Does anybody have some simple code for loading bitmaps to textures which doesn’t use glaux.h and is machine independant (even though bmps are not 
)
Cheers, Tom
Hello there, funny isn’t it, I have the SAME problem! I asked for the SIMPLEST sample code of how to load a texture onto a quad from a .bmp file and the code that I got was GOOD but it was for WINDOWS and I use Linux, it also uses GLAUX. SO I guess we are in the same boat! If you get any good code can you please send it to me at
osushkov@hotmail.com
I would really appreciate the help!
Hi guys,
try that, this code is taken from my tga loader and converted to a BMP loader (did this in 2-3 minutes, so don’t expect it to be too clean).
I tested it and it seemed to work. It’s simple c++ code that should work on any platform (for windows bitmaps, hé 
). If you want it in c, just remove the throw stuff and replace the operator new with calls to the malloc function.
unsigned char* LoadBMP(char *file_name, int &size, int bytes_to_store)
{
FILE *image_file; // Image file’s handle
char file_header[54]; // BMP file’s header
int image_size; // Size of the image in pixels
unsigned char *file_buffer; // Buffer that temporarily holds the data from the file
int pixpos; // Position of the pixel currently copied
int copied; // Number of bytes copied for the current pixel
int i, j; // Counter variables
unsigned char *dest; // Destination buffer
int file_name_length; // Length of the file’s name
// Try to open the file and check if it exists
image_file = fopen(file_name, "rb");
file_name_length = strlen(file_name);
if(image_file == NULL)
{
throw "no such file";
}
fread(file_header, 54, 1, image_file);
// Parse the header
image_size = (file_header[18] + 256 * file_header[19]) * (file_header[22] + 256 * file_header[23]);
int bpp = (int)file_header[28];
if(bpp < 24)
{
throw "file w/ -24bpp not supported";
}
// check the storage format to be a supported one
if((bytes_to_store != GL_RGB) && (bytes_to_store != GL_LUMINANCE))
{
throw "The storage format specified is not valid";
}
// Allocate memory
size = image_size * ((bytes_to_store == GL_RGB) ? 3 : 1);
dest = new unsigned char[size];
file_buffer = new unsigned char[image_size * 3];
fread(file_buffer, (image_size * 3), 1, image_file);
fclose(image_file);
// copying image data to memory
for(i = 0; i < image_size; i++)
{
// move current position
pixpos = i * 3;
// Compute and store Y
if(bytes_to_store == GL_LUMINANCE)
{
dest[i] = (unsigned char)(0.299 * file_buffer[pixpos + 2]) +
(0.587 * file_buffer[pixpos + 1]) + (0.114 * file_buffer[pixpos]);
}
else
{
// init number of bytes copied from current pixel
copied = 0;
// Copy BGR to RGB (swapping)
for(j = 2; j >= 0; j--)
{
dest[i * 3 + (copied++)] = file_buffer[pixpos + j];
}
}
}
// Free memory
delete [] file_buffer;
return dest;
}
you can call it with GL_RGB or GL_LUMINANCE as third param (with GL_LUMINANCE, it calculates the luminance of each pixel and store the image as 8bpp).
PS: you should consider using tga files as they can store an alpha channel.
Moz
[This message has been edited by Moz (edited 11-29-2000).]
Open Image Library. Cross platform, and works under many API’s. Does lots of file formats.
Cheers,
Nutty