[Tutorial] Drawing Lines with the engine

[d0h!]

hi peoples, here is a method to draw a line with the engine.
you will lose some fps on this method.

PHP Code:

float getAngle(DoublePoint self, DoublePoint target)
{
   float dx = target[0] - self[0]; //calculate the distance to the target on the x-axis
   float dy = target[1] - self[1]; //calculate the distance to the target on the y-axis
        
   float dist = sqrt(pow(dx, 2) + pow(dy, 2)); //calculate distance to the target by using pythagoras
   float dangle;      
        
    if (dy < 0) dangle = (M_PI * 2) - (acos(dx/dist));
    else dangle = acos(dx/dist); //calculate the angle
           
    return dangle;        
} 


PHP Code:

void cEngine::DrawLines()
{
    float x, y;
    float Screen[2];    
        DoublePoint dpLocal = {Refdef->Width/2, Refdef->Height};    
    
    for(int i=0; i<MAX_PLAYERS; i++)
    {
        CEntity* pEnt = getValidEnt();

        if(WorldToScreen(pEnt->vOrig, &Screen)
        {            
            DoublePoint dpTarget = {Screen[0], Screen[1]};
            float fAngle = getAngle(dpLocal, dpTarget);
            
            if(!fAngle)
                continue;        

            float fDist = getDist();        
            int size = fdist/lineDist;            

            for(int i=0; i<size; i++)
            {
                if(i == 0)
                {
                    x = (dpLocal[0] + lineDist * cos(fAngle));
                            y = (dpLocal[1] + lineDist * sin(fAngle));
                    CG_DrawPic(x, y, 10, 10, tRed, RegisterShader("compassping_enemyfiring", 7));                    
                }else
                                 {                
                        x = (x + lineDist * cos(fAngle));
                                y = (y + lineDist * sin(fAngle));
                        CG_DrawPic(x, y, 10, 10, tRed, RegisterShader("compassping_enemyfiring", 7));
                                 }
            }    
        }
    }
} 


by editing the linedist you can also make it look like a real line, or you can use other shaders

Credits:
cardoow