Files
OpenSceneGraph/src/osgPlugins/bmp/ReaderWriterBMP.cpp

422 lines
16 KiB
C++

#include <osg/Image>
#include <osg/Notify>
#include <osg/Geode>
#include <osg/Image>
#include <osg/GL>
#include <osgDB/Registry>
#include <osgDB/FileNameUtils>
/****************************************************************************
*
* Follows is code written by GWM and translated to fit with the OSG Ethos.
*
*
* Ported into the OSG as a plugin, Geoff Michel October 2001.
* For patches, bugs and new features
* please send them direct to the OSG dev team.
*
**********************************************************************/
#include <stdio.h>
#include <string.h>
#include <stdlib.h>
enum { ERROR_NO_ERROR =0,ERROR_READING_HEADER,ERROR_READING_PALETTE, ERROR_MEMORY, ERROR_READ_ERROR,
ERROR_NO_FILE,ERROR_READING_COLORS};
static int bmperror = ERROR_NO_ERROR;
// BMP format bits - at start of file is 512 bytes of pure garbage
enum ftype {MB=19778}; // magic number identifies a bmp file; actually chars 'B''M'
// allowed ftypes are 'BM' for windoze; OS2 allows:
//'BA' - Bitmap Array
//'CI' - Color Icon
//'CP' - Color Pointer (mouse cursor)
//'IC' - Icon
//'PT' - Pointer (mouse cursor)
enum ncol { BW=1, IA, RGB, RGBA};
struct bmpheader {
short FileType; //always MB
unsigned short siz[2]; // a dword for whole file size - make unsigned Feb 2002
short Reserved1, Reserved2; //reserved for future purposes
unsigned short offset[2]; //offset to image in bytes
};
struct BMPInfo {
long width; //width of the image in pixels
long height; // height of the image in pixels
short planes; //:word: number of planes (always 1)
short Colorbits; //word: number of bits used to describe color in each pixel
long compression; //compression used
long ImageSize; //image size in bytes
long XpixPerMeter; //pixels per meter in X
long YpixPerMeter; //pixels per meter in Y
long ColorUsed; //number of colors used
long Important; //number of "important" colors
// unsigned char rgbquad[4];
// long os2stuff[6]; // storage for os2.1 with 64 bytes to be read. Dont know what these are yet.
};
int
bmp_error(char *buffer, int bufferlen)
{
switch (bmperror)
{
case ERROR_READING_COLORS:
strncpy(buffer, "BMP loader: Error reading colours", bufferlen);
break;
case ERROR_READING_HEADER:
strncpy(buffer, "BMP loader: Error reading header", bufferlen);
break;
case ERROR_READING_PALETTE:
strncpy(buffer, "BMP loader: Error reading palette", bufferlen);
break;
case ERROR_MEMORY:
strncpy(buffer, "BMP loader: Out of memory error", bufferlen);
break;
case ERROR_READ_ERROR:
strncpy(buffer, "BMP loader: Read error", bufferlen);
break;
}
return bmperror;
}
/* byte order workarounds *sigh* */
void swapbyte(long *i)
{
char *vv=(char *)i;
char tmp=vv[0];
vv[0]=vv[3];
vv[3]=tmp;
tmp=vv[1];
vv[1]=vv[2];
vv[2]=tmp;
}
void swapbyte(unsigned long *i)
{
char *vv=(char *)i;
char tmp=vv[0];
vv[0]=vv[3];
vv[3]=tmp;
tmp=vv[1];
vv[1]=vv[2];
vv[2]=tmp;
}
void swapbyte(float *i)
{
char *vv=(char *)i;
char tmp=vv[0];
vv[0]=vv[3];
vv[3]=tmp;
tmp=vv[1];
vv[1]=vv[2];
vv[2]=tmp;
}
void swapbyte(unsigned short *i)
{
char *vv=(char *)i;
char tmp=vv[0];
vv[0]=vv[1];
vv[1]=tmp;
}
void swapbyte(short *i)
{
char *vv=(char *)i;
char tmp=vv[0];
vv[0]=vv[1];
vv[1]=tmp;
}
unsigned char *
bmp_load(const char *filename,
int *width_ret,
int *height_ret,
int *numComponents_ret)
{ // the main area of changes from the pic format loader.
