/[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 1.9 by joko, Sun Jul 2 00:24:17 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    BOOL VERBOSE = FALSE;
19    
20    
21  /* BMP Header */  /* BMP Header */
22  unsigned char header[54]={0x42,0x4d,              // signature BM  unsigned char header[54]={0x42,0x4d,              // signature BM
23                              0xe6,0x71,0x0b,0x0,   // filesize 750054                              0xe6,0x71,0x0b,0x0,   // filesize 750054
# Line 29  unsigned char header[54]={0x42,0x4d, Line 36  unsigned char header[54]={0x42,0x4d,
36                              0x0,0x0,0x0,0x0       // number of important colors                              0x0,0x0,0x0,0x0       // number of important colors
37                          };                          };
38    
39  int main(int argc, char *argv[])  
40  {  void printErrorAndExit(const char *msg, DWORD err) {
41      FILE *fd;          LPSTR lpMsgBuf;
42      int len,x,y;          if(FormatMessage(FORMAT_MESSAGE_ALLOCATE_BUFFER|
43      char bgr[3];                                    FORMAT_MESSAGE_FROM_SYSTEM |
44      short svalue;                                            FORMAT_MESSAGE_IGNORE_INSERTS,
45      int   lvalue;                                                  NULL,
46      //unsigned char header[54],*ptr=&header[0];                                                  err,
47                                              MAKELANGID(LANG_NEUTRAL, SUBLANG_DEFAULT), // Default language
48                                              (LPTSTR) &lpMsgBuf,
49                                              0,
50                                              NULL ))
51            {
52                    fprintf(stderr,"%s : %s\n",msg,lpMsgBuf);
53                    LocalFree(lpMsgBuf);
54            }
55            else
56            {
57                    fprintf(stderr,"Error at FormatMesage: %d\n",err=GetLastError());
58            }
59            exit(err);
60    }
61    
62    
63    void write_blank_file(char *filename) {
64    
65      FILE *fd;
66      int len, i, img_size;
67    
68      // open file handle
69      fd = fopen(filename, "wb+");
70      if (NULL == fd) {
71        perror("open");
72        exit(1);
73      }
74    
75      // write bmp header to file
76      len = fwrite(header, 1, sizeof(header), fd);
77      
78      // error checking
79      if (-1 == len || len != sizeof(header)) {
80        perror("write");
81        exit(2);
82      }
83      
84      // write three null-bytes for each pixel to file to create a black picture
85      img_size = XSIZE * YSIZE;
86      for (i = 0; i < img_size; i++) {
87        len = fwrite("\0\0\0", 1, 3, fd);
88        if (-1 == len || len != 3) {
89          perror("write");
90          exit(4);
91        }
92      }
93      
94      // close file handle
95      fclose(fd);
96    }
97    
98    
99    // arguments for each thread
100    typedef struct _WorkerArguments {
101      int start_row;
102      int number_of_rows;
103      unsigned char * pBitmap;
104    } WORKERARGS, *PWORKERARGS;
105    
106    // worker thread - main entry function
107    DWORD WINAPI fractal_thread (LPVOID lpParam) {
108      
109      // thread stuff
110      int thread_id;
111      PWORKERARGS args;
112      unsigned char *pDataBitmapSegment;
113    
114      // fractal calculation
115      int x, y;
116      char bgr[3];
117    
118      thread_id = GetCurrentThreadId();
119      
120      // get worker arguments
121      args = (PWORKERARGS)lpParam;
122    
123      // calculate pointer to beginning of segment
124      pDataBitmapSegment = (unsigned char *)((INT_PTR)args->pBitmap + (YSIZE - (args->start_row + args->number_of_rows)) * 3 * XSIZE);
125    
126      // debugging
127      if (VERBOSE) {
128        printf("----------------------------------------------\n");
129        printf("thread_id: %i\n", thread_id);
130        printf("arg.start_row: %i\n", args->start_row);
131        printf("arg.number_of_rows: %i\n", args->number_of_rows);
132        printf("segment_start: %p\n", pDataBitmapSegment);
133      }
134      
135      // calculate fractal
136      for (y = (args->start_row + args->number_of_rows) - 1; y >= args->start_row; y--) {
137        //printf("calc: thread=%i; y=%i            limits: %i,%i    p: %p\n", thread_id, y, args->start_row, args->number_of_rows, pDataBitmapSegment);
138        for (x = 0; x < XSIZE; x++) {
139          getColorValuesAt(x * (2.0 / XSIZE) - 1.5, y * (2.0 / YSIZE) - 1.0, &bgr[2], &bgr[1], &bgr[0]);
140          
141          // transfer color values to current pixel
142          pDataBitmapSegment[0] = bgr[0];
143          pDataBitmapSegment[1] = bgr[1];
144          pDataBitmapSegment[2] = bgr[2];
145          
146          // move pointer to next pixel
147          pDataBitmapSegment += 3;
148                
     fd=fopen("test.bmp","wb+");  
     if(NULL==fd)  
     {  
         perror("open"); exit(1);  
149      }      }
150        //no padding required because 1500%4 =0 ???
