/[cvs]/joko/Uni/BSArch/04/bmp_fractal.c
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revision 1.2 by joko, Sat Jul 1 09:40:29 2006 UTC revision 1.6 by joko, Sat Jul 1 13:56:54 2006 UTC
# Line 4  Line 4 
4   *   *
5   * Uebung 4.4   * Uebung 4.4
6   */   */
7    
8    // $Id$
9    
10    #include <windows.h>
11  #include <stdio.h>  #include <stdio.h>
12  #include <errno.h>  #include <errno.h>
13    
# Line 11  Line 15 
15  #define YSIZE 500  #define YSIZE 500
16  #include "algorithm.h"  #include "algorithm.h"
17    
18    
19  /* BMP Header */  /* BMP Header */
20  unsigned char header[54]={0x42,0x4d,              // signature BM  unsigned char header[54]={0x42,0x4d,              // signature BM
21                              0xe6,0x71,0x0b,0x0,   // filesize 750054                              0xe6,0x71,0x0b,0x0,   // filesize 750054
# Line 29  unsigned char header[54]={0x42,0x4d, Line 34  unsigned char header[54]={0x42,0x4d,
34                              0x0,0x0,0x0,0x0       // number of important colors                              0x0,0x0,0x0,0x0       // number of important colors
35                          };                          };
36    
37  int main(int argc, char *argv[])  
38  {  void printErrorAndExit(const char *msg, DWORD err) {
39      FILE *fd;          LPSTR lpMsgBuf;
40      int len,x,y;          if(FormatMessage(FORMAT_MESSAGE_ALLOCATE_BUFFER|
41      char bgr[3];                                    FORMAT_MESSAGE_FROM_SYSTEM |
42      short svalue;                                            FORMAT_MESSAGE_IGNORE_INSERTS,
43      int   lvalue;                                                  NULL,
44      //unsigned char header[54],*ptr=&header[0];                                                  err,
45                                              MAKELANGID(LANG_NEUTRAL, SUBLANG_DEFAULT), // Default language
46                                              (LPTSTR) &lpMsgBuf,
47                                              0,
48                                              NULL ))
49            {
50                    fprintf(stderr,"%s : %s\n",msg,lpMsgBuf);
51                    LocalFree(lpMsgBuf);
52            }
53            else
54            {
55                    fprintf(stderr,"Error at FormatMesage: %d\n",err=GetLastError());
56            }
57            exit(err);
58    }
59    
60    
61    void write_blank_file(char *filename) {
62    
63      FILE *fd;
64      int len, i, img_size;
65    
66      // open file handle
67      fd = fopen(filename, "wb+");
68      if (NULL == fd) {
69        perror("open");
70        exit(1);
71      }
72    
73      // write bmp header to file
74      len = fwrite(header, 1, sizeof(header), fd);
75      
76      // error checking
77      if (-1 == len || len != sizeof(header)) {
78        perror("write");
79        exit(2);
80      }
81      
82      // write three null-bytes for each pixel to file to create a black picture
83      img_size = XSIZE * YSIZE;
84      for (i = 0; i < img_size; i++) {
85        len = fwrite("\0\0\0", 1, 3, fd);
86        if (-1 == len || len != 3) {
87          perror("write");
88          exit(4);
89        }
90      }
91      
92      // close file handle
93      fclose(fd);
94    }
95    
96    
97    // arguments for each thread
98    typedef struct _WorkerArguments {
99      unsigned int start_row;
100      unsigned int number_of_rows;
101      unsigned char * pBitmap;
102    } WORKERARGS, *PWORKERARGS;
103    
104    // worker thread - main entry function
105    DWORD WINAPI fractal_thread (LPVOID lpParam) {
106      
107      // thread stuff
108      int thread_id;
109      PWORKERARGS args;
110    
111      // fractal calculation
112      int x, y;
113      char bgr[3];
114    
115      thread_id = GetCurrentThreadId();
116      
117      // get worker arguments
118      args = (PWORKERARGS)lpParam;
119      
120      printf("thread_id: %i\n", thread_id);
121      printf("arg.start_row: %i\n", args->start_row);
122      printf("arg.number_of_rows: %i\n", args->number_of_rows);
123      
124      // calculate fractal
125      for (y = (args->start_row + args->number_of_rows) - 1; y >= args->start_row; y--) {
126        for (x = 0; x < XSIZE; x++) {
127          getColorValuesAt(x * (2.0 / XSIZE) - 1.5, y * (2.0 / YSIZE) - 1.0, &bgr[2], &bgr[1], &bgr[0]);
128          
129          // debugging
130          //printf("pointer: %p\n", pDataBitmapCurrent);
131          
132          // transfer color values to current pixel
133          args->pBitmap[0] = bgr[0];
134          args->pBitmap[1] = bgr[1];
135          args->pBitmap[2] = bgr[2];
136          
137          // move pointer to next pixel
138          args->pBitmap += 3;
139                
     fd=fopen("test.bmp","wb+");  
     if(NULL==fd)  
     {  
         perror("open"); exit(1);  
140      }      }
141        //no padding required because 1500%4 =0
142      }
143    
144      len=fwrite(header,1,sizeof(header),fd); //write header    return 0;
145    
146    }
147    
148    
149    int main(int argc, char *argv[]) {
150    
151      // MMF support
152      DWORD err;
153      HANDLE hMap, hFile;
154      LPVOID pData;
155      unsigned char *pDataBitmap, *pDataBitmapCurrent;
