BSArch/04/bmp_fractal.c

/* Betriebssystem & Middleware
 *
 * Betriebssystemarchitektur SS 2006
 *
 * Uebung 4.4 
 */

// $Id: bmp_fractal.c,v 1.4 2006/07/01 11:58:49 joko Exp $

#include <windows.h>
#include <stdio.h>
#include <errno.h>

#define XSIZE 500
#define YSIZE 500
#include "algorithm.h"


/* BMP Header */
unsigned char header[54]={0x42,0x4d,              // signature BM
                            0xe6,0x71,0x0b,0x0,   // filesize 750054
                            0x0,0x0,0x0,0x0,      // reserved 
                            0x36,0x0,0x0,0x0,     // image offset 54
                            0x28,0x0,0x0,0x0,     // size of header follows 40
                            0xf4,0x1,0x0,0x0,     // with of image 500
                            0xf4,0x1,0x0,0x0,     // height of image 500
                            0x1,0x0,              // number of planes  1
                            0x18,0x0,             // number of pixel 24
                            0x0,0x0,0x0,0x0,      // compression  
                            0xb0,0x71,0x0b,0x0,   // size of image 750000
                            0x0,0x0,0x0,0x0,      // xres
                            0x0,0x0,0x0,0x0,      // yres   
                            0x0,0x0,0x0,0x0,      // number of colortables    
                            0x0,0x0,0x0,0x0       // number of important colors
                        };


void printErrorAndExit(const char *msg, DWORD err) {
        LPSTR lpMsgBuf;
        if(FormatMessage(FORMAT_MESSAGE_ALLOCATE_BUFFER|
                                  FORMAT_MESSAGE_FROM_SYSTEM | 
                                          FORMAT_MESSAGE_IGNORE_INSERTS,
                                                NULL,
                                                err,
                                          MAKELANGID(LANG_NEUTRAL, SUBLANG_DEFAULT), // Default language
                                          (LPTSTR) &lpMsgBuf,
                                          0,
                                          NULL ))
        {
                fprintf(stderr,"%s : %s\n",msg,lpMsgBuf);
                LocalFree(lpMsgBuf);
        }
        else
        {
                fprintf(stderr,"Error at FormatMesage: %d\n",err=GetLastError());
        }
        exit(err);
}


void write_blank_file(char *filename) {

  FILE *fd;
  int len, i, img_size;

  // open file handle
  fd = fopen(filename, "wb+");
  if (NULL == fd) {
    perror("open");
    exit(1);
  }

  // write bmp header to file
  len = fwrite(header, 1, sizeof(header), fd);
  
  // error checking
  if (-1 == len || len != sizeof(header)) {
    perror("write");
    exit(2);
  }
  
  // write three null-bytes for each pixel to file to create a black picture
  img_size = XSIZE * YSIZE;
  for (i = 0; i < img_size; i++) {
    len = fwrite("\0\0\0", 1, 3, fd);
    if (-1 == len || len != 3) {
      perror("write");
      exit(4);
    }
  }
  
  // close file handle
  fclose(fd);
}


int main(int argc, char *argv[]) {

  // MMF support
  DWORD err;
  HANDLE hMap, hFile;
  LPVOID pData;
  unsigned char *pDataBitmap, *pDataBitmapCurrent;

  // workers
  unsigned int workers = 3;
  unsigned int worker_index, worker_rows, worker_startrow;
  
  // fractal calculation
  int x, y;
  char bgr[3];
  
  
  // create empty bmp-file (black background)
  write_blank_file("test.bmp");

  /* open file for reading and writing */
  hFile = CreateFile("test.bmp", GENERIC_WRITE|GENERIC_READ, 0, NULL, OPEN_EXISTING, FILE_ATTRIBUTE_NORMAL, NULL);
  if (INVALID_HANDLE_VALUE == hFile) {
    err = GetLastError();
    printErrorAndExit("Error at CreateFile",err);
  }

