| <head> |
| <title>memlayer(3) - Plan 9 from User Space</title> |
| <meta content="text/html; charset=utf-8" http-equiv=Content-Type> |
| </head> |
| <body bgcolor=#ffffff> |
| <table border=0 cellpadding=0 cellspacing=0 width=100%> |
| <tr height=10><td> |
| <tr><td width=20><td> |
| <tr><td width=20><td><b>MEMLAYER(3)</b><td align=right><b>MEMLAYER(3)</b> |
| <tr><td width=20><td colspan=2> |
| <br> |
| <p><font size=+1><b>NAME </b></font><br> |
| |
| <table border=0 cellpadding=0 cellspacing=0><tr height=2><td><tr><td width=20><td> |
| |
| memdraw, memlalloc, memldelete, memlexpose, memlfree, memlhide, |
| memline, memlnorefresh, memload, memunload, memlorigin, memlsetrefresh, |
| memltofront, memltofrontn, memltorear, memltorearn – windows of |
| memory-resident images<br> |
| |
| </table> |
| <p><font size=+1><b>SYNOPSIS </b></font><br> |
| |
| <table border=0 cellpadding=0 cellspacing=0><tr height=2><td><tr><td width=20><td> |
| |
| <tt><font size=+1>#include <u.h> <br> |
| #include <libc.h> <br> |
| #include <draw.h> <br> |
| #include <memdraw.h> <br> |
| #include <memlayer.h> <br> |
| |
| <table border=0 cellpadding=0 cellspacing=0><tr height=5><td></table> |
| </font></tt> |
| <tt><font size=+1>typedef struct Memscreen Memscreen;<br> |
| typedef struct Memlayer Memlayer;<br> |
| typedef void (*Refreshfn)(Memimage*, Rectangle, void*);<br> |
| struct Memscreen<br> |
| {<br> |
| |
| <table border=0 cellpadding=0 cellspacing=0><tr height=2><td><tr><td width=20><td> |
| |
| Memimage *frontmost; /* frontmost layer on screen */<br> |
| Memimage *rearmost; /* rearmost layer on screen */<br> |
| Memimage *image; /* upon which all layers are drawn */<br> |
| Memimage *fill; /* if non−zero, picture to use when repainting |
| */<br> |
| |
| </table> |
| };<br> |
| struct Memlayer<br> |
| {<br> |
| |
| <table border=0 cellpadding=0 cellspacing=0><tr height=2><td><tr><td width=20><td> |
| |
| Rectangle screenr; /* true position of layer on screen */<br> |
| Point delta; /* add delta to go from image coords to screen */<br> |
| Memscreen *screen; /* screen this layer belongs to */<br> |
| Memimage *front; /* window in front of this one */<br> |
| Memimage *rear; /* window behind this one*/<br> |
| int clear; /* layer is fully visible */<br> |
| Memimage *save; /* save area for obscured parts */<br> |
| Refreshfn refreshfn; /* fn to refresh obscured parts if save==nil |
| */<br> |
| void *refreshptr;/* argument to refreshfn */<br> |
| |
| </table> |
| };<br> |
| |
| <table border=0 cellpadding=0 cellspacing=0><tr height=5><td></table> |
| </font></tt> |
| <tt><font size=+1>Memimage* memlalloc(Memscreen *s, Rectangle r, Refreshfn fn, void |
| *arg, ulong col)<br> |
| |
| <table border=0 cellpadding=0 cellspacing=0><tr height=5><td></table> |
| </font></tt> |
| <tt><font size=+1>void memlnorefresh(Memimage *i, Rectangle r, void *arg)<br> |
| |
| <table border=0 cellpadding=0 cellspacing=0><tr height=5><td></table> |
| </font></tt> |
| <tt><font size=+1>int memlsetrefresh(Memimage *i, Refreshfn fn, void *arg)<br> |
| |
| <table border=0 cellpadding=0 cellspacing=0><tr height=5><td></table> |
| </font></tt> |
| <tt><font size=+1>int memldelete(Memimage *i)<br> |
| |
| <table border=0 cellpadding=0 cellspacing=0><tr height=5><td></table> |
| </font></tt> |
| <tt><font size=+1>int memlfree(Memimage *i)<br> |
| |
| <table border=0 cellpadding=0 cellspacing=0><tr height=5><td></table> |
| </font></tt> |
| <tt><font size=+1>int memlexpose(Memimage *i, Rectangle r)<br> |
| |
| <table border=0 cellpadding=0 cellspacing=0><tr height=5><td></table> |
| </font></tt> |
| <tt><font size=+1>int memlhide(Memimage *i, Rectangle r)<br> |
