overlay: Rudiments of config files and option parsing

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>

8 files changed, 541 insertions, 86 deletions

diff --git a/overlay/Makefile.am b/overlay/Makefile.am
index 75a3338a..52a61270 100644
--- a/overlay/Makefile.am
+++ b/overlay/Makefile.am
@@ -8,10 +8,9 @@ LDADD = $(DRM_LIBS) $(PCIACCESS_LIBS) $(CAIRO_LIBS) $(OVERLAY_LIBS)
 
 intel_gpu_overlay_SOURCES = \
 	i915_pciids.h \
-	overlay.h \
-	overlay.c \
 	chart.h \
 	chart.c \
+	config.c \
 	cpu-top.h \
 	cpu-top.c \
 	debugfs.h \
@@ -26,6 +25,8 @@ intel_gpu_overlay_SOURCES = \
 	gpu-freq.c \
 	igfx.h \
 	igfx.c \
+	overlay.h \
+	overlay.c \
 	power.h \
 	power.c \
 	rc6.h \
@@ -33,6 +34,7 @@ intel_gpu_overlay_SOURCES = \
 	$(NULL)
 
 if BUILD_OVERLAY_XLIB
+both_x11_sources = x11/position.c x11/position.h
 AM_CFLAGS += $(OVERLAY_XLIB_CFLAGS)
 LDADD += $(OVERLAY_XLIB_LIBS)
 intel_gpu_overlay_SOURCES += \
@@ -41,6 +43,7 @@ intel_gpu_overlay_SOURCES += \
 endif
 
 if BUILD_OVERLAY_XVLIB
+both_x11_sources = x11/x11-position.c
 AM_CFLAGS += $(OVERLAY_XVLIB_CFLAGS)
 LDADD += $(OVERLAY_XVLIB_LIBS)
 intel_gpu_overlay_SOURCES += \
@@ -52,4 +55,6 @@ intel_gpu_overlay_SOURCES += \
 	$(NULL)
 endif
 
