ImageDrawText - Negative font sizes give text a new spin

I discovered today (completely by accident) that using a negative font size gives image text a whole new spin. It rotates the text 180 degrees. Similar code in java produces the same results. So it must be related to the underlying java classes.


The following ColdFusion code produces the image below.

Negative Font Size Example

<cfset img = ImageNew("", 200, 100)>
<cfset attr = { font="Arial", style="bold", size="-20" }>
<cfset ImageDrawText(img, "Transform Me", 190, 10, attr)>
<cfimage action="writeToBrowser" source="#img#"> 

The one code gotcha is the x coordinate. Since the text is rotated 180 degrees, the x coordinate is now relative to the right hand side. So if the desired x position is 10, you must use x = ImageGetWidth(img)-10 instead of x = 10.

Now I have not seen this documented anywhere. So I would use ImageRotateDrawingAxis instead. But it was still an interesting find ;)

Update: I corrected a typo in example/function name.

ImageRotateDrawingAxis

<cfset img = ImageNew("", 200, 100)>
<cfset ImageRotateDrawingAxis(img, 180, 100, 10)>
<cfset attr = { font="Arial", style="bold", size="20" }>
<cfset ImageDrawText(img, "Transform Me", 10, 10, attr)>
<cfimage action="writeToBrowser" source="#img#">