Merge pull request #296 from progandy/pixbuf

Support for more image formats for wallpapers with gdk-pixbuf (#282)

2 files changed, 120 insertions, 1 deletions

diff --git a/swaybg/CMakeLists.txt b/swaybg/CMakeLists.txt
index 71363d79..2588f9e7 100644
--- a/swaybg/CMakeLists.txt
+++ b/swaybg/CMakeLists.txt
@@ -2,6 +2,7 @@ include_directories(
 	${PROTOCOLS_INCLUDE_DIRS}
 	${WAYLAND_CLIENT_INCLUDE_DIR}
 	${CAIRO_INCLUDE_DIRS}
+	${GDK_PIXBUF_INCLUDE_DIRS}
 	${PANGO_INCLUDE_DIRS}
 )
 
@@ -15,6 +16,7 @@ target_link_libraries(swaybg
 	${WAYLAND_CLIENT_LIBRARIES}
 	${WAYLAND_CURSOR_LIBRARIES}
 	${CAIRO_LIBRARIES}
+	${GDK_PIXBUF_LIBRARIES}
 	${PANGO_LIBRARIES}
 	m
 )
diff --git a/swaybg/main.c b/swaybg/main.c
index b60c80e9..4a03f4a4 100644
--- a/swaybg/main.c
+++ b/swaybg/main.c
@@ -4,6 +4,7 @@
 #include <wayland-client.h>
 #include <time.h>
 #include <string.h>
+#include <gdk-pixbuf/gdk-pixbuf.h>
 #include "client/window.h"
 #include "client/registry.h"
 #include "log.h"
@@ -21,6 +22,111 @@ enum scaling_mode {
 	SCALING_MODE_TILE,
 };
 
+
+#ifndef GDK_PIXBUF_CHECK_VERSION
+#define GDK_PIXBUF_CHECK_VERSION(major,minor,micro) \
+	(GDK_PIXBUF_MAJOR > (major) || \
+		(GDK_PIXBUF_MAJOR == (major) && GDK_PIXBUF_MINOR > (minor)) || \
+		(GDK_PIXBUF_MAJOR == (major) && GDK_PIXBUF_MINOR == (minor) && \
+			GDK_PIXBUF_MICRO >= (micro)))
+#endif
+
+cairo_surface_t* __gdk_cairo_image_surface_create_from_pixbuf(const GdkPixbuf *gdkbuf)
+{
+
+	int chan = gdk_pixbuf_get_n_channels(gdkbuf);
+	if (chan < 3) return NULL;
+
+#if GDK_PIXBUF_CHECK_VERSION(2,32,0)
+	const guint8* gdkpix = gdk_pixbuf_read_pixels(gdkbuf);
+#else
+	const guint8* gdkpix = gdk_pixbuf_get_pixels(gdkbuf);
+#endif
+	if (!gdkpix) {
+		return NULL;
+	}
+	gint w = gdk_pixbuf_get_width(gdkbuf);
+	gint h = gdk_pixbuf_get_height(gdkbuf);
+	int stride = gdk_pixbuf_get_rowstride(gdkbuf);
+
+	cairo_format_t fmt = (chan == 3) ? CAIRO_FORMAT_RGB24 : CAIRO_FORMAT_ARGB32;
+	cairo_surface_t * cs = cairo_image_surface_create (fmt, w, h);
+	cairo_surface_flush (cs);
+	if ( !cs || cairo_surface_status(cs) != CAIRO_STATUS_SUCCESS) {
+		return NULL;
+	}
+
+	int cstride = cairo_image_surface_get_stride(cs);
+	unsigned char * cpix = cairo_image_surface_get_data(cs);
+
+	if (chan == 3) {
+		int i;
+		for (i = h; i; --i) {
+			const guint8 *gp = gdkpix;
+			unsigned char *cp = cpix;
+			const guint8* end = gp + 3*w;
+			while (gp < end) {
+#if G_BYTE_ORDER == G_LITTLE_ENDIAN
+				cp[0] = gp[2];
+				cp[1] = gp[1];
+				cp[2] = gp[0];
+#else
+				cp[1] = gp[0];
+				cp[2] = gp[1];
+				cp[3] = gp[2];
+#endif
+				gp += 3;
+				cp += 4;
+			}
+			gdkpix += stride;
+			cpix += cstride;
+		}
+	} else {
+		/* premul-color = alpha/255 * color/255 * 255 = (alpha*color)/255
+		 * (z/255) = z/256 * 256/255     = z/256 (1 + 1/255)
+		 *         = z/256 + (z/256)/255 = (z + z/255)/256
+		 *         # recurse once
+		 *         = (z + (z + z/255)/256)/256
+		 *         = (z + z/256 + z/256/255) / 256
+		 *         # only use 16bit uint operations, loose some precision,
+		 *         # result is floored.
+		 *       ->  (z + z>>8)>>8
+		 *         # add 0x80/255 = 0.5 to convert floor to round
+		 *       =>  (z+0x80 + (z+0x80)>>8 ) >> 8
+		 * ------
+		 * tested as equal to lround(z/255.0) for uint z in [0..0xfe02]
+		 */
+#define PREMUL_ALPHA(x,a,b,z) G_STMT_START { z = a * b + 0x80; x = (z + (z >> 8)) >> 8; } G_STMT_END
+		int i;
+		for (i = h; i; --i) {
+			const guint8 *gp = gdkpix;
+			unsigned char *cp = cpix;
+			const guint8* end = gp + 4*w;
+			guint z1, z2, z3;
+			while (gp < end) {
+#if G_BYTE_ORDER == G_LITTLE_ENDIAN
+				PREMUL_ALPHA(cp[0], gp[2], gp[3], z1);
+				PREMUL_ALPHA(cp[1], gp[1], gp[3], z2);
+				PREMUL_ALPHA(cp[2], gp[0], gp[3], z3);
+				cp[3] = gp[3];
+#else
+				PREMUL_ALPHA(cp[1], gp[0], gp[3], z1);
+				PREMUL_ALPHA(cp[2], gp[1], gp[3], z2);
+				PREMUL_ALPHA(cp[3], gp[2], gp[3], z3);
+				cp[0] = gp[3];
+#endif
+				gp += 4;
+				cp += 4;
+			}
+			gdkpix += stride;
+			cpix += cstride;
+		}
+#undef PREMUL_ALPHA
+	}
+	cairo_surface_mark_dirty(cs);
+	return cs;
+}
+
 void sway_terminate(void) {
 	int i;
 	for (i = 0; i < surfaces->length; ++i) {
@@ -56,7 +162,16 @@ int main(int argc, const char **argv) {
 	desktop_shell_set_background(registry->desktop_shell, output->output, window->surface);
 	list_add(surfaces, window);
 
-	cairo_surface_t *image = cairo_image_surface_create_from_png(argv[2]);
+	GError *err=NULL;
+	GdkPixbuf *pixbuf = gdk_pixbuf_new_from_file(argv[2],&err);
+	if (!pixbuf) {
+		sway_abort("Failed to load background image.");
+	}
+	cairo_surface_t *image=__gdk_cairo_image_surface_create_from_pixbuf(pixbuf);
+	g_object_unref(pixbuf);
+	if (!image) {
+		sway_abort("Failed to read background image.");
+	}
 	double width = cairo_image_surface_get_width(image);
 	double height = cairo_image_surface_get_height(image);
 
@@ -148,6 +263,8 @@ int main(int argc, const char **argv) {
 		}
 	}
 
+	cairo_surface_destroy(image);
+
 	while (wl_display_dispatch(registry->display) != -1);
 
 	for (i = 0; i < surfaces->length; ++i) {