1 files changed, 120 insertions, 0 deletions
diff --git a/src/libdraw/x11-alloc.c b/src/libdraw/x11-alloc.c
new file mode 100644
index 00000000..19475c74
--- /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);
+}
+