bmp.c

EGui是一个开源的图形系统软件,类似于QT/Embedded、GTK-FB、MicroWindow。目标是嵌入式平台整合解 决方案。基于Linux Framebuffer 设备驱动上实现。有完

#include <fcntl.h>
#include <stdio.h>
#include <stdlib.h>
#include <sys/stat.h>
#include <sys/types.h>
#include <unistd.h>
#include <string.h>

#include <Egui.h>
#include "bmp.h"

EGui_FBinfo Efbinfo;

char *
read_file (const char* filename, size_t* length)
{
  int fd;
  struct stat file_info;
  char* buffer;

  /* Open the file.  */
  fd = open (filename, O_RDONLY);
  if (fd<0)
    {
      printf ("Open file %s error\n",filename);
      exit ;
    }
  /* Get information about the file.  */
  fstat (fd, &file_info);
  *length = file_info.st_size;
  /* Make sure the file is an ordinary file.  */
  if (!S_ISREG (file_info.st_mode)) {
    /* It's not, so give up.  */
    close (fd);
    return NULL;
  }

  /* Allocate a buffer large enough to hold the file's contents.  */
  buffer = (char*) malloc (*length);
  if (buffer ==NULL)
    {
      printf ("malloc file buffer error\n");
      return NULL;
    }
  /* Read the file into the buffer.  */
  read (fd, buffer, *length);

  /* Finish up.  */
  close (fd);
  return buffer;
}

int
main(int argc, char **argv)
{
  char * rgbbuf;
  int width,height;
  Ecolor * bgcolor;
  int w,h;
  EGui_Window * ewindow;
  
  if (argc <2)
    {
      printf (" A 24 bits BMP display program for Egui\n");
      printf ("usage : %s filename\n",argv[0]);
      return;
    }

  if (Egui_open (&Efbinfo))
    return ;

  bgcolor = malloc (sizeof ( Ecolor));
  if (bgcolor == NULL)
    {
      printf ("malloc color ERROR\n");
      return -1;
    }

  bgcolor->r = bgcolor->g = bgcolor->b = 0xcc;
  /* create window will initial color's pixel. 
   */
  ewindow = Egui_CreateWindow (&Efbinfo,150,100,200,
			       150,bgcolor,EGUI_WINDOW_TOP);
  if (ewindow == NULL)
    {
      printf ("New windows failed\n");
      Egui_close ();
      return 1;
    }

  width  = 200 ;
  height = 150 ;

  rgbbuf = (char *) malloc ( width * height * 3);

  if (rgbbuf == NULL)
    {
      printf ("Get a buffer for RGB error!\n");
      return ;
    }

  get_bmpbuf(width,height,rgbbuf,argv[1]);

  Egui_drawwindow(ewindow);

  w = ewindow->frame_w;
  h = ewindow->title_h;
  Egui_drawrgb (w,w + h,width-1,height-1,rgbbuf,ewindow);
  free(rgbbuf);

  egui_loop ();

  Egui_CloseWindow (ewindow);
  free (bgcolor);
  Egui_close ();
}

int 
get_bmpbuf(int width,int height,char * rgbbuf, char * filename)
{
  char *buffer;
  size_t length;
  BITMAPFILE *bm;
  int i,j;
  char pad_num;
  char *aBitmapBits;
  int tmpwidth;
  
  buffer = read_file(filename, &length);
  bm = (BITMAPFILE *)buffer;
  
  if (bm->bmfh.bfType!=0x4D42 || bm->bmih.biBitCount != 24)
    {
      printf("Not a 24bit BITMAP.\n");
      return -1;
    }

  if ( bm->bmih.biCompression != 0)
    {
      printf ("I'm sorry,i don't read compression BMP file\n");
      return -1;
    }	
  pad_num = bm->bmih.biWidth * 3 %4==0? 0 : 4 - bm->bmih.biWidth * 3 %4;
  aBitmapBits = (char *)((char *)bm + bm->bmfh.bfOffBits);
  
  if (height > bm->bmih.biHeight)
    height = bm->bmih.biHeight;
  
  tmpwidth = width;
  if (width > bm->bmih.biWidth)
    tmpwidth = bm->bmih.biWidth;
   
 
  for (j=0,i=height-1; j < height; j ++,i--)
    {
    //line copy
       memcpy((rgbbuf + j * width * 3), (void *)(aBitmapBits + i * (bm->bmih.biWidth * 3 + pad_num)),tmpwidth * 3);	
    }
  free(buffer);
  
  return 0;
}