Merge pull request #1713 from emersion/swaybg-hidpi

swaybg: add HiDPI support

1 files changed, 56 insertions, 19 deletions

diff --git a/swaybg/main.c b/swaybg/main.c
index 203082f6..25a1d73a 100644
--- a/swaybg/main.c
+++ b/swaybg/main.c
@@ -47,6 +47,7 @@ struct swaybg_state {
 
         bool run_display;
         uint32_t width, height;
+        int32_t scale;
         struct pool_buffer buffers[2];
         struct pool_buffer *current_buffer;
 };
@@ -74,52 +75,53 @@ static void render_image(struct swaybg_state *state) {
         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;
+        int buffer_width = state->width * state->scale;
+        int buffer_height = state->height * state->scale;
 
         switch (state->args->mode) {
         case BACKGROUND_MODE_STRETCH:
-                cairo_scale(cairo, (double)wwidth / width, (double)wheight / height);
+                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)wwidth / wheight;
+                double window_ratio = (double)buffer_width / buffer_height;
                 double bg_ratio = width / height;
 
                 if (window_ratio > bg_ratio) {
-                        double scale = (double)wwidth / width;
+                        double scale = (double)buffer_width / width;
                         cairo_scale(cairo, scale, scale);
                         cairo_set_source_surface(cairo, image,
-                                        0, (double)wheight / 2 / scale - height / 2);
+                                        0, (double)buffer_height / 2 / scale - height / 2);
                 } else {
-                        double scale = (double)wheight / height;
+                        double scale = (double)buffer_height / height;
                         cairo_scale(cairo, scale, scale);
                         cairo_set_source_surface(cairo, image,
-                                        (double)wwidth / 2 / scale - width / 2, 0);
+                                        (double)buffer_width / 2 / scale - width / 2, 0);
                 }
                 break;
         }
         case BACKGROUND_MODE_FIT: {
-                double window_ratio = (double)wwidth / wheight;
+                double window_ratio = (double)buffer_width / buffer_height;
                 double bg_ratio = width / height;
 
                 if (window_ratio > bg_ratio) {
-                        double scale = (double)wheight / height;
+                        double scale = (double)buffer_height / height;
                         cairo_scale(cairo, scale, scale);
                         cairo_set_source_surface(cairo, image,
-                                        (double)wwidth / 2 / scale - width / 2, 0);
+                                        (double)buffer_width / 2 / scale - width / 2, 0);
                 } else {
-                        double scale = (double)wwidth / width;
+                        double scale = (double)buffer_width / width;
                         cairo_scale(cairo, scale, scale);
                         cairo_set_source_surface(cairo, image,
-                                        0, (double)wheight / 2 / scale - height / 2);
+                                        0, (double)buffer_height / 2 / scale - height / 2);
                 }
                 break;
         }
         case BACKGROUND_MODE_CENTER:
                 cairo_set_source_surface(cairo, image,
-                                (double)wwidth / 2 - width / 2,
-                                (double)wheight / 2 - height / 2);
+                                (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);
@@ -135,8 +137,8 @@ static void render_image(struct swaybg_state *state) {
 }
 
 static void render_frame(struct swaybg_state *state) {
-        state->current_buffer = get_next_buffer(state->shm,
-                        state->buffers, state->width, state->height);
+        state->current_buffer = get_next_buffer(state->shm, state->buffers,
+                state->width * state->scale, state->height * state->scale);
         cairo_t *cairo = state->current_buffer->cairo;
 
         switch (state->args->mode) {
@@ -149,6 +151,7 @@ static void render_frame(struct swaybg_state *state) {
                 break;
         }
 
+        wl_surface_set_buffer_scale(state->surface, state->scale);
         wl_surface_attach(state->surface, state->current_buffer->buffer, 0, 0);
         wl_surface_damage(state->surface, 0, 0, state->width, state->height);
         wl_surface_commit(state->surface);
@@ -212,12 +215,42 @@ struct zwlr_layer_surface_v1_listener layer_surface_listener = {
         .closed = layer_surface_closed,
 };
 
+static void output_geometry(void *data, struct wl_output *output, int32_t x,
+                int32_t y, int32_t width_mm, int32_t height_mm, int32_t subpixel,
+                const char *make, const char *model, int32_t transform) {
+        // Who cares
+}
+
+static void output_mode(void *data, struct wl_output *output, uint32_t flags,
+                int32_t width, int32_t height, int32_t refresh) {
+        // Who cares
+}
+
+static void output_done(void *data, struct wl_output *output) {
+        // Who cares
+}
+
+static void output_scale(void *data, struct wl_output *output, int32_t factor) {
+        struct swaybg_state *state = data;
+        state->scale = factor;
+        if (state->run_display) {
+                render_frame(state);
+        }
+}
+
+struct wl_output_listener output_listener = {
+        .geometry = output_geometry,
+        .mode = output_mode,
+        .done = output_done,
+        .scale = output_scale,
+};
+
 static void handle_global(void *data, struct wl_registry *registry,
                 uint32_t name, const char *interface, uint32_t version) {
         struct swaybg_state *state = data;
         if (strcmp(interface, wl_compositor_interface.name) == 0) {
                 state->compositor = wl_registry_bind(registry, name,
-                                &wl_compositor_interface, 1);
+                                &wl_compositor_interface, 3);
         } else if (strcmp(interface, wl_shm_interface.name) == 0) {
                 state->shm = wl_registry_bind(registry, name,
                                 &wl_shm_interface, 1);
@@ -225,7 +258,8 @@ static void handle_global(void *data, struct wl_registry *registry,
                 static int output_idx = 0;
                 if (output_idx == state->args->output_idx) {
                         state->output = wl_registry_bind(registry, name,
-                                        &wl_output_interface, 1);
+                                        &wl_output_interface, 3);
+                        wl_output_add_listener(state->output, &output_listener, state);
                 }
                 output_idx++;
         } else if (strcmp(interface, zwlr_layer_shell_v1_interface.name) == 0) {
@@ -287,6 +321,9 @@ int main(int argc, const char **argv) {
         wl_display_roundtrip(state.display);
         assert(state.compositor && state.layer_shell && state.output && state.shm);
 
+        // Second roundtrip to get output properties
+        wl_display_roundtrip(state.display);
+
         assert(state.surface = wl_compositor_create_surface(state.compositor));
 
         state.layer_surface = zwlr_layer_shell_v1_get_layer_surface(