| /****************************************************************************** |
| ** Filename : imageSgi.cpp |
| ** UNCLASSIFIED |
| ** |
| ** Description : Utility to read SGI image format files. This code was |
| ** originally a SGI image loading utility provided with the |
| ** Mesa 3D library @ http://www.mesa3d.org by Brain Paul. |
| ** This has been extended to read all SGI image formats |
| ** (e.g. INT, INTA, RGB, RGBA). |
| ** |
| ** Revision History: |
| ** Date Name Description |
| ** 06/07/99 BRC Initial Release |
| ** |
| ** Note: |
| ** |
| ** The SGI Image Data (if not RLE) |
| ** |
| ** If the image is stored verbatim (without RLE), then image data directly |
| ** follows the 512 byte header. The data for each scanline of the first |
| ** channel is written first. If the image has more than 1 channel, all |
| ** the data for the first channel is written, followed by the remaining |
| ** channels. If the BPC value is 1, then each scanline is written as XSIZE |
| ** bytes. If the BPC value is 2, then each scanline is written as XSIZE |
| ** shorts. These shorts are stored in the byte order described above. |
| ** |
| ******************************************************************************/ |
| #define __IMAGESGI_CPP |
| |
| #include "imagesgi.h" |
| |
| #include <stdlib.h> |
| #include <stdio.h> |
| #include <string.h> |
| #include <math.h> |
| #include <assert.h> |
| |
| struct sImageSgiRaw |
| { |
| struct sImageSgiHeader header; |
| unsigned char *chan0; |
| unsigned char *chan1; |
| unsigned char *chan2; |
| unsigned char *chan3; |
| unsigned int *rowStart; |
| int *rowSize; |
| }; |
| |
| // Static routines |
| static struct sImageSgiRaw *ImageSgiRawOpen(char const * const fileName); |
| static void ImageSgiRawClose(struct sImageSgiRaw *raw); |
| static void ImageSgiRawGetRow(struct sImageSgiRaw *raw, unsigned char *buf, |
| int y, int z); |
| static void ImageSgiRawGetData(struct sImageSgiRaw *raw, struct sImageSgi |
| *final); |
| static void *SwitchEndian16(void *value); |
| static void *SwitchEndian32(void *value); |
| |
| // Static variables |
| FILE *mFp = NULL; |
| unsigned char *mChanTmp = NULL; |
| |
| |
| /*****************************************************************************/ |
| struct sImageSgi *ImageSgiOpen(char const * const fileName) |
| { |
| struct sImageSgiRaw *raw = NULL; |
| struct sImageSgi *final = NULL; |
| |
| raw = ImageSgiRawOpen(fileName); |
| final = new struct sImageSgi; |
| |
| assert(final); |
| if(final) |
| { |
| final->header = raw->header; |
| final->data = NULL; |
| ImageSgiRawGetData(raw, final); |
| ImageSgiRawClose(raw); |
| } |
| |
| return final; |
| } // ImageSgiRawOpen |
| |
| |
| /*****************************************************************************/ |
| void ImageSgiClose(struct sImageSgi *image) |
| { |
| |
| if(image) |
| { |
| if(image->data) |
| delete[] image->data; |
| image->data = NULL; |
| delete image; |
| } |
| image = NULL; |
| |
| return; |
| } // ImageSgiClose |
| |
| |
| /*****************************************************************************/ |