| |
| <table border=0 cellpadding=0 cellspacing=0><tr height=5><td></table> |
| </font></tt> |
| <tt><font size=+1>void memltofront(Memimage *i)<br> |
| |
| <table border=0 cellpadding=0 cellspacing=0><tr height=5><td></table> |
| </font></tt> |
| <tt><font size=+1>void memltofrontn(Memimage**ia, int n)<br> |
| |
| <table border=0 cellpadding=0 cellspacing=0><tr height=5><td></table> |
| </font></tt> |
| <tt><font size=+1>void memltorear(Memimage *i)<br> |
| |
| <table border=0 cellpadding=0 cellspacing=0><tr height=5><td></table> |
| </font></tt> |
| <tt><font size=+1>void memltorearn(Memimage **ia , int n)<br> |
| |
| <table border=0 cellpadding=0 cellspacing=0><tr height=5><td></table> |
| </font></tt> |
| <tt><font size=+1>int memlorigin(Memimage *i, Point log, Point phys)<br> |
| |
| <table border=0 cellpadding=0 cellspacing=0><tr height=5><td></table> |
| </font></tt> |
| <tt><font size=+1>void memdraw(Image *dst, Rectangle r,<br> |
| |
| <table border=0 cellpadding=0 cellspacing=0><tr height=2><td><tr><td width=20><td> |
| |
| |
| <table border=0 cellpadding=0 cellspacing=0><tr height=2><td><tr><td width=20><td> |
| |
| Image *src, Point sp, Image *mask, Point mp, Drawop op)<br> |
| |
| </table> |
| |
| </table> |
| int memload(Memimage *i, Rectangle r,<br> |
| |
| <table border=0 cellpadding=0 cellspacing=0><tr height=2><td><tr><td width=20><td> |
| |
| |
| <table border=0 cellpadding=0 cellspacing=0><tr height=2><td><tr><td width=20><td> |
| |
| uchar *buf, int n, int iscompressed) |
| <table border=0 cellpadding=0 cellspacing=0><tr height=5><td></table> |
| |
| </table> |
| |
| </table> |
| </font></tt> |
| <table border=0 cellpadding=0 cellspacing=0><tr height=2><td><tr><td width=20><td> |
| |
| |
| <table border=0 cellpadding=0 cellspacing=0><tr height=2><td><tr><td width=20><td> |
| |
| |
| |
| </table> |
| |
| </table> |
| <tt><font size=+1>int memunload(Memimage *i, Rectangle r,<br> |
| |
| <table border=0 cellpadding=0 cellspacing=0><tr height=2><td><tr><td width=20><td> |
| |
| |
| <table border=0 cellpadding=0 cellspacing=0><tr height=2><td><tr><td width=20><td> |
| |
| uchar *buf, int n) |
| <table border=0 cellpadding=0 cellspacing=0><tr height=5><td></table> |
| |
| </table> |
| |
| </table> |
| </font></tt> |
| <table border=0 cellpadding=0 cellspacing=0><tr height=2><td><tr><td width=20><td> |
| |
| |
| <table border=0 cellpadding=0 cellspacing=0><tr height=2><td><tr><td width=20><td> |
| |
| |
| |
| </table> |
| |
| </table> |
| |
| </table> |
| <p><font size=+1><b>DESCRIPTION </b></font><br> |
| |
| <table border=0 cellpadding=0 cellspacing=0><tr height=2><td><tr><td width=20><td> |
| |
| These functions build upon the <a href="../man3/memdraw.html"><i>memdraw</i>(3)</a> interface to maintain |
| overlapping graphical windows on in-memory images. They are used |
| by the kernel to implement the windows interface presented by |
| <a href="../man3/draw.html"><i>draw</i>(3)</a> and <a href="../man3/window.html"><i>window</i>(3)</a> and probably have little use outside of |
| the kernel. |
| <table border=0 cellpadding=0 cellspacing=0><tr height=5><td></table> |
| |
| The basic function is to extend the definition of a <tt><font size=+1>Memimage</font></tt> (see |
| <a href="../man3/memdraw.html"><i>memdraw</i>(3)</a>) to include overlapping windows defined by the <tt><font size=+1>Memlayer</font></tt> |
| type. The first fields of the <tt><font size=+1>Memlayer</font></tt> structure are identical |
| to those in <tt><font size=+1>Memimage</font></tt>, permitting a function that expects a <tt><font size=+1>Memimage</font></tt> |
| to be passed a <tt><font size=+1>Memlayer</font></tt>, and vice versa. |
