Add hidpi support to swaylock

include/swaylock/swaylock.h

@@ -52,6 +52,7 @@ struct swaylock_surface {
 	struct pool_buffer buffers[2];
 	struct pool_buffer *current_buffer;
 	uint32_t width, height;
+	int32_t scale;
 	struct wl_list link;
 };
 

swaylock/main.c

@@ -56,12 +56,42 @@ static const 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 swaylock_surface *surface = data;
+	surface->scale = factor;
+	if (surface->state->run_display) {
+		render_frames(surface->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 swaylock_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);
@@ -80,7 +110,8 @@ static void handle_global(void *data, struct wl_registry *registry,
 			calloc(1, sizeof(struct swaylock_surface));
 		surface->state = state;
 		surface->output = wl_registry_bind(registry, name,
-				&wl_output_interface, 1);
+				&wl_output_interface, 3);
+		wl_output_add_listener(surface->output, &output_listener, surface);
 		wl_list_insert(&state->surfaces, &surface->link);
 	}
 }

swaylock/render.c

@@ -9,28 +9,32 @@
 void render_frame(struct swaylock_surface *surface) {
 	struct swaylock_state *state = surface->state;
 	surface->current_buffer = get_next_buffer(state->shm,
-			surface->buffers, surface->width, surface->height);
+			surface->buffers,
+			surface->width * surface->scale,
+			surface->height * surface->scale);
 	cairo_t *cairo = surface->current_buffer->cairo;
 	cairo_identity_matrix(cairo);
+
+	int buffer_width = surface->width * surface->scale;
+	int buffer_height = surface->height * surface->scale;
 	if (state->args.mode == BACKGROUND_MODE_SOLID_COLOR) {
 		cairo_set_source_u32(cairo, state->args.color);
 		cairo_paint(cairo);
 	} else {
-		// TODO: hidpi
 		render_background_image(cairo, surface->image,
-				state->args.mode, surface->width, surface->height, 1);
+				state->args.mode, buffer_width, buffer_height);
 	}
 	cairo_identity_matrix(cairo);
 
-	const int ARC_RADIUS = 50;
+	int ARC_RADIUS = 50 * surface->scale;
-	const int ARC_THICKNESS = 10;
+	int ARC_THICKNESS = 10 * surface->scale;
-	const float TYPE_INDICATOR_RANGE = M_PI / 3.0f;
+	float TYPE_INDICATOR_RANGE = M_PI / 3.0f;
-	const float TYPE_INDICATOR_BORDER_THICKNESS = M_PI / 128.0f;
+	float TYPE_INDICATOR_BORDER_THICKNESS = M_PI / 128.0f * surface->scale;
+
 	if (state->args.show_indicator && state->auth_state != AUTH_STATE_IDLE) {
 		// Draw circle
 		cairo_set_line_width(cairo, ARC_THICKNESS);
-		cairo_arc(cairo, surface->width / 2, surface->height / 2,
+		cairo_arc(cairo, buffer_width / 2, buffer_height / 2, ARC_RADIUS, 0, 2 * M_PI);
-				ARC_RADIUS, 0, 2 * M_PI);
 		switch (state->auth_state) {
 		case AUTH_STATE_INPUT:
 		case AUTH_STATE_BACKSPACE: {
@@ -74,9 +78,9 @@ void render_frame(struct swaylock_surface *surface) {
 			cairo_text_extents_t extents;
 			double x, y;
 			cairo_text_extents(cairo, text, &extents);
-			x = (surface->width / 2) -
+			x = (buffer_width / 2) -
 				(extents.width / 2 + extents.x_bearing);
-			y = (surface->height / 2) -
+			y = (buffer_height / 2) -
 				(extents.height / 2 + extents.y_bearing);
 
 			cairo_move_to(cairo, x, y);
@@ -91,7 +95,7 @@ void render_frame(struct swaylock_surface *surface) {
 			static double highlight_start = 0;
 			highlight_start +=
 				(rand() % (int)(M_PI * 100)) / 100.0 + M_PI * 0.5;
-			cairo_arc(cairo, surface->width / 2, surface->height / 2,
+			cairo_arc(cairo, buffer_width / 2, buffer_height / 2,
 					ARC_RADIUS, highlight_start,
 					highlight_start + TYPE_INDICATOR_RANGE);
 			if (state->auth_state == AUTH_STATE_INPUT) {
@@ -103,12 +107,12 @@ void render_frame(struct swaylock_surface *surface) {
 
 			// Draw borders
 			cairo_set_source_rgb(cairo, 0, 0, 0);
-			cairo_arc(cairo, surface->width / 2, surface->height / 2,
+			cairo_arc(cairo, buffer_width / 2, buffer_height / 2,
 					ARC_RADIUS, highlight_start,
 					highlight_start + TYPE_INDICATOR_BORDER_THICKNESS);
 			cairo_stroke(cairo);
 
-			cairo_arc(cairo, surface->width / 2, surface->height / 2,
+			cairo_arc(cairo, buffer_width / 2, buffer_height / 2,
 					ARC_RADIUS, highlight_start + TYPE_INDICATOR_RANGE,
 					highlight_start + TYPE_INDICATOR_RANGE +
 						TYPE_INDICATOR_BORDER_THICKNESS);
@@ -117,17 +121,18 @@ void render_frame(struct swaylock_surface *surface) {
 
 		// Draw inner + outer border of the circle
 		cairo_set_source_rgb(cairo, 0, 0, 0);
-		cairo_set_line_width(cairo, 2.0);
+		cairo_set_line_width(cairo, 2.0 * surface->scale);
-		cairo_arc(cairo, surface->width / 2, surface->height / 2,
+		cairo_arc(cairo, buffer_width / 2, buffer_height / 2,
 				ARC_RADIUS - ARC_THICKNESS / 2, 0, 2 * M_PI);
 		cairo_stroke(cairo);
-		cairo_arc(cairo, surface->width / 2, surface->height / 2,
+		cairo_arc(cairo, buffer_width / 2, buffer_height / 2,
 				ARC_RADIUS + ARC_THICKNESS / 2, 0, 2 * M_PI);
 		cairo_stroke(cairo);
 	}
 
+	wl_surface_set_buffer_scale(surface->surface, surface->scale);
 	wl_surface_attach(surface->surface, surface->current_buffer->buffer, 0, 0);
-	wl_surface_damage(surface->surface, 0, 0, surface->width, surface->height);
+	wl_surface_damage(surface->surface, 0, 0, buffer_width, buffer_height);
 	wl_surface_commit(surface->surface);
 	wl_display_roundtrip(state->display);
 }