| static struct sImageSgiRaw *ImageSgiRawOpen(char const * const fileName) |
| { |
| struct sImageSgiRaw *raw = NULL; |
| int x; |
| int i; |
| bool swapFlag = false; |
| union |
| { |
| int testWord; |
| char testByte[4]; |
| } endianTest; |
| endianTest.testWord = 1; |
| |
| // Determine endianess of platform. |
| if(endianTest.testByte[0] == 1) |
| swapFlag = true; |
| else |
| swapFlag = false; |
| |
| raw = new struct sImageSgiRaw; |
| |
| assert(raw); |
| if(raw) |
| { |
| raw->chan0 = NULL; |
| raw->chan1 = NULL; |
| raw->chan2 = NULL; |
| raw->chan3 = NULL; |
| raw->rowStart = NULL; |
| raw->rowSize = NULL; |
| mFp = fopen(fileName, "rb"); |
| assert(mFp); |
| |
| fread(&raw->header, sizeof(struct sImageSgiHeader), 1, mFp); |
| if(swapFlag == true) |
| { |
| SwitchEndian16(&raw->header.magic); |
| SwitchEndian16(&raw->header.type); |
| SwitchEndian16(&raw->header.dim); |
| SwitchEndian16(&raw->header.xsize); |
| SwitchEndian16(&raw->header.ysize); |
| SwitchEndian16(&raw->header.zsize); |
| } |
| |
| mChanTmp = new unsigned char[raw->header.xsize * raw->header.ysize]; |
| assert(mChanTmp); |
| switch(raw->header.zsize) |
| { |
| case 4: |
| raw->chan3 = new unsigned char[raw->header.xsize * |
| raw->header.ysize]; |
| assert(raw->chan3); |
| case 3: |
| raw->chan2 = new unsigned char[raw->header.xsize * |
| raw->header.ysize]; |
| assert(raw->chan2); |
| case 2: |
| raw->chan1 = new unsigned char[raw->header.xsize * |
| raw->header.ysize]; |
| assert(raw->chan1); |
| case 1: |
| raw->chan0 = new unsigned char[raw->header.xsize * |
| raw->header.ysize]; |
| assert(raw->chan0); |
| } |
| |
| if(raw->header.type == IMAGE_SGI_TYPE_RLE) |
| { |
| x = raw->header.ysize * raw->header.zsize * sizeof(unsigned int); |
| raw->rowStart = new unsigned int[x]; |
| raw->rowSize = new int[x]; |
| |
| fseek(mFp, sizeof(struct sImageSgiHeader), SEEK_SET); |
| fread(raw->rowStart, 1, x, mFp); |
| fread(raw->rowSize, 1, x, mFp); |
| |
| if(swapFlag == true) |
| { |
| for(i=0; i<x/sizeof(unsigned int); i++) |
| SwitchEndian32(&raw->rowStart[i]); |
| for(i=0; i<x/sizeof(int); i++) |
| SwitchEndian32(&raw->rowSize[i]); |
| } |
| |
| } |
| |
| } |
| |
| return raw; |
| } // ImageSgiRawOpen |
| |
| |
| /*****************************************************************************/ |
| static void ImageSgiRawClose(struct sImageSgiRaw *raw) |
| { |
| |
| fclose(mFp); |
| mFp = NULL; |
| |
| if(mChanTmp) |
| delete[] mChanTmp; |
| mChanTmp = NULL; |
| |
| if(raw->chan0) |
| delete[] raw->chan0; |
| raw->chan0 = NULL; |
| |
| if(raw->chan1) |
| delete[] raw->chan1; |
| raw->chan1 = NULL; |
| |
| if(raw->chan2) |
| delete[] raw->chan2; |
| raw->chan2 = NULL; |
| |
| if(raw->chan3) |
| delete[] raw->chan3; |
| raw->chan3 = NULL; |
| |
| if(raw) |
| delete raw; |
| raw = NULL; |
| |
| return; |
| } // ImageSgiRawClose |
| |
| |
| /*****************************************************************************/ |
| static void ImageSgiRawGetRow(struct sImageSgiRaw *raw, unsigned char *buf, |
| int y, int z) |
| { |
| unsigned char *iPtr = NULL; |
| unsigned char *oPtr = NULL; |
| unsigned char pixel; |
