Initial setup of window border rendering

Please don't complain to me about the performance of this

include/render.h

@@ -0,0 +1,7 @@
+#ifndef _SWAY_RENDER_H
+#define _SWAY_RENDER_H
+#include <wlc/wlc.h>
+
+void render_view_borders(wlc_handle view);
+
+#endif

sway/CMakeLists.txt

@@ -5,6 +5,8 @@ include_directories(
 	${JSONC_INCLUDE_DIRS}
 	${XKBCOMMON_INCLUDE_DIRS}
 	${LIBINPUT_INCLUDE_DIRS}
+	${CAIRO_INCLUDE_DIRS}
+	${PANGO_INCLUDE_DIRS}
 )
 
 add_executable(sway
@@ -24,6 +26,7 @@ add_executable(sway
 	output.c
 	resize.c
 	workspace.c
+    render.c
 )
 
 add_definitions(
@@ -39,6 +42,8 @@ target_link_libraries(sway
 	${JSONC_LIBRARIES}
 	${WAYLAND_SERVER_LIBRARIES}
 	${LIBINPUT_LIBRARIES}
+	${PANGO_LIBRARIES}
+	${JSONC_LIBRARIES}
 	m
 )
 

sway/handlers.c

@@ -9,6 +9,7 @@
 #include <ctype.h>
 
 #include "handlers.h"
+#include "render.h"
 #include "log.h"
 #include "layout.h"
 #include "config.h"
@@ -150,6 +151,10 @@ static void handle_output_post_render(wlc_handle output) {
 	ipc_get_pixels(output);
 }
 
+static void handle_view_pre_render(wlc_handle view) {
+	render_view_borders(view);
+}
+
 static void handle_output_resolution_change(wlc_handle output, const struct wlc_size *from, const struct wlc_size *to) {
 	sway_log(L_DEBUG, "Output %u resolution changed to %d x %d", (unsigned int)output, to->w, to->h);
 	swayc_t *c = swayc_by_handle(output);
@@ -716,6 +721,7 @@ void register_wlc_handlers() {
 	wlc_set_view_created_cb(handle_view_created);
 	wlc_set_view_destroyed_cb(handle_view_destroyed);
 	wlc_set_view_focus_cb(handle_view_focus);
+	wlc_set_view_render_pre_cb(handle_view_pre_render);
 	wlc_set_view_request_geometry_cb(handle_view_geometry_request);
 	wlc_set_view_request_state_cb(handle_view_state_request);
 	wlc_set_keyboard_key_cb(handle_key);

sway/render.c

@@ -0,0 +1,35 @@
+#include "render.h"
+#include <cairo.h>
+#include <stdlib.h>
+
+cairo_t *create_cairo_context(int width, int height, int channels,
+		cairo_surface_t **surf, unsigned char **buf) {
+	cairo_t *cr;
+	*buf = calloc(channels * width * height, sizeof(unsigned char));
+	if (!*buf) {
+		return NULL;
+	}
+	*surf = cairo_image_surface_create_for_data(*buf, CAIRO_FORMAT_ARGB32,
+		width, height, channels * width);
+	if (cairo_surface_status(*surf) != CAIRO_STATUS_SUCCESS) {
+		free(*buf);
+		return NULL;
+	}
+	cr = cairo_create(*surf);
+	if (cairo_status(cr) != CAIRO_STATUS_SUCCESS) {
+		free(*buf);
+		return NULL;
+	}
+	return cr;
+}
+
+void render_view_borders(wlc_handle view) {
+	unsigned char *surf_data;
+	cairo_surface_t *surf;
+	int texture_id;
+	const struct wlc_geometry *geo = wlc_view_get_geometry(view);
+	cairo_t *cr = create_cairo_context(geo->size.w, geo->size.h, 4, &surf, &surf_data);
+	// TODO
+	cairo_destroy(cr);
+	free(surf_data);
+}