scripts

commit 251edb4ded6f864024e63d2388744b045cc26b22
parent 55bc884e3a04655cc59702fa0cc23074a65dc49c
Author: lostd <lostd@2f30.org>
Date:   Sun,  8 Dec 2013 14:15:07 +0200

Xlib and cairo example code to draw a png image

Diffstat:
A
see/Makefile
 | 
13
+++++++++++++
A
see/see.c
 | 
99
+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++

2 files changed, 112 insertions(+), 0 deletions(-)
diff --git a/see/Makefile b/see/Makefile
@@ -0,0 +1,13 @@
+LOCALBASE = /usr/local
+X11BASE = /usr/X11R6
+
+CFLAGS = -I$(LOCALBASE)/include -I$(X11BASE)/include
+LDFLAGS = -L$(LOCALBASE)/lib -L$(X11BASE)/lib
+LDLIBS = -lX11 -lcairo
+
+BIN = see
+
+all: $(BIN)
+
+clean:
+	rm -f $(BIN)
diff --git a/see/see.c b/see/see.c
@@ -0,0 +1,99 @@
+#include <err.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <X11/Xlib.h>
+#include <cairo/cairo.h>
+#include <cairo/cairo-xlib.h>
+
+/* draw a png image inside an xlib window using cairo */
+
+int
+main(int argc, char *argv[])
+{
+	Display *dpy;
+	Window root, win;
+	XEvent e;
+	int scr;
+	cairo_surface_t *cs, *img;
+	cairo_t *c;
+	int winw, winh;
+	int imgw, imgh;
+	char *imgpath;
+
+	imgpath = argv[1];
+	if (imgpath == NULL) {
+		fprintf(stderr, "usage: see image.png\n");
+		exit(1);
+	}
+
+	/* load image and get dimantions */
+	img = cairo_image_surface_create_from_png(imgpath);
+	if (cairo_surface_status(img) != CAIRO_STATUS_SUCCESS)
+		errx(1, "load image");
+	imgw = cairo_image_surface_get_width(img);
+	imgh = cairo_image_surface_get_height(img);
+
+	/* init screen and get dimensions */
+	dpy = XOpenDisplay(NULL);
+	if (dpy == NULL)
+		errx(1, "open display");
+	scr = DefaultScreen(dpy);
+	winw = DisplayWidth(dpy, scr);
+	winh = DisplayHeight(dpy, scr);
+
+	/* resize window if img is smaller */
+#define MIN(x, y) ((x) < (y) ? (x) : (y))
+	winw = MIN(winw, imgw);
+	winh = MIN(winh, imgh);
+#undef MIN
+
+	/* create window */
+	root = RootWindow(dpy, scr);
+	win = XCreateSimpleWindow(dpy, root, 0, 0, winw, winh, 0,
+	    BlackPixel(dpy, scr), BlackPixel(dpy, scr));
+
+	/* register for events */
+	XSelectInput(dpy, win, ExposureMask | KeyPressMask);
+
+	/* name window */
+	XStoreName(dpy, win, imgpath);
+
+	/* draw window */
+	XMapWindow(dpy, win);
+
+	/* create surface in window */
+	cs = cairo_xlib_surface_create(dpy, win, DefaultVisual(dpy, scr),
+	    winw, winh);
+	c = cairo_create(cs);
+
+	/* put image on surface centered */
+	cairo_set_source_surface(c, img,
+	    (winw - imgw) / 2, (winh - imgh) / 2);
+
+	while (1) {
+		XNextEvent(dpy, &e);
+
+		switch (e.type) {
+		case Expose:
+			/* redraw if damaged */
+			if (e.xexpose.count < 1)
+				cairo_paint(c);
+			break;
+		case KeyPress:
+			/* quit on q pressed */
+			if (XLookupKeysym(&(e.xkey), 0) ==
+			    XStringToKeysym("q"))
+				goto out;
+			break;
+		}
+	}
+
+out:
+	/* free */
+	cairo_destroy(c);
+	cairo_surface_destroy(cs);
+	cairo_surface_destroy(img);
+	XCloseDisplay(dpy);
+
+	return 0;
+}