/[cvs]/joko/Uni/BSArch/04/bmp_fractal.c
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revision 1.3 by joko, Sat Jul 1 11:45:35 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  int main(int argc, char *argv[]) {  // arguments for each thread
100    int len,x,y;  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];    char bgr[3];
   short svalue;  
   int lvalue;  
117    
118    HANDLE hMap, hFile;    thread_id = GetCurrentThreadId();
   DWORD err, size;  
   int elems;  
119        
120    LPVOID pData;    // get worker arguments
121    unsigned char *pDataBitmap, *pDataBitmapCurrent;    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    int offset;    // 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[]) {
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 file (black background)    // create empty bmp-file (black background)
176    write_blank_file("test.bmp");    write_blank_file("test.bmp");
     
177    
178    /* open file for reading and writing */    /* open file for reading and writing */
179    hFile = CreateFile("test.bmp", GENERIC_WRITE|GENERIC_READ, 0, NULL, OPEN_EXISTING, FILE_ATTRIBUTE_NORMAL, NULL);    hFile = CreateFile("test.bmp", GENERIC_WRITE|GENERIC_READ, 0, NULL, OPEN_EXISTING, FILE_ATTRIBUTE_NORMAL, NULL);
# Line 137  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 fractal    // allocate memory for bitmap
217    for (y=YSIZE-1; y>=0; y--) {    /*
218            for (x=0; x<XSIZE; x++) {    if ((pDataBitmap = malloc(XSIZE * YSIZE * 3 * sizeof(pDataBitmap[0]))) == NULL)
219              getColorValuesAt(x * (2.0 / XSIZE) - 1.5, y * (2.0 / YSIZE) - 1.0, &bgr[2], &bgr[1], &bgr[0]);      perror("malloc"), exit(1);
220                  */
             // debugging  
             //printf("pointer: %p\n", pDataBitmapCurrent);  
               
             // transfer color values to current pixel  
             //*pDataBitmapCurrent = (unsigned char *)bgr;  
             pDataBitmapCurrent[0] = bgr[0];  
             pDataBitmapCurrent[1] = bgr[1];  
             pDataBitmapCurrent[2] = bgr[2];  
               
             // move pointer to next pixel  
             pDataBitmapCurrent += 3;  
               
           }  
           //no padding required because 1500%4 =0  
   }  
   
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        // number of row to start for each worker
242        worker_startrow = worker_index * worker_rows;
243        
244        // 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        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      // 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 */    /* write the result into the file */
281    if (!FlushViewOfFile(pData, 0)) {    if (!FlushViewOfFile(pData, 0)) {
282      err = GetLastError();      err = GetLastError();
# Line 193  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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