  /* create the file mapping object */
  hMap = CreateFileMapping(hFile, NULL, PAGE_READWRITE, 0, 0, NULL);
  if (NULL == hMap) {
    printErrorAndExit("Error at CreateFileMapping", GetLastError());
  }
  
  /* map the whole file into the process context */
  pData = MapViewOfFile(hMap, FILE_MAP_WRITE, 0, 0, 0);
  if (NULL == pData) {
    printErrorAndExit("Error at MapViewOfFile", GetLastError());
  }

  
  // calculate pointer to beginning of bitmap
  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;

  /*
  // turn bitmap into white wand
  for (offset = 0; offset < 500 * 500 * 3; offset++) {
    //pDataBitmap[offset] = 255;
    *pDataBitmapCurrent = 255;
    pDataBitmapCurrent++;
  }
  */

  // calculate segments of bitmap for worker threads/processes
  worker_rows = YSIZE / workers;
  printf("rows for each worker: %i\n", worker_rows);
  for (worker_index = 0; worker_index < workers; worker_index++) {
    
    // 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;
      printf("rows for last worker: %i\n", worker_rows);
    }
  }

  // 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
  }

  
  /* write the result into the file */
  if (!FlushViewOfFile(pData, 0)) {
    err = GetLastError();
    printErrorAndExit("Error at UnmapViewOfFile", err);
  }

  /* remove the mapped file */
  if (!UnmapViewOfFile(pData)) {
    err = GetLastError();
    printErrorAndExit("Error at UnmapViewOfFile", err);
    exit(err);
  }
  
  /* cleanup handles */
  if (!CloseHandle(hMap) || !CloseHandle(hFile) ) {
    err = GetLastError();
    printErrorAndExit("Error at CloseHandle", err);
  }