+intel_gpu_overlay_SOURCES += $(both_x11_sources)
+
 EXTRA_DIST=README
diff --git a/overlay/config.c b/overlay/config.c
new file mode 100644
index 00000000..f0f7ce8b
--- /dev/null
+++ b/overlay/config.c
@@ -0,0 +1,282 @@
+/*
+ * Copyright © 2013 Intel Corporation
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a
+ * copy of this software and associated documentation files (the "Software"),
+ * to deal in the Software without restriction, including without limitation
+ * the rights to use, copy, modify, merge, publish, distribute, sublicense,
+ * and/or sell copies of the Software, and to permit persons to whom the
+ * Software is furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice (including the next
+ * paragraph) shall be included in all copies or substantial portions of the
+ * Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
+ * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+ * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
+ * IN THE SOFTWARE.
+ *
+ */
+
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <sys/mman.h>
+#include <stdlib.h>
+#include <stdio.h>
+#include <string.h>
+#include <ctype.h>
+#include <unistd.h>
+#include <fcntl.h>
+#include <errno.h>
+
+#include "overlay.h"
+
+#define DEFAULT_SECTION "window"
+
+static const char *skip_whitespace(const char *s, const char *end)
+{
+	while (s < end && isspace(*s))
+		s++;
+	return s;
+}
+
+static const char *trim_whitespace(const char *s, const char *end)
+{
+	if (end == NULL)
+		return end;
+
+	while (end > s && isspace(*--end))
+		;
+
+	return end + 1;
+}
+
+static const char *skip_past_newline(const char *s, const char *end)
+{
+	while (s < end && *s++ != '\n')
+		;
+
+	return s;
+}
+
+static const char *find(const char *s, const char *end, int c)
+{
+	while (s < end && *s != c) {
+		if (*s == '#')
+			break;
+
+		if (*s == '\n')
+			return NULL;
+		s++;
+	}
+
+	return s;
+}
+
+static int parse(const char *buf, int len,
+		 int (*func)(const char *section,
+			     const char *name,
+			     const char *value,
+			     void *data),
+		 void *data)
+{
+	char section[128] = DEFAULT_SECTION, name[128], value[128];
+	const char *buf_end = buf + len;
+	const char *end;
+	int line = 0;
+
+	for (line = 0 ; ++line; buf = skip_past_newline(buf, buf_end)) {
+		++line;
+		buf = skip_whitespace(buf, buf_end);
+		if (buf >= buf_end)
+			break;
+
+		if (*buf == ';' || *buf == '#') {
+			/* comment */
+		} else if (*buf == '[') { /* new section */
+			end = find(++buf, buf_end, ']');
+			end = trim_whitespace(buf, end);
+			if (end <= buf)
+				continue;
+
+			len = end - buf;
+			if (len == 0 || len >= sizeof(section))
+				return line;
+
+			memcpy(section, buf, len);
+			section[len] = '\0';
+		} else { /* name = value */
+			const char *sep;
+			int has_value = 1;
+
+			sep = find(buf, buf_end, '=');
+			if (sep == NULL)
+				sep = find(buf, buf_end, ':');
+			if (sep == NULL) {
+				sep = find(buf, buf_end, '\n');
+				has_value = 0;
+			}
+			end = trim_whitespace(buf, sep);
+			if (end <= buf)
+				continue;
+
+			len = end - buf;
+			if (len == 0 || len >= sizeof(name))
+				return line;
+
+			memcpy(name, buf, len);
+			name[len] = '\0';
+
+			if (has_value) {
+				buf = skip_whitespace(sep + 1, buf_end);
+				end = find(buf, buf_end, '\n');
+				end = trim_whitespace(buf, end);
+
+				len = end - buf;
+				if (len >= sizeof(name))
+					return line;
+
+				memcpy(value, buf, len);
+				value[len] = '\0';
+			} else
+				value[0] = '\0';
+
+			if (!func(section, name, value, data))
+				return line;
+		}
+	}
+
+	return 0;
+}
+
+static int add_value(const char *section,
+		     const char *name,
+		     const char *value,
+		     void *data)
+{
+	struct config *c = data;
+	struct config_section *s;
+	struct config_value *v, **prev;
+
+	for (s = c->sections; s != NULL; s = s->next)
+		if (strcmp(s->name, section) == 0)
+			break;
+	if (s == NULL) {
+		int len = strlen(section) + 1;
+
+		s = malloc(sizeof(*s)+len);
+		if (s == NULL)
+			return 0;
+
+		memcpy(s->name, section, len);
+		s->next = c->sections;
+		c->sections = s;
+	}
+
+	for (prev = &s->values; (v = *prev) != NULL; prev = &v->next) {
+		if (strcmp(v->name, name) == 0) {
+			*prev = v->next;
+			free(v);
+			break;
+		}
+	}
+	{
+		int name_len = strlen(name) + 1;
+		int value_len = *value ? strlen(value) + 1 : 0;
+
+		v = malloc(sizeof(*v) + name_len + value_len);
+		if (v == NULL)
+			return 0;
+
+		v->name = memcpy(v+1, name, name_len);
+
+		if (*value)
+			v->value = memcpy(v->name + name_len, value, value_len);
+		else
+			v->value = NULL;
+
+		v->next = s->values;
+		s->values = v;
+	}
+
+	return 1;
+}
+
+static int config_init_from_file(struct config *config, const char *filename)
+{
+	struct stat st;
+	int fd, err = -1;
+	char *str;
+
+	fd = open(filename, 0);
+	if (fd < 0)
+		return -1;
+
+	if (fstat(fd, &st) < 0)
+		goto err_fd;
+
+	if ((str = mmap(0, st.st_size, PROT_READ, MAP_SHARED, fd, 0)) == (void *)-1)
+		goto err_fd;
+
+	err = parse(str, st.st_size, add_value, config);
+	munmap(str, st.st_size);
+
+err_fd:
+	close(fd);
+	return err;
+}
+
+void config_init(struct config *config)
+{
+	memset(config, 0, sizeof(*config));
+}
+
+void config_parse_string(struct config *config, const char *str)
+{
+	int err;
+
+	if (str == NULL)
+		return;
+
+	err = config_init_from_file(config, str);
+	if (err == -1)
+		err = parse(str, strlen(str), add_value, config);
+	if (err) {
+		fprintf(stderr, "Failed to parse config string at line %d\n", err);
+		exit(1);
+	}
+}
+
+void config_set_value(struct config *c,
+		      const char *section,
+		      const char *name,
+		      const char *value)
+{
+	add_value(section, name, value, c);
+}
+
+const char *config_get_value(struct config *c,
+			     const char *section,
+			     const char *name)
+{
+	struct config_section *s;
+	struct config_value *v;
+
+	for (s = c->sections; s != NULL; s = s->next) {
+		if (strcmp(s->name, section))
+			continue;
+
+		for (v = s->values; v != NULL; v = v->next) {
+			if (strcmp(v->name, name))
+				continue;
+
+			return v->value;
+		}
+	}
+
+	return NULL;
+}
diff --git a/overlay/overlay.c b/overlay/overlay.c
index e783a6f4..ce3b6453 100644
--- a/overlay/overlay.c
+++ b/overlay/overlay.c
@@ -33,9 +33,11 @@
 #include <fcntl.h>
 #include <errno.h>
 #include <signal.h>
+#include <getopt.h>
 
