[SOLVED] PHP GD Image Rotation with building PHP Graphs

[thepip3r]

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in my graph, the x axis heading values are actual date strings and they are vertically oriented using imagestringup().  i've tried assigning the value of imagestringup to a variable and then use that for the imagerotate() but i get an error when i do that.  can anyone point me in the right direction pls?

 

for($i=0;$i< $total_points; $i++){ 
# ------ Extract key and value pair from the current pointer position
list($key,$value)=each($array); 
$x1 = $margins + $gap + $i * ($gap+$bar_width);
$x2 = $x1 + $bar_width; 
$y1 = $margins + $graph_height - intval($value * $ratio) ;
$y2 = $img_height-$margins;
imagestring($img,0,intval(($bar_width-(strlen(trim($value)) * 6.5)) / 2) + $x1,$y1-10,$value,$bar_color); # numeric values written to screen
$temp = imagestringup($img,0,$x1-2,$img_height-5, date("m/d/y D", $key),$bar_color);	# x-axis heading values	
imagerotate($img, 90, 0);
imagefilledellipse($img,$x1,$y1,5,5,$bar_color);
if ($i > 0) { imageline($img, $x0, $y0, $x1, $y1, $bar_color); }
$x0 = $x1;
$y0 = $y1;		
}
header("Content-type:image/png");
imagepng($img);

[premiso]

What is the error you are getting? Providing that will help us out a bit

[thepip3r]

Warning: imagerotate() expects parameter 1 to be resource, boolean given in public_html/trigeo/graph_line.php on line 157

 

when i change the above code to:

 

$temp = imagestringup($img,0,$x1-2,$img_height-5, date("m/d/y D", $key),$bar_color);	# x-axis heading values	
imagerotate($temp, 90, 0);

[Alex]

Well that's because imagestringup() (as you can see in the manual) returns true or false depending on whether or not the operation was successful, which is not what imageroate() expects Exactly what're are you trying to do?

[premiso]

I think you need an imagecreate function to create the initial image resource before continuing...I am no expert at GD, just gathered that from the manual.

[thepip3r]

right and i understood that... i'm trying to rotate the x-axis headers say 45 degrees so they're not vertical but slightly angled.  all of the examples i can find are just creating a rotated image on the fly but not one that is created within the context of an existing "graph" image. 

 

do i ahve to create that x axis value as a separate image or something and then merge it into the graph body in order to get the x-axis headers rotated correctly?

[Alex]

Oh, now I understand what you mean. You might consider using imagettftext() as it includes an angle parameter for drawing the text.

[thepip3r]

thanx gents -- i will look into both of these.

[thepip3r]

Alex -- worked like a champ.  http://www.zigsdigs.com/trigeo/graph_line.php

 

now i just have to figure out how to calculate the x-offset so the end of the line is adjusted to the actual point instead of the start of the lean.

 

i always read the manual, i just got to imagerotate() and got stuck and never looked any further -- my bad.  ty for the help guys.