From 383401a5e46855bc36fca8f9f2c98bb9f814f21a Mon Sep 17 00:00:00 2001
From: Nick Bowler <draconx@gmail.com>
Date: Mon, 28 Apr 2008 18:06:21 -0400
Subject: [PATCH] Add a C tool to determine the physical aspect ratio of a
 display.

---
 scripts/C/.gitignore |  2 +
 scripts/C/Makefile   | 13 +++++++
 scripts/C/xaspect.c  | 88 ++++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 103 insertions(+)
 create mode 100644 scripts/C/.gitignore
 create mode 100644 scripts/C/Makefile
 create mode 100644 scripts/C/xaspect.c

diff --git a/scripts/C/.gitignore b/scripts/C/.gitignore
new file mode 100644
index 0000000..bb2bc77
--- /dev/null
+++ b/scripts/C/.gitignore
@@ -0,0 +1,2 @@
+*.o
+xaspect
diff --git a/scripts/C/Makefile b/scripts/C/Makefile
new file mode 100644
index 0000000..5d61541
--- /dev/null
+++ b/scripts/C/Makefile
@@ -0,0 +1,13 @@
+CFLAGS  = -O2 -Wall -Wextra -Wno-sign-compare
+LDFLAGS = 
+
+CC = c89
+LD = $(CC)
+
+all: xaspect
+
+.c.o:
+	$(CC) -c -o $@ $(CFLAGS) $<
+
+xaspect: xaspect.o
+	$(LD) -o xaspect $^ -lm -lxcb $(LDFLAGS)
diff --git a/scripts/C/xaspect.c b/scripts/C/xaspect.c
new file mode 100644
index 0000000..0dbc83d
--- /dev/null
+++ b/scripts/C/xaspect.c
@@ -0,0 +1,88 @@
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <math.h>
+#include <xcb/xcb.h>
+
+#define MKASPECT(w, h) { (double)w/h, #w ":" #h }
+
+/* Table of common monitor aspect ratios.  Add to this as necessary. */
+static struct aspect {
+	double ratio;
+	char *name;
+} aspects[] = {
+	MKASPECT(16, 10),
+	MKASPECT(16, 9),
+	MKASPECT(8, 5),
+	MKASPECT(5, 4),
+	MKASPECT(4, 3)
+};
+
+/*
+ * Get the xcb screen structure for the specified screen, or NULL if it doesn't
+ * exist.
+ */
+static xcb_screen_t *getscreen(xcb_connection_t *c, int screen)
+{
+	xcb_screen_iterator_t iter;
+
+	iter = xcb_setup_roots_iterator(xcb_get_setup(c));
+	while (iter.rem) {
+		if (screen == 0)
+			return iter.data;
+		screen--;
+		xcb_screen_next(&iter);
+	}
+
+	return NULL;
+}
+
+char *testaspect(xcb_screen_t *screen)
+{
+	unsigned int w = screen->width_in_millimeters;
+	unsigned int h = screen->height_in_millimeters;
+
+	double ratio = (double)w/h;
+	double diff = 0;
+	char *best = NULL;
+	int i;
+
+	for (i = 0; i < (sizeof aspects / sizeof aspects[0]); i++) {
+		if (!best || fabs(aspects[i].ratio - ratio) < diff) {
+			best = aspects[i].name;
+			diff = fabs(aspects[i].ratio - ratio);
+		}
+	}
+
+	return best;
+}
+
+int main(int argc, char **argv)
+{
+	xcb_connection_t *display;
+	xcb_screen_t     *screen;
+	char *dpynam = NULL;
+	int screen_num;
+
+	if (argc > 2 && strcmp(argv[1], "-display") == 0)
+		dpynam = argv[2];
+	
+	display = xcb_connect(dpynam, &screen_num);
+	if (xcb_connection_has_error(display)) {
+		fprintf(stderr, "Failed to open display.\n");
+		xcb_disconnect(display);
+		return EXIT_FAILURE;
+	}
+
+	screen = getscreen(display, screen_num);
+	if (!screen) {
+		fprintf(stderr, "Invalid screen number.\n");
+		xcb_disconnect(display);
+		return EXIT_FAILURE;
+	}
+
+	printf("%s\n", testaspect(screen));
+
+	xcb_disconnect(display);
+	return EXIT_SUCCESS;
+}
-- 
2.43.0