 #include "overlay.h"
 #include "chart.h"
+#include "config.h"
 #include "cpu-top.h"
 #include "debugfs.h"
 #include "gem-objects.h"
@@ -710,24 +712,49 @@ static void signal_snapshot(int sig)
 
 int main(int argc, char **argv)
 {
+	static struct option long_options[] = {
+		{"config", 1, 0, 'c'},
+		{"geometry", 1, 0, 'G'},
+		{"position", 1, 0, 'P'},
+		{NULL, 0, 0, 0,}
+	};
 	struct overlay_context ctx;
-	int i = 0;
+	struct config config;
+	int index;
+	int i;
+
+	config_init(&config);
+
+	opterr = 0;
+	while ((i = getopt_long(argc, argv, "c:", long_options, &index)) != -1) {
+		switch (i) {
+		case 'c':
+			config_parse_string(&config, optarg);
+			break;
+		case 'G':
+			config_set_value(&config, "window", "geometry", optarg);
+			break;
+		case 'P':
+			config_set_value(&config, "window", "position", optarg);
+			break;
+		}
+	}
 
-	if (argc > 1) {
+	if (argc > optind) {
 		x11_overlay_stop();
 		return 0;
 	}
 
-	signal(SIGUSR1, signal_snapshot);
-
 	ctx.width = 640;
 	ctx.height = 236;
-	ctx.surface = x11_overlay_create(POS_TOP_RIGHT, &ctx.width, &ctx.height);
+	ctx.surface = x11_overlay_create(&config, &ctx.width, &ctx.height);
 	if (ctx.surface == NULL)
-		ctx.surface = x11_window_create(POS_TOP_RIGHT, &ctx.width, &ctx.height);
+		ctx.surface = x11_window_create(&config, &ctx.width, &ctx.height);
 	if (ctx.surface == NULL)
 		return ENOMEM;
 
+	signal(SIGUSR1, signal_snapshot);
+
 	debugfs_init();
 
 	init_gpu_top(&ctx, &ctx.gpu_top);
@@ -735,6 +762,7 @@ int main(int argc, char **argv)
 	init_gpu_freq(&ctx, &ctx.gpu_freq);
 	init_gem_objects(&ctx, &ctx.gem_objects);
 
+	i = 0;
 	while (1) {
 		usleep(500*1000);
 
diff --git a/overlay/overlay.h b/overlay/overlay.h
index 7794b577..f7b94d16 100644
--- a/overlay/overlay.h
+++ b/overlay/overlay.h
@@ -64,18 +64,40 @@ struct overlay {
 
 extern const cairo_user_data_key_t overlay_key;
 
