--- joko/Uni/BSArch/04/bmp_fractal.c	2006/07/01 11:58:49	1.4
+++ joko/Uni/BSArch/04/bmp_fractal.c	2006/07/02 00:24:17	1.9
@@ -5,7 +5,7 @@
  * Uebung 4.4 
  */
 
-// $Id: bmp_fractal.c,v 1.4 2006/07/01 11:58:49 joko Exp $
+// $Id: bmp_fractal.c,v 1.9 2006/07/02 00:24:17 joko Exp $
 
 #include <windows.h>
 #include <stdio.h>
@@ -15,6 +15,8 @@
 #define YSIZE 500
 #include "algorithm.h"
 
+BOOL VERBOSE = FALSE;
+
 
 /* BMP Header */
 unsigned char header[54]={0x42,0x4d,              // signature BM
@@ -94,18 +96,81 @@
 }
 
 
+// arguments for each thread
+typedef struct _WorkerArguments {
+  int start_row;
+  int number_of_rows;
+  unsigned char * pBitmap;
+} WORKERARGS, *PWORKERARGS;
+
+// worker thread - main entry function
+DWORD WINAPI fractal_thread (LPVOID lpParam) {
+  
+  // thread stuff
+  int thread_id;
+  PWORKERARGS args;
+  unsigned char *pDataBitmapSegment;
+
+  // fractal calculation
+  int x, y;
+  char bgr[3];
+
+  thread_id = GetCurrentThreadId();
+  
+  // get worker arguments
+  args = (PWORKERARGS)lpParam;
+
+  // calculate pointer to beginning of segment
+  pDataBitmapSegment = (unsigned char *)((INT_PTR)args->pBitmap + (YSIZE - (args->start_row + args->number_of_rows)) * 3 * XSIZE);
+
+  // debugging
+  if (VERBOSE) {
+    printf("----------------------------------------------\n");
+    printf("thread_id: %i\n", thread_id);
+    printf("arg.start_row: %i\n", args->start_row);
+    printf("arg.number_of_rows: %i\n", args->number_of_rows);
+    printf("segment_start: %p\n", pDataBitmapSegment);
+  }
+  
+  // calculate fractal
+  for (y = (args->start_row + args->number_of_rows) - 1; y >= args->start_row; y--) {
+    //printf("calc: thread=%i; y=%i            limits: %i,%i    p: %p\n", thread_id, y, args->start_row, args->number_of_rows, pDataBitmapSegment);
+    for (x = 0; x < XSIZE; x++) {
+      getColorValuesAt(x * (2.0 / XSIZE) - 1.5, y * (2.0 / YSIZE) - 1.0, &bgr[2], &bgr[1], &bgr[0]); 
+      
+      // transfer color values to current pixel
+      pDataBitmapSegment[0] = bgr[0];
+      pDataBitmapSegment[1] = bgr[1];
+      pDataBitmapSegment[2] = bgr[2];
+      
+      // move pointer to next pixel
+      pDataBitmapSegment += 3;
+      
+    }
+    //no padding required because 1500%4 =0 ???
+  }
+
+  if (VERBOSE)
+    printf("thread finished: %i\n", thread_id);
+  return 0;
+
+}
+
+
 int main(int argc, char *argv[]) {
 
   // MMF support
   DWORD err;
   HANDLE hMap, hFile;
   LPVOID pData;
-  unsigned char *pDataBitmap, *pDataBitmapCurrent;
+  unsigned char *pDataBitmap;
+
+  // workers
+  int workers = 50;
+  int worker_index, worker_rows, worker_startrow;
+  HANDLE *worker_handles;
+  PWORKERARGS worker_args;
 
-  // fractal calculation
-  int x, y;
-  char bgr[3];
-  
   
   // create empty bmp-file (black background)
   write_blank_file("test.bmp");
@@ -134,42 +199,84 @@
   pDataBitmap = (unsigned char *)((INT_PTR)pData + sizeof(header));
   
