/[cvs]/joko/Uni/BSArch/04/bmp_fractal.c
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revision 1.5 by joko, Sat Jul 1 12:19:46 2006 UTC revision 1.9 by joko, Sun Jul 2 00:24:17 2006 UTC
# Line 15  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
# Line 94  void write_blank_file(char *filename) { Line 96  void write_blank_file(char *filename) {
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          
149        }
150        //no padding required because 1500%4 =0 ???
151      }
152    
153      if (VERBOSE)
154        printf("thread finished: %i\n", thread_id);
155      return 0;
156    
157    }
158    
159    
160  int main(int argc, char *argv[]) {  int main(int argc, char *argv[]) {
161    
162    // MMF support    // MMF support
163    DWORD err;    DWORD err;
164    HANDLE hMap, hFile;    HANDLE hMap, hFile;
165    LPVOID pData;    LPVOID pData;
166    unsigned char *pDataBitmap, *pDataBitmapCurrent;    unsigned char *pDataBitmap;
167    
168    // workers    // workers
169    unsigned int workers = 3;    int workers = 50;
170    unsigned int worker_index, worker_rows, worker_startrow;    int worker_index, worker_rows, worker_startrow;
171        HANDLE *worker_handles;
172    // fractal calculation    PWORKERARGS worker_args;
173    int x, y;  
   char bgr[3];  
     
174        
175    // create empty bmp-file (black background)    // create empty bmp-file (black background)
176    write_blank_file("test.bmp");    write_blank_file("test.bmp");
# Line 138  int main(int argc, char *argv[]) { Line 199  int main(int argc, char *argv[]) {
199    pDataBitmap = (unsigned char *)((INT_PTR)pData + sizeof(header));    pDataBitmap = (unsigned char *)((INT_PTR)pData + sizeof(header));
200        
201    // debugging    // debugging
202    printf("pos. of file: %p\n", pData);    if (VERBOSE) {
203    printf("pos. of bitmap: %p\n", pDataBitmap);      printf("pos. of file: %p\n", pData);
204        printf("pos. of bitmap: %p\n", pDataBitmap);
205    // pointer to current pixel    }
   pDataBitmapCurrent = pDataBitmap;  
206    
207    /*    /*
208    // turn bitmap into white wand    // turn bitmap into white canvas
209    for (offset = 0; offset < 500 * 500 * 3; offset++) {    for (offset = 0; offset < 500 * 500 * 3; offset++) {
210      //pDataBitmap[offset] = 255;      *pDataBitmap = 255;
211      *pDataBitmapCurrent = 255;      pDataBitmap++;
     pDataBitmapCurrent++;  
212    }    }
213      exit(0);
214    */    */
215    
216    // calculate segments of bitmap for worker threads/processes    // 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;    worker_rows = YSIZE / workers;
233    printf("rows for each worker: %i\n", worker_rows);    if (VERBOSE)
234        printf("rows for each worker: %i\n", worker_rows);
235    for (worker_index = 0; worker_index < workers; worker_index++) {    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      // number of row to start for each worker      // number of row to start for each worker
242      worker_startrow = worker_index * worker_rows;      worker_startrow = worker_index * worker_rows;
243            
244      // recalculate number of rows for last worker if (YSIZE mod workers) != 0      // recalculate number of rows for last worker if (YSIZE mod workers) != 0
245      if (worker_index == workers - 1) {      if (worker_index == workers - 1) {
246        worker_rows = YSIZE - worker_startrow;        worker_rows = YSIZE - worker_startrow;
247        printf("rows for last worker: %i\n", worker_rows);        if (VERBOSE)
248            printf("rows for last worker: %i\n", worker_rows);
249      }      }
250        
251        worker_args[worker_index].start_row = worker_startrow;
252        worker_args[worker_index].number_of_rows = worker_rows;
253        worker_args[worker_index].pBitmap = pDataBitmap;
254        
255        worker_handles[worker_index] = CreateThread(
256          NULL,                          // LPSECURITY_ATTRIBUTES lpThreadAttributes,
257          0,                             // SIZE_T dwStackSize,
258          &fractal_thread,                // LPTHREAD_START_ROUTINE lpStartAddress,
259          &worker_args[worker_index],    // LPVOID lpParameter,
260          0,                             // DWORD dwCreationFlags,
261          NULL                           // LPDWORD lpThreadId
262        );
263        
264    }    }
265    
266    // calculate fractal    // wait for all threads
267    for (y=YSIZE-1; y>=0; y--) {    if (VERBOSE)
268            for (x=0; x<XSIZE; x++) {      printf("waiting...\n");
269              getColorValuesAt(x * (2.0 / XSIZE) - 1.5, y * (2.0 / YSIZE) - 1.0, &bgr[2], &bgr[1], &bgr[0]);    if (WaitForMultipleObjects(workers, worker_handles, TRUE, INFINITE) == WAIT_FAILED)
270                    perror("WaitForMultipleObjects");
271              // debugging  
272              //printf("pointer: %p\n", pDataBitmapCurrent);    // debugging: just run single thread
273                  //if (WaitForSingleObject(worker_handles[0], INFINITE) == WAIT_FAILED)
274              // transfer color values to current pixel    //  perror("WaitForSingleObject");
275              pDataBitmapCurrent[0] = bgr[0];  
276              pDataBitmapCurrent[1] = bgr[1];    // close all worker handles
277              pDataBitmapCurrent[2] = bgr[2];    for (worker_index = 0; worker_index < workers; worker_index++)
278                    CloseHandle(worker_handles[worker_index]);
279              // move pointer to next pixel      
             pDataBitmapCurrent += 3;  
               
           }  
           //no padding required because 1500%4 =0  
   }  
   
     
280    /* write the result into the file */    /* write the result into the file */
281    if (!FlushViewOfFile(pData, 0)) {    if (!FlushViewOfFile(pData, 0)) {
282      err = GetLastError();      err = GetLastError();
# Line 208  int main(int argc, char *argv[]) { Line 296  int main(int argc, char *argv[]) {
296      printErrorAndExit("Error at CloseHandle", err);      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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