Added DearIMGUI bindings to AngelScript

[ohlidalp]

Terrain scripts can now draw arbitrary GUI using DearIMGUI. Can be useful for tutorials, missions, minigames, diagnostic views, custom minimaps, anything.

Example terrain:
workshop.zip

[tritonas00]

A warning:

In file included from /home/babis/Downloads/ror-dependencies/rigs-of-rods/source/main/phc.h:37,
                 from /home/babis/Downloads/ror-dependencies/rigs-of-rods/source/main/CMakeFiles/RoR.dir/cmake_pch.hxx:5,
                 from <command-line>:
/home/babis/Downloads/ror-dependencies/rigs-of-rods/source/main/scripting/ImGuiAngelscript.cpp: In lambda function:
/home/babis/Downloads/ror-dependencies/rigs-of-rods/source/main/scripting/ImGuiAngelscript.cpp:173:22: warning: cast to pointer from integer of different size [-Wint-to-pointer-cast]
  173 |         ImGui::Image((ImTextureID)u, ImVec2(v.x, v.y));

Works fine though, nice one!

[ohlidalp]

Turns out I have the same warning:

4>C:\Users\Petr\source\rigs-of-rods\source\main\scripting\ImGuiAngelscript.cpp(174,1): warning C4312: 'type cast': conversion from 'unsigned int' to 'ImTextureID' of greater size

Fixed by merging more old "Angelhud" code :)