+struct config {
+	struct config_section {
+		struct config_section *next;
+		struct config_value {
+			struct config_value *next;
+			char *name;
+			char *value;
+		} *values;
+		char name[0];
+	} *sections;
+};
+
+void config_init(struct config *config);
+void config_parse_string(struct config *config, const char *str);
+void config_set_value(struct config *config,
+		      const char *section,
+		      const char *name,
+		      const char *value);
+const char *config_get_value(struct config *config,
+			     const char *section,
+			     const char *name);
+
 #ifdef HAVE_OVERLAY_XVLIB
-cairo_surface_t *x11_overlay_create(enum position pos, int *width, int *height);
+cairo_surface_t *x11_overlay_create(struct config *config, int *width, int *height);
 void x11_overlay_stop(void);
 #else
-static inline cairo_surface_t *x11_overlay_create(enum position pos, int *width, int *height) { return NULL; }
+static inline cairo_surface_t *x11_overlay_create(struct config *config, int *width, int *height) { return NULL; }
 static inline void x11_overlay_stop(void) { }
 #endif
 
 #ifdef HAVE_OVERLAY_XLIB
-cairo_surface_t *x11_window_create(enum position pos, int *width, int *height);
+cairo_surface_t *x11_window_create(struct config *config, int *width, int *height);
 #else
-static inline cairo_surface_t *x11_window_create(enum position pos, int *width, int *height) { return NULL; }
+static inline cairo_surface_t *x11_window_create(struct config *config, int *width, int *height) { return NULL; }
 #endif
 
