the plane passing the moon

Hi ppl;Window section or game section?

in this program ,how can i make the plane pass the moon so it is
blocking the moon rather than moon blocking the plane?

i made 3 regions one for the moon and its effect.
one for the whole window."dont ask me why .it works somehow"
and one for the star section.

i should have used SetWindowExtEx and viewport to make my job easier on logical units but i was lazy to
go back and restart after all this is just a learning program for me to practice on effects in GDI.and i wanted the filling tank to be a region. but
i thought it would conflict with other regions.

i tried to have few more timers with different offsets for different movement but it screwed up the whole timer routin so i just stuck with one.

can u find a way around it?

*note
u can change the volume of water coming out of the pipe by using

"vol+" and it will show the current volume at the bottom of the screen.eventhough the random "lines creating the sea" are kinda
obscuring it.
im attaching a exe zip i hope the thread will accept it .if not u can run the code urself,

cheers!

check this sight out good place for trigonometry and vectors:

http://chortle.ccsu.ctstateu.edu/vec...ctorIndex.html

Code:

---

/*------------------------------------------------------------
  sia k    feb 17 2002
  ------------------------------------------------------------*/

#include <windows.h>
#include <stdio.h>
#include <stdlib.h>
#include <time.h>
#define ID_TIMER 1

LRESULT CALLBACK WndProc (HWND, UINT, WPARAM, LPARAM) ;

int WINAPI WinMain (HINSTANCE hInstance, HINSTANCE hPrevInstance,
                    PSTR szCmdLine, int iCmdShow)
{
    static TCHAR szAppName[] = TEXT ("sia0008") ;
    HWND        hwnd ;
    MSG          msg ;
    WNDCLASSEX    wndclass ;
    wndclass.cbSize        = sizeof(WNDCLASSEX);
    wndclass.style        = CS_HREDRAW | CS_VREDRAW | CS_OWNDC ;
    wndclass.lpfnWndProc  = WndProc ;
    wndclass.cbClsExtra    = 0 ;
    wndclass.cbWndExtra    = 0 ;
    wndclass.hInstance    = hInstance ;
    wndclass.hIcon        = LoadIcon (hInstance, MAKEINTRESOURCE(30)) ;
    wndclass.hCursor      = LoadCursor (NULL, IDC_ARROW) ;
    wndclass.hbrBackground = (HBRUSH) GetStockObject (BLACK_BRUSH) ;
    wndclass.lpszMenuName  = szAppName;
    wndclass.lpszClassName = szAppName ;
    wndclass.hIconSm      = LoadIcon (hInstance, MAKEINTRESOURCE(30));
    RegisterClassEx (&wndclass);
   
         
                   
        hwnd = CreateWindow (szAppName,               
                          TEXT ("sia0008 sara Loves Chocolate"),
                          WS_OVERLAPPEDWINDOW,     
                          CW_USEDEFAULT,         
                          CW_USEDEFAULT,           
                          CW_USEDEFAULT,         
                          CW_USEDEFAULT,       
                          NULL,                   
                          NULL,                   
                          hInstance,               
                          NULL) ;                   
   
    ShowWindow (hwnd, iCmdShow) ;
    UpdateWindow (hwnd) ;
   
    while (GetMessage (&msg, NULL, 0, 0))
    {
          TranslateMessage (&msg) ;
          DispatchMessage (&msg) ;
    }
    return msg.wParam ;
}
void listdatetime(HWND hwnd, int cyclient,  char *t){
        SYSTEMTIME st;
        HDC hdc;
 static char  a2[70], a3[30], a4[70];
              hdc = GetDC(hwnd);
          GetLocalTime(&st);
                  GetDateFormat(LOCALE_SYSTEM_DEFAULT, DATE_LONGDATE, &st, NULL, a2, sizeof(a2));
                  SetBkColor(hdc, RGB(0, 0, 0));
                  TextOut(hdc, 0, cyclient - 120, a4, wsprintf(a4, "%s", a2));                  // display time date
                  TextOut(hdc, 0, cyclient - 100, a3, wsprintf(a3, "%s %2d:%2d:%2d", t,      //function
                          st.wHour, st.wMinute, st.wSecond));
                  ReleaseDC(hwnd, hdc);
}

LRESULT CALLBACK WndProc (HWND hwnd, UINT message, WPARAM wParam, LPARAM lParam)
{
static    HDC        hdc ;
          PAINTSTRUCT ps ;
static    RECT        rect, rc1, rc2;
static    HBRUSH hbrush;
static          HPEN  hpen;
char      *t = "Time is";
static char array[50];
static  int  x, y, n, m, i, j = 0, p = 20, s = 0, g = 0, a = 0, q, r = 0, v = 70, w = 80;

static int a1[8] = {45, 10, 35, 35, 15, 40, 3, 9};
static    BOOL flip = FALSE, flop = FALSE;
static int  cxclient, cyclient;
          COLORREF c;
static        POINT point[10] = {35, 50, 30, 30, 20, 50, 15, 30, 0, 30, 5, 0, 10, 20, 35, 15, 60, 30,
                40, 30};
       
static        HRGN hrgn, ergn, frgn ;
   
