Split swaybg into a standalone project

1 files changed, 120 insertions, 0 deletions

diff --git a/background-image.c b/background-image.c
new file mode 100644
index 0000000..63c9810
--- /dev/null
+++ b/background-image.c
@@ -0,0 +1,120 @@
+#include <assert.h>
+#include "background-image.h"
+#include "cairo.h"
+#include "log.h"
+
+enum background_mode parse_background_mode(const char *mode) {
+	if (strcmp(mode, "stretch") == 0) {
+		return BACKGROUND_MODE_STRETCH;
+	} else if (strcmp(mode, "fill") == 0) {
+		return BACKGROUND_MODE_FILL;
+	} else if (strcmp(mode, "fit") == 0) {
+		return BACKGROUND_MODE_FIT;
+	} else if (strcmp(mode, "center") == 0) {
+		return BACKGROUND_MODE_CENTER;
+	} else if (strcmp(mode, "tile") == 0) {
+		return BACKGROUND_MODE_TILE;
+	} else if (strcmp(mode, "solid_color") == 0) {
+		return BACKGROUND_MODE_SOLID_COLOR;
+	}
+	swaybg_log(LOG_ERROR, "Unsupported background mode: %s", mode);
+	return BACKGROUND_MODE_INVALID;
+}
+
+cairo_surface_t *load_background_image(const char *path) {
+	cairo_surface_t *image;
+#if HAVE_GDK_PIXBUF
+	GError *err = NULL;
+	GdkPixbuf *pixbuf = gdk_pixbuf_new_from_file(path, &err);
+	if (!pixbuf) {
+		swaybg_log(LOG_ERROR, "Failed to load background image (%s).",
+				err->message);
+		return NULL;
+	}
+	image = gdk_cairo_image_surface_create_from_pixbuf(pixbuf);
+	g_object_unref(pixbuf);
+#else
+	image = cairo_image_surface_create_from_png(path);
+#endif // HAVE_GDK_PIXBUF
+	if (!image) {
+		swaybg_log(LOG_ERROR, "Failed to read background image.");
+		return NULL;
+	}
+	if (cairo_surface_status(image) != CAIRO_STATUS_SUCCESS) {
+		swaybg_log(LOG_ERROR, "Failed to read background image: %s."
+#if !HAVE_GDK_PIXBUF
+				"\nSway was compiled without gdk_pixbuf support, so only"
+				"\nPNG images can be loaded. This is the likely cause."
+#endif // !HAVE_GDK_PIXBUF
+				, cairo_status_to_string(cairo_surface_status(image)));
+		return NULL;
+	}
+	return image;
+}
+
+void render_background_image(cairo_t *cairo, cairo_surface_t *image,
+		enum background_mode mode, int buffer_width, int buffer_height) {
+	double width = cairo_image_surface_get_width(image);
+	double height = cairo_image_surface_get_height(image);
+
+	cairo_save(cairo);
+	switch (mode) {
+	case BACKGROUND_MODE_STRETCH:
+		cairo_scale(cairo,
+				(double)buffer_width / width,
+				(double)buffer_height / height);
+		cairo_set_source_surface(cairo, image, 0, 0);
+		break;
+	case BACKGROUND_MODE_FILL: {
+		double window_ratio = (double)buffer_width / buffer_height;
+		double bg_ratio = width / height;
+
+		if (window_ratio > bg_ratio) {
+			double scale = (double)buffer_width / width;
+			cairo_scale(cairo, scale, scale);
+			cairo_set_source_surface(cairo, image,
+					0, (double)buffer_height / 2 / scale - height / 2);
+		} else {
+			double scale = (double)buffer_height / height;
+			cairo_scale(cairo, scale, scale);
+			cairo_set_source_surface(cairo, image,
+					(double)buffer_width / 2 / scale - width / 2, 0);
+		}
+		break;
+	}
+	case BACKGROUND_MODE_FIT: {
+		double window_ratio = (double)buffer_width / buffer_height;
+		double bg_ratio = width / height;
+
+		if (window_ratio > bg_ratio) {
+			double scale = (double)buffer_height / height;
+			cairo_scale(cairo, scale, scale);
+			cairo_set_source_surface(cairo, image,
+					(double)buffer_width / 2 / scale - width / 2, 0);
+		} else {
+			double scale = (double)buffer_width / width;
+			cairo_scale(cairo, scale, scale);
+			cairo_set_source_surface(cairo, image,
+					0, (double)buffer_height / 2 / scale - height / 2);
+		}
+		break;
+	}
+	case BACKGROUND_MODE_CENTER:
+		cairo_set_source_surface(cairo, image,
+				(double)buffer_width / 2 - width / 2,
+				(double)buffer_height / 2 - height / 2);
+		break;
+	case BACKGROUND_MODE_TILE: {
+		cairo_pattern_t *pattern = cairo_pattern_create_for_surface(image);
+		cairo_pattern_set_extend(pattern, CAIRO_EXTEND_REPEAT);
+		cairo_set_source(cairo, pattern);
+		break;
+	}
+	case BACKGROUND_MODE_SOLID_COLOR:
+	case BACKGROUND_MODE_INVALID:
+		assert(0);
+		break;
+	}
+	cairo_paint(cairo);
+	cairo_restore(cairo);
+}