| Writlaus |
Apr 6th, 2006 7:49 PM |
Vectors and Classes
I hate to keep coming back here and asking questions left and right. I feel like I'm getting really annoying.
Anyway, I'm not sure if this is a problem with how I'm using vectors, or how I'm using classes. All I'm trying to do is create an empty vector, add two MyDot objects to it, and then have them bounce around the window, each with their own unique randomly generated starting position and energy. However, when I run the program, it just gives me one dot. The Vector has two items, though, so I'm thinking there are two dots there that are just somehow linked.
Here's my code... any help would be greatly appreciated, as always.
:
#include <windows.h>
#include <ctime>
#include <cstdlib>
#include <iostream>
#include <vector>
using namespace std;
int randInt(int end)
{
return (int)((rand()*1.0/RAND_MAX)*end);
}
const char g_szClassName[] = "myWindowClass";
const int windowWidth=200;
const int windowHeight=200;
const int drawableWidth=windowWidth-13;
const int drawableHeight=windowHeight-39;
class MyDot
{
public:
int x,y;
float realX,realY,energyY,energyX;
void initialize()
{
for (int i=0;i<20;i++)
{
rand();
}
energyX=((rand()*1.0/RAND_MAX)-.5);
energyY=((rand()*1.0/RAND_MAX)-.5);
x=randInt(drawableWidth);y=randInt(drawableHeight);
realX=x;realY=y;
}
void draw(HDC hdc)
{
SetPixel(hdc,x,y,RGB(157,4,170));
SetPixel(hdc,x+1,y,RGB(157,4,170));
SetPixel(hdc,x,y+1,RGB(157,4,170));
SetPixel(hdc,x+1,y+1,RGB(157,4,170));
}
void go()
{
realX+=energyX;realY+=energyY;
x=(int)realX;y=(int)realY;
}
void push(float forceX,float forceY)
{
energyX+=forceX;
energyY+=forceY;
}
};
int a=0;
vector<MyDot> dots;
RECT myRect;
HBRUSH myBrush;
MyDot dot;
HDC hdcBuffer;
HDC hdc;
HBITMAP hbmBuffer;
HBITMAP hbmOldBuffer;
void paintStuff(HDC hdc)
{
FillRect(hdcBuffer,&myRect,myBrush);
dot=dots[0];
dot.draw(hdcBuffer);
BitBlt(hdc,0,0,windowWidth,windowHeight,hdcBuffer,0,0,SRCCOPY);
}
// Step 4: the Window Procedure
LRESULT CALLBACK WndProc(HWND hwnd, UINT msg, WPARAM wParam, LPARAM lParam)
{
switch(msg)
{
case WM_CREATE:
{
srand((unsigned)time(NULL));
dots.push_back(dot);
MyDot anotherDot;
dots.push_back(anotherDot);
srand((unsigned)time(NULL));
for (int i=0;i<dots.size();i++)
{
dots[i].initialize();
}
myBrush=CreateSolidBrush(RGB(255,255,255));
SetRect(&myRect, 0, 0, windowWidth, windowHeight);
SetTimer(hwnd,1,17,NULL);
hdc=GetDC(hwnd);
hdcBuffer=CreateCompatibleDC(hdc);
hbmBuffer=CreateCompatibleBitmap(hdc,drawableWidth,drawableHeight);
SelectObject(hdcBuffer,hbmBuffer);
}
break;
case WM_TIMER:
{
a++;
hdc=GetDC(hwnd);
paintStuff(hdc);
ReleaseDC(hwnd, hdc);
for (int i=0;i<dots.size();i++)
{
dots[i].push(0,0.1);
}
//Bouncing:
for (int i=0;i<dots.size();i++)
{
if (dots[i].realY>drawableHeight & dots[i].energyY>0)
{
dots[i].energyY*=-1;
}
if (dots[i].realY<0 & dots[i].energyY<0)
{
dots[i].energyY*=-1;
}
if (dots[i].realX>drawableWidth & dots[i].energyX>0)
{
dots[i].energyX*=-1;
}
if (dots[i].realX<0 & dots[i].energyX<0)
{
dots[i].energyX*=-1;
}
}
for (int i=0;i<dots.size();i++)
{
dots[i].go();
}
}
break;
case WM_PAINT:
{
PAINTSTRUCT ps;
hdc=BeginPaint(hwnd,&ps);
paintStuff(hdc);
EndPaint(hwnd,&ps);
}
break;
case WM_LBUTTONDOWN:
{
char szFileName[MAX_PATH];
HINSTANCE hInstance = GetModuleHandle(NULL);
GetModuleFileName(hInstance, szFileName, MAX_PATH);
MessageBox(hwnd, szFileName, "This program is:", MB_OK | MB_ICONINFORMATION);
}
break;
case WM_MBUTTONDOWN:
{
HDC hdc=GetDC(hwnd);
TextOut(hdc,a,10,"Hello World",11);
ReleaseDC(hwnd, hdc);
}
break;
case WM_RBUTTONDOWN:
{
}
break;
case WM_CLOSE:
DestroyWindow(hwnd);
break;
case WM_DESTROY:
{
KillTimer(hwnd,1);
PostQuitMessage(0);
}
break;
default:
return DefWindowProc(hwnd, msg, wParam, lParam);
}
return 0;
}
int WINAPI WinMain(HINSTANCE hInstance, HINSTANCE hPrevInstance,
LPSTR lpCmdLine, int nCmdShow)
{
WNDCLASSEX wc;
HWND hwnd;
MSG Msg;
//Step 1: Registering the Window Class
wc.cbSize = sizeof(WNDCLASSEX);
wc.style = 0;
wc.lpfnWndProc = WndProc;
wc.cbClsExtra = 0;
wc.cbWndExtra = 0;
wc.hInstance = hInstance;
wc.hIcon = LoadIcon(NULL, IDI_APPLICATION);
wc.hCursor = LoadCursor(NULL, IDC_ARROW);
wc.hbrBackground = (HBRUSH)(COLOR_WINDOW+1);
wc.lpszMenuName = NULL;
wc.lpszClassName = g_szClassName;
wc.hIconSm = LoadIcon(NULL, IDI_APPLICATION);
if(!RegisterClassEx(&wc))
{
MessageBox(NULL, "Window Registration Failed!", "Error!",
MB_ICONEXCLAMATION | MB_OK);
return 0;
}
// Step 2: Creating the Window
hwnd = CreateWindowEx(
WS_EX_CLIENTEDGE,
g_szClassName,
"The title of my window",
WS_OVERLAPPEDWINDOW,
CW_USEDEFAULT, CW_USEDEFAULT, windowWidth, windowHeight,
NULL, NULL, hInstance, NULL);
if(hwnd == NULL)
{
MessageBox(NULL, "Window Creation Failed!", "Error!",
MB_ICONEXCLAMATION | MB_OK);
return 0;
}
ShowWindow(hwnd, nCmdShow);
UpdateWindow(hwnd);
// Step 3: The Message Loop
while(GetMessage(&Msg, NULL, 0, 0) > 0)
{
TranslateMessage(&Msg);
DispatchMessage(&Msg);
}
return Msg.wParam;
}
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