FPS Problem, pls help

Im making my own DX8 engine in C++ but I have a small problem in FPS.
You see, when I made my DX8 engine in VB6, I used to get 1800+ fps in an empty window, with just begining/ending the scene. Now, in C++ I get 400 the most!! I use the same FPS code. Somebody help pls!

Post the part of the code where you determine the fps, sounds like the VB code is wrong.

No, the code is correct. Ive checked it many times. Something is wrong with the C++ version. My code is a regular fps counter, im sure it works. Any ideas? Also, my fullscreen app is 2x or even 3x faster than the windowed one.

How are we suppose to know without seeing the code you used? You say something is wrong with the c++ version, try posting that version and then someone could help you. You can't just say that something is wrong, without posting code or giving a little more information.

>No, the code is correct. Ive checked it many times.

what are you system specs?

>Also, my fullscreen app is 2x or even 3x faster than the windowed one.

as it very well should be.

Ok, this is my code:

Code:

---

RTTimeServer::RTTimeServer()
{
        //Initialize the timer.
        if (FAILED(QueryPerformanceFrequency((LARGE_INTEGER*)&g->TimeAndFPS.nFreq)))
                g->TimeAndFPS.mInited = false;

        g->TimeAndFPS.mInited = true;
       
}

int RTTimeServer::GetFPS()
{
        if (!g->TimeAndFPS.mInited)
                return 0;

        INT64 ThisCount=0;
        INT64 Diff=0;
       
        QueryPerformanceCounter((LARGE_INTEGER*)&ThisCount);
        g->TimeAndFPS.mFrameCount++;
        Diff = ThisCount - g->TimeAndFPS.lTickCount;
        if (Diff >= g->TimeAndFPS.nFreq)
        {
                g->TimeAndFPS.mFrameRate = g->TimeAndFPS.mFrameCount;
                g->TimeAndFPS.mFrameCount =0;
                g->TimeAndFPS.lTickCount = ThisCount;
        }
        return (g->TimeAndFPS.mFrameRate);
}

---

Im using VC++6. My system is PIII 500, 256 RAM, GF2 MX400 and WinXP with the latest nvidia detonators.

Sorry for my n00byness, but thats in C++ write?

I think this is your problem you need to set

g->TimeAndFPS.mFrameCount and g->mFrameRate to 0 and you need to set

g->TimeAndFPS.lTickCount to
QueryPerformanceCounter((LARGE_INTEGER*)&lTickCoun t);
in the constructor.
Otherwise g->TimeAndFPS.lTickCount has garbage and when you call getFPS Diff = ThisCount - g->TimeAndFPS.lTickCount;
Diff will also become garbage.

Oh yes, you were right about the QueryPerfCounter in the constructor, but now my fps is even lower. This is more correct though I think cause it subtracts the correct time (lTickCount) which was initated in the constructor. But i should get around 2000 fps in windowed mode, right? Like i did in VB6. Also, if I dont clear the screen and perform no DX8 operations, I get around 35000 fps!

Here's some code that I wrote that gives me a
fps about 30. I would be really suprised if you could
get your actual game to run at 2000 fps since most games run at 50 or less fps.

Code:

---

#include <windows.h>
#include <iostream>
using std::cout;
using std::endl;

class Timer {
public:
        enum { INVALID_FPS = 0 };

        Timer() : frame_count(0), fps(INVALID_FPS), invalid_timer(false)
        {
                if (FAILED(QueryPerformanceFrequency((LARGE_INTEGER*)&freq)))
                        invalid_timer = true;

                QueryPerformanceCounter((LARGE_INTEGER*)&tick_count);
        }

        INT64 get_freq() const { return freq; }

        // should be called every frame
        void set_frame()
        {
                INT64 count_now;
                INT64 diff;

                QueryPerformanceCounter((LARGE_INTEGER*)&count_now);
                frame_count++;
                diff = count_now - tick_count;
                if (diff > get_freq()) {
                        fps = frame_count;
                        tick_count = count_now;
                        frame_count = 0;
                }
        }

        int get_fps() const
        {
                return fps;
        }

        bool invalid() const { return invalid_timer;  }
        bool fps_invalid() const { return fps == INVALID_FPS; }
private:
        INT64 tick_count;
        INT64 freq;
        int frame_count;
        int fps;
        bool invalid_timer;
};


int main()
{       
        int fps;
        DWORD start_time;
        Timer timer;
        for(;;) {
                start_time = GetTickCount();


                if (!timer.invalid()) {
                        timer.set_frame();
                        if (!timer.fps_invalid()) {
                                fps = timer.get_fps();
                                cout << "fps = " << fps << endl;
                        }
                }

                while(GetTickCount() - start_time < 33)
                        continue;
        }


        return 0;
}

---

Geforce 2 MX400 should run around 30-60 FPS in a 3D game.

ok first a window drawing nothing on a mid ro high range system will run at around 450 - 600 fps in windowed and 900 - 1800 in full screen...

but when you start drawing things his will start to drop off significantly.

>But i should get around 2000 fps in windowed mode, right?

no, what are your system specs? what resolution are you drawing in?

if you drawing at 320 - 280 you probably should get 2000 fps in windowed, anything in higher res most likely will not.

>Also, if I dont clear the screen and perform no DX8 operations, I get around 35000 fps!

thats cause you doing nothing.