我从here复制了源代码。
试图在MPI上进行图像处理并得到这些错误：
/tmp/cc0Z7iuC.o: In function `rotate' :
image.c:(.text+0xd1):undefined reference to `cos'
image.c:(.text+0xfa):undefined reference to `sin'
image.c:(.text+0x147):undefined reference to `sin'
image.c:(.text+0x170):undefined reference to `cos'
collect2: ld returned 1 exit status
不确定MPI计划是如何运作的，因为我是新手。
这是代码：
#include<stdio.h>
#include<stdlib.h>
#include<unistd.h>
#include<stdint.h>
#include<string.h>
#include<math.h>
#include<mpi.h>
#define BM 0x4D42 // Value of a bitmap type
#define MAX_FILENAME 256
#define PI 3.14159265
#define BLOCK_LOW(id,p,n) ((id)*(n)/(p))
#define BLOCK_HIGH(id,p,n) \
(BLOCK_LOW((id)+1,p,n)-1)
#define BLOCK_SIZE(id,p,n) \
(BLOCK_LOW((id)+1)-BLOCK_LOW(id))
#define BLOCK_OWNER(index,p,n) \
(((p)*((index)+1)-1)/(n))
// Struct to hold a 2d vector
#pragma pack(push, 1)
typedef struct Vector
{
int x,y;
} Vector;
#pragma pack(pop)
typedef enum { NS, SHIFT, SCALE, ROTATE } operation;
typedef struct Options
{
operation op;
char * inputfile;
char * filename;
Vector v;
double param;
int flag;
void (*func)(Vector *v, Vector *r, int p, int row, double sf);
} Options;
// BITMAP header
#pragma pack(push, 1)
typedef struct
{
uint16_t type;
uint32_t size;
uint16_t reserved1, reserved2;
uint32_t offset;
} HEADER;
#pragma pack(pop)
// BITMAP information header
#pragma pack(push, 1)
typedef struct
{
uint32_t size;
int32_t width, height;
uint16_t planes;
uint16_t bits;
uint32_t compression;
uint32_t isize;
int32_t xres,yres;
uint32_t colors;
uint32_t impcolors;
} IHEADER;
#pragma pack(pop)
// Pixel
#pragma pack(push, 1)
typedef struct Pixel
{
uint8_t b,g,r;
} Pixel;
#pragma pack(pop)
// Struct to hold info on a bitmap
#pragma pack(push, 1)
typedef struct
{
HEADER header;
IHEADER iheader;
Pixel ** array;
} BMP;
#pragma pack(pop)
// Printed if a filename is not supplied
void usage()
{
//while((c = getopt(argc, argv, "f:o:x:y:r:s:")) != -1)
printf("Usage: image_manip: -f <filename> [OPTS]\n\
The program can be run without the following options for a menu.\n\
Otherwise, an output file name is required.\n\
Operations are mutually exclusive.\n\
-o <filename>\tName of output file.\n\
-x <int>\t\tAmount to shift in x direction. Requires -y\n\
-y <int>\t\tAmount to shift in y direction. Requires -x\n\
-r <double>\t\tAmount to rotate image.\n\
-s <double>\t\tAmount to scale image.\n");
exit(1);
}
void shift(Vector * v, Vector * r, int p, int row, double sf)
{
(*r).x = p + (*v).x;
(*r).y = row + (*v).y;
}
void scale(Vector * v, Vector * r, int p, int row, double sf)
{
(*r).x = (int)p*sf;
(*r).y = (int)row*sf;
}
void rotate(Vector * v, Vector *r, int p, int row, double sf)
{
(*r).x = (int)p*cos(sf*PI/180)+row*sin(sf*PI/180);
(*r).y = (int)-1*p*sin(sf*PI/180)+row*cos(sf*PI/180);
}
// Performs an image shift
void do_op(BMP * img, Options * opt)
{
int rank, size;
MPI_Comm_rank(MPI_COMM_WORLD, &rank);
MPI_Comm_size(MPI_COMM_WORLD, &size);
// Number of bits in a line
int linebits = (*img).iheader.width * (*img).iheader.bits;
// 4 byte alignment
