test-c::b

/*This source code copyrighted by Lazy Foo' Productions (2004-2009) and may not
be redestributed without written permission.*/
 
//The headers
#include "SDL/SDL.h"
#include "SDL/SDL_opengl.h"
 
//Screen attributes
const int SCREEN_WIDTH = 640;
const int SCREEN_HEIGHT = 480;
const int SCREEN_BPP = 32;
 
//The attributes of the square
const int SQUARE_SIZE = 20;
const int SQUARE_SPEED = 100;
 
//Event handler
SDL_Event event;
 
//Quit flag
bool    quit = false;
int     timer = 0;
 
//The square
class Square
{
private:
    //The offsets
    float x, y;
 
    //The velocity of the square
    float xVel, yVel;
 
    //The rotatioon
    float rVel, rotation;
 
public:
    //Initializes
    Square();
 
    //Handles key presses
    void handle_input();
 
    //Moves the square
    void move(Uint32 deltaTicks);
 
    //Shows the square on the screen
    void show();
};
 
bool init_GL()
{
    //Set clear color
    glClearColor( 0, 0, 0, 0 );
 
    //Set projection
    glMatrixMode( GL_PROJECTION );
    glLoadIdentity();
    glOrtho( 0, SCREEN_WIDTH, SCREEN_HEIGHT, 0, -1, 1 );
 
    //Initialize modelview matrix
    glMatrixMode( GL_MODELVIEW );
    glLoadIdentity();
 
    //If there was any errors
    if ( glGetError() != GL_NO_ERROR )
    {
        return false;
    }
 
    //If everything initialized
    return true;
}
 
bool init()
{
    //Initialize SDL
    if ( SDL_Init( SDL_INIT_EVERYTHING ) < 0 )
    {
        return false;
    }
 
    //Create Window
    if ( SDL_SetVideoMode( SCREEN_WIDTH, SCREEN_HEIGHT, SCREEN_BPP, SDL_OPENGL ) == NULL )
    {
        return false;
    }
 
    //Initialize OpenGL
    if ( init_GL() == false )
    {
        return false;
    }
 
    //Set caption
    SDL_WM_SetCaption( "OpenGL Test", NULL );
 
    return true;
}
 
void clean_up()
{
    //Quit SDL
    SDL_Quit();
}
 
Square::Square()
{
    //Initialize offsets
    x = 0;
    y = 0;
 
    //Initialize velocity
    xVel = 0;
    yVel = 0;
 
    rVel = 0;
    rotation = 0;
}
 
void Square::handle_input()
{
    //If a key was pressed
    if ( event.type == SDL_KEYDOWN )
    {
        //Adjust the velocity
        switch ( event.key.keysym.sym )
        {
        case SDLK_UP:
            yVel -= SQUARE_SPEED;
            break;
        case SDLK_DOWN:
            yVel += SQUARE_SPEED;
            break;
        case SDLK_LEFT:
            xVel -= SQUARE_SPEED;
            break;
        case SDLK_RIGHT:
            xVel += SQUARE_SPEED;
            break;
        case SDLK_w:
            rVel += 60;
            break;
        case SDLK_e:
            rVel -= 60;
            break;
        case SDLK_q:
            quit = true;
            break;
        }
    }
    //If a key was released
    else if ( event.type == SDL_KEYUP )
    {
        //Adjust the velocity
        switch ( event.key.keysym.sym )
        {
        case SDLK_UP:
            yVel += SQUARE_SPEED;
            break;
        case SDLK_DOWN:
            yVel -= SQUARE_SPEED;
            break;
        case SDLK_LEFT:
            xVel += SQUARE_SPEED;
            break;
        case SDLK_RIGHT:
            xVel -= SQUARE_SPEED;
            break;
        case SDLK_w:
            rVel -= 60;
            break;
        case SDLK_e:
            rVel += 60;
            break;
        }
    }
}
 
void Square::move(Uint32 deltaTicks)
{
    //Move the square left or right
    x += xVel* ( deltaTicks / 1000.f );
 
    //If the square went too far
    if ( ( x < 0 ) || ( x + SQUARE_SIZE > SCREEN_WIDTH ) )
    {
        //Move back
        x -= xVel* ( deltaTicks / 1000.f );
    }
 
    //Move the square up or down
    y += yVel* ( deltaTicks / 1000.f );
 
    //If the square went too far
    if ( ( y < 0 ) || ( y + SQUARE_SIZE > SCREEN_HEIGHT ) )
    {
        //Move back
        y -= yVel* ( deltaTicks / 1000.f );
    }
 
    rotation += rVel* ( deltaTicks / 1000.f );
}
 
void Square::show()
{
    //Move to offset
    glTranslatef( x, y, 0 );
    glRotatef( rotation, 0, 0, 1);
 
    //Start quad
    glBegin( GL_QUADS );
    {
        //Set color to white
        glColor4f( 1.0, 1.0, 1.0, 1.0 );
 
        //Draw square
        glVertex3f( -SQUARE_SIZE, -SQUARE_SIZE, 0 );
        glVertex3f(  SQUARE_SIZE, -SQUARE_SIZE, 0 );
        glVertex3f(  SQUARE_SIZE,  SQUARE_SIZE, 0 );
        glVertex3f( -SQUARE_SIZE,  SQUARE_SIZE, 0 );
    }
    //End quad
    glEnd();
 
    //Reset
    glLoadIdentity();
}
 
 
 
int main ( int argc, char *argv[] )
{
    //Initialize
    if ( init() == false )
    {
        return 1;
    }
 
    //Our square object
    Square square;
 
 
    timer = SDL_GetTicks();
 
    //Wait for user exit
    while ( quit == false )
    {
        //While there are events to handle
        while ( SDL_PollEvent( &event ) )
        {
            //Handle key presses
            square.handle_input();
 
            if ( event.type == SDL_QUIT )
            {
                quit = true;
            }
        }
 
        //Move the square
        square.move( SDL_GetTicks() - timer );
        timer = SDL_GetTicks();
 
        //Clear the screen
        glClear( GL_COLOR_BUFFER_BIT );
 
        //Show the square
        square.show();
 
        //Update screen
        SDL_GL_SwapBuffers();
    }
 
    //Clean up
    clean_up();
 
    return 0;
}