   // debugging
-  printf("pos. of file: %p\n", pData);
-  printf("pos. of bitmap: %p\n", pDataBitmap);
-
-  // pointer to current pixel
-  pDataBitmapCurrent = pDataBitmap;
+  if (VERBOSE) {
+    printf("pos. of file: %p\n", pData);
+    printf("pos. of bitmap: %p\n", pDataBitmap);
+  }
 
   /*
-  // turn bitmap into white wand
+  // turn bitmap into white canvas
   for (offset = 0; offset < 500 * 500 * 3; offset++) {
-    //pDataBitmap[offset] = 255;
-    *pDataBitmapCurrent = 255;
-    pDataBitmapCurrent++;
+    *pDataBitmap = 255;
+    pDataBitmap++;
   }
+  exit(0);
   */
 
-  // calculate fractal
-  for (y=YSIZE-1; y>=0; y--) {
-          for (x=0; x<XSIZE; x++) {
-            getColorValuesAt(x * (2.0 / XSIZE) - 1.5, y * (2.0 / YSIZE) - 1.0, &bgr[2], &bgr[1], &bgr[0]); 
-            
-            // debugging
-            //printf("pointer: %p\n", pDataBitmapCurrent);
-            
-            // transfer color values to current pixel
-            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
-  }
-
+  // allocate memory for bitmap
+  /*
+  if ((pDataBitmap = malloc(XSIZE * YSIZE * 3 * sizeof(pDataBitmap[0]))) == NULL)
+    perror("malloc"), exit(1);
+  */
+  
+  // allocate memory for table of all worker handles
+  if ((worker_handles = malloc(workers * sizeof(worker_handles[0]))) == NULL)
+    perror("malloc"), exit(1);
+
+  // allocate memory for table of all worker arguments
+  if ((worker_args = malloc(workers * sizeof(worker_args[0]))) == NULL)
+    perror("malloc"), exit(1);
   
+  
+  // calculate segments of bitmap for worker threads/processes and start them
+  worker_rows = YSIZE / workers;
+  if (VERBOSE)
+    printf("rows for each worker: %i\n", worker_rows);
+  for (worker_index = 0; worker_index < workers; worker_index++) {
+    
+    // debugging: just run single thread
+    //if (worker_index == 1)
+    //  continue;
+    
+    // number of row to start for each worker
+    worker_startrow = worker_index * worker_rows;
+    
+    // recalculate number of rows for last worker if (YSIZE mod workers) != 0
+    if (worker_index == workers - 1) {
+      worker_rows = YSIZE - worker_startrow;
+      if (VERBOSE)
+        printf("rows for last worker: %i\n", worker_rows);
+    }
+    
+    worker_args[worker_index].start_row = worker_startrow;
+    worker_args[worker_index].number_of_rows = worker_rows;
+    worker_args[worker_index].pBitmap = pDataBitmap;
+    
+    worker_handles[worker_index] = CreateThread(
+      NULL,                          // LPSECURITY_ATTRIBUTES lpThreadAttributes,
+      0,                             // SIZE_T dwStackSize,
+      &fractal_thread,                // LPTHREAD_START_ROUTINE lpStartAddress,
+      &worker_args[worker_index],    // LPVOID lpParameter,
+      0,                             // DWORD dwCreationFlags,
+      NULL                           // LPDWORD lpThreadId
+    );
+    
+  }
+
+  // wait for all threads
+  if (VERBOSE)
+    printf("waiting...\n");
+  if (WaitForMultipleObjects(workers, worker_handles, TRUE, INFINITE) == WAIT_FAILED)
+    perror("WaitForMultipleObjects");
+
+  // debugging: just run single thread
+  //if (WaitForSingleObject(worker_handles[0], INFINITE) == WAIT_FAILED)
+  //  perror("WaitForSingleObject");
+
+  // close all worker handles
+  for (worker_index = 0; worker_index < workers; worker_index++)
+    CloseHandle(worker_handles[worker_index]);
+    
   /* write the result into the file */
   if (!FlushViewOfFile(pData, 0)) {
     err = GetLastError();
@@ -189,4 +296,9 @@
     printErrorAndExit("Error at CloseHandle", err);
   }
 
+  free(worker_args);
+  free(worker_handles);
+  
+  return 0;
+  
 }