}
1	/* Betriebssystem & Middleware
2	*
3	* Betriebssystemarchitektur SS 2006
4	*
5	* Uebung 4.4
6	*/
7
8	// $Id: bmp_fractal.c,v 1.4 2006/07/01 11:58:49 joko Exp $
9
10	#include <windows.h>
11	#include <stdio.h>
12	#include <errno.h>
13
14	#define XSIZE 500
15	#define YSIZE 500
16	#include "algorithm.h"
17
18
19	/* BMP Header */
20	unsigned char header[54]={0x42,0x4d, // signature BM
21	0xe6,0x71,0x0b,0x0, // filesize 750054
22	0x0,0x0,0x0,0x0, // reserved
23	0x36,0x0,0x0,0x0, // image offset 54
24	0x28,0x0,0x0,0x0, // size of header follows 40
25	0xf4,0x1,0x0,0x0, // with of image 500
26	0xf4,0x1,0x0,0x0, // height of image 500
27	0x1,0x0, // number of planes 1
28	0x18,0x0, // number of pixel 24
29	0x0,0x0,0x0,0x0, // compression
30	0xb0,0x71,0x0b,0x0, // size of image 750000
31	0x0,0x0,0x0,0x0, // xres
32	0x0,0x0,0x0,0x0, // yres
33	0x0,0x0,0x0,0x0, // number of colortables
34	0x0,0x0,0x0,0x0 // number of important colors
35	};
36
37
38	void printErrorAndExit(const char *msg, DWORD err) {
39	LPSTR lpMsgBuf;
40	if(FormatMessage(FORMAT_MESSAGE_ALLOCATE_BUFFER\|
41	FORMAT_MESSAGE_FROM_SYSTEM \|
42	FORMAT_MESSAGE_IGNORE_INSERTS,
43	NULL,
44	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	int main(int argc, char *argv[]) {
98
99	// MMF support
100	DWORD err;
101	HANDLE hMap, hFile;
102	LPVOID pData;
103	unsigned char pDataBitmap, pDataBitmapCurrent;
104
105	// workers
106	unsigned int workers = 3;
107	unsigned int worker_index, worker_rows, worker_startrow;
108
109	// fractal calculation
110	int x, y;
111	char bgr[3];
112
113
114	// create empty bmp-file (black background)
115	write_blank_file("test.bmp");
116
117	/* open file for reading and writing */
118	hFile = CreateFile("test.bmp", GENERIC_WRITE\|GENERIC_READ, 0, NULL, OPEN_EXISTING, FILE_ATTRIBUTE_NORMAL, NULL);
119	if (INVALID_HANDLE_VALUE == hFile) {
120	err = GetLastError();
121	printErrorAndExit("Error at CreateFile",err);
122	}
123
124	/* create the file mapping object */
125	hMap = CreateFileMapping(hFile, NULL, PAGE_READWRITE, 0, 0, NULL);
126	if (NULL == hMap) {
127	printErrorAndExit("Error at CreateFileMapping", GetLastError());
128	}
129
130	/* map the whole file into the process context */
131	pData = MapViewOfFile(hMap, FILE_MAP_WRITE, 0, 0, 0);
132	if (NULL == pData) {
133	printErrorAndExit("Error at MapViewOfFile", GetLastError());
134	}
135
136
137	// calculate pointer to beginning of bitmap
138	pDataBitmap = (unsigned char *)((INT_PTR)pData + sizeof(header));
139
140	// debugging
141	printf("pos. of file: %p\n", pData);
142	printf("pos. of bitmap: %p\n", pDataBitmap);
143
144	// pointer to current pixel
145	pDataBitmapCurrent = pDataBitmap;
146
147	/*
148	// turn bitmap into white wand
149	for (offset = 0; offset < 500 * 500 * 3; offset++) {
150	//pDataBitmap[offset] = 255;
151	*pDataBitmapCurrent = 255;
152	pDataBitmapCurrent++;
153	}
154	*/
155
156	// calculate segments of bitmap for worker threads/processes
157	worker_rows = YSIZE / workers;
158	printf("rows for each worker: %i\n", worker_rows);
159	for (worker_index = 0; worker_index < workers; worker_index++) {
160
161	// number of row to start for each worker
162	worker_startrow = worker_index * worker_rows;
163
164	// recalculate number of rows for last worker if (YSIZE mod workers) != 0
165	if (worker_index == workers - 1) {
166	worker_rows = YSIZE - worker_startrow;
167	printf("rows for last worker: %i\n", worker_rows);
168	}
169	}
170
171	// calculate fractal
172	for (y=YSIZE-1; y>=0; y--) {
173	for (x=0; x<XSIZE; x++) {
174	getColorValuesAt(x * (2.0 / XSIZE) - 1.5, y * (2.0 / YSIZE) - 1.0, &bgr[2], &bgr[1], &bgr[0]);
175
176	// debugging
177	//printf("pointer: %p\n", pDataBitmapCurrent);
178
179	// transfer color values to current pixel
180	pDataBitmapCurrent[0] = bgr[0];
181	pDataBitmapCurrent[1] = bgr[1];
182	pDataBitmapCurrent[2] = bgr[2];
183
184	// move pointer to next pixel
185	pDataBitmapCurrent += 3;
186
187	}
188	//no padding required because 1500%4 =0
189	}
190
191
192	/* write the result into the file */
193	if (!FlushViewOfFile(pData, 0)) {
194	err = GetLastError();
195	printErrorAndExit("Error at UnmapViewOfFile", err);
196	}
197
198	/* remove the mapped file */
199	if (!UnmapViewOfFile(pData)) {
200	err = GetLastError();
201	printErrorAndExit("Error at UnmapViewOfFile", err);
202	exit(err);
203	}
204
205	/* cleanup handles */
206	if (!CloseHandle(hMap) \|\| !CloseHandle(hFile) ) {
207	err = GetLastError();
208	printErrorAndExit("Error at CloseHandle", err);
209	}
210
211	}
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