int linebytes = ((linebits + 31)/32)*4;
Pixel * current;
Vector newvec;
// Accounting
int row = 0;
int p = 0;
int count = sizeof(Pixel)*linebytes;
MPI_Status status;
// Master
if(rank == 0)
{
// Open the new file
FILE * nf;
nf = fopen((*opt).filename,"w");
// Make sure we are at the beginning
fseek(nf,0,SEEK_SET);
// Write the headers
fwrite(&(*img).header,1,sizeof((*img).header),nf);
fwrite(&(*img).iheader,1,sizeof((*img).iheader),nf);
// Allocate memory for a new pixel array
Pixel ** newimg = malloc(sizeof(Pixel*) * (*img).iheader.height);
// For every row
for(row = 0; row < (*img).iheader.height; row++)
{
current = (Pixel *) malloc(sizeof(Pixel)*linebytes);
memset(current,0,sizeof(Pixel)*linebytes);
MPI_Recv(current, count,MPI_BYTE, MPI_ANY_SOURCE, MPI_ANY_TAG, MPI_COMM_WORLD, &status);
newimg[status.MPI_TAG] = current;
}
// Write the new image
for(row = (*img).iheader.height-1; row >= 0; row--)
fwrite(&newimg[row][0],1,linebytes,nf);
fclose(nf);
free(newimg);
}
else
{
current = (Pixel *) malloc(sizeof(Pixel)*linebytes);
// For every row
int r = BLOCK_LOW(rank-1,size-1,(*img).iheader.height);
Pixel blank;
blank.r = blank.g = blank.b = 0;
for(row = r; row <= BLOCK_HIGH(rank-1,size-1,(*img).iheader.height); row++)
{
// fprintf(stderr,"Rank,row [%d][%d]\n",rank,row);
// Set the memory to 0 by default (black), this also pads zeroes
memset(current,0,sizeof(current));
// For every pixel in the row (3 bytes)
for(p = 0; p < linebytes/3; p++)
{
// Calc x,y
(*opt).func(&(*opt).v, &newvec, p, row, (*opt).param);
// Make sure they are on the canvas
if(newvec.x >= 0 && newvec.x < linebytes/3 && newvec.y < (*img).iheader.height && newvec.y >= 0)
current[p] = (*img).array[newvec.y][newvec.x];
else
current[p] = blank;
}
MPI_Send(current, count, MPI_BYTE, 0, row, MPI_COMM_WORLD);
}
}
// fprintf(stderr, "Rank %d: %d->%d\n",rank,BLOCK_LOW(rank-1,size-1,(*img).iheader.height),BLOCK_HIGH(rank-1,size-1,(*img).iheader.height));
free(current);
}
// Program menu
int do_menu(BMP * img, Options * opts)
{
int rank,size;
int choice;
char * name = (char *) malloc(sizeof(char) * MAX_FILENAME);
MPI_Comm_rank(MPI_COMM_WORLD, &rank);
MPI_Comm_size(MPI_COMM_WORLD, &size);
//fprintf(stderr,"[%s][%d] %d\n",__FILE__,__LINE__,rank);
if(rank == 0)
{
printf("\
Options\n\
=======\n\
1. Shift\n\
2. Scale\n\
3. Rotate\n\
4. Exit\n\
Enter a selection: ");
fflush(stdout);
scanf("%d",&choice);
if(choice == 1 || choice == 2 || choice == 3)
{
printf("Enter a filename for the new image: ");
fflush(stdout);
scanf("%s",name);
(*opts).filename = name;
}
}
// \TODO: Merge this
if(rank == 0)
{
switch(choice)
{
case 1:
printf("Enter integer delta x: ");
fflush(stdout);
scanf("%d",&(*opts).v.x);
printf("Enter integer delta y: ");
fflush(stdout);
scanf("%d",&(*opts).v.y);
(*opts).func = shift;
break;
case 2:
printf("Enter a decimal scale factor: ");
fflush(stdout);
scanf("%lf",&(*opts).param);
(*opts).func = scale;
break;
case 3:
printf("Enter decimal degrees to rotate: ");
fflush(stdout);
scanf("%lf",&(*opts).param);
(*opts).func = rotate;
