SDL2 Draw scene to texture. SDL2 RenderTexture like SFML - c++

Question

I've been developing a 2D Engine using SFML + ImGui.
The editor is rendered using ImGui and the scene window is a sf::RenderTexture where I draw the GameObjects and then is converted to ImGui::Image to render it in the editor.
Now I need to create a 3D Engine during this year in my Bachelor Degree but using SDL2 + ImGui and I want to recreate what I did with the 2D Engine.
I've managed to render the editor like I did in the 2D Engine using this Example that comes with ImGui.
But I don't know how to create an equivalent of sf::RenderTexture in SDL2, so I can draw the 3D scene there and convert it to ImGui::Image to show it in the editor.
If you can provide code will be better. And if you want me to provide any specific code tell me.

Answer 1

Here's my solution.
SDL2window::SDL2window()
{
SDL_Init(SDL_INIT_VIDEO);
window = SDL_CreateWindow(...);
renderer = SDL_CreateRenderer(window,...);
texture = SDL_CreateTexture(renderer,..., width, height);
// create another texture for your imgui window here
ImTexture = SDL_CreateTexture(renderer,..., tex_width, tex_height);
...
}
void SDL2window::update(Uint32 *framebuffer)
{
...
// update your main window is necessary
SDL_RenderCopyEx(renderer, texture, NULL, NULL, 0, 0, SDL_FLIP_VERTICAL);
// be care of the size of framebuffer
SDL_UpdateTexture(ImTexture, NULL, framebuffer, tex_width * sizeof(Uint32));
ImGui::Render();
ImGui_ImplSDLRenderer_RenderDrawData(ImGui::GetDrawData());
SDL_RenderPresent(renderer);
}
void SDL2window::MyImgui()
{
...
ImGui::Begin("My Texture");
ImGui::Image(ImTexture, ImVec2(tex_width, tex_height));
ImGui::End();
}
Then run MyImgui() in your main loop, it will work.
ImTexture Window
P.S. I like your SFML 2D engine's UI, it looks great.

Answer 2

Think you're looking for something like this:
// Create a render texture
SDL_Texture *target = SDL_CreateTexture(renderer, SDL_PIXELFORMAT_RGBA8888, SDL_TEXTUREACCESS_TARGET, width, height);
// Activate the render texture
SDL_SetRenderTarget(renderer, target);
// (Do your rendering here)
// Disable the render texture
SDL_SetRenderTarget(renderer, NULL);
// (Use the render texture)