C# Draw Random Rectangles

Question

i wrote a little code like one from Flappy Bird (game) and in one of my timer i wrote the following code but when i'm starting this timer it's just showing me one up and one down pipe 3 times and then the painting just going black and it's showing me no more pipes. If you guys telling me where's the problem, that would be thankful..

private void timer2_Tick(object sender, EventArgs e)
    {
        if (Pipe1[0] + PipeWidth <= 0 | start == true)
        {
            Random rnd = new Random();
            int px = this.Width;
            int py = rnd.Next(40, (this.Height - PipeDifferentY));
            var p2x = px;
            var p2y = py + PipeDifferentY;
            int[] p1 = { px, py, p2x, p2y };
            Pipe1 = p1;
        }
        else
        {
            Pipe1[0] = Pipe1[0] - 2;
            Pipe1[2] = Pipe1[2] - 2;
        }
        if (Pipe2[0] + PipeWidth <= 0)
        {
            Random rnd = new Random();
            int px = this.Width;
            int py = rnd.Next(40, (this.Height - PipeDifferentY));
            var p2x = px;
            var p2y = py + PipeDifferentY;
            int[] p1 = { px, py, p2x, p2y };
            Pipe1 = p1;
        }
        else
        {
            Pipe2[0] = Pipe2[0] - 2;
            Pipe2[2] = Pipe2[2] - 2;
        }
        if (start == true)
        {
            start = false;
        }
    }

And here is the declares:

int[] Pipe1 = { 0, 0, 0, 0 };
int[] Pipe2 = { 0, 0, 0, 0 };
int PipeWidth = 55;
int PipeDifferentY = 140;
int PipeDifferentX = 180;
bool start = true;

Here is the Load Form part:

Random rnd = new Random();
int py = rnd.Next(40, (this.Height - PipeDifferentY));
int py2 = py + PipeDifferentY;
int[] p1 = { this.Width, py, this.Width, py2 };
Pipe1 = p1;

py = rnd.Next(40, (this.Height - PipeDifferentY));
py2 = py + PipeDifferentY;
int[] p2 = { this.Width + PipeDifferentX, py, this.Width + PipeDifferentX, py2 };
Pipe2 = p2;

Here is the painting part:

e.Graphics.FillRectangle(Brushes.LightCyan, new Rectangle(Pipe1[0], 0, PipeWidth, Pipe1[1]));
        e.Graphics.FillRectangle(Brushes.LightCyan, new Rectangle(Pipe1[2], Pipe1[3], PipeWidth, this.Height - Pipe1[3]));

        e.Graphics.FillRectangle(Brushes.LightCyan, new Rectangle(Pipe2[0], 0, PipeWidth, Pipe2[1]));
        e.Graphics.FillRectangle(Brushes.LightCyan, new Rectangle(Pipe2[2], Pipe2[3], PipeWidth, this.Height - Pipe2[3]));

And the first timer has just:

this.Invalidate();

This is maybe not related to your problem, but you should make the `Random` object a field in your class and create it in the constructor. Do not create it in the timer handler. Otherwise it might keep producing the same value if the timer tick interval is very short. — Matthew Watson, Feb 28 '14 at 12:20
It's a bit hard to see what might be wrong from just this code. One other unrelated thing though: You seem to be using `dynamic` where you should be using `var`. — Matthew Watson, Feb 28 '14 at 12:23
Yes, that's unrelated, but you shouldn't be using `dynamic` instead of `var`. — Matthew Watson, Feb 28 '14 at 12:28
oke, please look down what i commented to Starscream1984, if you can help me with it. — Castiel, Feb 28 '14 at 12:29
Here's my suggestion: Take that code and put it into a Console test app and call it from a loop rather than a timer. Then you'll be able to run it under the debugger and see what's going wrong. — Matthew Watson, Feb 28 '14 at 12:37
Hey Matthew, but i have this at the beggining: int[] Pipe1 = { 0, 0, 0, 0 }; and i made that int[] p1 with those values, because i couln't put it dirrectly into Pipe1 — Castiel, Feb 28 '14 at 12:51

Starscream1984 · Accepted Answer · 2014-02-28T13:11:08.907

2

You have a stray Pipe1 at the bottom of your Pipe2 if statement.

