Developers: Do you want to create a Nutcracker 3.0 effect?

[smeighan]

Are you a C++ developer? If not, skip the rest of this post.

Want to make a new cool effect for Nutcracker?

 

I have written 3 tutorials to help you. Remember that I am not a C++ programmer, now a windows developer. I have learned enough to know how to add new effects to the Nutcracker code that Matt wrote.

 

Part1: Setting up your machine to be able to build the xLights project file.

You need just 3 parts to build xlights/nutcracker, Code::Blocks, mingw and wxWidgets.

https://vimeo.com/61068045

 

 

Part2: Now that you can compile the current copy of xLights, we need to add our new effect into the wxWidgets gui. After this tutorial you should know how to add a pnale, a slider bar and stuff.

https://vimeo.com/61068046

 

Part3: Now that we have added the gui stuff, lets actually modify the code to make an effect. We will use the spirograph effect as our straw man.

https://vimeo.com/61153242

 

The source files can be downloaded from https://github.com/smeighan/nutcracker_c

 

in the nutcracker/docs directory is a document, "How_To_Add_effects_To_Nutcracker.pdf". This is referenced in the 3rd tutorial.

 

Check out the code, build a project, add an effect.

 

 

Here are two examples of the C++ code that makes effects you have used. You will notice they are not that complicated.

 

First the Twinkle effect

 

void RgbEffects::RenderTwinkle(int Count)

{

 

    int x,y,i,i7,r,ColorIdx;

    int lights = (BufferHt*BufferWi)*(Count/100.0); // Count is in range of 1-100 from slider bar

    int step=BufferHt*BufferWi/lights;

    if(step<1) step=1;

    srand(1); // always have the same random numbers for each frame (state)

    wxImage::HSVValue hsv; //   we will define an hsv color model. The RGB colot model would have been "wxColour color;"

 

    size_t colorcnt=GetColorCount();

 

    i=0;

 

    for (y=0; y<BufferHt; y++) // For my 20x120 megatree, BufferHt=120

    {

        for (x=0; x<BufferWi; x++) // BufferWi=20 in the above example

        {

            i++;

            if(i%step==0) // Should we draw a light?

            {

                // Yes, so now decide on what color it should be

 

                ColorIdx=rand() % colorcnt; // Select random numbers from 0 up to number of colors the user has checked. 0-5 if 6 boxes checked

                palette.GetHSV(ColorIdx, hsv); // Now go and get the hsv value for this ColorIdx

                i7=(state/4+rand())%9; // Our twinkle is 9 steps. 4 ramping up, 5th at full brightness and then 4 more ramping down

                //  Note that we are adding state to this calculation, this causes a different blink rate for each light

 

                if(i7==0 || i7==8)  hsv.value = 0.1;

                if(i7==1 || i7==7)  hsv.value = 0.3;

                if(i7==2 || i7==6)  hsv.value = 0.5;

                if(i7==3 || i7==5)  hsv.value = 0.7;

                if(i7==4  )  hsv.value = 1.0;

                //  we left the Hue and Saturation alone, we are just modifiying the Brightness Value

                SetPixel(x,y,hsv); // Turn pixel on

            }

        }

    }

}

 

 

The second effect is Spirograph

void RgbEffects::RenderSpirograph(int int_R, int int_r, int int_d)

{

#define PI 3.14159265

    int i,x,y,k,xc,yc,ColorIdx;

    int mod1440,state360;

    srand(1);

    float R,r,d,d_orig,t;

    wxImage::HSVValue hsv,hsv0,hsv1; //   we will define an hsv color model. The RGB colot model would have been "wxColour color;"

    size_t colorcnt=GetColorCount();

 

    xc= (int)(BufferWi/2); // 20x100 flex strips with 2 fols per strip = 40x50

    yc= (int)(BufferHt/2);

    R=xc*(int_R/100.0);   //  Radius of the large circle just fits in the width of model

    r=xc*(int_r/100.0); // start little circle at 1/4 of max width

    if(r>R) r=R;

    d=xc*(int_d/100.0);

    ColorIdx=rand() % colorcnt; // Select random numbers from 0 up to number of colors the user has checked. 0-5 if 6 boxes checked

    palette.GetHSV(ColorIdx, hsv); // Now go and get the hsv value for this ColorIdx

    palette.GetHSV(0, hsv0);

    palette.GetHSV(1, hsv1);

//

//    A hypotrochoid is a roulette traced by a point attached to a circle of radius r rolling around the inside of a fixed circle of radius R, where the point is a distance d from the center of the interior circle.

//The parametric equations for a hypotrochoid are:[citation needed]

//

//  more info: http://en.wikipedia.org/wiki/Hypotrochoid

//

//x(t) = (R-r) * cos t + d*cos ((R-r/r)*t);

//y(t) = (R-r) * sin t + d*sin ((R-r/r)*t);

 

    mod1440=state%1440;

    state360 = state%360;

    d_orig=d;

    for(i=1; i<=360; i++)

    {

        d = (int)(d_orig+state/2)%100;

        t = (i+mod1440)*PI/180;

        x = (R-r) * cos (t) + d*cos ((R-r/r)*t) + xc;

        y = (R-r) * sin (t) + d*sin ((R-r/r)*t) + yc;

        if(i<=state360) SetPixel(x,y,hsv0); // Turn pixel on

        else SetPixel(x,y,hsv1);

    }

}

I would ask that you NOT check back your changes without contacting me first. So, go ahead, try out some effects!

 

thanks

sean