Sorry, it is too many to fix them quickly now, so here is the list. Float to int conversions are quite slow. If you can't avoid them and are fine with rounding instead of truncation, you can use ftoi_r from utMath.h for better performance.
Code:
Warning   1   warning C4244: '=' : conversion from 'const float' to 'int', possible loss of data   c:\users\nicolas\desktop\mgottschlag-horde3dgui-4a4e495\extensions\gui\source\screenposition.h   120   
Warning   2   warning C4244: '=' : conversion from 'const float' to 'int', possible loss of data   c:\users\nicolas\desktop\mgottschlag-horde3dgui-4a4e495\extensions\gui\source\screenposition.h   121   
Warning   3   warning C4267: '=' : conversion from 'size_t' to 'unsigned int', possible loss of data   c:\users\nicolas\desktop\mgottschlag-horde3dgui-4a4e495\extensions\gui\source\guiskinresource.h   85   
Warning   4   warning C4267: 'initializing' : conversion from 'size_t' to 'unsigned int', possible loss of data   c:\users\nicolas\desktop\mgottschlag-horde3dgui-4a4e495\extensions\gui\source\guiskinresource.h   145   
Warning   5   warning C4267: 'initializing' : conversion from 'size_t' to 'unsigned int', possible loss of data   c:\users\nicolas\desktop\mgottschlag-horde3dgui-4a4e495\extensions\gui\source\guiskinresource.h   154   
Warning   6   warning C4800: 'int' : forcing value to bool 'true' or 'false' (performance warning)   c:\users\nicolas\desktop\mgottschlag-horde3dgui-4a4e495\extensions\gui\source\checkbox.cpp   135   
Warning   7   warning C4244: '=' : conversion from 'const float' to 'int', possible loss of data   c:\users\nicolas\desktop\mgottschlag-horde3dgui-4a4e495\extensions\gui\source\screenposition.h   120   
Warning   8   warning C4244: '=' : conversion from 'const float' to 'int', possible loss of data   c:\users\nicolas\desktop\mgottschlag-horde3dgui-4a4e495\extensions\gui\source\screenposition.h   121   
Warning   9   warning C4267: '=' : conversion from 'size_t' to 'unsigned int', possible loss of data   c:\users\nicolas\desktop\mgottschlag-horde3dgui-4a4e495\extensions\gui\source\guiskinresource.h   85   
Warning   10   warning C4267: 'initializing' : conversion from 'size_t' to 'unsigned int', possible loss of data   c:\users\nicolas\desktop\mgottschlag-horde3dgui-4a4e495\extensions\gui\source\guiskinresource.h   145   
Warning   11   warning C4267: 'initializing' : conversion from 'size_t' to 'unsigned int', possible loss of data   c:\users\nicolas\desktop\mgottschlag-horde3dgui-4a4e495\extensions\gui\source\guiskinresource.h   154   
Warning   12   warning C4800: 'int' : forcing value to bool 'true' or 'false' (performance warning)   c:\users\nicolas\desktop\mgottschlag-horde3dgui-4a4e495\extensions\gui\source\extension.cpp   334   
Warning   13   warning C4267: 'initializing' : conversion from 'size_t' to 'stbtt_int32', possible loss of data   c:\users\nicolas\desktop\mgottschlag-horde3dgui-4a4e495\extensions\gui\source\stb_truetype.h   1769   
Warning   14   warning C4244: '=' : conversion from 'float' to 'int', possible loss of data   c:\users\nicolas\desktop\mgottschlag-horde3dgui-4a4e495\extensions\gui\source\fontfileresource.cpp   162   
Warning   15   warning C4244: '=' : conversion from 'const float' to 'int', possible loss of data   c:\users\nicolas\desktop\mgottschlag-horde3dgui-4a4e495\extensions\gui\source\screenposition.h   120   
Warning   16   warning C4244: '=' : conversion from 'const float' to 'int', possible loss of data   c:\users\nicolas\desktop\mgottschlag-horde3dgui-4a4e495\extensions\gui\source\screenposition.h   121   
Warning   17   warning C4267: '=' : conversion from 'size_t' to 'unsigned int', possible loss of data   c:\users\nicolas\desktop\mgottschlag-horde3dgui-4a4e495\extensions\gui\source\guiskinresource.h   85   
