/* Bring in gd library functions */#include "gd.h"/* Bring in standard I/O so we can output the PNG to a file */#include <stdio.h>
int main() { /* Declare the image */ gdImagePtr im; /* Declare output files */ FILE *pngout, *jpegout; /* Declare color indexes */ int black; int white; /* Allocate the image: 64 pixels across by 64 pixels tall */ im = gdImageCreate(64, 64); /* Allocate the color black (red, green and blue all minimum). Since this is the first color in a new image, it will be the background color. */ black = gdImageColorAllocate(im, 0, 0, 0); /* Allocate the color white (red, green and blue all maximum). */ white = gdImageColorAllocate(im, 255, 255, 255); /* Draw a line from the upper left to the lower right, using white color index. */ gdImageLine(im, 0, 0, 63, 63, white); /* Open a file for writing. "wb" means "write binary", important under MSDOS, harmless under Unix. */ pngout = fopen("test.png", "wb"); /* Do the same for a JPEG-format file. */ jpegout = fopen("test.jpg", "wb"); /* Output the image to the disk file in PNG format. */ gdImagePng(im, pngout); /* Output the same image in JPEG format, using the default JPEG quality setting. */ gdImageJpeg(im, jpegout, -1); /* Close the files. */ fclose(pngout); fclose(jpegout); /* Destroy the image in memory. */ gdImageDestroy(im);}
