Question

We just started learning windows programming in C++. We have to make a program that has 4 die on the screen, and when the user presses ‘SpaceBar’, the die roll, or the number of dots on the die change randomly. Our professor hasent given us a lot of information, so I am kind of just looking for some direction.

Right now, I have 4 squares drawn on the screen, made with the Rectangle() function.

Rectangle(hDC,30,100,130,200);
Rectangle(hDC,180,100,280,200);
Rectangle(hDC,330,100,430,200); 
Rectangle(hDC,480,100,580,200);  

My question is 1) how would I go about drawing dots on these ‘squares’ and not on the ‘screen’. So if I move the die upwards, the dots move with the square and dont just stay stationed painted on the screen. And 2.) How would I go about making those dots randomly change when spacebar is pressed (simulating that they have been rolled)?
Just looking for some direction, thanks.

Answer 1

1)
You will still have to draw them on the screen, but you can structure your program to realize the dots as part of the square.

void moveSquare()
{
    //change square position
    //change dots positions the same as you changed the square
}

---

2)
You can capture keypresses in your window with the WM_KEYDOWN and WM_KEYUP messages, or the WM_CHAR message. Just start a chain of changing how many dots are supposed to appear on the die when space is pressed (SetTimer could be handy), and let WM_PAINT do the work of painting the dots (or call something to calculate the positions of the dots, and let WM_PAINT loop through each dot it needs to draw.

void OnSpacePressed()
{
    //start changing dots every so often, handled elsewhere
    //maybe check if finished rolling before doing so
}

void calculateDotPositions()
{
    switch (numberOfDots) {...} //hint: use the square as a reference point
}

void OnPaint()
{ 
    //paint each sqaure
    //paint each dot in the correct position, which should be updated with square
}

void OnChangeDots()
{
    //change number of dots
    //also start a new change to happen later if not done rolling
}

For drawing dots, use Warren P’s reference link.