| Both structures have a <tt><font size=+1>save</font></tt> field, which is nil in a <tt><font size=+1>Memimage</font></tt> |
| and points to ‘backing store’ in a <tt><font size=+1>Memlayer</font></tt>. The layer routines |
| accept <tt><font size=+1>Memimages</font></tt> or <tt><font size=+1>Memlayers</font></tt>; if the image is a <tt><font size=+1>Memimage</font></tt> the |
| underlying <tt><font size=+1>Memimage</font></tt> routine is called; otherwise the layer routines |
| recursively subdivide the geometry, reducing the |
| operation into a smaller component that ultimately can be performed |
| on a <tt><font size=+1>Memimage</font></tt>, either the display on which the window appears, |
| or the backing store. |
| <table border=0 cellpadding=0 cellspacing=0><tr height=5><td></table> |
| |
| <tt><font size=+1>Memlayers</font></tt> are associated with a <tt><font size=+1>Memscreen</font></tt> that holds the data |
| structures to maintain the windows and connects them to the associated |
| <tt><font size=+1>image</font></tt>. The <tt><font size=+1>fill</font></tt> color is used to paint the background when a window |
| is deleted. There is no function to establish a <tt><font size=+1>Memscreen</font></tt>; to |
| create one, allocate the memory, zero |
| <tt><font size=+1>frontmost</font></tt> and <tt><font size=+1>rearmost</font></tt>, set <tt><font size=+1>fill</font></tt> to a valid fill color or image, |
| and set <tt><font size=+1>image</font></tt> to the <tt><font size=+1>Memimage</font></tt> (or <tt><font size=+1>Memlayer</font></tt>) on which the windows |
| will be displayed. |
| <table border=0 cellpadding=0 cellspacing=0><tr height=5><td></table> |
| |
| <i>Memlalloc</i> allocates a <tt><font size=+1>Memlayer</font></tt> of size <i>r</i> on <tt><font size=+1>Memscreen</font></tt> <i>s</i>. If <i>col</i> |
| is not <tt><font size=+1>DNofill</font></tt>, the new window will be initialized by painting |
| it that color. |
| <table border=0 cellpadding=0 cellspacing=0><tr height=5><td></table> |
| |
| The refresh function <i>fn</i> and associated argument <i>arg</i> will be called |
| by routines in the library to restore portions of the window uncovered |
| due to another window being deleted or this window being pulled |
| to the front of the stack. The function, when called, receives |
| a pointer to the image (window) being refreshed, the |
| rectangle that has been uncovered, and the <i>arg</i> recorded when the |
| window was created. A couple of predefined functions provide built-in |
| management methods: <i>memlnorefresh</i> does no backup at all, useful |
| for making efficient temporary windows; while a <i>nil</i> function specifies |
| that the backing store |
| (<tt><font size=+1>Memlayer.save</font></tt>) will be used to keep the obscured data. Other |
| functions may be provided by the client. <i>Memlsetrefresh</i> allows |
| one to change the function associated with the window. |
| <table border=0 cellpadding=0 cellspacing=0><tr height=5><td></table> |
| |
| <i>Memldelete</i> deletes the window <i>i</i>, restoring the underlying display. |
| <i>Memlfree</i> frees the data structures without unlinking the window |
| from the associated <tt><font size=+1>Memscreen</font></tt> or doing any graphics. |
| <table border=0 cellpadding=0 cellspacing=0><tr height=5><td></table> |
| |
| <i>Memlexpose</i> restores rectangle <i>r</i> within the window, using the backing |
| store or appropriate refresh method. <i>Memlhide</i> goes the other way, |
| backing up <i>r</i> so that that portion of the screen may be modified |
| without losing the data in this window. |