// reads filename, and returns the buffer
// bmp is very very simple format
// even Master Gates could have invented it.
// It is extremely expensive on disk space - every RGB pixel uses 3 bytes plus a header!
// BMP - sponsored by Seagate.
// unsigned char palette[256][3];
unsigned char *buffer=NULL; // returned to sender & as read from the disk
bmperror = ERROR_NO_FILE;
FILE *fp = fopen(filename, "rb");
if (!fp) return NULL;
int ncolours;
int ncomp=0;
bool swap=false; // dont need to swap bytes
// actual size of the bitmap header; 12=os2; 40 = normal; 64=os2.1
struct bmpheader hd;
struct BMPInfo inf;
bmperror = ERROR_NO_ERROR;
fread((char *)&hd, sizeof(bmpheader), 1, fp);
if (hd.FileType != MB) {
swapbyte(&(hd.FileType));
swap=true;
if (hd.FileType != MB) {
bmperror=ERROR_READING_HEADER;
}
}
if (hd.FileType == MB) {
long infsize; //size of BMPinfo in bytes
unsigned char *cols=NULL; // dynamic colour palette
unsigned char *imbuff; // returned to sender & as read from the disk
fread((char *)&infsize, sizeof(long), 1, fp); // insert inside 'the file is bmp' clause
if (swap) swapbyte(&infsize);
unsigned char *hdr=new unsigned char[infsize]; // to hold the new header
fread((char *)hdr, 1,infsize-sizeof(long), fp);
long hsiz=sizeof(inf); // minimum of structure size &
if(infsize<=hsiz) hsiz=infsize;
memcpy(&inf,hdr, hsiz/*-sizeof(long)*/); // copy only the bytes I can cope with
delete [] hdr;
osg::notify(osg::INFO) << "loading "<<filename <<" "<<swap<<" "<<infsize<< " "<<sizeof(inf) << " "<<sizeof(bmpheader) << std::endl;
if (swap) { // inverse the field of the header which need swapping
swapbyte(&hd.siz[0]);
swapbyte(&hd.siz[1]);
swapbyte(&inf.Colorbits);
swapbyte(&inf.width);
swapbyte(&inf.height);
swapbyte(&inf.ImageSize);
}
if (infsize==12) { // os2, protect us from our friends ? || infsize==64
int wd = inf.width&0xffff; // shorts replace longs
int ht = inf.width>>16;
int npln = inf.height&0xffff; // number of planes
int cbits = inf.height>>16;
inf.width=wd;
inf.height=ht;
inf.planes=npln;
inf.Colorbits=cbits;
inf.ColorUsed=(long)pow(2.0,(double)inf.Colorbits); // infer the colours
}
osg::notify(osg::INFO) << "readbmp " <<inf.width<< " "<<inf.height << std::endl;
// previous size calculation, see new calcs below.
long size_prev = hd.siz[1]+hd.siz[0]*65536;
osg::notify(osg::INFO) << "previous size calc = "<<size_prev<<" hd.siz[1]="<<hd.siz[1]<<" hd.siz[0]="<<hd.siz[0]<<std::endl;
// order of size calculation swapped, by Christo Zietsman to fix size bug.
long size = hd.siz[1]*65536+hd.siz[0];
osg::notify(osg::INFO) << "new size calc = "<<size<<" hd.siz[1]="<<hd.siz[1]<<" hd.siz[0]="<<hd.siz[0]<<std::endl;
int ncpal=4; // default number of colours per palette entry
size -= sizeof(bmpheader)+infsize;
if (inf.ImageSize<size) inf.ImageSize=size;
imbuff = (unsigned char *)malloc( inf.ImageSize); // read from disk
fread((char *)imbuff, sizeof(unsigned char),inf.ImageSize, fp);
ncolours=inf.Colorbits/8;
switch (ncolours) {
case 1:
ncomp = BW; // actually this is a 256 colour, paletted image
inf.Colorbits=8; // so this is how many bits there are per index
inf.ColorUsed=256; // and number of colours used
cols=imbuff; // colour palette address - uses 4 bytes/colour
break;
case 2:
ncomp = IA;
break;
case 3:
ncomp = RGB;
break;
case 4:
ncomp = RGBA;
break;
default:
cols=imbuff; // colour palette address - uses 4 bytes/colour
if (infsize==12 || infsize==64) ncpal=3; // OS2 - uses 3 colours per palette entry
else ncpal=4; // Windoze uses 4!
