note 112764 added to function.imagecopyresampled

FOUR RECTANGLES -- The Tools to Use this Function Creatively A rectangle is not an image, but every image has a Rectangled boundary with x=0 and y=0. The width and height are obtained with the getimagesize function. Because this function allows subimage areas to be defined, there are actually four rectangled areas that we need to be aware of. * R1 -- Source Image Boundaries * R2 -- Source Copy Area Boundaries * R3 -- Destination Image Boundaries * R4 -- Destination Resampled Placement Area Boundaries +-----------------------+ +-----------------+ | R1 | | R3 | | | | | | +------------+ | | | | | | | | | | | | | | +------+ | | | R2 | | | | | | | | | | | | R4 | | | | | | | | | | | | | | | +------+ | | +------------+ | | | | | +-----------------+ | | +-----------------------+ R1 contains all of the original pixel data. If R2 goes outside of R1 in any direction, then R2 will contain stuff that doesn't help. A lot of the time R2 == R1 exactly. R3 defines the area that holds the resampled image data. If R4 goes outside of R3 in any direction, then the resampled image data in R4 will be clipped by R3. In other words, R3 has the final say as to which of R4's pixels will be included in the final image. Most of the time, R4 == R3. In the end, R2 (and the pixels in it) will be strecthed, squeezed, and placed exactly over R4. There are plenty of good examples on this page to create thumbnails etc. But what if R3 was not destined to be a thumbnail? What if we wanted to take the entire R1 image and shrink it to fit inside R2 for example, leaving the original picture as a border? With the knowledge we have just gained it is a simple matter of creating the Source & Destination Images from the same .jpg file, then R2 should be equal to R1, and R4 should be smaller and completely inside R3. When we think of these rectangles as tools and not images, it becomes easier to see what's going on. ---- Server IP: 69.147.83.199 Probable Submitter: 69.85.145.136 ---- Manual Page -- http://php.net/manual/en/function.imagecopyresampled.php Edit -- https://master.php.net/note/edit/112764 Del: integrated -- https://master.php.net/note/delete/112764/integrated Del: useless -- https://master.php.net/note/delete/112764/useless Del: bad code -- https://master.php.net/note/delete/112764/bad+code Del: spam -- https://master.php.net/note/delete/112764/spam Del: non-english -- https://master.php.net/note/delete/112764/non-english Del: in docs -- https://master.php.net/note/delete/112764/in+docs Del: other reasons-- https://master.php.net/note/delete/112764 Reject -- https://master.php.net/note/reject/112764 Search -- https://master.php.net/manage/user-notes.php