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1

C / sfCircleShape_move

« on: March 11, 2023, 03:47:37 pm »

Draw a circle, trying to move it.
The sfCircleShape_move function must move the object by the given offset. But the movement goes along the coordinates specified in the parameters of this function, or a generally incomprehensible result

        sfCircleShape *circle = sfCircleShape_create();
        sfCircleShape_setRadius(circle, 20 - 3);
        sfCircleShape_setOutlineThickness(circle, 3);
        sfCircleShape_setOutlineColor(circle, sfBlack);
        sfCircleShape_setFillColor(circle, sfWhite);

        sfVector2f CirclePosOld = {800 / 2, 600 / 2};
        sfCircleShape_setPosition(circle, CirclePosOld) ;

        sfVector2f CirclePosNew = { 50, 50 } ;
        sfCircleShape_move(circle, CirclePosNew );

        float fPosOld_x = CirclePosOld.x ;
        float fPosNew_x = sfCircleShape_getPosition(circle).x ;

        float fPosOld_y = CirclePosOld.y ;
        float fPosNew_y = sfCircleShape_getPosition(circle).y ;

 

Result:


Works:

        sfVector2f CirclePosOld = {800 / 2, 600 / 2};
        sfCircleShape_setPosition(circle, CirclePosOld) ;
        sfVector2f CirclePosNew = {CirclePosOld.x + 50, CirclePosOld.y + 50 } ;
        sfCircleShape_setPosition(circle, CirclePosNew) ;
 

It feels like I'm the only one with the problems.

2

C / How sfClock_getElapsedTime() works ?

« on: March 08, 2023, 08:21:44 am »

I don't understand how the function works. It feels like too little time has passed since the clock was updated, and therefore the counter value is always 0.

       
        float time = sfTime_asSeconds( sfClock_restart(clock) ) ;
        delta_time = sfClock_getElapsedTime(clock) ;
        timer += sfTime_asMicroseconds(delta_time);
 

But timer always 0.

Also:

CSFML:

        sfTime PreviousTime = sfTime_Zero ;
        sfTime  CurrentTime = sfClock_getElapsedTime(clock) ;
        sfTime  FrameTime = CurrentTime - PreviousTime ;
        PreviousTime = CurrentTime ;
        float DeltaTime = sfTime_asMicroseconds(FrameTime) ;
 

Error: [bcc32 Error] main.cpp(76): E2093 'operator-' not implemented in type 'sfTime' for arguments of the same type

SFML:

        sf::Clock clock;
        sf::Time previousTime{ sf::Time::Zero };
        const sf::Time currentTime{ clock.getElapsedTime() };
        const sf::Time frameTime{ currentTime - previousTime };
        previousTime = currentTime;
        const float dt{ frameTime.asSeconds() };
 

Compiles without errors.

What am I doing wrong?

Upd.

Works:

        sfClock *clock = sfClock_create();
        sfTime PreviousTime = sfTime_Zero ;
        sfTime  CurrentTime = sfClock_getElapsedTime(clock) ;
        float DeltaTime = sfTime_asMicroseconds(CurrentTime) -  sfTime_asMicroseconds(PreviousTime) ;
        PreviousTime = CurrentTime ;
 

The problem with the timer occurs if 2 clock sources are declared.

Not works:

        sfClock *clock = sfClock_create();
        sfClock *clock2 = sfClock_create();
        sfTime PreviousTime = sfTime_Zero ;
        sfTime  CurrentTime = sfClock_getElapsedTime(clock) ;
        float DeltaTime = sfTime_asMicroseconds(CurrentTime) -  sfTime_asMicroseconds(PreviousTime) ;
        PreviousTime = CurrentTime ;
 

This is a quest. It's a pity there is no description for CSFML.

3

C / sfTime allways have zero value

« on: March 05, 2023, 04:55:57 pm »

I assign a value to a variable ways, but in the debugger the value is always 0.
In theory, everything should work. Maybe I'm doing something wrong?

sfTime time1 = sfSeconds(0.1f) ;
sfTime time2 = sfMilliseconds(100000);

CSFML 2.5.1
C++ Builder 11.3