time/RealTimeClock/source/main.c

/*-----------------

Very simple RTC example with a cheesy watch face

\*----------------*/

#include <nds.h>

#include <stdio.h>
#include <time.h>

const char* months[12] = {"January", "February", "March", "April", "May", "June", "July", "August", "September", "October", "November", "December"};

const char* weekDays[7] = {"Sunday", "Monday", "Tuesday", "Wednesday", "Thursday", "Friday", "Saturday"};

const u16 daysAtStartOfMonthLUT[12] =
{
    0   %7, //januari       31
    31  %7, //februari      28+1(leap year)
    59  %7, //maart         31
    90  %7, //april         30
    120 %7, //mei           31
    151 %7, //juni          30
    181 %7, //juli          31
    212 %7, //augustus      31
    243 %7, //september     30
    273 %7, //oktober       31
    304 %7, //november      30
    334 %7  //december      31
};

#define isLeapYear(year) (((year)%4) == 0)

uint getDayOfWeek(uint day, uint month, uint year)
{
    //http://en.wikipedia.org/wiki/Calculating_the_day_of_the_week

    day += 2*(3-((year/100)%4));
    year %= 100;
    day += year + (year/4);
    day += daysAtStartOfMonthLUT[month] - (isLeapYear(year) && (month <= 1));
    return day % 7;
}



void init3D();
void update3D(int hours, int seconds, int minutes);


int main()
{
    int hours, seconds, minutes, day, month, year;

    consoleDemoInit();

    init3D();

    while(true)
    {
        time_t unixTime = time(NULL);
        struct tm* timeStruct = gmtime((const time_t *)&unixTime);

        hours = timeStruct->tm_hour;
        minutes = timeStruct->tm_min;
        seconds = timeStruct->tm_sec;
        day = timeStruct->tm_mday;
        month = timeStruct->tm_mon;
        year = timeStruct->tm_year +1900;

        printf("\x1b[2J%02i:%02i:%02i", hours, minutes, seconds);
        printf("\n%s %s %i %i", weekDays[getDayOfWeek(day, month, year)], months[month], day, year);


        update3D(hours, seconds, minutes);

        swiWaitForVBlank();
    }

    return 0;
}





//draw a watch hands
void DrawQuad(float x, float y, float width, float height)
{

    glBegin(GL_QUADS);
    glVertex3f(x - width / 2, y, 0);
    glVertex3f(x + width / 2, y, 0);
    glVertex3f(x  + width / 2, y  + height, 0);
    glVertex3f(x - width / 2, y  + height, 0);
    glEnd();
}

void init3D()
{
    //put 3D on top
    lcdMainOnTop();

    // Setup the Main screen for 3D
    videoSetMode(MODE_0_3D);

    // Reset the screen and setup the view
    glInit();

    // Set our viewport to be the same size as the screen
    glViewport(0,0,255,191);

    // Specify the Clear Color and Depth
    glClearColor(0,0,0,31);
    glClearDepth(0x7FFF);

    //ds specific, several attributes can be set here
    glPolyFmt(POLY_ALPHA(31) | POLY_CULL_NONE);

    // Set the current matrix to be the model matrix
    glMatrixMode(GL_MODELVIEW);
    glLoadIdentity();

    glMatrixMode(GL_PROJECTION);
    glLoadIdentity();
    gluPerspective(70, 256.0 / 192.0, 0.1, 100);
    gluLookAt(  0.0, 0.0, 3.0,      //camera possition
                0.0, 0.0, 0.0,      //look at
                0.0, 1.0, 0.0);     //up
}


void update3D(int hours, int seconds, int minutes)
{
    //Push our original Matrix onto the stack (save state)
    glPushMatrix();

    //draw second hand
    glColor3f(0,0,1);
    glRotateZ(-seconds * 360 / 60);
    glTranslatef(0,1.9,0);
    DrawQuad(0,0,.2,.2);

    // Pop our Matrix from the stack (restore state)
    glPopMatrix(1);

    //Push our original Matrix onto the stack (save state)
    glPushMatrix();

    //draw minute hand
    glColor3f(0,1,0);
    glRotateZ(-minutes * 360 / 60);
    DrawQuad(0,0,.2,2);

    // Pop our Matrix from the stack (restore state)
    glPopMatrix(1);

    //Push our original Matrix onto the stack (save state)
    glPushMatrix();

    //draw hourhand
    glColor3f(1,0,0);
    glRotateZ(-hours * 360 / 12);
    DrawQuad(0,0,.3,1.8);

    // Pop our Matrix from the stack (restore state)
    glPopMatrix(1);

    // flush to screen
    glFlush(0);
}