| <table border=0 cellpadding=0 cellspacing=0><tr height=5><td></table> |
| |
| <i>Memltofront</i> pulls <i>i</i> to the front of the stack of windows, making |
| it fully visible. <i>Memltofrontn</i> pulls the <i>n</i> windows in the array |
| <i>ia</i> to the front as a group, leaving their internal order unaffected. |
| <i>Memltorear</i> and <i>memltorearn</i> push the windows to the rear. |
| <table border=0 cellpadding=0 cellspacing=0><tr height=5><td></table> |
| |
| <i>Memlorigin</i> changes the coordinate systems associated with the |
| window <i>i</i>. The points <i>log</i> and <i>phys</i> represent the upper left corner |
| (<tt><font size=+1>min</font></tt>) of the window’s internal coordinate system and its physical |
| location on the screen. Changing <i>log</i> changes the interpretation |
| of coordinates within the window; for example, setting it |
| to (0, 0) makes the upper left corner of the window appear to |
| be the origin of the coordinate system, regardless of its position |
| on the screen. Changing <i>phys</i> changes the physical location of |
| the window on the screen. When a window is created, its logical |
| and physical coordinates are the same, so |
| |
| <table border=0 cellpadding=0 cellspacing=0><tr height=2><td><tr><td width=20><td> |
| |
| |
| <table border=0 cellpadding=0 cellspacing=0><tr height=2><td><tr><td width=20><td> |
| |
| <tt><font size=+1>memlorigin(i, i−>r.min, i−>r.min)<br> |
| </font></tt> |
| </table> |
| |
| </table> |
| would be a no-op. |
| <table border=0 cellpadding=0 cellspacing=0><tr height=5><td></table> |
| |
| <i>Memdraw</i> and <i>memline</i> are implemented in the layer library but provide |
| the main entry points for drawing on memory-resident windows. |
| They have the signatures of <i>memimagedraw</i> and <i>memimageline</i> (see |
| <a href="../man3/memdraw.html"><i>memdraw</i>(3)</a>) but accept <tt><font size=+1>Memlayer</font></tt> or <tt><font size=+1>Memimage</font></tt> arguments both. |
| <table border=0 cellpadding=0 cellspacing=0><tr height=5><td></table> |
| |
| <i>Memload</i> and <i>memunload</i> are similarly layer-savvy versions of <i>loadmemimage</i> |
| and <i>unloadmemimage</i>. The <i>iscompressed</i> flag to <i>memload</i> specifies |
| whether the <i>n</i> bytes of data in <i>buf</i> are in compressed image format |
| (see <a href="../man7/image.html"><i>image</i>(7)</a>).<br> |
| |
| </table> |
| <p><font size=+1><b>SOURCE </b></font><br> |
| |
| <table border=0 cellpadding=0 cellspacing=0><tr height=2><td><tr><td width=20><td> |
| |
| <tt><font size=+1>/usr/local/plan9/src/libdraw<br> |
| </font></tt> |
| </table> |
| <p><font size=+1><b>SEE ALSO </b></font><br> |
| |
| <table border=0 cellpadding=0 cellspacing=0><tr height=2><td><tr><td width=20><td> |
| |
| <a href="../man3/graphics.html"><i>graphics</i>(3)</a>, <a href="../man3/memdraw.html"><i>memdraw</i>(3)</a>, <a href="../man3/stringsize.html"><i>stringsize</i>(3)</a>, <a href="../man3/window.html"><i>window</i>(3)</a>, <a href="../man3/draw.html"><i>draw</i>(3)</a><br> |
| |
| </table> |
| <p><font size=+1><b>BUGS </b></font><br> |
| |
| <table border=0 cellpadding=0 cellspacing=0><tr height=2><td><tr><td width=20><td> |
| |
| These functions are archived into <i>libdraw</i>.<br> |
| |
| </table> |
| |
| <td width=20> |
| <tr height=20><td> |
| </table> |
| <!-- TRAILER --> |
| <table border=0 cellpadding=0 cellspacing=0 width=100%> |
| <tr height=15><td width=10><td><td width=10> |
| <tr><td><td> |
| <center> |
| <a href="../../"><img src="../../dist/spaceglenda100.png" alt="Space Glenda" border=1></a> |
| </center> |
| </table> |
| <!-- TRAILER --> |
| </body></html> |
