line drawing

for(int i = 1;i<100;i+=2) {
    // calculate our extents
    srect16 r(i*(lcd.dimensions().width/100.0),
            i*(lcd.dimensions().height/100.0),
            lcd.dimensions().width-i*(lcd.dimensions().width/100.0)-1,
            lcd.dimensions().height-i*(lcd.dimensions().height/100.0)-1);
    // draw the four lines
    draw::line(lcd,srect16(0,r.y1,r.x1,lcd.dimensions().height-1),lcd_color::light_blue);
    draw::line(lcd,srect16(r.x2,0,lcd.dimensions().width-1,r.y2),lcd_color::hot_pink);
    draw::line(lcd,srect16(0,r.y2,r.x1,0),lcd_color::pale_green);
    draw::line(lcd,srect16(lcd.dimensions().width-1,r.y1,r.x2,lcd.dimensions().height-1),lcd_color::yellow);

}