Topics

1

General / Static Library Linking

« on: April 01, 2010, 10:11:45 pm »

I'm trying to create a Static Library (.a) based on SFML with Code::Blocks.  I've created a simple library to test, but even that isn't working.

Here is the code of the library:

Code: [Select]


// File Test.h
#ifndef TEST_H
#define TEST_H

class Test
{
    public:
        Test( );
        void Function( );
};

#endif

// File Test.cpp
#include <iostream>
#include <SFML/System.hpp>
#include "Test.h"

Test::Test( )
{
    std::cout << "Test::Test( ) " << sf::Randomizer::Random( 0, 10 ) << std::endl;
}

void Test::Function( )
{
    std::cout << "Test::Function( ) " << sf::Randomizer::Random( 50, 100 ) << std::endl;
}


I then add libsfml-system-s.a into the library using ar.

Code: [Select]


ar x libsfml-system-s.a
ar rs libStaticSFMLTest.a *.o

I'm pretty sure it works, since the file size of the library increases, after adding SFML System.

When I try to compile a project using the new library, I get linker errors:

Code: [Select]


C:\Documents and Settings\Eternal Warrior\My Documents\CodeBlocksProjects\StaticSFMLTest\libStaticSFMLTest.a(Test.o):Test.cpp:(.text+0x2f)||undefined reference to `sf::Randomizer::Random(int, int)'|


I'm sure I'm doing something wrong, but I can't figure out what.  Any help is appreciated.

2

General / Delta Time and Jumping

« on: March 28, 2010, 05:34:49 am »

Hello.  I'm currently working on a platform game, and I'm using Delta timing for synchronization.  The problem is that my computer is rather slow, and lags often so every time a lag spike occurs, the player jumps higher than normal (Delta time compensation).  Is there any way I can prevent this, or is it just an inherent flaw of using Delta time?  Thanks.

Edit: Here's my code for reference

Main game loop:

Code: [Select]


player.Input( window.GetInput( ) );

deltaTime = window.GetFrameTime( ) * 60.0f; // Synchronize to 60 FPS
player.Update( deltaTime );


Player definition:

Code: [Select]


void Player::Input( const sf::Input& input )
{
    if( input.IsKeyDown( sf::Key::W ) )
    {
        if( y >= 448.0f )
        {
            verticalSpeed = -6.0f;
        }
    }
}

void Player::Update( float deltaTime )
{
    y += verticalSpeed * deltaTime;

    if( y >= 448.0f )
    {
        verticalSpeed = 0.0f;
        y = 448.0f;
    }

    if( y < 448.0f ) verticalSpeed += 0.1f;

    sprite.SetPosition( x, y );
}


3

Graphics / Load Font from Memory

« on: December 12, 2009, 04:40:51 am »

Hi, I'm trying to load a font from memory, because I plan to use a custom font file type in the future already used in my engine.

Right now, though, I'm just trying to load a file into a std::string, and then use font.LoadFromFile( ) to get the font.

This is the code I'm using:

Code: [Select]


std::string& OpenFile( std::string filename )
{
    int length;
    char* buffer;
    std::string* encrypted;

    std::ifstream file;
    file.open( filename.c_str( ), std::ios::binary | std::ios::ate );

    file.seekg( 0, std::ios::end );
    length = file.tellg( );
    file.seekg( 0, std::ios::beg );

    buffer = new char[ length ];

    file.read( buffer, length );
    file.close( );

    *encrypted = buffer;

    delete( buffer );

    return( *encrypted );
}


And this is the code I use to load the font:

Code: [Select]


sf::Font font;

std::string file = OpenFile( "Arial.ttf" );
font.LoadFromMemory( file.c_str( ), file.length( ) );


The file is valid, and the error I get from SFML is an invalid stream operation.

Any help is appreciated.