
<?php



//cgi/cli call of program:

//php -q onepixelimage.php colorname_or_6hexdigits >imagefilename.png

if (!isset($_SERVER['REQUEST_METHOD'])) {

  //make a one pixel image.

  //run with -q

  //argv1 is color name or 6 hex digit RGB, else white.

  //redirect output.

  

  $im = ImageCreateTrueColor(1, 1);

  

  if ($argc != 2)

    $color = ImageColorAllocate($im, 255, 255, 255);

  else {

    $color = getcolor($argv[1]);



    //             somehow black is false???

    if (!$color && strtolower($argv[1])!="black") {   //argv[1] not a valid colorname, so see if is 6 hex digits

      $arg1 = strtolower($argv[1]);

      if (strlen($arg1)!=6 || strspn($arg1,'abcdef0123456789')!=6) {

    $stderr = fopen("php://stderr","w");

    fwrite($stderr, "gack! must be 6 hex digits or a standard color name\n");

    exit();

      }

      $hexes = sscanf($arg1,"%2s%2s%2s");

      $color = ImageColorAllocate($im,hexdec($hexes[0]),hexdec($hexes[1]),hexdec($hexes[2]));

    }  

  }

  ImageAlphaBlending($im, false);

  ImageFilledRectangle($im, 0, 0, 1, 1, $color);

  ImagePNG($im);

  // ImageGIF($im);

}



//initial GET of web page

else if (!isset($_GET['colorname']) && !isset($_GET['hex6digits'])) {

echo <<< endofgetpage

<html>

<head>

<title>Make a one pixel image</title>



<script language="javascript">

<!--Hide from non-JavaScript browsers



//form submittal verifier.

//Check that either a colorname selected or 6 hex digits entered



function verify() {

  var msg;              //string to contain error msgs

  

  if (document.colorform.colorname.selectedIndex==0 &&

      document.colorform.hex6digits.value.match(/^ *$/))

    msg = "Either select a color name or enter 6 hex digits";



  else if (document.colorform.hex6digits.value.length>0 &&

       !document.colorform.hex6digits.value.match(/^[0-9a-fA-F]{6}$/))

    msg = "Must be 6 hex digits (0123456789abcdef)";

 

  if (msg.length > 0) {       //if any error

    alert(msg);                 //inform user of the errors.

    return false;               //prevents form submittal

  }

  else

    return true;                //form is OK, submit to server

}    

//-->

</script>

</head>

<body>

Make a one pixel image

<br>

Select a color name or enter 6 hex digits of RGB

<br>

<form name="colorform" action="$PHP_SELF" onsubmit="return verify();">

RGB 6 hex digits

<input type="text" size="6" maxlength="6" name="hex6digits">

Color name

<select name="colorname">

<option>

<option>white

<option>black

<option>red

<option>blue

<option>lime

<option>green

<option>yellow

<option>aqua_cyan

<option>fuchsia_magenta

<option>gray

<option>html_green

<option>maroon

<option>navy

<option>olive

<option>silver

<option>teal

</select>

<input type="submit" value="Make it and send it to me now">

</form>

</body>

</html>

endofgetpage;

}



else if ($_GET['hex6digits'] != "") {



  $arg1 = strtolower($_GET['hex6digits']);

  if (strlen($arg1)!=6 || strspn($arg1,'abcdef0123456789')!=6) {

    echo "gack! must be 6 hex digits or a standard color name\n";

    exit();

  }



  $im = ImageCreateTrueColor(1, 1);



  $hexes = sscanf($arg1,"%2s%2s%2s");

  $color = ImageColorAllocate($im,hexdec($hexes[0]),hexdec($hexes[1]),hexdec($hexes[2]));

  

  ImageAlphaBlending($im, false);

  ImageFilledRectangle($im, 0, 0, 1, 1, $color);

  header("Content-type: image/png");  

  ImagePNG($im);

}



else if ($_GET['colorname'] != "") {

  $im = ImageCreateTrueColor(1, 1);

  

  $color = getcolor($_GET['colorname']);



  ImageAlphaBlending($im, false);

  ImageFilledRectangle($im, 0, 0, 1, 1, $color);

  header("Content-type: image/png");  

  ImagePNG($im);

}





function getcolor($colorname) {

  global $im;

  switch (strtolower($colorname)) {

  case 'white': $color = ImageColorAllocate($im, 255, 255, 255);

    break;

  case 'black': $color = ImageColorAllocate($im, 0, 0, 0);

    break;

  case 'red': $color = ImageColorAllocate($im, 255, 0, 0);

    break;

  case 'blue': $color = ImageColorAllocate($im, 0, 0, 255);

    break;

  case 'lime':

  case 'green': $color = ImageColorAllocate($im, 0, 255, 0);

    break;

  case 'yellow': $color = ImageColorAllocate($im, 255, 255, 0);

    break;

  case 'aqua':

  case 'cyan': $color = ImageColorAllocate($im, 0, 255, 255);

    break;

  case 'fuchsia':

  case 'magenta': $color = ImageColorAllocate($im, 255, 0, 255);

    break;

  case 'gray': $color = ImageColorAllocate($im,128,128,128);

    break;

  case 'html_green': $color = ImageColorAllocate($im, 0,128,0);

    break;

  case 'maroon': $color = ImageColorAllocate($im,128,0,0);

    break;

  case 'navy': $color = ImageColorAllocate($im,0,0,128);

    break;

  case 'olive': $color = ImageColorAllocate($im,128,128,0);

    break;

  case 'silver': $color = ImageColorAllocate($im,192,192,192);

    break;

  case 'teal': $color = ImageColorAllocate($im,0,128,128);

    break;

  default: return false;

  }

  return $color;

}  



?>