}
if (ncomp>0) buffer = (unsigned char *)malloc( (ncomp==BW?3:ncomp)*inf.width*inf.height*sizeof(unsigned char)); // to be returned
else buffer = (unsigned char *)malloc( 3*inf.width*inf.height*sizeof(unsigned char)); // default full colour to be returned
unsigned long off=0;
unsigned long rowbytes=ncomp*sizeof(unsigned char)*inf.width;
unsigned long doff=(rowbytes)/4;
if ((rowbytes%4)) doff++; // round up if needed
doff*=4; // to find dword alignment
for(int j=0; j<inf.height; j++) {
if (ncomp>BW) memcpy(buffer+j*rowbytes, imbuff+off, rowbytes); // pack bytes closely
else { // find from the palette..
unsigned char *imptr=imbuff+inf.ColorUsed*ncpal; // add size of the palette- start of image
int npixperbyte=8/inf.Colorbits; // no of pixels per byte
for (int ii=0; ii<inf.width/npixperbyte; ii++) {
unsigned char mask=0x00; // masked with index to extract colorbits bits
unsigned char byte=imptr[(j*inf.width/npixperbyte)+ii];
int jj;
for (jj=0; jj<inf.Colorbits; jj++) mask |= (0x80>>jj); // fill N High end bits
for (jj=0; jj<npixperbyte; jj++) {
int colidx=(byte&mask)>>((npixperbyte-1-jj)*inf.Colorbits);
buffer[3*(j*inf.width+ii*npixperbyte+jj)+0]=cols[ncpal*colidx+2];
buffer[3*(j*inf.width+ii*npixperbyte+jj)+1]=cols[ncpal*colidx+1];
buffer[3*(j*inf.width+ii*npixperbyte+jj)+2]=cols[ncpal*colidx];
mask>>=inf.Colorbits;
}
}
}
off+=doff;
if (ncomp>2) { // yes bill, colours are usually BGR aren't they
for(int i=0; i<inf.width; i++) {
int ijw=i+j*inf.width;
unsigned char blu=buffer[3*ijw+0];
buffer[3*ijw+0]=buffer[3*ijw+2]; // swap order of colours
buffer[3*ijw+2]=blu;
}
}
}
free(imbuff); // free the on-disk storage
fclose(fp);
}
else // else error in header
{
fclose(fp);
return NULL;
}
*width_ret = inf.width;
*height_ret = inf.height;
switch (ncomp) {
case BW:
*numComponents_ret = 3;
break;
case IA:
case RGB:
case RGBA:
*numComponents_ret = ncomp;
break;
default:
*numComponents_ret = 3;
break;
}
return buffer;
}
class ReaderWriterBMP : public osgDB::ReaderWriter
{
public:
virtual const char* className() { return "BMP Image Reader"; }
virtual bool acceptsExtension(const std::string& extension) { return extension=="bmp"; }
virtual ReadResult readImage(const std::string& fileName, const osgDB::ReaderWriter::Options*)
{
std::string ext = osgDB::getFileExtension(fileName);
if (!acceptsExtension(ext)) return ReadResult::FILE_NOT_HANDLED;
unsigned char *imageData = NULL;
int width_ret;
int height_ret;
int numComponents_ret;
imageData = bmp_load(fileName.c_str(),&width_ret,&height_ret,&numComponents_ret);
if (imageData==NULL) return ReadResult::FILE_NOT_HANDLED;
int s = width_ret;
int t = height_ret;
int r = 1;
int internalFormat = numComponents_ret;
unsigned int pixelFormat =
numComponents_ret == 1 ? GL_LUMINANCE :
numComponents_ret == 2 ? GL_LUMINANCE_ALPHA :
numComponents_ret == 3 ? GL_RGB :
numComponents_ret == 4 ? GL_RGBA : (GLenum)-1;
unsigned int dataType = GL_UNSIGNED_BYTE;
osg::Image* pOsgImage = new osg::Image;
pOsgImage->setFileName(fileName.c_str());
pOsgImage->setImage(s,t,r,
internalFormat,
pixelFormat,
dataType,
imageData);
