X-Git-Url: http://git.hungrycats.org/cgi-bin/gitweb.cgi?a=blobdiff_plain;f=hacks%2Fswirl.c;h=5ea1598c54efe007530ea299307c6151fe22f471;hb=ce3185de9d9705e259f2b60dd4b5509007fa17d4;hp=7f3764f02a75f9b5de626cf7186e7ca6fdf407c5;hpb=f3e0240915ed9f9b3a61781f5c7002d587563fe0;p=xscreensaver

diff --git a/hacks/swirl.c b/hacks/swirl.c
index 7f3764f0..5ea1598c 100644
--- a/hacks/swirl.c
+++ b/hacks/swirl.c
@@ -19,7 +19,7 @@ static const char sccsid[] = "@(#)swirl.c	4.00 97/01/01 xlockmore";
  * event will the author be liable for any lost revenue or profits or
  * other special, indirect and consequential damages.
  *
- * 13-May-97: jwz@netscape.com: turned into a standalone program.
+ * 13-May-97: jwz@jwz.org: turned into a standalone program.
  * 21-Apr-95: improved startup time for TrueColour displays
  *            (limited to 16bpp to save memory) S.Early <sde1000@cam.ac.uk>
  * 09-Jan-95: fixed colour maps (more colourful) and the image now spirals
@@ -36,13 +36,18 @@ static const char sccsid[] = "@(#)swirl.c	4.00 97/01/01 xlockmore";
 # define swirl_opts					xlockmore_opts
 # define DEFAULTS	"*count:		5       \n"			\
 					"*delay:		10000   \n"			\
-					"*ncolors:		200     \n"
+					"*ncolors:		200     \n"			\
+					"*useSHM:		True    \n"
 # define SMOOTH_COLORS
 # define WRITABLE_COLORS
 # include "xlockmore.h"				/* from the xscreensaver distribution */
 # include <X11/Xutil.h>
+# ifdef HAVE_XSHM_EXTENSION
+#  include "xshm.h"
+# endif /* HAVE_XSHM_EXTENSION */
 #else  /* !STANDALONE */
 # include "xlock.h"					/* from the xlockmore distribution */
+# undef HAVE_XSHM_EXTENSION
 #endif /* !STANDALONE */
 
 ModeSpecOpt swirl_opts = {
@@ -241,37 +246,33 @@ initialise_swirl(ModeInfo * mi, SWIRL_P swirl)
  * -      swirl is the swirl data
  */
 static void
-initialise_image(Display * dpy, SWIRL_P swirl)
+initialise_image(ModeInfo * mi, SWIRL_P swirl)
 {
-	unsigned int pad;
-	int         bytes_per_line;
-	int image_depth = swirl->rdepth;
-	int data_depth = image_depth;
-
-	/* On SGIs at least, using an XImage of depth 24 on a Visual of depth 24
-	   requires the XImage data to use 32 bits per pixel.  I don't understand
-	   how one is supposed to determine this -- maybe XListPixmapFormats?
-	   But on systems that don't work this way, allocating 32 bpp instead of
-	   24 will be wasteful but non-fatal.  -- jwz, 16-May-97. */
-	if (data_depth >= 24 && data_depth < 32)
-	  data_depth = 32;
-
-	/* get the bitmap pad */
-	pad = BitmapPad(dpy);
-	/* destroy the old image (destroy XImage and data) */
-	if (swirl->ximage != NULL)
-		XDestroyImage(swirl->ximage);
-
-	/* how many bytes per line? (bits rounded up to pad) */
-	bytes_per_line = ((swirl->width * data_depth + pad - 1) / pad) * (pad / 8);
-
-	/* allocate space for the image */
-	swirl->image = (unsigned char *) calloc(bytes_per_line * swirl->height, 1);
-
-	/* create an ximage with this */
-	swirl->ximage = XCreateImage(dpy, swirl->visual, image_depth, ZPixmap,
-				     0, (char *) swirl->image, swirl->width,
-				     swirl->height, pad, bytes_per_line);
+  Display *dpy = MI_DISPLAY(mi);
+
+  if (swirl->ximage != NULL)
+	XDestroyImage(swirl->ximage);
+
+  swirl->ximage = 0;
+#ifdef HAVE_XSHM_EXTENSION
+  if (mi->use_shm)
+	{
+	  swirl->ximage = create_xshm_image(dpy, swirl->visual, swirl->rdepth,
+										ZPixmap, 0, &mi->shm_info,
+										swirl->width, swirl->height);
+	  if (!swirl->ximage)
+		mi->use_shm = False;
+	}
+#endif /* HAVE_XSHM_EXTENSION */
+
+  if (!swirl->ximage)
+	{
+	  swirl->ximage = XCreateImage(dpy, swirl->visual, swirl->rdepth, ZPixmap,
+								   0, 0, swirl->width, swirl->height,
+								   8, 0);
+	  swirl->ximage->data = swirl->image =
+		(char *) calloc(swirl->height, swirl->ximage->bytes_per_line);
+	}
 }
 
 /****************************************************************/
@@ -1126,10 +1127,17 @@ draw_point(ModeInfo * mi, SWIRL_P swirl)
 		draw_block(swirl->ximage, x, y, r, do_point(swirl, x, y));
 
 	/* update the screen */
-/* PURIFY 4.0.1 on SunOS4 and on Solaris 2 reports a 256 byte memory leak on * 
-   the next line. */
-	XPutImage(MI_DISPLAY(mi), MI_WINDOW(mi), MI_GC(mi), swirl->ximage,
-		  x, y, x, y, r, r);
+
+#ifdef HAVE_XSHM_EXTENSION
+	if (mi->use_shm)
+	  XShmPutImage(MI_DISPLAY(mi), MI_WINDOW(mi), MI_GC(mi), swirl->ximage,
+				   x, y, x, y, r, r, False);
+	else
+#endif /* !HAVE_XSHM_EXTENSION */
+	  /* PURIFY 4.0.1 on SunOS4 and on Solaris 2 reports a 256 byte memory
+		 leak on the next line. */
+	  XPutImage(MI_DISPLAY(mi), MI_WINDOW(mi), MI_GC(mi), swirl->ximage,
+				x, y, x, y, r, r);
 }
 
 /****************************************************************/
@@ -1272,7 +1280,7 @@ init_swirl(ModeInfo * mi)
 		swirl->depth = 16;
 
 	/* initialise image for speeding up drawing */
-	initialise_image(display, swirl);
+	initialise_image(mi, swirl);
 
 	/* clear the window (before setting the colourmap) */
 	XClearWindow(display, MI_WINDOW(mi));