Comments for allanpetersen.com

Comment on TOpenGLAPPanel for XE2 by Allan

Allan — Fri, 16 Dec 2011 08:55:17 +0000

It is already available under downloads

http://allanpetersen.com/downloads/

Comment on TOpenGLAPPanel for XE2 by Pawel

Pawel — Fri, 16 Dec 2011 03:07:25 +0000

I would be very happy to have this comopnent on C++B XE. I got used to use it!

Comment on Demo of OpenGL Text 2D/3D by Hans

Hans — Fri, 02 Sep 2011 16:37:15 +0000

Hello! I have just downloaded the clock exemple and run it with the panel. Very good,indeed, but somewhat ´difficult for someone who is just begining OpenGL. I have tried to run simple console apps without success – I think it is there I must begin, I am totally new to OGL. Do You know anyplace I can find very simple exemples for RAD Studio console programs – I have problems with linking (aux etc). Greetings hans

Comment on VCL Component (TOpenGLAPPanel) by TzuYuan Lin

TzuYuan Lin — Sat, 12 Mar 2011 13:09:44 +0000

I’m appreciate your components.
Thanks for your sharing.
Good job!

Comment on FBO and Bitmap Layer Demo by Allan

Allan — Thu, 27 Jan 2011 20:13:50 +0000

Thanks…

Comment on FBO and Bitmap Layer Demo by Lauren

Lauren — Sun, 23 Jan 2011 19:04:38 +0000

Epic, this was *exactly* what I needed Pretty much everywhere I looked, people were saying that this effect isn’t possible with OpenGL and to use DirectX, which isn’t really an option when developing cross-platform. Again, absolutely epic – cheers!

Comment on VCL Component (TOpenGLAPPanel) by Allan

Allan — Sat, 25 Sep 2010 08:53:30 +0000

Here is a clue….:-)

//—- begin
// Get client geometry
int ii, Bytes, bb;
SIZE glsize;
unsigned char *pPixelData;

OpenGLPanel->MakeOpenGLPanelCurrent();
ClearSelection ();
Redraw ();

glsize.cx = OpenGLPanel->ClientWidth;
glsize.cy = OpenGLPanel->ClientHeight;

// —- Lines have to be 32 bytes aligned, suppose 24 bits per pixel
// —- just cropped it
glsize.cx -= glsize.cx % 4;

// —- Create a bitmap and select it in the device context
// —- Note that this will never be used but no matter

// —- Alloc pixel bytes
Bytes = 3 * glsize.cx * glsize.cy;
pPixelData = new unsigned char [Bytes];

// —- Copy from OpenGL
glReadPixels (0,0,glsize.cx,glsize.cy, GL_RGB, GL_UNSIGNED_BYTE, pPixelData);

// —- Pixel data is stored as GRB, not RGB
for (ii=0; ii bb = pPixelData[ii+1];
pPixelData[ii+1] = pPixelData[ii];
pPixelData[ii] = bb;
}

// ---- Fill header
// --- BITMAPINFOHEADER header;
BITMAPINFO header;

header.bmiHeader.biWidth = glsize.cx;
header.bmiHeader.biHeight = glsize.cy;
header.bmiHeader.biSizeImage = Bytes;
header.bmiHeader.biSize = 40;
header.bmiHeader.biPlanes = 1;
header.bmiHeader.biBitCount = 24; // RGB
header.bmiHeader.biCompression = 0;
header.bmiHeader.biXPelsPerMeter = 0;
header.bmiHeader.biYPelsPerMeter = 0;
header.bmiHeader.biClrUsed = 0;
header.bmiHeader.biClrImportant = 0;

// ---- Generate handle
HANDLE handle = (HANDLE)GlobalAlloc (GHND,sizeof(BITMAPINFO) + Bytes);
if (handle != NULL) {
// Lock handle
char *pData = (char *) ::GlobalLock((HGLOBAL)handle);
// Copy header and data
memcpy(pData,&header,sizeof(BITMAPINFO));
memcpy(pData+sizeof(BITMAPINFO),pPixelData,Bytes);
// Unlock
GlobalUnlock((HGLOBAL)handle);

// Push DIB in clipboard
OpenClipboard(OpenGLPanel->Handle);
EmptyClipboard();
SetClipboardData(CF_DIB, handle);
CloseClipboard();
}

delete [] pPixelData;
// —- End

Comment on VCL Component (TOpenGLAPPanel) by Phil

Phil — Fri, 24 Sep 2010 22:23:27 +0000

All working very well. I would appreciate any clues regarding copying my OpenGLAPP image to clipboard please.

Thanks

Comment on VCL Component (TOpenGLAPPanel) by Allan

Allan — Fri, 27 Aug 2010 22:04:43 +0000

Builder is including the headers to make sure no compiler errors occur when we compile.
unfortunally it is not very good to remove them when we delete a component again.

for repeated calls, headers normally include defines like

#ifndef TOpenGLAPPanelH
#define TOpenGLAPPanelH
… code
#endif

this ensures only one interpretation of the linker.

Comment on VCL Component (TOpenGLAPPanel) by Phil

Phil — Thu, 26 Aug 2010 11:56:59 +0000

Hi
OpenGLAP working well so far but my new installation of Builder2010 forces certain include files to appear in the header files of units containing forms, and forces #include “TOpenGLAPPanel.h” to appear before pragma hdrstop in the main unit, although it is already called in a subsequent header file (I have them daisychained to minimise repeated calls). Can anyone explain the logic behind this and whether it should be a problem.

I am also getting Linker warnings “Public symbol -gtd appearing in both module… and module…, and similarly for _dfb and _m but I think this is a legacy problem.