PrimeViewer.cpp

#include <iostream>
#include <vector> // For vector
#include <cmath> // For floor, sqrt
#include "raylib.h"
#include "raymath.h"
#define RAYGUI_IMPLEMENTATION
#include "raygui.h"

//Four ways to visualize the distribution of primes under 1,000,000
//Press 1, 2, 3 or 4 to change views
//Mode 1 = 3D view of distribution of primes in a 100x100x100 cube
//Mode 2 = 3D Sieve of Erathosthenes, showing primes in white, and eliminated non-primes in color
//          The color represents the lowest prime factor which divides the non-prime.
//          Use the sliders to display only the factors you want, and the check box to draw primes or not
//Mode 3 = Factor wheel, using sectors.  Google "Wheel Factorization" for details.
//Mode 4 = Factor wheel, using points, which displays better when using a high factor base for the wheel
//Code and concepts by Eric J. Jenislawski.
//Thanks to Ramon Santamaria for the great RayLib and RayGUI libraries

using namespace std;

Color cubecolor(int f, int transparency) {
//separating color vals by 8, and using range 128-248, that leaves us: 15*15*15=3375 distinct colors
    Color retcol;
    int red, green, blue;
    blue=120+(f%15)*8;
    red=120+((f/15)%15)*8;
    green=120+((f/255)%15)*8;
    retcol=(Color){red,green,blue,transparency};
    //cout<<"f="<<f<<" RGB"<<red<<" "<<green<<" "<<blue<<endl;
    return retcol;
}


int main()
{
    unsigned int maxval=1000000;
    unsigned int bound;
    int viewmode=1;
    int transparency=64, lowerval=2, upperval=1000;
    float factorbase=60;
    int fbase=60;
    bool boolDrawPrimes=true;
    Vector3 position={0.0,0.0,0.0};
    Vector3 posOffset={50,0,50};
    Vector3 unitV={1.0,1.0,1.0};
    Color cubecol={255,255,255,32};
    vector<unsigned int> plist(maxval,1);
    cout<<"Array initialized"<<endl;

    for (uint i=2;i*i<maxval;i++){
        if (plist[i]==1) {
            bound=maxval/i;
            for (uint x=bound;x>=i;x--){
                if (plist[x]==1) {
                        plist[x*i]=i;
                }
            }
        }
    }
    cout<<"Primes to "<<maxval<<" sieved."<<endl;

//Init raylib
    InitWindow(1000, 1000, "Prime viewer");
    SetWindowPosition(400,100);

    Camera camera = { 0 };
    camera.position = (Vector3){1.0, 0.0, 150.0};
    camera.target=(Vector3){0.0,0.0,0.0};
    camera.up = (Vector3){ 0.0f, 1.0f, 0.0f };
    camera.fovy = 60.0f;
    camera.projection = CAMERA_PERSPECTIVE;
    SetCameraMode(camera,CAMERA_FREE);
    SetTargetFPS(60);

//LOOP

    while (!WindowShouldClose()){

    //Process any input here
    if (IsKeyPressed(KEY_ONE)) {viewmode=1;}
    if (IsKeyPressed(KEY_TWO)) {viewmode=2;}
    if (IsKeyPressed(KEY_THREE)) {viewmode=3;}
    if (IsKeyPressed(KEY_FOUR)) {viewmode=4;}

//3D cube, only primes
    if (viewmode==1) {
        BeginDrawing();
        ClearBackground(BLACK);
        BeginMode3D(camera);
        DrawGrid(100, 1.0f);
        DrawGizmo({0,0,0});

        for (uint i=2;i<maxval;i++){
            if (plist[i]==1) {
                position=(Vector3){(i % 100),((i/100) % 100),((i/10000) % 100)};
                DrawCubeV(Vector3Subtract(position,posOffset),unitV,cubecol);
            }
        }

        UpdateCamera(&camera);
        EndMode3D();
        DrawFPS(10,10);
        EndDrawing();
        }


//3D cube, all numbers by factor
    if (viewmode==2) {
        BeginDrawing();
        ClearBackground(BLACK);
        BeginMode3D(camera);
        DrawGrid(100, 1.0f);
        DrawGizmo({0,0,0});

        for (uint i=2;i<maxval;i++){
            if ((plist[i]==1)&&(boolDrawPrimes)) {
                position=(Vector3){(i % 100),((i/100) % 100),((i/10000) % 100)};
                DrawCubeV(Vector3Subtract(position,posOffset),unitV,RAYWHITE);
            }
            if ((plist[i]>lowerval)&&(plist[i]<upperval)) {
                position=(Vector3){(i % 100),((i/100) % 100),((i/10000) % 100)};
                DrawCubeV(Vector3Subtract(position,posOffset),unitV,cubecolor(plist[i],transparency));
            }
        }

        UpdateCamera(&camera);
        EndMode3D();
        transparency=GuiSlider({200,10,100,10},"Transparency",transparency,16,255,true);
        boolDrawPrimes=GuiCheckBox({350,10,10,10},"Draw Primes",boolDrawPrimes);
        lowerval=GuiSlider({200,30,400,10},"Draw factors above:",lowerval,2,1000,true);
        upperval=GuiSlider({200,50,400,10},"Draw factors below:",upperval,2,1000,true);
        DrawFPS(10,10);
        EndDrawing();
        }

//Sector wheel
    if (viewmode==3) {
        float inrad, outrad;
        int startangle,endangle;
        Color segcolor=WHITE;
        BeginDrawing();
        ClearBackground(BLACK);

        for (uint i=2;i<5000;i++) {
            if (plist[i]==1) {
                //segcolor=(Color){16*(i%15),16*(i%15),16*(i%15),64};
                inrad=30+floor((i+30)/30)*3;
                outrad=inrad+3;
                startangle=(360/factorbase)*(i%fbase);
                endangle=startangle+(360/factorbase)-1;
                DrawRing((Vector2){500,500}, inrad, outrad, startangle, endangle, 20, segcolor);
                //cout<<"i="<<i<<" inner rad="<<inrad<<" outer rad="<<outrad<<" Start angle="<<startangle<<" End angle="<<endangle<<endl;
            }
        }

    GuiSpinner({5,30,100,40},&fbase,2,180,false);
    factorbase = (float)fbase;
    DrawFPS(10,10);
    EndDrawing();
    }


//Point wheel
    if (viewmode==4) {
        //cin>>factorbase;
        float inrad,startangle;
        BeginDrawing();
        ClearBackground(BLACK);

        for (uint i=2;i<50000;i++) {
            if (plist[i]==1) {
                //segcolor=(Color){16*(i%15),16*(i%15),16*(i%15),64};
                inrad=30+floor((i+30)/30);
                startangle=(3.14159*2.0/factorbase)*(float)(i%fbase);
                DrawPixel(inrad*cos(startangle)+500,inrad*sin(startangle)+500,WHITE);
                //cout<<"i="<<i<<" inner rad="<<inrad<<" Start angle="<<startangle<<endl;
            }
        }

    GuiSpinner({5,30,100,40},&fbase,2,100,false);
    factorbase = (float)fbase;

        DrawFPS(10,10);
        EndDrawing();
    }

    } //End LOOP



}