 #endif /* OVERLAY_H */
diff --git a/overlay/x11/position.c b/overlay/x11/position.c
new file mode 100644
index 00000000..0dcfc8de
--- /dev/null
+++ b/overlay/x11/position.c
@@ -0,0 +1,131 @@
+/*
+ * Copyright © 2013 Intel Corporation
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a
+ * copy of this software and associated documentation files (the "Software"),
+ * to deal in the Software without restriction, including without limitation
+ * the rights to use, copy, modify, merge, publish, distribute, sublicense,
+ * and/or sell copies of the Software, and to permit persons to whom the
+ * Software is furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice (including the next
+ * paragraph) shall be included in all copies or substantial portions of the
+ * Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
+ * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+ * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
+ * IN THE SOFTWARE.
+ *
+ */
+
+#include <X11/Xlib.h>
+#include <string.h>
+#include <stdio.h>
+
+#include "position.h"
+#include "../overlay.h"
+
+static enum position get_position(struct config *config)
+{
+	const char *v = config_get_value(config, "window", "position");
+	if (v == NULL)
+		return POS_UNSET;
+
+	if (strcmp(v, "top-left") == 0)
+		return POS_TOP_LEFT;
+
+	if (strcmp(v, "top-centre") == 0)
+		return POS_TOP_CENTRE;
+
+	if (strcmp(v, "top-right") == 0)
+		return POS_TOP_RIGHT;
+
+	if (strcmp(v, "middle-left") == 0)
+		return POS_MIDDLE_LEFT;
+
+	if (strcmp(v, "middle-centre") == 0)
+		return POS_MIDDLE_CENTRE;
+
+	if (strcmp(v, "middle-right") == 0)
+		return POS_MIDDLE_RIGHT;
+
+	if (strcmp(v, "bottom-left") == 0)
+		return POS_BOTTOM_LEFT;
+
+	if (strcmp(v, "bottom-centre") == 0)
+		return POS_BOTTOM_CENTRE;
+
+	if (strcmp(v, "bottom-right") == 0)
+		return POS_BOTTOM_RIGHT;
+
+	return POS_UNSET;
+}
+
+enum position
+x11_position(Screen *scr, int width, int height,
+	     struct config *config,
+	     int *x, int *y, int *w, int *h)
+{
+	enum position position = POS_UNSET;
+	const char *geometry;
+
+	*x = *y = 0;
+	*w = width;
+	*h = height;
+
+	geometry = config_get_value(config, "window", "geometry");
+	if (geometry) {
+		sscanf(geometry, "%dx%d+%d+%d", w, h, x, y);
+		if (*w < width)
+			*w = width;
+		if (*h < height)
+			*h = height;
+	} else {
+		position = get_position(config);
+		if (position != POS_UNSET) {
+			if (width == -1) {
+				*w = scr->width;
+				switch (position & 7) {
+				default:
+				case 0:
+				case 2: *w >>= 1; break;
+				}
+			} else if (width > scr->width) {
+				*w = scr->width;
+			} else
+				*w = width;
+
+			if (height == -1) {
+				*h = scr->height;
+				switch ((position >> 4) & 7) {
+				default:
+				case 0:
+				case 2: *h >>= 1; break;
+				}
+			} else if (height > scr->height)
+				*h = scr->height;
+			else
+				*h = height;
+
+			switch (position & 7) {
+			default:
+			case 0: *x = 0; break;
+			case 1: *x = (scr->width - *w)/2; break;
+			case 2: *x = scr->width - *w; break;
+			}
+
+			switch ((position >> 4) & 7) {
+			default:
+			case 0: *y = 0; break;
+			case 1: *y = (scr->height - *h)/2; break;
+			case 2: *y = scr->height - *h; break;
+			}
+		}
+	}
+
+	return position;
+}
diff --git a/overlay/x11/position.h b/overlay/x11/position.h
new file mode 100644
index 00000000..6221109f
--- /dev/null
+++ b/overlay/x11/position.h
@@ -0,0 +1,38 @@
+/*
+ * Copyright © 2013 Intel Corporation
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a
+ * copy of this software and associated documentation files (the "Software"),
+ * to deal in the Software without restriction, including without limitation
+ * the rights to use, copy, modify, merge, publish, distribute, sublicense,
+ * and/or sell copies of the Software, and to permit persons to whom the
+ * Software is furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice (including the next
+ * paragraph) shall be included in all copies or substantial portions of the
+ * Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
+ * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+ * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
+ * IN THE SOFTWARE.
+ *
+ */
+
+#ifndef X11_POSITION_H
+#define X11_POSITION_H
+
+#include <X11/Xlib.h>
+
+struct config;
+enum position;
+
+enum position
+x11_position(Screen *scr, int width, int height,
+	     struct config *config,
+	     int *x, int *y, int *w, int *h);
+
+#endif /* X11_POSITION_H */
diff --git a/overlay/x11/x11-overlay.c b/overlay/x11/x11-overlay.c
index c2693d38..f57bd55d 100644
--- a/overlay/x11/x11-overlay.c
+++ b/overlay/x11/x11-overlay.c
@@ -38,6 +38,7 @@
 #include <i915_drm.h>
 #include "../overlay.h"
 #include "dri2.h"
+#include "position.h"
 #include "rgb2yuv.h"
 
 #ifndef ALIGN
@@ -142,7 +143,7 @@ static void x11_overlay_destroy(void *data)
 }
 
 cairo_surface_t *
-x11_overlay_create(enum position position, int *width, int *height)
+x11_overlay_create(struct config *config, int *width, int *height)
 {
 	Display *dpy;
 	Screen *scr;
@@ -152,11 +153,12 @@ x11_overlay_create(enum position position, int *width, int *height)
 	struct drm_i915_gem_mmap_gtt map;
 	struct x11_overlay *priv;
 	unsigned int count, i, j;
-	int fd, w, h;
+	int fd, x, y, w, h;
 	XvAdaptorInfo *info;
 	XvImage *image;
 	XvPortID port = -1;
 	void *ptr, *mem;
+	enum position position;
 
 	dpy = XOpenDisplay(NULL);
 	if (dpy == NULL)
@@ -195,29 +197,7 @@ x11_overlay_create(enum position position, int *width, int *height)
 
