

Now it should be fixed. When components are loaded, they use previous texture for the new state until new one is loaded.

PS: There is a not nice visual effect when components are loading first time (there are no textures ready). But this is out of this task (new issue should be created).

[dalerank]

thanks