Starting with Unreal Engine 2 UnrealScript classes/structs support cpptext(prefix for C++text) block declarations. The cpptext is a block declaration where programmers can implement C++ functions it also can only be declared in native classes, any text within this block will then be exported to the corresponding native class prefixClasses.h
file when compiled.
Note: structs use cppstruct instead and starting with Unreal Engine 3 it was renamed to structcpptext.
Example
Taken from Canvas.uc
.
cpptext { //... void DrawTile(UTexture* Tex, FLOAT X, FLOAT Y, FLOAT XL, FLOAT YL, FLOAT U, FLOAT V, FLOAT UL, FLOAT VL, const FLinearColor& Color); //... }
This exports DrawTile
into class UCanvas
in file EngineClasses.h
e.g.
class UCanvas : public UObject { //... void DrawTile(UTexture* Tex, FLOAT X, FLOAT Y, FLOAT XL, FLOAT YL, FLOAT U, FLOAT V, FLOAT UL, FLOAT VL, const FLinearColor& Color); //... };
Why use cpptext over native functions
Even though you can just make a native UnrealScript function that will also get exported the same way but then translated to C++, it doesn't support all formats thus in that case the native coder can implement functions that cannot be declared in UnrealScript but also because the native coder might not want you to be able to call a function from within UnrealScript.
See also
- Native Coding
- Native-only classes
Declarations | Preprocessor • Classes • Interfaces • Cpptext • Constants • Enums • Structs • Variables (Metadata) • Replication block • Operators • Delegates • Functions • States • Defaultproperties (Subobjects) |
---|---|
Types | bool • byte • float • int • name • string • Object • Class • Enums • Structs (Vector ⋅ Rotator ⋅ Quat ⋅ Color) • Static arrays • Dynamic arrays • Delegates • Typecasting |
Literals | Boolean • Float • Integer • Names • Objects (None ⋅ Self) • Vectors • Rotators • Strings |
Flow | GoTo • If • Assert • Return • Stop • Switch • While • Do...Until • For • ForEach • Break • Continue |
Specifiers | Super • Global • Static • Default • Const |
UnrealScript | Syntax • .UC • .UCI • .UPKG • Comments • #directives • Native |