GDI+ for EBASIC

[ckoehn]

How do you use the GDI+ commands in EBASIC.  Below is a program that I tried (based on something ficko placed on the forum I think).  It doesn't generate any errors, but it doesn't do anything either.  Can someone give me some help?

Thanks,
Clint

Code Select Expand

$INCLUDE "windowssdk.inc"
$INCLUDE "gdiplus.inc"

GdiPlusStartupInput GDI_Start

UINT GDI_Token

WINDOW w
INT hdc,gdi_ret

OPENWINDOW w,0,0,1024,768,@MINBOX|@MAXBOX|@SIZE|@MAXIMIZED,0,"GDI Test",&main

STARTTIMER w,500

run=1
WAITUNTIL run=0
CLOSEWINDOW w
END

SUB main
SELECT @MESSAGE
CASE @IDCREATE
CENTERWINDOW w
GDI_Start.GdiPlusVersion=1
gdi_ret = GdiPlusStartup(&GDI_Token,&GDI_Start,NULL)

CASE @IDCLOSEWINDOW
GdiPlusShutdown(GDI_Token)
run=0
CASE @IDTIMER
UINT pPen,pGraphics
STRING Buffer

STOPTIMER w

hdc = GETHDC(w)
IF gdi_ret=0
GdipCreateFromHDC(hdc, pGraphics)
'The color is ARGB
'UnitPixel,SmoothingModeAntiAlias are enums
'See "GdiPlusEnums.inc"
GdipCreatePen1(0xFF000000,1,UnitPixel,pPen)
GdipSetSmoothingMode(pGraphics,SmoothingModeAntiAlias)
FOR A = 1 TO 300 STEP 10
GdipDrawLineI(pGraphics,pPen,A,300,450,300 - A)
GdipDrawLineI(pGraphics,pPen,450,300 - A,900 - A,300)
GdipDrawLineI(pGraphics,pPen,A,300,450,300 + A)
GdipDrawLineI(pGraphics,pPen,450,300 + A,900 - A,300)
NEXT A
GdipDeletePen(pPen)
GdipDeleteGraphics(pGraphics)

ELSE
FormatMessage(0x1000, 0, GetLastError(), 0, Buffer, 254, 0)
MESSAGEBOX 0,Buffer,"GDI ERROR"
ENDIF
RELEASEHDC w,hdc
ENDSELECT
ENDSUB

[LarryMc]

This version works

LarryMc

Code Select Expand

$INCLUDE "windowssdk.inc"
$INCLUDE "gdiplus.inc"

GdiPlusStartupInput GDI_Start

UINT GDI_Token

WINDOW w
INT hdc,gdi_ret

OPENWINDOW w,0,0,1024,768,@MINBOX|@MAXBOX|@SIZE|@MAXIMIZED|@noautodraw,0,"GDI Test",&main

STARTTIMER w,500

run=1
WAITUNTIL run=0
CLOSEWINDOW w
END

SUB main
SELECT @MESSAGE
CASE @IDCREATE
CENTERWINDOW w
GDI_Start.GdiPlusVersion=1
gdi_ret = GdiPlusStartup(&GDI_Token,&GDI_Start,NULL)

CASE @IDCLOSEWINDOW
GdiPlusShutdown(GDI_Token)
run=0
CASE @IDTIMER
'pointer pPen=0,pGraphics=0
'STRING Buffer

STOPTIMER w
      case WM_PAINT
pointer pPen=0,pGraphics=0
STRING Buffer
hdc = GETHDC(w)
IF gdi_ret=0

GdipCreateFromHDC(hdc, &pGraphics)
'The color is ARGB
'UnitPixel,SmoothingModeAntiAlias are enums
'See "GdiPlusEnums.inc"
GdipCreatePen1(0xFF000000,1,UnitPixel,&pPen)
GdipSetSmoothingMode(&pGraphics,SmoothingModeAntiAlias)
FOR A = 1 TO 300 STEP 10
GdipDrawLineI(pGraphics,pPen,A,300,450,300 - A)
GdipDrawLineI(pGraphics,pPen,450,300 - A,900 - A,300)
GdipDrawLineI(pGraphics,pPen,A,300,450,300 + A)
GdipDrawLineI(pGraphics,pPen,450,300 + A,900 - A,300)
NEXT A
IF pPen THEN GdipDeletePen(pPen)
IF pGraphics then GdipDeleteGraphics(pGraphics) :pGraphics=0

ELSE
FormatMessage(0x1000, 0, GetLastError(), 0, Buffer, 254, 0)
MESSAGEBOX 0,Buffer,"GDI ERROR"
ENDIF
RELEASEHDC w,hdc
return 0
ENDSELECT
ENDSUB

[ckoehn]

Thanks, Larry.  I copied and it drew lines like it should, except they didn't look smooth.  Am I missing something?

Later,
Clint

[ckoehn]

Found it. This line: GdipSetSmoothingMode(&pGraphics,SmoothingModeAntiAlias)

needs to be this: GdipSetSmoothingMode(pGraphics,SmoothingModeAntiAlias)

GdipSetSmoothingMode needs to send the value, not the pointer.

Later,
Clint

[ckoehn]

Here is my preferred method of doing this.  My style of programming. 

You need to clear your graphics with GdipGraphicsClear(pGraphics,color) function before drawing to it.  Otherwise when the screen is resized the smoothing is removed.  Clearing the screen to your background color and then drawing on that takes care of the resize problem.

