Function ImFontAtlasTextureAdd

src/imgui/imgui_draw.cpp:3943–3978

Create a new texture, discard previous one

// Create a new texture, discard previous one
ImTextureData* ImFontAtlasTextureAdd(ImFontAtlas* atlas, int w, int h)
{
    ImTextureData* old_tex = atlas->TexData;
    ImTextureData* new_tex;

    // FIXME: Cannot reuse texture because old UV may have been used already (unless we remap UV).
    /*if (old_tex != NULL && old_tex->Status == ImTextureStatus_WantCreate)
    {
        // Reuse texture not yet used by backend.
        IM_ASSERT(old_tex->TexID == ImTextureID_Invalid && old_tex->BackendUserData == NULL);
        old_tex->DestroyPixels();
        old_tex->Updates.clear();
        new_tex = old_tex;
        old_tex = NULL;
    }
    else*/
    {
        // Add new
        new_tex = IM_NEW(ImTextureData)();
        new_tex->UniqueID = atlas->TexNextUniqueID++;
        atlas->TexList.push_back(new_tex);
    }
    if (old_tex != NULL)
    {
        // Queue old as to destroy next frame
        old_tex->WantDestroyNextFrame = true;
        IM_ASSERT(old_tex->Status == ImTextureStatus_OK || old_tex->Status == ImTextureStatus_WantCreate || old_tex->Status == ImTextureStatus_WantUpdates);
    }

    new_tex->Create(atlas->TexDesiredFormat, w, h);
    atlas->TexIsBuilt = false;

    ImFontAtlasBuildSetTexture(atlas, new_tex);

    return new_tex;
}

#if 0
#define STB_IMAGE_WRITE_IMPLEMENTATION