| int count; |
| |
| if((raw->header.type & 0xFF00) == 0x0100) |
| { |
| fseek(mFp, raw->rowStart[y+z*raw->header.ysize], SEEK_SET); |
| fread(mChanTmp, 1, (unsigned int)raw->rowSize[y+z*raw->header.ysize], |
| mFp); |
| iPtr = mChanTmp; |
| oPtr = buf; |
| while(1) |
| { |
| pixel = *iPtr++; |
| count = (int)(pixel & 0x7F); |
| if(!count) |
| { |
| return; |
| } |
| if (pixel & 0x80) |
| { |
| while (count--) |
| { |
| *oPtr++ = *iPtr++; |
| } |
| } |
| else |
| { |
| pixel = *iPtr++; |
| while (count--) |
| { |
| *oPtr++ = pixel; |
| } |
| } |
| } |
| } |
| else |
| { |
| fseek(mFp, |
| sizeof(struct sImageSgiHeader)+(y*raw->header.xsize) + |
| (z*raw->header.xsize*raw->header.ysize), |
| SEEK_SET); |
| fread(buf, 1, raw->header.xsize, mFp); |
| } |
| |
| return; |
| } // ImageSgiRawGetRow |
| |
| |
| /*****************************************************************************/ |
| static void ImageSgiRawGetData(struct sImageSgiRaw *raw, struct sImageSgi |
| *final) |
| { |
| unsigned char *ptr = NULL; |
| int i, j; |
| |
| final->data = |
| new unsigned |
| char[raw->header.xsize*raw->header.ysize*raw->header.zsize]; |
| assert(final->data); |
| |
| ptr = final->data; |
| for(i=0; i<raw->header.ysize; i++) |
| { |
| switch(raw->header.zsize) |
| { |
| case 1: |
| ImageSgiRawGetRow(raw, raw->chan0, i, 0); |
| for(j=0; j<raw->header.xsize; j++) |
| *(ptr++) = raw->chan0[j]; |
| break; |
| case 2: |
| ImageSgiRawGetRow(raw, raw->chan0, i, 0); |
| ImageSgiRawGetRow(raw, raw->chan1, i, 1); |
| for(j=0; j<raw->header.xsize; j++) |
| { |
| *(ptr++) = raw->chan0[j]; |
| *(ptr++) = raw->chan1[j]; |
| } |
| break; |
| case 3: |
| ImageSgiRawGetRow(raw, raw->chan0, i, 0); |
| ImageSgiRawGetRow(raw, raw->chan1, i, 1); |
| ImageSgiRawGetRow(raw, raw->chan2, i, 2); |
| for(j=0; j<raw->header.xsize; j++) |
| { |
| *(ptr++) = raw->chan0[j]; |
| *(ptr++) = raw->chan1[j]; |
| *(ptr++) = raw->chan2[j]; |
| } |
| break; |
| case 4: |
| ImageSgiRawGetRow(raw, raw->chan0, i, 0); |
| ImageSgiRawGetRow(raw, raw->chan1, i, 1); |
| ImageSgiRawGetRow(raw, raw->chan2, i, 2); |
| ImageSgiRawGetRow(raw, raw->chan3, i, 3); |
| for(j=0; j<raw->header.xsize; j++) |
| { |
| *(ptr++) = raw->chan0[j]; |
| *(ptr++) = raw->chan1[j]; |
| *(ptr++) = raw->chan2[j]; |
| *(ptr++) = raw->chan3[j]; |
| } |
| break; |
| } |
| } |
| |
| return; |
| } // ImageSgiRawGetData |
| |
| |
| /*****************************************************************************/ |
| static void *SwitchEndian16(void *value) |
| { |
| short value16 = *(short *) value; |
| value16 = ((value16 & 0xff00) >> 8L) + |
| ((value16 & 0x00ff) << 8L); |
| *(short *)value = value16; |
| return value; |
| } // SwitchEndian16 |
| |
| |
| /*****************************************************************************/ |
| static void *SwitchEndian32(void *value) |
| { |
| int value32 = *(int *) value; |
| value32 = ((value32 & 0xff000000) >> 24L) + |
| ((value32 & 0x00ff0000) >> 8) + |
| ((value32 & 0x0000ff00) << 8) + |
| ((value32 & 0x000000ff) << 24L); |
| *(int *)value = value32; |
| return value; |
| } // SwitchEndian32 |
| |