On Screen Display

[Porsche]

DrawText() doesn't seem to be working properly. I keep getting the following error:

 

error C2665: 'DrawTextW' : none of the 2 overloads could convert all the argument types

 

I've tried these two implementations:

 

1.

// in struct creation
string output;

//in default constructor
output = "Default Setup";

// in game loop
DrawText(32,32,aiONE->output);

 

2.

// Before game loop
std::string text = "Hello, world!";

// in Game loop
DrawText(0, 0, text.c_str());

 

Just trying to get it to display a variable defined earlier. I am obviously not handling the string right in some way.

 

This works of course:

 

DrawText(0, 0, "Hello World");

 

 

Also, what's the easiest way to display FPS?

 

 

-Thanks,

Porsche

[Qbound]

Hi Porsche,

 

take a look into the thread with the scrennshot command http://leadwerks.com/werkspace/index.php?/topic/293-take-screenshots/

there you have the sprintf command. But the easiest way to display FPS is with DrawText( 10, 10, "FPS: %f", FPS() );

and you have to convert (in your code above) your text.c_str() to (str) like this (str)text.c_str();

 

cu

Oliver

[DaDonik]

The DrawTextA and DrawTextW are windows functions (or C++...).

 

to make your command work, you need to cast the const char the c_str() returns

into a char*.

 

DrawText(0, 0, (char*)text.c_str());

[Canardia]

You can display STL strings in 2 ways:

#include "engine.h"
#include <string>
using namespace std;

...

int main()
{
string s="Hello World!";

...

DrawText(1,14,(str)s.c_str());
DrawText(1,28,"%s",s.c_str());
}

[Porsche]

Thanks to both of you. =]

[Masterxilo]

You can display STL strings in 2 ways:

...

While

DrawText(1,14,(str)s.c_str());

is the bad one.

[Porsche]

While

DrawText(1,14,(str)s.c_str());

is the bad one.

 

Any reason why it's worse than the other?

[Masterxilo]

Yes there is.

Imagine s is "Hello %f %x %s there!, how are you?".

sprintf (just as printf) would look for three parameters while you passed none. I would mess up your memory.

[TylerH]

str is just a typedef for char* isn't it? So a bit redundant to explicitly cast to char*, besides, what if you have dangling pointer and non-mutable access to that particular string?

 

You should use const_cast<char*>(s.c_str()) to be 100% safe, though what Masterxilo stated about the memory problems still apply.

[Canardia]

str is "the null terminated C string which LE uses", it's not the same as char*, although it might be currently similar.

 

At the moment it's also unsigned char*, since not all C++ compilers work with signed chars for strings. In future str might be also unsigned int*, if there are some multibyte string functions. The whole point of declaring your own types is that your code stays compatible with all current and future OS and hardware.

 

LE uses also flt instead of float (which is used as "the floating point resolution which LE uses for GPU floating point numbers"), since GPUs might soon be all 64-bit, so you don't have to change any code then either, as the headers will then have flt defined as double.

Note that for pure mathematical functions you should always use double, as it's about twice as fast as float. bool is also twice as fast as int.