Initial revision
diff --git a/src/libdraw/x11-alloc.c b/src/libdraw/x11-alloc.c
new file mode 100644
index 0000000..19475c7
--- /dev/null
+++ b/src/libdraw/x11-alloc.c
@@ -0,0 +1,120 @@
+#include "x11-inc.h"
+
+#include <u.h>
+#include <libc.h>
+#include <draw.h>
+#include <memdraw.h>
+#include "x11-memdraw.h"
+
+/*
+ * Allocate a Memimage with an optional pixmap backing on the X server.
+ */
+Memimage*
+xallocmemimage(Rectangle r, u32int chan, int pixmap)
+{
+ int d, offset;
+ Memimage *m;
+ Xmem *xm;
+ XImage *xi;
+
+ m = _allocmemimage(r, chan);
+ if(chan != GREY1 && chan != _x.chan)
+ return m;
+
+ /*
+ * For bootstrapping, don't bother storing 1x1 images
+ * on the X server. Memimageinit needs to allocate these
+ * and we memimageinit before we do the rest of the X stuff.
+ * Of course, 1x1 images on the server are useless anyway.
+ */
+ if(Dx(r)==1 && Dy(r)==1)
+ return m;
+
+ xm = mallocz(sizeof(Xmem), 1);
+ if(xm == nil){
+ freememimage(m);
+ return nil;
+ }
+
+ /*
+ * Allocate backing store. What we call a 32-bit image
+ * the X server calls a 24-bit image.
+ */
+ d = m->depth;
+ if(pixmap != PMundef)
+ xm->pixmap = pixmap;
+ else
+ xm->pixmap = XCreatePixmap(_x.display, _x.drawable,
+ Dx(r), Dy(r), d==32 ? 24 : d);
+
+ /*
+ * We want to align pixels on word boundaries.
+ */
+ if(d == 24)
+ offset = r.min.x&3;
+ else
+ offset = r.min.x&(31/m->depth);
+ r.min.x -= offset;
+ assert(wordsperline(r, m->depth) <= m->width);
+
+ /*
+ * Wrap our data in an XImage structure.
+ */
+ xi = XCreateImage(_x.display, _x.vis, d==32 ? 24 : d,
+ ZPixmap, 0, (char*)m->data->bdata, Dx(r), Dy(r),
+ 32, m->width*sizeof(u32int));
+ if(xi == nil){
+ freememimage(m);
+ if(xm->pixmap != pixmap)
+ XFreePixmap(_x.display, xm->pixmap);
+ return nil;
+ }
+
+ xm->xi = xi;
+ xm->r = r;
+
+ /*
+ * Set the XImage parameters so that it looks exactly like
+ * a Memimage -- we're using the same data.
+ */
+ if(m->depth < 8 || m->depth == 24)
+ xi->bitmap_unit = 8;
+ else
+ xi->bitmap_unit = m->depth;
+ xi->byte_order = LSBFirst;
+ xi->bitmap_bit_order = MSBFirst;
+ xi->bitmap_pad = 32;
+ XInitImage(xi);
+ XFlush(_x.display);
+
+ m->X = xm;
+ return m;
+}
+
+Memimage*
+allocmemimage(Rectangle r, u32int chan)
+{
+ return xallocmemimage(r, chan, PMundef);
+}
+
+void
+freememimage(Memimage *m)
+{
+ Xmem *xm;
+
+ if(m == nil)
+ return;
+
+ xm = m->X;
+ if(xm && m->data->ref == 1){
+ if(xm->xi){
+ xm->xi->data = nil;
+ XFree(xm->xi);
+ }
+ XFreePixmap(_x.display, xm->pixmap);
+ free(xm);
+ m->X = nil;
+ }
+ _freememimage(m);
+}
+