Warning   18   warning C4267: 'initializing' : conversion from 'size_t' to 'unsigned int', possible loss of data   c:\users\nicolas\desktop\mgottschlag-horde3dgui-4a4e495\extensions\gui\source\guiskinresource.h   145   
Warning   19   warning C4267: 'initializing' : conversion from 'size_t' to 'unsigned int', possible loss of data   c:\users\nicolas\desktop\mgottschlag-horde3dgui-4a4e495\extensions\gui\source\guiskinresource.h   154   
Warning   20   warning C4244: '=' : conversion from 'const float' to 'int', possible loss of data   c:\users\nicolas\desktop\mgottschlag-horde3dgui-4a4e495\extensions\gui\source\screenposition.h   120   
Warning   21   warning C4244: '=' : conversion from 'const float' to 'int', possible loss of data   c:\users\nicolas\desktop\mgottschlag-horde3dgui-4a4e495\extensions\gui\source\screenposition.h   121   
Warning   22   warning C4267: '=' : conversion from 'size_t' to 'unsigned int', possible loss of data   c:\users\nicolas\desktop\mgottschlag-horde3dgui-4a4e495\extensions\gui\source\guiskinresource.h   85   
Warning   23   warning C4267: 'initializing' : conversion from 'size_t' to 'unsigned int', possible loss of data   c:\users\nicolas\desktop\mgottschlag-horde3dgui-4a4e495\extensions\gui\source\guiskinresource.h   145   
Warning   24   warning C4267: 'initializing' : conversion from 'size_t' to 'unsigned int', possible loss of data   c:\users\nicolas\desktop\mgottschlag-horde3dgui-4a4e495\extensions\gui\source\guiskinresource.h   154   
Warning   25   warning C4244: '=' : conversion from 'const float' to 'int', possible loss of data   c:\users\nicolas\desktop\mgottschlag-horde3dgui-4a4e495\extensions\gui\source\screenposition.h   120   
Warning   26   warning C4244: '=' : conversion from 'const float' to 'int', possible loss of data   c:\users\nicolas\desktop\mgottschlag-horde3dgui-4a4e495\extensions\gui\source\screenposition.h   121   
Warning   27   warning C4267: '=' : conversion from 'size_t' to 'unsigned int', possible loss of data   c:\users\nicolas\desktop\mgottschlag-horde3dgui-4a4e495\extensions\gui\source\guiskinresource.h   85   
Warning   28   warning C4267: 'initializing' : conversion from 'size_t' to 'unsigned int', possible loss of data   c:\users\nicolas\desktop\mgottschlag-horde3dgui-4a4e495\extensions\gui\source\guiskinresource.h   145   
Warning   29   warning C4267: 'initializing' : conversion from 'size_t' to 'unsigned int', possible loss of data   c:\users\nicolas\desktop\mgottschlag-horde3dgui-4a4e495\extensions\gui\source\guiskinresource.h   154   
Warning   30   warning C4267: 'initializing' : conversion from 'size_t' to 'unsigned int', possible loss of data   c:\users\nicolas\desktop\mgottschlag-horde3dgui-4a4e495\extensions\gui\source\gui.cpp   84   
Warning   31   warning C4267: 'initializing' : conversion from 'size_t' to 'unsigned int', possible loss of data   c:\users\nicolas\desktop\mgottschlag-horde3dgui-4a4e495\extensions\gui\source\gui.cpp   109   
Warning   32   warning C4244: 'argument' : conversion from 'int' to 'float', possible loss of data   c:\users\nicolas\desktop\mgottschlag-horde3dgui-4a4e495\extensions\gui\source\gui.cpp   150   
Warning   33   warning C4267: 'argument' : conversion from 'size_t' to 'Horde3DGUI::ElementHandle', possible loss of data   c:\users\nicolas\desktop\mgottschlag-horde3dgui-4a4e495\extensions\gui\source\gui.cpp   308   
Warning   34   warning C4267: 'return' : conversion from 'size_t' to 'Horde3DGUI::ElementHandle', possible loss of data   c:\users\nicolas\desktop\mgottschlag-horde3dgui-4a4e495\extensions\gui\source\gui.cpp   309   
Warning   35   warning C4244: 'argument' : conversion from 'float' to 'int', possible loss of data   c:\users\nicolas\desktop\mgottschlag-horde3dgui-4a4e495\extensions\gui\source\gui.cpp   383   
Warning   36   warning C4244: 'argument' : conversion from 'float' to 'int', possible loss of data   c:\users\nicolas\desktop\mgottschlag-horde3dgui-4a4e495\extensions\gui\source\gui.cpp   383   
