ColorEdit4: Show preview colors in sliders?

[jeffkdev]

Version/Branch of Dear ImGui:

Version: Dear ImGui 1.79 Branch: master

My Issue/Question:

Is there interest in expanding the color picker so it has the option to show preview colors in the RGB and/or HSV sliders?

Screenshots/Video Use case:

Working prototype:

Standalone, minimal, complete and verifiable example: I only implemented this locally for RGB sliders. So probably would need to do something different for HSV:

IMGUI_API bool          SliderScalarGradient(const char* label, ImGuiDataType data_type, void* p_data, const void* p_min, const void* p_max, const ImU32 color_start, const ImU32 color_end, const char* format = NULL, ImGuiSliderFlags flags = 0);

I made calling this new function the default behavior in my ColorEdit4, but it could be made optional by using one of the few remaining ImGuiColorEditFlags_. Feel free to close if this is something best left outside the main library.

[ocornut]

It would probably be interesting to have this as an option, but seeing we don't have proper standardized support for sRGB/Linear the preview may be incorrect unless manually tesselated (the equivalent HSV preview would need manual tesselation either way). If you still have the code around may be nice posting.

[jeffkdev]

Sure, here is a gist of the code along with some TODO items:

https://gist.github.com/jeffkdev/ea8458af09c40271b7ba5c62cc8a3a78

ADMIN added a copy: ea8458af09c40271b7ba5c62cc8a3a78-491f6d170f0f62abadd42e63e4f0867e5a1fa508.zip