break;
case 4:
return 0;
break;
default: break;
}
}
MPI_Bcast(opts,sizeof(*opts),MPI_BYTE,0,MPI_COMM_WORLD);
do_op(img, opts);
return 0;
}
// Read bitmap header
int get_bmp_header(FILE * fp, BMP * img)
{
if(sizeof((*img).header) != fread(&(*img).header,1,sizeof((*img).header),fp))
{
perror("Unable to read file");
exit(1);
}
if(sizeof((*img).iheader) != fread(&(*img).iheader,1,sizeof((*img).iheader),fp))
{
perror("Unable to read file");
exit(1);
}
if((*img).header.type != BM)
{
printf("Error: Not a valid bitmap file.\n");
exit(1);
}
return 0;
}
// Print attributes
int print_bmp_attr(BMP * bmp)
{
printf("File: \n\t\
Type: %X\n\t\
Size: %d\n\t\
Offset: %d\n\t\
Width: %d\n\t\
Height: %d\n\t\
Image Size: %u\n\t\
Bits/Pixel: %u\n\t\
Compression: %u\n\t\
Number of colors: %u\n\t\
Important colors: %u\n", (*bmp).header.type, (*bmp).header.size, (*bmp).header.offset,(*bmp).iheader.width,(*bmp).iheader.height,(*bmp).iheader.isize, (*bmp).iheader.bits, (*bmp).iheader.compression,(*bmp).iheader.colors,(*bmp).iheader.impcolors);
return 0;
}
void parse_args(int argc, char **argv, Options * opts)
{
// Parse options
int c = 0;
while((c = getopt(argc, argv, "f:o:x:y:r:s:")) != -1)
{
switch(c)
{
case 'f':
(*opts).inputfile = optarg;
break;
case 'o':
(*opts).filename = optarg;
break;
case 'x':
(*opts).flag++;
(*opts).op = SHIFT;
(*opts).func = shift;
(*opts).v.x = atoi(optarg);
break;
case 'y':
(*opts).flag++;
(*opts).v.y = atoi(optarg);
break;
case 'r':
(*opts).op = ROTATE;
(*opts).func = rotate;
(*opts).param = atof(optarg);
break;
case 's':
(*opts).op = SCALE;
(*opts).func = scale;
(*opts).param = atof(optarg);
default:
break;
}
}
}
// Main
int main(int argc, char **argv)
{
if(MPI_Init(&argc,&argv) != MPI_SUCCESS)
{
perror("Unable to initialize MPI\n");
exit(1);
}
FILE * fp = 0;
BMP bmp;
Options opts;
opts.op = NS;
opts.filename = 0;
opts.flag = 0;
parse_args(argc, argv, &opts);
if((fp = fopen(opts.inputfile,"rw")) == NULL)
{
usage();
perror("Unable to open file");
exit(1);
}
get_bmp_header(fp, &bmp);
// print_bmp_attr(&bmp);
int linebits = bmp.iheader.width * bmp.iheader.bits;
int linebytes = ((linebits + 31)/32)*4;
Pixel ** img = malloc(sizeof(Pixel*) * bmp.iheader.height);
fseek(fp, bmp.header.offset, SEEK_SET);
int row = 0;
int byte = 0;
int column = 0;
//int rank, size;
Pixel * current;
for(row = bmp.iheader.height-1; row >= 0; row--)
{
current = (Pixel *) malloc(linebytes);
column = 0;
for(byte = 0; byte < linebytes; byte+=3)
{
fread(¤t[column++],1,sizeof(Pixel),fp);
}
img[row] = current;
fseek(fp, bmp.header.offset + (bmp.iheader.height-1-row) * linebytes, SEEK_SET);
}
fclose(fp);
bmp.array = img;
if(opts.op == NS)
do_menu(&bmp,&opts);
else if(opts.filename == 0)
usage();
else
{
switch(opts.op)
{
case SCALE:
opts.func = scale;
break;
case SHIFT:
if(opts.flag == 2)
opts.func = shift;
else
usage();
break;
case ROTATE:
opts.func = rotate;
break;
case NS:
default:
usage();
break;
}
do_op(&bmp, &opts);
}
free(img);
MPI_Finalize();
return 0;
}
之前感谢
答案 0 :(得分：1)
您需要链接数学库：
gcc .... -lm