Warning   37   warning C4244: 'argument' : conversion from 'float' to 'int', possible loss of data   c:\users\nicolas\desktop\mgottschlag-horde3dgui-4a4e495\extensions\gui\source\gui.cpp   385   
Warning   38   warning C4244: 'argument' : conversion from 'float' to 'int', possible loss of data   c:\users\nicolas\desktop\mgottschlag-horde3dgui-4a4e495\extensions\gui\source\gui.cpp   385   
Warning   39   warning C4244: 'argument' : conversion from 'float' to 'int', possible loss of data   c:\users\nicolas\desktop\mgottschlag-horde3dgui-4a4e495\extensions\gui\source\gui.cpp   390   
Warning   40   warning C4244: 'argument' : conversion from 'float' to 'int', possible loss of data   c:\users\nicolas\desktop\mgottschlag-horde3dgui-4a4e495\extensions\gui\source\gui.cpp   390   
Warning   41   warning C4244: 'argument' : conversion from 'float' to 'int', possible loss of data   c:\users\nicolas\desktop\mgottschlag-horde3dgui-4a4e495\extensions\gui\source\gui.cpp   391   
Warning   42   warning C4244: 'argument' : conversion from 'float' to 'int', possible loss of data   c:\users\nicolas\desktop\mgottschlag-horde3dgui-4a4e495\extensions\gui\source\gui.cpp   391   
Warning   43   warning C4244: 'argument' : conversion from 'float' to 'int', possible loss of data   c:\users\nicolas\desktop\mgottschlag-horde3dgui-4a4e495\extensions\gui\source\gui.cpp   406   
Warning   44   warning C4244: 'argument' : conversion from 'float' to 'int', possible loss of data   c:\users\nicolas\desktop\mgottschlag-horde3dgui-4a4e495\extensions\gui\source\gui.cpp   406   
Warning   45   warning C4244: 'argument' : conversion from 'float' to 'int', possible loss of data   c:\users\nicolas\desktop\mgottschlag-horde3dgui-4a4e495\extensions\gui\source\gui.cpp   408   
Warning   46   warning C4244: 'argument' : conversion from 'float' to 'int', possible loss of data   c:\users\nicolas\desktop\mgottschlag-horde3dgui-4a4e495\extensions\gui\source\gui.cpp   408   
Warning   47   warning C4018: '>' : signed/unsigned mismatch   c:\users\nicolas\desktop\mgottschlag-horde3dgui-4a4e495\extensions\gui\source\gui.cpp   454   
Warning   48   warning C4267: 'argument' : conversion from 'size_t' to 'uint32', possible loss of data   c:\users\nicolas\desktop\mgottschlag-horde3dgui-4a4e495\extensions\gui\source\gui.cpp   488   
Warning   49   warning C4244: 'argument' : conversion from 'float' to 'int', possible loss of data   c:\users\nicolas\desktop\mgottschlag-horde3dgui-4a4e495\extensions\gui\source\gui.cpp   509   
Warning   50   warning C4244: 'argument' : conversion from 'float' to 'int', possible loss of data   c:\users\nicolas\desktop\mgottschlag-horde3dgui-4a4e495\extensions\gui\source\gui.cpp   509   
Warning   51   warning C4244: '=' : conversion from 'double' to 'float', possible loss of data   c:\users\nicolas\desktop\mgottschlag-horde3dgui-4a4e495\extensions\gui\source\gui.cpp   534   
Warning   52   warning C4244: '=' : conversion from 'double' to 'float', possible loss of data   c:\users\nicolas\desktop\mgottschlag-horde3dgui-4a4e495\extensions\gui\source\gui.cpp   535   
Warning   53   warning C4244: '=' : conversion from 'double' to 'float', possible loss of data   c:\users\nicolas\desktop\mgottschlag-horde3dgui-4a4e495\extensions\gui\source\gui.cpp   539   
Warning   54   warning C4244: '=' : conversion from 'double' to 'float', possible loss of data   c:\users\nicolas\desktop\mgottschlag-horde3dgui-4a4e495\extensions\gui\source\gui.cpp   540   
Warning   55   warning C4244: '=' : conversion from 'double' to 'float', possible loss of data   c:\users\nicolas\desktop\mgottschlag-horde3dgui-4a4e495\extensions\gui\source\gui.cpp   544   
