Original Post
Ok, I am writing a routine to load bitmap images from .bmp files in GL_RBG format and have run into a problem: in the code below I determine the size of and allocate an array of bytes to hold the rgb values of the bitmap and then attempt to read them in from the file. The "file.read(..." line that I have commented out works fine while the for loop version doesn't. Why not?
In the for loop I am reading in 3 bytes (one R, one G, one B) every iteration and optionally reading in an extra byte for padding if the bitcount value in the bitmap header info structure is 32 instead of 24 per iteration with dataSize/3 iterations which is one iteration per pixel. Why am I getting different data than doing straight read on the file stream?
peace and (trance) out
Mage
[edited by - Mage2k on May 9, 2003 2:25:00 PM]
GLint dataSize;
if(bmp.bmiHeader.biSizeImage == 0){
if(bmp.bmiHeader.biBitCount == 24)
dataSize = bmiHeader.biWidth*bmiHeader.biHeight*3;
else
dataSize = bmiHeader.biWidth*bmiHeader.biHeight*4;
}
else
dataSize = bmiHeader.biSizeImage;
//allocate and clear memory for the image data
GLubyte *mData = new GLubyte[dataSize];
memset(mData, 0, dataSize);
//now read in the data
GLubyte *tempData = mData;
GLubyte pad;
file.seekg(bmfHeader.bfOffBits, ios::beg);
//file.read((char*) mData, dataSize);
for(int i=0; i < dataSize; tempData+=3, i+=3){
file >> tempData[0];
file >> tempData[1];
file >> tempData[2];
if(bmp.bmiHeader.biBitCount == 32){
file >> pad;
++i;
}
}
