C语言乱谈（一） 20行代码生成BMP

 1 #include <stdio.h>
 2 #include <stdlib.h>
 3 #define w 200
 4 #define h 200
 5 void WriteBMP(char*img,const char* filename)
 6 {
 7     int l=(w*3+3)/4*4;
 8     int bmi[]= {l*h+54,0,54,40,w,h,1|3*8<<16,0,l*h,0,0,100,0};
 9     FILE *fp = fopen(filename,"wb");
10     fprintf(fp,"BM");
11     fwrite(&bmi,52,1,fp);
12     fwrite(img,1,l*h,fp);
13     fclose(fp);
14 }
15 int main()
16 {
17     char img[w*h*3];
18     for(int i=0; i<w*h*3; i++)img[i]=rand()%256;
19     WriteBMP(img,"test.bmp");
20     system("test.bmp");
21     return 0;
22 }