Getting a screen shot

void glReadPixels(GLint x, GLint y, GLsizei width, GLsizei height, GLenum format, GLenum type, GLvoid *pixels);

// to take a screenshot

void *data;
glReadPixels(0, 0, screenWidth, screenHeight, GL_RGB, GL_UNSIGNED_BYTE, data);
// now write data to a file


// NOTE: remember that 0, 0 in OpenGL is the _bottom_ left corner of the screen

hope that helps
Matt

hi thanks for the quick reply.
emm the data i get in are in this format right?
data(0)=r
data(1)=g
data(2)=b

can i get it in this format
data(0)= integer where equal to hex bbggrr

Thanks alot again.

[edited by - Dark Kai on March 11, 2004 12:10:58 AM]

void Engine::CaptureScreen()
{
static int captures=0;
char filename[20];

sprintf( filename, "Data/screen%.2d.bmp", captures );
captures++;

BITMAPFILEHEADER bf;
BITMAPINFOHEADER bi;

char *image = new char[Width*Height*3];
FILE *file = fopen( filename, "wb");

if( image!=NULL )
{
if( file!=NULL )
{
glReadPixels( 0, 0, Width, Height, GL_BGR_EXT, GL_UNSIGNED_BYTE, image );

memset( &bf, 0, sizeof( bf ) );
memset( &bi, 0, sizeof( bi ) );

bf.bfType = ''MB'';
bf.bfSize = sizeof(bf)+sizeof(bi)+Width*Height*3;
bf.bfOffBits = sizeof(bf)+sizeof(bi);
bi.biSize = sizeof(bi);
bi.biWidth = Width;
bi.biHeight = Height;
bi.biPlanes = 1;
bi.biBitCount = 24;
bi.biSizeImage = Width*Height*3;

fwrite( &bf, sizeof(bf), 1, file );
fwrite( &bi, sizeof(bi), 1, file );
fwrite( image, sizeof(unsigned char), Height*Width*3, file );

fclose( file );
}
delete[] image;
}
}

Umm the return data for
glReadPixels(0, 0, screenWidth, screenHeight, GL_RGB, GL_UNSIGNED_BYTE, data);

had paddings rite ? And i''ve tried changing the width and height a few times and in result the padding size vary. Is there a solution for this or am I doing something wrong?

Thanks for the code CrystalClear, but i don''t quite understand some part of it couze I''m coding in vb.net.

I''ve no idea what does this chunk does.

memset( &bf, 0, sizeof( bf ) );
memset( &bi, 0, sizeof( bi ) );

bf.bfType = ''MB'';
bf.bfSize = sizeof(bf)+sizeof(bi)+Width*Height*3;
bf.bfOffBits = sizeof(bf)+sizeof(bi);
bi.biSize = sizeof(bi);
bi.biWidth = Width;
bi.biHeight = Height;
bi.biPlanes = 1;
bi.biBitCount = 24;
bi.biSizeImage = Width*Height*3;

Thanks anyway.