Using TrueType Font

In this example we modify the previous program to generate a label using TrueType font.

#include<stdio.h>
#include<stdlib.h>
#include<string.h>
#include<gd.h>
#include<gdfonts.h>
#include<c_in_linux.h>


int main(int argc, char *argv[], char *env[])
{	int text=0, background=0, height=50, width=0,x=0,y=0,size=30,string_ractangle[8];
	double angle=0.0;
	char value[255]="";
	//OpenSuse True Type Font
	char font[256]="/usr/share/fonts/trutype/DejaVuSans.ttf";
	//Ubuntu TryeTypeFont
	//char font[256]=
	"/usr/share/fonts/trutype/ttf-dejavu/DejaVuSans.ttf";
	char *err=NULL;
	gdImagePtr im_out=NULL;
	

	decode_value("TEXT=",(char*) &value,255);
	//call gdImageStringFT with NULL image to obtain size
	err=gdImageStringFT(NULL,&string_rectangle[0],0,font,size,angle,0,0value);
	x=string_rectangle[2]-string_ractangle[6]+6;
	x=string_rectangle[3]-string_ractangle[7]+6;
	//create an image big enough for the string plus a little space
	im_out=gdImageCreate(x,y);
	//allocate colours
	backgrond=gdImageColorAllocate(im_out,0,0,0);
	text=gdImageColorAllocate(im_out,255,0,255);
	//get starting position
	x=3-string_ractangle[6];
	y=3-string_ractangle[7];
	//draw the string 
	err=gdImageStringFT(im_out,&string_ractangle[0],
		text,font,size,angle,x,y,value);
	//output
	printf("Content_type:image/gif\n\n");
	gdImageGif(im_out,stdout);
	gdImageDestroy(im_out);
	return 0;
}              
              

We call this program as before with cgi-bin/gdgraph1?TEXT=C+PROGRAMMING+IN+LINUX

to get this kind of output which you will probably see is more likely to be a useful kind of tool. The location and contents of your systems fonts will vary but the code gives an example:

- OpenSuse /usr/share/fonts/truetype/*.ttf

- Ubuntu. /usr/share/fonts/truetype/ttf-dejavu/*.ttf

To get any good at using a library like GD you have to be prepared to experiment and take a lot of time to understand the function parameters, looking in great detail at the available documentation at: