Function SDL_SetRenderTarget

deps/SDL2/src/render/SDL_render.c:1853–1930

}

int
SDL_SetRenderTarget(SDL_Renderer *renderer, SDL_Texture *texture)
{
    if (!SDL_RenderTargetSupported(renderer)) {
        return SDL_Unsupported();
    }
    if (texture == renderer->target) {
        /* Nothing to do! */
        return 0;
    }

    FlushRenderCommands(renderer);  /* time to send everything to the GPU! */

    /* texture == NULL is valid and means reset the target to the window */
    if (texture) {
        CHECK_TEXTURE_MAGIC(texture, -1);
        if (renderer != texture->renderer) {
            return SDL_SetError("Texture was not created with this renderer");
        }
        if (texture->access != SDL_TEXTUREACCESS_TARGET) {
            return SDL_SetError("Texture not created with SDL_TEXTUREACCESS_TARGET");
        }
        if (texture->native) {
            /* Always render to the native texture */
            texture = texture->native;
        }
    }

    SDL_LockMutex(renderer->target_mutex);

    if (texture && !renderer->target) {
        /* Make a backup of the viewport */
        renderer->viewport_backup = renderer->viewport;
        renderer->clip_rect_backup = renderer->clip_rect;
        renderer->clipping_enabled_backup = renderer->clipping_enabled;
        renderer->scale_backup = renderer->scale;
        renderer->logical_w_backup = renderer->logical_w;
        renderer->logical_h_backup = renderer->logical_h;
    }
    renderer->target = texture;

    if (renderer->SetRenderTarget(renderer, texture) < 0) {
        SDL_UnlockMutex(renderer->target_mutex);
        return -1;
    }

    if (texture) {
        renderer->viewport.x = 0;
        renderer->viewport.y = 0;
        renderer->viewport.w = texture->w;
        renderer->viewport.h = texture->h;
        SDL_zero(renderer->clip_rect);
        renderer->clipping_enabled = SDL_FALSE;
        renderer->scale.x = 1.0f;
        renderer->scale.y = 1.0f;
        renderer->logical_w = texture->w;
        renderer->logical_h = texture->h;
    } else {