Warning   56   warning C4244: '=' : conversion from 'double' to 'float', possible loss of data   c:\users\nicolas\desktop\mgottschlag-horde3dgui-4a4e495\extensions\gui\source\gui.cpp   545   
Warning   57   warning C4244: '=' : conversion from 'double' to 'float', possible loss of data   c:\users\nicolas\desktop\mgottschlag-horde3dgui-4a4e495\extensions\gui\source\gui.cpp   549   
Warning   58   warning C4244: '=' : conversion from 'double' to 'float', possible loss of data   c:\users\nicolas\desktop\mgottschlag-horde3dgui-4a4e495\extensions\gui\source\gui.cpp   550   
Warning   59   warning C4244: '=' : conversion from 'const float' to 'int', possible loss of data   c:\users\nicolas\desktop\mgottschlag-horde3dgui-4a4e495\extensions\gui\source\screenposition.h   120   
Warning   60   warning C4244: '=' : conversion from 'const float' to 'int', possible loss of data   c:\users\nicolas\desktop\mgottschlag-horde3dgui-4a4e495\extensions\gui\source\screenposition.h   121   
Warning   61   warning C4267: '=' : conversion from 'size_t' to 'unsigned int', possible loss of data   c:\users\nicolas\desktop\mgottschlag-horde3dgui-4a4e495\extensions\gui\source\guiskinresource.h   85   
Warning   62   warning C4267: 'initializing' : conversion from 'size_t' to 'unsigned int', possible loss of data   c:\users\nicolas\desktop\mgottschlag-horde3dgui-4a4e495\extensions\gui\source\guiskinresource.h   145   
Warning   63   warning C4267: 'initializing' : conversion from 'size_t' to 'unsigned int', possible loss of data   c:\users\nicolas\desktop\mgottschlag-horde3dgui-4a4e495\extensions\gui\source\guiskinresource.h   154   
Warning   64   warning C4800: 'int' : forcing value to bool 'true' or 'false' (performance warning)   c:\users\nicolas\desktop\mgottschlag-horde3dgui-4a4e495\extensions\gui\source\guielement.cpp   166   
Warning   65   warning C4244: '=' : conversion from 'const float' to 'int', possible loss of data   c:\users\nicolas\desktop\mgottschlag-horde3dgui-4a4e495\extensions\gui\source\screenposition.h   120   
Warning   66   warning C4244: '=' : conversion from 'const float' to 'int', possible loss of data   c:\users\nicolas\desktop\mgottschlag-horde3dgui-4a4e495\extensions\gui\source\screenposition.h   121   
Warning   67   warning C4267: '=' : conversion from 'size_t' to 'unsigned int', possible loss of data   c:\users\nicolas\desktop\mgottschlag-horde3dgui-4a4e495\extensions\gui\source\guiskinresource.h   85   
Warning   68   warning C4267: 'initializing' : conversion from 'size_t' to 'unsigned int', possible loss of data   c:\users\nicolas\desktop\mgottschlag-horde3dgui-4a4e495\extensions\gui\source\guiskinresource.h   145   
Warning   69   warning C4267: 'initializing' : conversion from 'size_t' to 'unsigned int', possible loss of data   c:\users\nicolas\desktop\mgottschlag-horde3dgui-4a4e495\extensions\gui\source\guiskinresource.h   154   
Warning   70   warning C4244: '=' : conversion from 'const float' to 'int', possible loss of data   c:\users\nicolas\desktop\mgottschlag-horde3dgui-4a4e495\extensions\gui\source\screenposition.h   120   
Warning   71   warning C4244: '=' : conversion from 'const float' to 'int', possible loss of data   c:\users\nicolas\desktop\mgottschlag-horde3dgui-4a4e495\extensions\gui\source\screenposition.h   121   
Warning   72   warning C4267: '=' : conversion from 'size_t' to 'unsigned int', possible loss of data   c:\users\nicolas\desktop\mgottschlag-horde3dgui-4a4e495\extensions\gui\source\guiskinresource.h   85   
Warning   73   warning C4267: 'initializing' : conversion from 'size_t' to 'unsigned int', possible loss of data   c:\users\nicolas\desktop\mgottschlag-horde3dgui-4a4e495\extensions\gui\source\guiskinresource.h   145   
Warning   74   warning C4267: 'initializing' : conversion from 'size_t' to 'unsigned int', possible loss of data   c:\users\nicolas\desktop\mgottschlag-horde3dgui-4a4e495\extensions\gui\source\guiskinresource.h   154   