               
        switch (message)
    {
    case WM_CREATE:
               
        // PlaySound (TEXT ("sia0008.wav"), NULL, SND_FILENAME | SND_ASYNC) ;
                hdc = GetDC(hwnd);
               
       
                SetTimer(hwnd, 1, 100, NULL);
                ReleaseDC(hwnd, hdc);
          return 0 ;
        case WM_TIMER:
               
                flip = !flip;
               
            GetClientRect(hwnd, &rc2);
 
                InvalidateRect(hwnd, NULL, TRUE);
           

               
                return 0;
    case WM_SIZE:
                cxclient = LOWORD (lParam) ;
                cyclient = HIWORD (lParam) ;
                return 0;
         
    case WM_PAINT:
         
                BeginPaint (hwnd, &ps) ;
       
                srand(time(NULL));
               
                frgn =  CreateRectRgn(0, 0, cxclient, 70);

                  SelectObject(hdc, frgn);
                  DeleteObject(frgn);
                  for(g = 0; g < 800; g++){                  //first region the stars
                        x = 0 + rand() % cxclient;
                        y = 0 + rand() % 70;
                        SetPixel(hdc, x, y, RGB(0 + rand() % 255, 255, 255));
               
                }
                  hpen = CreatePen(PS_SOLID, 1, RGB(100, 100, 100));
                  SelectObject(hdc, hpen);
                  hbrush = CreateSolidBrush(RGB(136, 136, 136));
                SelectObject(hdc, hbrush);
                  //GetStockObject(BS_HOLLOW);
                  SetPolyFillMode(hdc, WINDING);
                  Polygon(hdc, point, 10);
              DeleteObject(hbrush);
                  DeleteObject(hpen);
                  MoveToEx(hdc, a1[1], 20, NULL);
                  LineTo(hdc, a1[0], 20);
                  MoveToEx(hdc, a1[2], 15, NULL);
                  LineTo(hdc, a1[3], 20);
                 
                  hbrush = CreateSolidBrush(RGB(250,250, 0));
                  SelectObject(hdc, hbrush);
                  Ellipse(hdc, a1[4], 20, a1[5], 30);
                  SetRect(&rc1, a1[4], 20, a1[5], 30);
                  SetBkColor(hdc, RGB(250, 250, 0));
                  DrawText(hdc, "sara", -1, &rc1, DT_SINGLELINE | DT_CENTER | DT_VCENTER);
                  DeleteObject(hbrush);
                 
               
               
                  if(flip == FALSE){
                  hbrush = CreateSolidBrush(RGB(255, 0, 0));
                  SelectObject(hdc, hbrush);                   
                  Ellipse(hdc, a1[6], 5, a1[7], 10);      //beamming light on plane 
                  DeleteObject(hbrush);
               
                }
       
        if(a <= 160){
    for(q = 0; q <=7; q++)        //line&image incremented on plane
                a1[q] += 5;
   
                  for(q = 0; q < 10; q++)

                         
                         
                        point[q].x = point[q].x + 5;
                }       
        else{

                                  for(q = 0; q < 10; q++){
                                         
                                        point[q].x = point[q].x - a * 5;
                         
                                  }
        for(q = 0;q <= 7;q++)
                       
                        a1[q] = a1[q] - a * 5;      //line&image to orig loc on plane window
       
                  a = 0;
                          }
                      a++;

                        ergn = CreateEllipticRgn(cxclient - 80, 30, cxclient - 30, 80);    //moon
        SetRect(&rc1, cxclient - 80, 30, cxclient - 30, 80);
                        hbrush = CreateSolidBrush(RGB(255, 255, 255));
                  SelectObject(hdc, ergn);
                FillRgn(hdc, ergn, hbrush);
                SetBkColor(hdc, RGB(255, 255, 255));
                SetTextColor(hdc, RGB(210, 210, 210));
               
                DrawText(hdc,TEXT( "@*&*"), -1, &rc1, DT_SINGLELINE | DT_CENTER | DT_VCENTER);  //2nd dark region moon
                DrawText(hdc, TEXT("**"), -1, &rc1, DT_SINGLELINE | DT_CENTER);
               
                DeleteObject(ergn);                       
               
        for(i = 0; i < 750; i++){
                                        x = cxclient - 80 + rand() % 50;
                                        y = 30            + rand() % 50;
                                        SetPixel(hdc, x, y, RGB(200, 200, 200));
                                }
                hbrush = CreateSolidBrush(RGB(186, 130, 67));
                SelectObject(hdc, hbrush);
        Ellipse(hdc,cxclient - w, 55,cxclient - v, 65);  //satelite
               