Later,
Clint

Code Select Expand

$INCLUDE "windowssdk.inc"
$INCLUDE "gdiplus.inc"

GdiPlusStartupInput GDI_Start

UINT GDI_Token

WINDOW w
INT hdc,gdi_ret

OPENWINDOW w,0,0,640,480,@MINBOX|@MAXBOX|@SIZE|@MAXIMIZED,0,"GDI Test",&main

RedrawScreen()

run=1
WAITUNTIL run=0
CLOSEWINDOW w
END

SUB main
SELECT @MESSAGE
CASE @IDCREATE
CENTERWINDOW w
GDI_Start.GdiPlusVersion=1
gdi_ret = GdiPlusStartup(&GDI_Token,&GDI_Start,NULL)

CASE @IDCLOSEWINDOW
GdiPlusShutdown(GDI_Token)
run=0

CASE @IDSIZECHANGED
RedrawScreen()
ENDSELECT
ENDSUB

SUB RedrawScreen()
pointer pPen=0,pGraphics=0
STRING Buffer
hdc = GETHDC(w)
IF gdi_ret=0

GdipCreateFromHDC(hdc, &pGraphics)

'clear the screen
GdipGraphicsClear(pGraphics,RGBA(255,255,255,255))

GdipCreatePen1(RGBA(0,0,0,255),1,UnitPixel,&pPen)
GdipSetSmoothingMode(pGraphics,SmoothingModeAntiAlias)
FOR A = 1 TO 300 STEP 10
GdipDrawLineI(pGraphics,pPen,A,300,450,300 - A)
GdipDrawLineI(pGraphics,pPen,450,300 - A,900 - A,300)
GdipDrawLineI(pGraphics,pPen,A,300,450,300 + A)
GdipDrawLineI(pGraphics,pPen,450,300 + A,900 - A,300)
NEXT A
IF pPen THEN GdipDeletePen(pPen)
IF pGraphics then GdipDeleteGraphics(pGraphics) :pGraphics=0

ELSE
FormatMessage(0x1000, 0, GetLastError(), 0, Buffer, 254, 0)
MESSAGEBOX 0,Buffer,"GDI ERROR"
ENDIF
RELEASEHDC w,hdc
ENDSUB


[sapero]

The code below uses simple caching to increase window resizing performance (more memory = faster)

Code Select Expand

$INCLUDE "windowssdk.inc"
$INCLUDE "gdiplus.inc"

GdiPlusStartupInput GDI_Start
UINT GDI_Token
WINDOW w
INT gdi_ret
HDC g_hdcCache

OPENWINDOW w,0,0,640,480,@MINBOX|@MAXBOX|@SIZE|@MAXIMIZED,0,"GDI Test",&main

RedrawScreen()

run=1
WAITUNTIL run=0
CLOSEWINDOW w
DeleteDC(g_hdcCache)
END

SUB main
SELECT @MESSAGE
CASE @IDCREATE
CENTERWINDOW w
GDI_Start.GdiPlusVersion=1
gdi_ret = GdiPlusStartup(&GDI_Token, &GDI_Start, NULL)

CASE @IDCLOSEWINDOW
GdiPlusShutdown(GDI_Token)
run=0

CASE @IDSIZECHANGED
RedrawScreen()
ENDSELECT
ENDSUB

SUB RedrawScreen(opt BOOL force=false)
pointer pPen=0,pGraphics=0
'STRING Buffer

if (!g_hdcCache)
HDC hdcdesk = GetDC(0)
g_hdcCache = CreateCompatibleDC(hdcdesk)
int screenX = GetSystemMetrics(SM_CXSCREEN)
int screenY = GetSystemMetrics(SM_CYSCREEN)
DeleteObject(SelectObject(g_hdcCache, CreateCompatibleBitmap(hdcdesk, screenX, screenY)))
force = true
endif

if (!gdi_ret and force)
GdipCreateFromHDC(g_hdcCache, &pGraphics)

'clear the screen
GdipGraphicsClear(pGraphics,RGBA(255,255,255,255))

GdipCreatePen1(RGBA(0,0,0,255),1,UnitPixel,&pPen)
GdipSetSmoothingMode(pGraphics,SmoothingModeAntiAlias)
FOR A = 1 TO 300 STEP 10
GdipDrawLineI(pGraphics,pPen,A,300,450,300 - A)
GdipDrawLineI(pGraphics,pPen,450,300 - A,900 - A,300)
GdipDrawLineI(pGraphics,pPen,A,300,450,300 + A)
GdipDrawLineI(pGraphics,pPen,450,300 + A,900 - A,300)
NEXT A
IF pPen THEN GdipDeletePen(pPen)
IF pGraphics then GdipDeleteGraphics(pGraphics)

ELSE if (gdi_ret)
' FormatMessage does not support gdiplus error codes (see Status enumeration in GdiplusTypes.inc)
'FormatMessage(0x1000, 0, GetLastError(), 0, Buffer, 254, 0)
MESSAGEBOX 0,"GDI ERROR", *<string>(pPen&0)
ENDIF

' copy to window
HDC hdcWindow = GetHDC(w)
WINRECT rc
GetClientRect(w.hwnd, &rc)
BitBlt(hdcWindow, 0, 0, rc.right, rc.bottom, g_hdcCache, 0,0, SRCCOPY)
RELEASEHDC w,hdcWindow
ENDSUB

[ckoehn]

sapero,

Thanks for your help.  It is always appreciated.

Later,
Clint