Implement image backgrounds

1 files changed, 112 insertions, 2 deletions

diff --git a/swaybg/main.c b/swaybg/main.c
index 4473869b..29cce251 100644
--- a/swaybg/main.c
+++ b/swaybg/main.c
@@ -26,8 +26,14 @@ struct swaybg_args {
         enum scaling_mode mode;
 };
 
+struct swaybg_context {
+        uint32_t color;
+        cairo_surface_t *image;
+};
+
 struct swaybg_state {
         const struct swaybg_args *args;
+        struct swaybg_context context;
 
         struct wl_display *display;
         struct wl_compositor *compositor;
@@ -62,6 +68,71 @@ bool is_valid_color(const char *color) {
         return true;
 }
 
+static void render_image(struct swaybg_state *state) {
+        cairo_t *cairo = state->current_buffer->cairo;
+        cairo_surface_t *image = state->context.image;
+        double width = cairo_image_surface_get_width(image);
+        double height = cairo_image_surface_get_height(image);
+        int wwidth = state->width;
+        int wheight = state->height;
+
+        switch (state->args->mode) {
+        case SCALING_MODE_STRETCH:
+                cairo_scale(cairo, (double)wwidth / width, (double)wheight / height);
+                cairo_set_source_surface(cairo, image, 0, 0);
+                break;
+        case SCALING_MODE_FILL: {
+                double window_ratio = (double)wwidth / wheight;
+                double bg_ratio = width / height;
+
+                if (window_ratio > bg_ratio) {
+                        double scale = (double)wwidth / width;
+                        cairo_scale(cairo, scale, scale);
+                        cairo_set_source_surface(cairo, image,
+                                        0, (double)wheight / 2 / scale - height / 2);
+                } else {
+                        double scale = (double)wheight / height;
+                        cairo_scale(cairo, scale, scale);
+                        cairo_set_source_surface(cairo, image,
+                                        (double)wwidth / 2 / scale - width / 2, 0);
+                }
+                break;
+        }
+        case SCALING_MODE_FIT: {
+                double window_ratio = (double)wwidth / wheight;
+                double bg_ratio = width / height;
+
+                if (window_ratio > bg_ratio) {
+                        double scale = (double)wheight / height;
+                        cairo_scale(cairo, scale, scale);
+                        cairo_set_source_surface(cairo, image,
+                                        (double)wwidth / 2 / scale - width / 2, 0);
+                } else {
+                        double scale = (double)wwidth / width;
+                        cairo_scale(cairo, scale, scale);
+                        cairo_set_source_surface(cairo, image,
+                                        0, (double)wheight / 2 / scale - height / 2);
+                }
+                break;
+        }
+        case SCALING_MODE_CENTER:
+                cairo_set_source_surface(cairo, image,
+                                (double)wwidth / 2 - width / 2,
+                                (double)wheight / 2 - height / 2);
+                break;
+        case SCALING_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 SCALING_MODE_SOLID_COLOR:
+                // Should never happen
+                break;
+        }
+        cairo_paint(cairo);
+}
+
 static void render_frame(struct swaybg_state *state) {
         if (!state->run_display) {
                 return;
@@ -73,11 +144,11 @@ static void render_frame(struct swaybg_state *state) {
 
         switch (state->args->mode) {
         case SCALING_MODE_SOLID_COLOR:
-                cairo_set_source_u32(cairo, parse_color(state->args->path));
+                cairo_set_source_u32(cairo, state->context.color);
                 cairo_paint(cairo);
                 break;
         default:
-                exit(1);
+                render_image(state);
                 break;
         }
 
@@ -86,6 +157,41 @@ static void render_frame(struct swaybg_state *state) {
         wl_surface_commit(state->surface);
 }
 
+static bool prepare_context(struct swaybg_state *state) {
+        if (state->args->mode == SCALING_MODE_SOLID_COLOR) {
+                state->context.color = parse_color(state->args->path);
+                return is_valid_color(state->args->path);
+        }
+#ifdef WITH_GDK_PIXBUF
+        GError *err = NULL;
+        GdkPixbuf *pixbuf = gdk_pixbuf_new_from_file(state->args->path, &err);
+        if (!pixbuf) {
+                wlr_log(L_ERROR, "Failed to load background image.");
+                return false;
+        }
+        state->context.image = gdk_cairo_image_surface_create_from_pixbuf(pixbuf);
+        g_object_unref(pixbuf);
+#else
+        state->context.image = cairo_image_surface_create_from_png(
+                        state->args->path);
+#endif //WITH_GDK_PIXBUF
+        if (!state->context.image) {
+                wlr_log(L_ERROR, "Failed to read background image.");
+                return false;
+        }
+        if (cairo_surface_status(state->context.image) != CAIRO_STATUS_SUCCESS) {
+                wlr_log(L_ERROR, "Failed to read background image: %s."
+#ifndef WITH_GDK_PIXBUF
+                                "\nSway was compiled without gdk_pixbuf support, so only"
+                                "\nPNG images can be loaded. This is the likely cause."
+#endif //WITH_GDK_PIXBUF
+                                , cairo_status_to_string(
+                                cairo_surface_status(state->context.image)));
+                return false;
+        }
+        return true;
+}
+
 static void layer_surface_configure(void *data,
                 struct zwlr_layer_surface_v1 *surface,
                 uint32_t serial, uint32_t width, uint32_t height) {
@@ -217,6 +323,10 @@ int main(int argc, const char **argv) {
         wl_surface_commit(state.surface);
         wl_display_roundtrip(state.display);
 
+        if (!prepare_context(&state)) {
+                return 1;
+        }
+
         state.run_display = true;
         render_frame(&state);
         while (wl_display_dispatch(state.display) != -1 && state.run_display) {