                DeleteObject(hbrush);
                if(w > 20 && v > 20){
                        v--;w--;
                }else{
                        v = 70;w = 80;
                }
               
                hrgn = CreateRectRgn(0, 0,cxclient, cyclient);  //make the senior region
        SelectObject(hdc, hrgn);
        DeleteObject(hrgn);
                hpen = CreatePen(PS_SOLID, 2, RGB(130,130 , 130));
                  SelectObject(hdc, hpen);
               
                MoveToEx(hdc, cxclient / 4 + 23, cyclient / 4 - 18, NULL);
                LineTo(hdc, cxclient / 4 + 23, cyclient / 4);
                SetRect(&rc1, 0, cyclient / 4 - 18, cxclient / 4 + 20, cyclient / 4);
                  hbrush = CreateSolidBrush(RGB(100, 100, 100));
               
                  FillRect(hdc, &rc1, hbrush);

                  Ellipse(hdc, cxclient / 4, cyclient / 4 - 8, cxclient / 4 + 15, cyclient / 4 + 8);
                  SetTextColor(hdc, RGB(250, 0, 0));
                 
               
                SetRect(&rc1, cxclient / 6, cyclient / 4 + 60, cxclient / 3 + 20, cyclient - 60); //fill tank
          FillRect(hdc, &rc1, hbrush);;
               
                  hbrush = CreateSolidBrush(RGB(100,100, 100));
                  SelectObject(hdc, hbrush);
                Ellipse(hdc, cxclient / 6, cyclient / 4 + 65, cxclient / 3 + 20, cyclient / 4 + 55);
                DeleteObject(hbrush);
                  SetBkColor(hdc, RGB(100, 100, 100));
                  DrawText(hdc, TEXT("THE FILLING TANK"), -1, &rc1, DT_SINGLELINE | DT_CENTER | DT_VCENTER);
                     
                  DeleteObject(hbrush);                       
       
          SetRect(&rect, cxclient / 4, cyclient / 4 - 5, cxclient / 4 + 15, cyclient / 4 + 60);
                  listdatetime(hwnd, cyclient, t);    ////////
                 
          hbrush = CreateSolidBrush(RGB(0, 0, 0));
                  SelectObject(hdc, hbrush);
                  FillRect(hdc, &rect, hbrush);
                  SetBkMode(hdc, OPAQUE);
                  c = RGB(201, 201, 201);
                  for(i = 0; i <= p; i++){
                  x = cxclient / 4 + rand() % 15;
          y = cyclient / 4 - 5 + rand() % 65;
                         
                          SetPixel(hdc, x, y, c);
                         
                        }
                DeleteObject(hbrush);
             
                 
                SetRect(&rc1,30, cyclient / 4- 18, 60, cyclient / 4);
               
                  Ellipse(hdc, 30, cyclient / 4 - 18, 60, cyclient / 4);
                 
                  SetBkColor(hdc, RGB(0, 0, 0));
                  DrawText(hdc, "vol+", -1, &rc1, DT_SINGLELINE | DT_CENTER | DT_VCENTER);
        SetRect(&rc1, 80, cyclient / 4 - 18, 110, cyclient / 4);
               
               
               
                  Ellipse(hdc, 80, cyclient / 4 - 18, 110, cyclient / 4);
                  DrawText(hdc, "vol-", -1, &rc1, DT_SINGLELINE | DT_CENTER | DT_VCENTER);
                  hbrush = CreateSolidBrush(RGB(0, 0, 230));
        SetRect(&rc1, cxclient / 6, cyclient - 60, cxclient / 3 + 20, (cyclient - 60) - j );//red fill up

                  FillRect(hdc, &rc1, hbrush);
               
         
          DeleteObject(hpen);
                  DeleteObject(hbrush);
                 
          j++;
                 
               
                  if(j == 280){
                          j = 0;
                          hbrush = CreateSolidBrush(RGB(100, 100, 100));
                          FillRect(hdc, &rc1, hbrush);
                    DeleteObject(hbrush);
               
                       
                  }
            SetBkColor(hdc, RGB(0, 0, 0));
                wsprintf(array, "The Volume In Tank is %d", p);
                TextOut(hdc,s , cyclient - 18, array, lstrlen(array));

                if(s < 250)
                        s++;
                hpen = CreatePen(PS_SOLID, 1, RGB(0, 0, 250));
                SelectObject(hdc, hpen);

                for(q = 0; q < 450; q++){
                       
     
                       
