#include <os.h>
#include <SDL/SDL.h>
#include <SDL/SDL_gfxPrimitives.h>
#include <libndls.h>

SDL_Surface *screen;
nSDL_Font *font;
SDL_bool done = SDL_FALSE;

#define MANDEL_VERSION "1.0a"

int PIXELZOOM = 1;
int SPEED_UP = 1;


#define SCR_WIDTH   320
#define SCR_HEIGHT  240

int SCR_WID_PIXEL;
int SCR_HEI_PIXEL;

int MAX_ITERATION;

float cr, ci;
Uint32 timerstart;
Uint32 timerend;

bool INFO_ON_SCREEN = SDL_TRUE;


void init_SDL(void)
{
    if(SDL_Init(SDL_INIT_VIDEO) == -1)
    {
        printf("Sorry, can't init SDL: %s\n", SDL_GetError());
        exit(EXIT_FAILURE);
    }
    screen = SDL_SetVideoMode(320, 240, has_colors ? 16 : 8, SDL_SWSURFACE);
    if(screen == NULL)
    {
        printf("Sorry, can't init display: %s\n", SDL_GetError());
        SDL_Quit();
        exit(EXIT_FAILURE);
    }
    SDL_ShowCursor(SDL_DISABLE);
    
    font = nSDL_LoadFont(NSDL_FONT_TINYTYPE, 255, 255, 255);
    SDL_EnableKeyRepeat(SDL_DEFAULT_REPEAT_DELAY, SDL_DEFAULT_REPEAT_INTERVAL);
}

void quit(void)
{
    SDL_Quit();
}

void draw_fractal_Julia_Quick( void )
{
    float zr, zi;
    int u;
    int maxiter = MAX_ITERATION;
    float tmp,zr2,zi2;
    
    float xmin, xmax, ymin, ymax;
    float xinc, yinc;
    
    xmin = -1.6f;
    xmax = 1.6f;
    ymin = -1.2f;
    ymax = 1.2f;

    xinc = (xmax-xmin)/SCR_WID_PIXEL;
    yinc = (ymax-ymin)/SCR_HEI_PIXEL;
        
    
    for(int j=0; j<=SCR_HEI_PIXEL/2; j++)
    {
        for(int i=0; i<=SCR_WID_PIXEL; i++)
        {
            zr=xmin+i*xinc;
            zi=ymax-j*yinc;
            zi2=zi*zi;
            zr2=zr*zr;
            u=0;
            
            while(((zr2+zi2)<4) && (u<maxiter))
            {
                tmp =zr;
                zr2=zr*zr;
                zi2=zi*zi;
                
                zr = zr2 - zi2 + cr;
                zi = 2*zi*tmp + ci;               
                u++;
            } 
        
            if (u==maxiter)
            {
                boxRGBA( screen, i*PIXELZOOM, j*PIXELZOOM, (i+1)*PIXELZOOM-1, (j+1)*PIXELZOOM-1, 0, 0, 0, 255);
                boxRGBA( screen, SCR_WIDTH-i*PIXELZOOM, SCR_HEIGHT-j*PIXELZOOM, SCR_WIDTH-(i+1)*PIXELZOOM+1, SCR_HEIGHT-(j+1)*PIXELZOOM+1, 0, 0, 0, 255);
            }
            else
            {
                int sr=0;
                int sg=0;
                int sb=0;

                if (u < MAX_ITERATION/4 /SPEED_UP)
                {
                    sr=0;
                    sg=u*4*SPEED_UP;
                    sb=255;
                }
                else if (u < 2*MAX_ITERATION/4 /SPEED_UP)
                {
                    sr=0;
                    sg=255;
                    sb=(255-(u-MAX_ITERATION/4 /SPEED_UP)*4*SPEED_UP);
                }
                else if (u < 3*MAX_ITERATION/4 /SPEED_UP)
                {
                    sr=(u-2*MAX_ITERATION/4 /SPEED_UP)*4*SPEED_UP;
                    sg=255;
                    sb=0;
                }
                else if (u < MAX_ITERATION /SPEED_UP)
                {
                    sr=255;
                    sg=(256-(u-3*MAX_ITERATION/4 /SPEED_UP)*4*SPEED_UP);
                    sb=0;
                }          
                
                boxRGBA( screen, i*PIXELZOOM, j*PIXELZOOM, (i+1)*PIXELZOOM-1, (j+1)*PIXELZOOM-1, sr, sg, sb, 255);
                boxRGBA( screen, SCR_WIDTH-i*PIXELZOOM, SCR_HEIGHT-j*PIXELZOOM, SCR_WIDTH-(i+1)*PIXELZOOM+1, SCR_HEIGHT-(j+1)*PIXELZOOM+1, sr, sg, sb, 255);
                