Warning   75   warning C4244: '=' : conversion from 'const float' to 'int', possible loss of data   c:\users\nicolas\desktop\mgottschlag-horde3dgui-4a4e495\extensions\gui\source\screenposition.h   120   
Warning   76   warning C4244: '=' : conversion from 'const float' to 'int', possible loss of data   c:\users\nicolas\desktop\mgottschlag-horde3dgui-4a4e495\extensions\gui\source\screenposition.h   121   
Warning   77   warning C4267: '=' : conversion from 'size_t' to 'unsigned int', possible loss of data   c:\users\nicolas\desktop\mgottschlag-horde3dgui-4a4e495\extensions\gui\source\guiskinresource.h   85   
Warning   78   warning C4267: 'initializing' : conversion from 'size_t' to 'unsigned int', possible loss of data   c:\users\nicolas\desktop\mgottschlag-horde3dgui-4a4e495\extensions\gui\source\guiskinresource.h   145   
Warning   79   warning C4267: 'initializing' : conversion from 'size_t' to 'unsigned int', possible loss of data   c:\users\nicolas\desktop\mgottschlag-horde3dgui-4a4e495\extensions\gui\source\guiskinresource.h   154   
Warning   80   warning C4244: 'argument' : conversion from 'double' to 'float', possible loss of data   c:\Users\Nicolas\Desktop\mgottschlag-Horde3DGUI-4a4e495\Extensions\GUI\Sample\app.cpp   355   
Warning   81   warning C4244: 'argument' : conversion from 'double' to 'float', possible loss of data   c:\Users\Nicolas\Desktop\mgottschlag-Horde3DGUI-4a4e495\Extensions\GUI\Sample\app.cpp   355   
Thanks for your feedback, that's always welcome.
phoenix64 wrote:
- Creating unique names for dynamically created resources (also added to the outside API for manually creating resources on the user side) like "internal_resource_124521".
We have something like that for resource cloning: if you specify an empty name string, a unique name is generated.  Something similar could make sense for addResource.
phoenix64 wrote:
- Texture mipmaps - can they somehow automatically produced? I didn't see any solution when I created the font texture, while I would expect it to automatically generate smaller mipmaps (that OpenGL variable is set somewhere for mipmap textures), I had to manually create all mipmaps for mipmapping to work properly. Probably my mistake, please someone help me there.
At the moment we are either loading them directly from dds or have GL generate them (GL_GENERATE_MIPMAP). But it makes definitely sense to have our own mip generation function in the future.
phoenix64 wrote:
- Extensions currently are not what they should be - they usually have to be compiled into the engine as horde3ds internals are usually hidden to the outer world. This is a good thing, but it greatly limits external plugins. I currently don't see any real workaround, to me exporting the internals and adding a version check to be used by plugins is the only thing that could work.
We had this discussion before and my standpoint is that extensions are not meant as plugins (more like OGL or phpbb extensions, not like Photoshop plugins) and for a development library I don't see any advantage from dynamically linking add-ins. Extensions as DLLs would be slower (less global optimizations and function inlining), have memory allocation issues (freeing memory allocated in another DLL does not work) and would be unsafer (users can exchange extensions for cheating). They would only be marginally easier to use but cause major headaches under Windows with how to expose all classes (you can't pass most STL containers across DLLs). And they would compromise the encapsulation and abstraction that we have now (the strict separation between internal and external interface). Did I miss anything? 

phoenix64 wrote:
Next on my TODO list are now finally edit boxes, modal widgets, list boxes, GUI layout resources (like scene graph resources).
Looking forward to that. Keep up the great work!