 	XSetErrorHandler(noop);
 
-	if (*width == -1) {
-		w = scr->width;
-		switch (position & 7) {
-		default:
-		case 0:
-		case 2: w >>= 1; break;
-		}
-	} else if (*width > scr->width) {
-		w = scr->width;
-	} else
-		w = *width;
-
-	if (*height == -1) {
-		h = scr->height;
-		switch ((position >> 4) & 7) {
-		default:
-		case 0:
-		case 2: h >>= 1; break;
-		}
-	} else if (*height > scr->height)
-		h = scr->height;
-	else
-		h = *height;
+	position = x11_position(scr, *width, *height, config, &x, &y, &w, &h);
 
 	image = XvCreateImage(dpy, port, FOURCC_RGB565, NULL, w, h);
 	if (image == NULL)
@@ -308,18 +288,22 @@ x11_overlay_create(enum position position, int *width, int *height)
 	priv->name = flink.name;
 	priv->visible = false;
 
-	switch (position & 7) {
-	default:
-	case 0: priv->x = 0; break;
-	case 1: priv->x = (scr->width - image->width)/2; break;
-	case 2: priv->x = scr->width - image->width; break;
-	}
+	priv->x = x;
+	priv->y = y;
+	if (position != POS_UNSET) {
+		switch (position & 7) {
+		default:
+		case 0: priv->x = 0; break;
+		case 1: priv->x = (scr->width - image->width)/2; break;
+		case 2: priv->x = scr->width - image->width; break;
+		}
 
-	switch ((position >> 4) & 7) {
-	default:
-	case 0: priv->y = 0; break;
-	case 1: priv->y = (scr->height - image->height)/2; break;
-	case 2: priv->y = scr->height - image->height; break;
+		switch ((position >> 4) & 7) {
+		default:
+		case 0: priv->y = 0; break;
+		case 1: priv->y = (scr->height - image->height)/2; break;
+		case 2: priv->y = scr->height - image->height; break;
+		}
 	}
 
 
diff --git a/overlay/x11/x11-window.c b/overlay/x11/x11-window.c
index b77f5375..7f7d6d72 100644
--- a/overlay/x11/x11-window.c
+++ b/overlay/x11/x11-window.c
@@ -32,6 +32,7 @@
 #include <unistd.h>
 
 #include "../overlay.h"
+#include "position.h"
 
 struct x11_window {
 	struct overlay base;
@@ -109,7 +110,7 @@ static void x11_window_destroy(void *data)
 }
 
 cairo_surface_t *
-x11_window_create(enum position position, int *width, int *height)
+x11_window_create(struct config *config, int *width, int *height)
 {
 	Display *dpy;
 	Screen *scr;
@@ -129,43 +130,7 @@ x11_window_create(enum position position, int *width, int *height)
 
 	XSetErrorHandler(noop);
 
-	if (*width == -1) {
-		w = scr->width;
-		switch (position & 7) {
-		default:
-		case 0:
-		case 2: w >>= 1; break;
-		}
-	} else if (*width > scr->width) {
-		w = scr->width;
-	} else
-		w = *width;
-
-	if (*height == -1) {
-		h = scr->height;
-		switch ((position >> 4) & 7) {
-		default:
-		case 0:
-		case 2: h >>= 1; break;
-		}
-	} else if (*height > scr->height)
-		h = scr->height;
-	else
-		h = *height;
-
-	switch (position & 7) {
-	default:
-	case 0: x = 0; break;
-	case 1: x = (scr->width - w)/2; break;
-	case 2: x = scr->width - w; break;
-	}
-
-	switch ((position >> 4) & 7) {
-	default:
-	case 0: y = 0; break;
-	case 1: y = (scr->height - h)/2; break;
-	case 2: y = scr->height - h; break;
-	}
+	x11_position(scr, *width, *height, config, &x, &y, &w, &h);
 
 	attr.override_redirect = True;
 	win = XCreateWindow(dpy, DefaultRootWindow(dpy),