return pOsgImage;
}
virtual WriteResult writeImage(const osg::Image &img,const std::string& fileName, const osgDB::ReaderWriter::Options*)
{
std::string ext = osgDB::getFileExtension(fileName);
if (!acceptsExtension(ext)) return WriteResult::FILE_NOT_HANDLED;
FILE *fp = fopen(fileName.c_str(), "wb");
if (!fp) return WriteResult::ERROR_IN_WRITING_FILE;
// its easier for me to write a binary write using stdio than streams
struct bmpheader hd;
unsigned long nx=img.s(),ny=img.t(); // unsigned long ndep=img.r();
unsigned long size, wordsPerScan;
long infsize; //size of BMPinfo in bytes
wordsPerScan=(nx*3+3)/4; // rounds up to next 32 bit boundary
size=4*ny*wordsPerScan; // rounded to 4bytes * number of scan lines
hd.FileType=MB;
hd.Reserved1=hd.Reserved2=0; // offset to image
hd.offset[0]=sizeof(long)+sizeof(BMPInfo)+sizeof(hd); // 26; // offset to image
hd.offset[1]=0; // offset to image
// previous way round.
// hd.siz[0]=(size&0xffff0000)>>16; // high word
// hd.siz[1]=(size&0xffff); // low word
// new round to be consistent with the swap in the size calclation in the reading code.
hd.siz[0]=(size&0xffff); // low word
hd.siz[1]=(size&0xffff0000)>>16; // high word
fwrite(&hd, sizeof(hd), 1, fp);
struct BMPInfo inf;
osg::notify(osg::INFO) << "sizes "<<size << " "<<sizeof(inf)<< std::endl;
inf.width=nx; //width of the image in pixels
inf.height=ny; // height of the image in pixels
inf.planes=1; //:word: number of planes (always 1)
inf.Colorbits=24; //word: number of bits used to describe color in each pixel
inf.compression=0; //compression used windows says 0= no compression
inf.ImageSize=size; //nx*ny*3; //image size in bytes
inf.XpixPerMeter=1000; //pixels per meter in X
inf.YpixPerMeter=1000; //pixels per meter in Y
inf.ColorUsed=0; //number of colors used
inf.Important=0; //number of "important" colors
// inf.os2stuff[6]; // allows os2.1 with 64 bytes to be read. Dont know what these are yet.
infsize=sizeof(BMPInfo)+sizeof(long);
fwrite(&infsize, sizeof(long), 1, fp);
fwrite(&inf, sizeof(inf), 1, fp); // one dword shorter than the structure defined by MS
// the infsize value (above) completes the structure.
osg::notify(osg::INFO) << "save screen "<<fileName <<inf.width<< " "<<inf.height << std::endl;
osg::notify(osg::INFO) << "sizes "<<size << " "<<infsize <<" "<<sizeof(inf)<< std::endl;
// now output the bitmap
// 1) swap Blue with Red - needed for Windoss.
unsigned char *dta=new unsigned char[size];
unsigned char tmp;
memcpy(dta,img.data(),size*sizeof(unsigned char));
for(unsigned int i=0;i<ny;i++) { // per scanline
int ioff=4*wordsPerScan*i;
for(unsigned int j=0;j<nx;j++) {
tmp=dta[3*j+ioff]; // swap r with b, thanks to good ole Bill -
//"Let's use BGR it's more logical than rgb which everyone else uses."
dta[3*j+ioff]=dta[3*j+ioff+2];
dta[3*j+ioff+2]=tmp;
}
}
fwrite(dta, sizeof(unsigned char), size, fp);
delete [] dta;
fclose(fp);
return WriteResult::FILE_SAVED;
}
};
// now register with Registry to instantiate the above
// reader/writer.
osgDB::RegisterReaderWriterProxy<ReaderWriterBMP> g_readerWriter_BMP_Proxy;