Update:

Try change declares to:

List<int> Pipe1 = new List<int>();
List<int> Pipe2 = new List<int>();
int PipeWidth = 55;
int PipeDifferentY = 140;
int PipeDifferentX = 180;
bool start = true;

and timer function to:

 private void timer2_Tick(object sender, EventArgs e)
        {
            if (Pipe1[0] + PipeWidth <= 0 | start == true)
            {
                Random rnd = new Random();
                int px = this.Width;
                int py = rnd.Next(40, (this.Height - PipeDifferentY));
                var p2x = px;
                var p2y = py + PipeDifferentY;
                Pipe1.Clear();
                Pipe1.Add(px);
                Pipe1.Add(py);
                Pipe1.Add(p2x);
                Pipe1.Add(p2y);
            }
            else
            {
                Pipe1[0] = Pipe1[0] - 2;
                Pipe1[2] = Pipe1[2] - 2;
            }
            if (Pipe2[0] + PipeWidth <= 0)
            {
                Random rnd = new Random();
                int px = this.Width;
                int py = rnd.Next(40, (this.Height - PipeDifferentY));
                var p2x = px;
                var p2y = py + PipeDifferentY;
                int[] p1 = { px, py, p2x, p2y };
                Pipe2.Clear();
                Pipe2.Add(px);
                Pipe2.Add(py);
                Pipe2.Add(p2x);
                Pipe2.Add(p2y);
            }
            else
            {
                Pipe2[0] = Pipe2[0] - 2;
                Pipe2[2] = Pipe2[2] - 2;
            }
            if (start == true)
            {
                start = false;
            }
        }

and your load form part:

Random rnd = new Random();
int py = rnd.Next(40, (this.Height - PipeDifferentY));
int py2 = py + PipeDifferentY;
Pipe1.Clear();
Pipe1.Add(this.Width);
Pipe1.Add(py);
Pipe1.Add(this.Width);
Pipe1.Add(p2y);

py = rnd.Next(40, (this.Height - PipeDifferentY));
py2 = py + PipeDifferentY;
Pipe2.Clear();
Pipe2.Add(this.Width + PipeDifferentX);
Pipe2.Add(py);
Pipe2.Add(this.Width + PipeDifferentX);
Pipe2.Add(p2y);

painting part should be ok

edited Feb 28 '14 at 13:11

answered Feb 28 '14 at 12:23

Starscream1984

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yes because i gave to pipe1, which is a int array, that new value from p1, cus i couldn't give it to it easier. – Castiel Feb 28 '14 at 12:25
any help resolving this? – Castiel Feb 28 '14 at 12:27
i have this at the beggining: int[] Pipe1 = { 0, 0, 0, 0 }; and i made that int[] p1 with those values, because i couln't put it dirrectly into Pipe1 – Castiel Feb 28 '14 at 12:28
Can you tell me how to put directly values to that int[] Pipe1 ? – Castiel Feb 28 '14 at 12:46
You could probably use a generic list instead of array for adding values directly on the fly: `List Pipe1 as new List;` – Starscream1984 Feb 28 '14 at 12:51
and then `Pipe1.Add(x1)` etc and you can still refer to them by index for getting later like `Pipe1[0]` – Starscream1984 Feb 28 '14 at 12:53
I don't really understand what the Pipe2 array is for when you put into Pipe1 array both times. – Starscream1984 Feb 28 '14 at 12:53
Hey but it won't work like that, because i have to specify into the New Rectangle(...) the x and y from Pipe1 which are Pipe[0] and Pipe[2] – Castiel Feb 28 '14 at 12:56
Why can't you do that, it should work fine? `new Rectangle(Pipe1[0], Pipe1[1], Pipe1[2], Pipe1[3])` – Starscream1984 Feb 28 '14 at 13:00
i tried but i didn't work like that, take a look now to my code, i put it all, maybe now can you understand more. – Castiel Feb 28 '14 at 13:01
Starscream, can you know be more clearly? I really need to finish this..help me – Castiel Feb 28 '14 at 13:07
It' giving me a huge white and red crossed X, maybe i need to change something in Form_Load too, do i? – Castiel Feb 28 '14 at 13:16
It's working very good, many thanks Starscream1984. Thank you. – Castiel Feb 28 '14 at 13:19
No problem, I think even without the changing of array to list, your main problem was assigning values meant for Pipe2 into Pipe1 by mistake. – Starscream1984 Feb 28 '14 at 13:22

C# Draw Random Rectangles

1 Answers1