        MoveToEx(hdc, 0 + rand() % cxclient, (cyclient - 60) + rand() % 60, NULL);
        LineTo(hdc, 0 + rand() % cxclient + 10, q % 10 == 0 ?(cyclient - 60) : (cyclient - 80) + rand() % 60);
                DeleteObject(hpen);
                }
                DeleteObject(hpen);
                                  EndPaint (hwnd, &ps) ;
          return 0 ;
      case  WM_LBUTTONDOWN:
         
                  n = LOWORD (lParam);
                  m = HIWORD (lParam);
                  if(n < 60 && n > 30)
          p += 5;
                  if(n < 110 && n > 80)                      //volume for liquide
                  p -= 5;
                  if(p == 0){
                          KillTimer(hwnd, 1);
                  InvalidateRect(hwnd, NULL, TRUE);
                  }
                 
          return 0;
    case WM_DESTROY:
               
                KillTimer(hwnd, 1);
                DeleteObject(hpen);
               
                DeleteObject(hbrush);
          PostQuitMessage (0) ;
               
               
          return 0 ;
    }
    return DefWindowProc (hwnd, message, wParam, lParam) ;
}

---

A little confused question, but you're wondering how to get the plane in front of the moon?
Well, are you rendering (drawing) the moon first and then the plane? If you're doing the opposite, you get the effect you're describing.

it has 3 regions stars, moon, and the rest, ur solution works partialy .
but,the reason i didnt render the moon first is because ,the stars would appear on the surface of the moon and the other solution would appear to make the star region:
(0, 0, cxclient, 70) to (0, 0, cxclient - 70, 70) which prevents stars to be drawn pass the border of the moon region.

i guess if i want to fix it, i have to change the rendering logic fundamentaly probably getting rid of the regions and start a differnt aproach.may be some other time.
:)

some errors

>>srand(time(NULL));

do this only once, in WM_INIT or WM_CREATE.
In the WM_PAINT all paint msg's withing around 5 millisec will have same seed so will get same random number generated.

WM_PAINT
this should be small and fast. Not an epic.

May I suggest you look at what is returned from the call to BeginPaint() and the members / elements of the PAINTSTRUCT. You may find them helpful.

MAJOR POINT :: You can NOT delete a GDI object WHILE it is selected into a HDC (or DC)
You must return the original object (ie select it back in) then delete or release.

All drawing should be done before you call for the screen to be updated. Your app should be able to assemble /draw one frame WHILE it is painting the last one to the screen.

frgn = CreateRectRgn(0, 0, cxclient, 70);
SelectObject(hdc, frgn);
DeleteObject(frgn);

Why create a region,
then select it into a DC (not catching the currently selected region == memory leak)
then try to delete the region while it is selected into a DC(which will ALWAYS fail == memory leak)?

Same with the pens and brush.

This app will run a PC out of GDI resources in a few minutes. More if you stimulate the painting by passing a messagebox over the top of the app while it is running.

thx nova your points well taken .but keep in mind just like the last

thing"remember moving in tunnel" i did this without any concernes
for a structured programming ,but just to practice on how to create effects , i so lazily put everything in WM_PAINT section rather than do the major init in WM_CREATE or some other msg.
or go one frame at the time.

otherwise for example i would follow the rule like this for brush:

hbrush = CreateSolidBrush(RGB(,,,,,,,,,));
hbrush = SelectObject(hdc, hbrush)

do what you want here

DeleteObject(SelectObject(hdc, hbrush));
ReleaseDC(,,,,,,,,,,,,,);

which reinstate the old brush which, was saved earlier and the same goes for pens and fonts and alike.

but your point about rgn.

frgn = CreateRectRgn(0, 0, cxclient, 70);
SelectObject(hdc, frgn);
DeleteObject(frgn);

i had always assumed that regions are different than other GDI
objects in the fact that , we can delete them right after we select them into DC ,and we dont have to wait until the end of process(drawing into them) to delete them.

one of these days im gone crash my system with my sloppy work.
:p

by the way if you find a way to move plane over the moon within
my code let me know.

i know gives gives me a headache just to look at it:confused:

>>i had always assumed that regions are different than other GDI

AFAIK no but I may be wrong.

Regions may or may not be deleted while selected into a HDC (as a drawing GDI object can't) but unless you test the return from the delete you can not be 100% that the region is deleted.

My question was more why create one to delete it straight away.

I think that the fact you are using a rectangular one in a rectangular hdc masks any resulting error.

yes you are right again .because if i didnt have thay rect region

i would get uncertain results on execution time.
i tested it a few times without it, and thats why i thought of that method as a solution.
as i wrote earlier
with regions wether you do it this way

frgn = CreateRectRgn(0, 0, cxclient, 70);
SelectObject(hdc, frgn);
DeleteObject(frgn);


or this way

frgn = CreateRectRgn(0, 0, cxclient, 70);
SelectObject(hdc, frgn);

do some stuff,,,,,,,,,,,,
DeleteObject(frgn);

the result is the same.

atleast thats what i think.i could be wrong.