            }

        }  

    }
    
}

void handle_keydown(SDLKey key)
{
    switch(key)
    {
        case SDLK_LCTRL:      
                cr=0.285f;
                ci=0.010f;
                SPEED_UP = 1;
                PIXELZOOM = 1;    
            break;
        
        case SDLK_TAB:      
                INFO_ON_SCREEN = !INFO_ON_SCREEN;
            break;
        
        case SDLK_UP:
                ci+=0.02f;
            break;
            
        case SDLK_DOWN:
                ci-=0.02f;
            break;
        
        case SDLK_LEFT:
                cr-=0.02f;
            break;
        
        case SDLK_RIGHT:
                cr+=0.02f;
            break;
               
        case SDLK_8:
                if (SPEED_UP<4) SPEED_UP++; 
            break;
            
        case SDLK_9:
                if (SPEED_UP>1) SPEED_UP--;                             
            break;
            
        case SDLK_5:
                if (PIXELZOOM>1) PIXELZOOM--;           
            break;
            
        case SDLK_6:
                if (PIXELZOOM<5) PIXELZOOM++;                     
            break;
            
        case SDLK_ESCAPE:
            done = SDL_TRUE;
            break;
        
        default:
            break;
    }
    
    SCR_WID_PIXEL = (SCR_WIDTH/PIXELZOOM);
    SCR_HEI_PIXEL = (SCR_HEIGHT/PIXELZOOM);
    MAX_ITERATION =  (256/SPEED_UP);
    
    timerstart = SDL_GetTicks();   
    draw_fractal_Julia_Quick();
    timerend = SDL_GetTicks();
    if (INFO_ON_SCREEN)
    {
        nSDL_DrawString( screen, font, 5, 5, "Dt= %d ms", timerend-timerstart );
        nSDL_DrawString( screen, font, 5, 15, "Cr= %f", cr );
        nSDL_DrawString( screen, font, 5, 25, "Ci= %f", ci );
        nSDL_DrawString( screen, font, 5, 35, "IT = %d", MAX_ITERATION/SPEED_UP );
        nSDL_DrawString( screen, font, 5, 45, "[%dx%dpx]", PIXELZOOM, PIXELZOOM );
    }
    SDL_Flip(screen);
}


int main(void)
{
    SDL_Event event;
    
    SCR_WID_PIXEL = SCR_WIDTH/PIXELZOOM;
    SCR_HEI_PIXEL = SCR_HEIGHT/PIXELZOOM;
    MAX_ITERATION = 256/SPEED_UP;
    
    init_SDL();  
    
    cr=0.285f;
    ci=0.010f;
    
    Uint32 timerstart = SDL_GetTicks();   
    draw_fractal_Julia_Quick();
    Uint32 timerend = SDL_GetTicks();
    
    nSDL_DrawString( screen, font, 5, 5, "Dt= %d ms", timerend-timerstart );
    nSDL_DrawString( screen, font, 5, 15, "Cr= %f", cr );
    nSDL_DrawString( screen, font, 5, 25, "Ci= %f", ci );
    nSDL_DrawString( screen, font, 5, 35, "IT = %d", MAX_ITERATION/SPEED_UP );
    nSDL_DrawString( screen, font, 5, 45, "[%dx%dpx]", PIXELZOOM, PIXELZOOM );
    
    SDL_Flip(screen);   
    
    
    while(!done)
    {
       
        while(SDL_PollEvent(&event))
        {
            switch(event.type)
            {
                case SDL_KEYDOWN:
                    handle_keydown(event.key.keysym.sym);
                    break;
                    
                default:
                    break;
            }
        }
    }
    
    nSDL_FreeFont(font);
    
    quit();
    
    return EXIT_SUCCESS;
}