151      }
152    
153      len=fwrite(header,1,sizeof(header),fd); //write header    if (VERBOSE)
154        printf("thread finished: %i\n", thread_id);
155      return 0;
156    
157    }
158    
159    
160    int main(int argc, char *argv[]) {
161    
162      // MMF support
163      DWORD err;
164      HANDLE hMap, hFile;
165      LPVOID pData;
166      unsigned char *pDataBitmap;
167    
168      // workers
169      int workers = 50;
170      int worker_index, worker_rows, worker_startrow;
171      HANDLE *worker_handles;
172      PWORKERARGS worker_args;
173    
174      
175      // create empty bmp-file (black background)
176      write_blank_file("test.bmp");
177    
178      /* open file for reading and writing */
179      hFile = CreateFile("test.bmp", GENERIC_WRITE|GENERIC_READ, 0, NULL, OPEN_EXISTING, FILE_ATTRIBUTE_NORMAL, NULL);
180      if (INVALID_HANDLE_VALUE == hFile) {
181        err = GetLastError();
182        printErrorAndExit("Error at CreateFile",err);
183      }
184    
185      /* create the file mapping object */
186      hMap = CreateFileMapping(hFile, NULL, PAGE_READWRITE, 0, 0, NULL);
187      if (NULL == hMap) {
188        printErrorAndExit("Error at CreateFileMapping", GetLastError());
189      }
190      
191      /* map the whole file into the process context */
192      pData = MapViewOfFile(hMap, FILE_MAP_WRITE, 0, 0, 0);
193      if (NULL == pData) {
194        printErrorAndExit("Error at MapViewOfFile", GetLastError());
195      }
196    
197      
198      // calculate pointer to beginning of bitmap
199      pDataBitmap = (unsigned char *)((INT_PTR)pData + sizeof(header));
200      
201      // debugging
202      if (VERBOSE) {
203        printf("pos. of file: %p\n", pData);
204        printf("pos. of bitmap: %p\n", pDataBitmap);
205      }
206    
207      /*
208      // turn bitmap into white canvas
209      for (offset = 0; offset < 500 * 500 * 3; offset++) {
210        *pDataBitmap = 255;
211        pDataBitmap++;
212      }
213      exit(0);
214      */
215    
216      // allocate memory for bitmap
217      /*
218      if ((pDataBitmap = malloc(XSIZE * YSIZE * 3 * sizeof(pDataBitmap[0]))) == NULL)
219        perror("malloc"), exit(1);
220      */
221      
222      // allocate memory for table of all worker handles
223      if ((worker_handles = malloc(workers * sizeof(worker_handles[0]))) == NULL)
224        perror("malloc"), exit(1);
225    
226      // allocate memory for table of all worker arguments
227      if ((worker_args = malloc(workers * sizeof(worker_args[0]))) == NULL)
228        perror("malloc"), exit(1);
229      
230      
231      // calculate segments of bitmap for worker threads/processes and start them
232      worker_rows = YSIZE / workers;
233      if (VERBOSE)
234        printf("rows for each worker: %i\n", worker_rows);
235      for (worker_index = 0; worker_index < workers; worker_index++) {
236        
237        // debugging: just run single thread
238        //if (worker_index == 1)
239        //  continue;
240            
241      if(-1==len || len!=sizeof(header))      // number of row to start for each worker
242      {      worker_startrow = worker_index * worker_rows;
243          perror("write");      
244          exit(2);      // recalculate number of rows for last worker if (YSIZE mod workers) != 0
245        if (worker_index == workers - 1) {
246          worker_rows = YSIZE - worker_startrow;
247          if (VERBOSE)
248            printf("rows for last worker: %i\n", worker_rows);
249      }      }
250            
251      for(y=YSIZE-1;y>=0;y--)      worker_args[worker_index].start_row = worker_startrow;
252      {      worker_args[worker_index].number_of_rows = worker_rows;
253              for(x=0;x<XSIZE;x++)      worker_args[worker_index].pBitmap = pDataBitmap;
254              {      
255                  getColorValuesAt(x * (2.0 / XSIZE) - 1.5, y * (2.0 / YSIZE) - 1.0,&bgr[2],&bgr[1],&bgr[0]);      worker_handles[worker_index] = CreateThread(
256                          NULL,                          // LPSECURITY_ATTRIBUTES lpThreadAttributes,
257                  len=fwrite(bgr,1,3,fd);        0,                             // SIZE_T dwStackSize,
258                  if(-1==len || len!=3)        &fractal_thread,                // LPTHREAD_START_ROUTINE lpStartAddress,
259                  {        &worker_args[worker_index],    // LPVOID lpParameter,
260                      perror("write");        0,                             // DWORD dwCreationFlags,
261                      exit(4);        NULL                           // LPDWORD lpThreadId
262                  }      );
             }  
             /*no padding required because 1500%4 =0*/  
     }          
     fclose(fd);  
263            
264      }
265    
266      // wait for all threads
267      if (VERBOSE)
268        printf("waiting...\n");
269      if (WaitForMultipleObjects(workers, worker_handles, TRUE, INFINITE) == WAIT_FAILED)
270        perror("WaitForMultipleObjects");
271    
272      // debugging: just run single thread
273      //if (WaitForSingleObject(worker_handles[0], INFINITE) == WAIT_FAILED)
274      //  perror("WaitForSingleObject");
275    
276      // close all worker handles
277      for (worker_index = 0; worker_index < workers; worker_index++)
278        CloseHandle(worker_handles[worker_index]);
279        
280      /* write the result into the file */
281      if (!FlushViewOfFile(pData, 0)) {
282        err = GetLastError();
283        printErrorAndExit("Error at UnmapViewOfFile", err);
284      }
285    
286      /* remove the mapped file */
287      if (!UnmapViewOfFile(pData)) {
288        err = GetLastError();
289        printErrorAndExit("Error at UnmapViewOfFile", err);
290        exit(err);
291      }
292      
293      /* cleanup handles */
294      if (!CloseHandle(hMap) || !CloseHandle(hFile) ) {
295        err = GetLastError();
296        printErrorAndExit("Error at CloseHandle", err);
297      }
298    
299      free(worker_args);
300      free(worker_handles);
301      
302      return 0;
303      
304  }  }
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