An Intro to Using the GD Image Library with PHP - More Functions
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int ImageFilledEllipse (resource im, int cx, int cy, int w, int h, int col)
With ImageFilledEllipse, we can create filled ellipses, or ovals and circles. We pass it the pointer to the image we are working on, a center point designated by cx and cy, its width and height and a color we have created.
int ImageFilledArc (int im, int cx, int cy, int w, int h, int s, int e, int col, int style)
This function is a bit more complicated, but still not hard to use at all. Just think of it as cutting a piece of pie or cake. You pass it the image you are working on, a center point (think the middle of the pie) represented by cx and cy, its width and height, its start and end points in degrees (we'll touch on this in a second), a color you have created and its style (we'll also touch on this).
To visualize the start and end points, let's think of our pie again. Let's say we are really hungry and want to cut ourselves a piece of pie that is 1/4 of the entire pie. We would pass the function a start point of 0 degrees and an end point of 90 degrees. There are 360 degrees in a circle, so a total on 90 degrees would be one fourth of it. You can vary the start and end degrees to decide "where" your piece of the pie comes from.
With the style of the arc you can do some pretty cool stuff. There are four styles: IMG_ARC_PIE IMG_ARC_CHORD IMG_ARC_NOFILL IMG_ARC_EDGED. Using IMG_ARC_PIE is going to give you your traditional pie piece. The IMG_ARC_CHORD style produces a flat outer edge, rather than the traditional pie piece shape. With IMG_ARC_CHORD, you can make things like hexagons and other flat sided designs just by filling a circle with them. IMG_ARC_NOFILL tells the function not to fill the arc and IMG_ARC_EDGED tells it to connect up all the lines and have a border. If you need to use more than one of these, use the OR bitwise operator. I.e., IMG_ARC_CHORD | IMG_ARC_NOFILL.