156    
157      // workers
158      unsigned int workers = 3;
159      unsigned int worker_index, worker_rows, worker_startrow;
160      HANDLE *worker_handles;
161      //struct WorkerArguments *worker_args;
162      PWORKERARGS worker_args;
163    
164      
165      // create empty bmp-file (black background)
166      write_blank_file("test.bmp");
167    
168      /* open file for reading and writing */
169      hFile = CreateFile("test.bmp", GENERIC_WRITE|GENERIC_READ, 0, NULL, OPEN_EXISTING, FILE_ATTRIBUTE_NORMAL, NULL);
170      if (INVALID_HANDLE_VALUE == hFile) {
171        err = GetLastError();
172        printErrorAndExit("Error at CreateFile",err);
173      }
174    
175      /* create the file mapping object */
176      hMap = CreateFileMapping(hFile, NULL, PAGE_READWRITE, 0, 0, NULL);
177      if (NULL == hMap) {
178        printErrorAndExit("Error at CreateFileMapping", GetLastError());
179      }
180      
181      /* map the whole file into the process context */
182      pData = MapViewOfFile(hMap, FILE_MAP_WRITE, 0, 0, 0);
183      if (NULL == pData) {
184        printErrorAndExit("Error at MapViewOfFile", GetLastError());
185      }
186    
187      
188      // calculate pointer to beginning of bitmap
189      pDataBitmap = (unsigned char *)((INT_PTR)pData + sizeof(header));
190      
191      // debugging
192      printf("pos. of file: %p\n", pData);
193      printf("pos. of bitmap: %p\n", pDataBitmap);
194    
195      // pointer to current pixel
196      pDataBitmapCurrent = pDataBitmap;
197    
198      /*
199      // turn bitmap into white wand
200      for (offset = 0; offset < 500 * 500 * 3; offset++) {
201        //pDataBitmap[offset] = 255;
202        *pDataBitmapCurrent = 255;
203        pDataBitmapCurrent++;
204      }
205      */
206    
207    
208      // allocate memory for table of all worker handles
209      if ((worker_handles = malloc(workers * sizeof worker_handles[0])) == NULL)
210        perror("malloc"), exit(1);
211    
212      /*
213      // allocate memory for table of all worker arguments
214      if ((worker_args = malloc(workers * sizeof worker_args[0])) == NULL)
215        perror("malloc"), exit(1);
216      */
217      // allocate memory for table of all worker arguments
218      worker_args = (PWORKERARGS) HeapAlloc(GetProcessHeap(), HEAP_ZERO_MEMORY, workers * sizeof(WORKERARGS));
219      
220      // calculate segments of bitmap for worker threads/processes and start them
221      worker_rows = YSIZE / workers;
222      printf("rows for each worker: %i\n", worker_rows);
223      for (worker_index = 0; worker_index < workers; worker_index++) {
224            
225      if(-1==len || len!=sizeof(header))      // number of row to start for each worker
226      {      worker_startrow = worker_index * worker_rows;
227          perror("write");      
228          exit(2);      // recalculate number of rows for last worker if (YSIZE mod workers) != 0
229        if (worker_index == workers - 1) {
230          worker_rows = YSIZE - worker_startrow;
231          printf("rows for last worker: %i\n", worker_rows);
232      }      }
233            
234      for(y=YSIZE-1;y>=0;y--)      worker_args[worker_index].start_row = worker_startrow;
235      {      worker_args[worker_index].number_of_rows = worker_rows;
236              for(x=0;x<XSIZE;x++)      worker_args[worker_index].pBitmap = pDataBitmap;
237              {      
238                  getColorValuesAt(x * (2.0 / XSIZE) - 1.5, y * (2.0 / YSIZE) - 1.0,&bgr[2],&bgr[1],&bgr[0]);      worker_handles[worker_index] = CreateThread(
239                          NULL,                          // LPSECURITY_ATTRIBUTES lpThreadAttributes,
240                  len=fwrite(bgr,1,3,fd);        0,                             // SIZE_T dwStackSize,
241                  if(-1==len || len!=3)        fractal_thread,                // LPTHREAD_START_ROUTINE lpStartAddress,
242                  {        &worker_args[worker_index],    // LPVOID lpParameter,
243                      perror("write");        0,                             // DWORD dwCreationFlags,
244                      exit(4);        NULL                           // LPDWORD lpThreadId
245                  }      );
             }  
             /*no padding required because 1500%4 =0*/  
     }          
     fclose(fd);  
246            
247      }
248    
249      // wait for all threads
250      if (WaitForMultipleObjects(workers, worker_handles, TRUE, INFINITE) == WAIT_FAILED)
251        perror("WaitForMultipleObjects");
252      
253      /* write the result into the file */
254      if (!FlushViewOfFile(pData, 0)) {
255        err = GetLastError();
256        printErrorAndExit("Error at UnmapViewOfFile", err);
257      }
258    
259      /* remove the mapped file */
260      if (!UnmapViewOfFile(pData)) {
261        err = GetLastError();
262        printErrorAndExit("Error at UnmapViewOfFile", err);
263        exit(err);
264      }
265      
266      /* cleanup handles */
267      if (!CloseHandle(hMap) || !CloseHandle(hFile) ) {
268        err = GetLastError();
269        printErrorAndExit("Error at CloseHandle", err);
270      }
271    
272  }  }
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