I need your help :'(
Here is a simple program that I use to try. I have done it in at least 10 different languages but I am stuck here.
I thought I could do this one and add it to the example programs that I am putting together.
In the DrawBalls method Aurora crashes out in the if clauses. I have tried all I can think of. I need your eyes and brains.
/Lasse
#autodefine "off"
#typedef uint unsigned int
#define WINDOW_WIDTH 400
#define WINDOW_HEIGHT 400
#define RADIUS 10
#define NUM_BALLS 2
#define MAX_VELOCITY 3
#define WHITE 0xFFFFFF
#define RED 0x0000FF
declare import, GetTickCount(),uint;
struct SBall
{
int posX; //to hold the balls coordinates
int posY;
int velX; //and velocity
int velY;
}
class mywindow : window
{
//overridden functions.
declare OnClose(),int;
declare OnCreate(),int;
declare OnPaint(),int;
declare DrawBalls(),int;
declare SetUpBalls(),int;
RECT rect;
int cxClient, cyClient, cwClient, chClient;
SBall balls[NUM_BALLS];
//pointer pBalls[NUM_BALLS];
}
global sub main()
{
mywindow w;
w.Create(0,0,WINDOW_WIDTH,WINDOW_HEIGHT,AWS_CAPTION|AWS_VISIBLE|AWS_SYSMENU,0,"Silly balls!!",0);
do
{
wait();
}until w.m_hwnd = 0;
return;
}
mywindow::OnClose(),int
{
Destroy();
return TRUE;
}
mywindow::OnCreate(),int
{
//messagebox(null,"OnCreate","");
CenterWindow();
if SetUpBalls()
return true;
}
mywindow::OnPaint(),int
{
if DrawBalls()
return true;
}
mywindow::SetUpBalls(),int
{
rect = GetClientRect();
cxClient = rect.left;
cyClient = rect.top;
cwClient = rect.right-rect.left;
chClient = rect.bottom-rect.top;
//DrawRect(cxClient, cyClient, cwClient, chClient, WHITE, WHITE);
//messagebox(null,str$(cxClient) + " " + str$(cyClient) + " " + str$(cwClient) + " " + str$(chClient),"rect");
//seed random number generator
seedrnd(GetTickCount());
//set up the balls with random positions and velocities
for (int i=0; i<NUM_BALLS; i++)
{
balls[i].posX = Rand((RADIUS/2), cwClient - (RADIUS/2));
balls[i].posY = Rand((RADIUS/2), chClient - (RADIUS/2));
balls[i].velX = Rand(1,MAX_VELOCITY);
balls[i].velY = Rand(1,MAX_VELOCITY);
//messagebox(null,"Balls ready!\nHere is velX and velY:\n" + str$(balls[i].velX) + " " + str$(balls[i].velY) +
// "\nand posX and posY:\n" + str$(balls[i].posX) + " " + str$(balls[i].posY)," ");
}
//DrawBalls();
return true;
}
mywindow::DrawBalls(),int
{
//uint cacheDC;
//cacheDC = GetHDC();
//DrawMode(TRANSPARENT);
for (int j=0; j<NUM_BALLS; j++)
{
//check to see if they have hit any walls and reverse velocity
//accordingly
if ((balls[j].posX + (RADIUS/2)) >= cwClient or (balls[j].posX - (RADIUS/2)) < 0)
{
balls[j].velX = -balls[j].velX;
}
if ((balls[j].posY + (RADIUS/2)) >= chClient or (balls[j].posY - (RADIUS/2)) < 0)
{
balls[j].velY = -balls[j].velY;
}
// update their position
balls[j].posX += balls[j].velX;
balls[j].posY += balls[j].velY;
//render to display
Circle(balls[j].posX, balls[j].posY, RADIUS, RED,RED);
//messagebox(null,"Boll " + str$(i) + " klar.",str$(balls[i].posX) + " " + str$(balls[i].posY) + " " + str$(RADIUS));
}
//DrawMode(OPAQUE);
//WriteText(rect.left+20,rect.bottom-20, "Ball number: " + str$(i) + " ready. " + str$(balls[i].velX) + " " + str$(balls[i].velY) + " " + str$(RADIUS));
//messagebox(null,"Alla bollar ritade.","");
//ReleaseHDC(cacheDC);
return true;
}
You are declaring the array in the wrong place. I don't believe the Constructor is right.
I made it a global (outside of all class definitions and subroutines) and it works.
Thank you
I thought I had tried that ??? :-[.
Fresh eyes are worth a lot.
I just got frustrated after a while.
Anyway, it works so now I can go on with the fun parts :).
Thank's
Lasse
De nada.
This is all new to me. I was able to find your error because I made it myself - more than once.
That is called experience. Once you have made lots of errors you become
an expert. At my current error rate I will be well advanced soon, either that
or just stupid. :)
I do not understand why I am not able to declare an array in the class? Is it a problem with the struct thing? With the use of #define??
In the Keno example Pauil is doing this in the class: int balls[80]. ???
Uh!?
Were is the catch?
I am confused (default)
/Lasse
Should work. I look at your code when I get time. Still deep in IDE code right now.
One thing...don't do this:
mywindow::OnPaint(),int
{
if DrawBalls()
return true;
}
Your ounly returning TRUE if DrawBalls returns true. Otherwise your not returning. Should be:
mywindow::OnPaint(),int
{
if DrawBalls()
return true;
return false;
}
A test program I have uses a class member variable that's an array of pointers (see one of my earlier posts) without a problem. I'm using the latest build of the Alpha 2 compiler.
Good point about the return. I hope that down the road, you have the compiler display a warning if the code can "fall through" without an explicit return; it's kind of a big "gotcha" there. Is there any reason you can't emit a return (even if it duplicates an explicit return) at the end of a function? It would probably save some hair pulling.
Well there is a bug in the compiler somewhere. It works if I change the second IF statement in DrawBalls to use the 'this' pointer when accessing the member variable.
if ((this->balls[j].posY + (RADIUS/2)) >= chClient) or ((this->balls[j].posY - (RADIUS/2)) < 0)
{
balls[j].velY = -balls[j].velY;
}
Somewhere the compiler is losing track of the class reference during that statement. Still digging ;)
OK found and fixed. I'll update later today.
Thank you Paul.
Good to know that all bugs is not in my own head.
QuoteYour ounly returning TRUE if DrawBalls returns true. Otherwise your not returning.
I know. This was a stripped version in frustration. I'll post the complete code together with some other examples for this boards to check.
I hope they can end up among our examples.
I will try to comment the code not to much and not to sparse.