cairo-gtk: Add support for rendering to gtk window

Makefile

@@ -144,6 +144,17 @@ else ifeq ($(SCENIC_LOCAL_TARGET),cairo-fb)
 		$(CAIRO_COMMON_SRCS) \
 		c_src/device/cairo/cairo_fb.c
 
+else ifeq ($(SCENIC_LOCAL_TARGET),cairo-gtk)
+# need libgtk-3-dev libsystemd-dev libwebp-dev libzstd-dev
+	LDFLAGS += `pkg-config --static --libs freetype2 cairo gtk+-3.0`
+	CFLAGS += `pkg-config --static --cflags freetype2 cairo gtk+-3.0`
+	LDFLAGS += -lm
+	CFLAGS ?= -O2 -Wall -Wextra -Wno-unused-parameter -pedantic
+	CFLAGS += -std=gnu99
+
+	DEVICE_SRCS += \
+		$(CAIRO_COMMON_SRCS) \
+		c_src/device/cairo/cairo_gtk.c
 else
 $(info ------ no SCENIC_LOCAL_TARGET set ------)
 $(info If you get here, then you are probably using a custom Nerves system)

c_src/device/cairo/cairo_gtk.c

@@ -0,0 +1,144 @@
+#include <cairo.h>
+#include <errno.h>
+#include <fcntl.h>
+#include <linux/fb.h>
+#include <stdlib.h>
+#include <sys/ioctl.h>
+#include <sys/mman.h>
+#include <sys/stat.h>
+#include <sys/types.h>
+
+#include <gtk/gtk.h>
+
+#include "cairo_ctx.h"
+#include "comms.h"
+#include "device.h"
+#include "fontstash.h"
+#include "script_ops.h"
+
+typedef struct {
+  GThread* main;
+  GtkWidget* window;
+  GMutex draw_mutex;
+  GCond draw_finished;
+} cairo_gtk_t;
+
+cairo_gtk_t g_cairo_gtk;
+
+extern device_info_t g_device_info;
+extern device_opts_t g_opts;
+
+static gpointer cairo_gtk_main(gpointer user_data)
+{
+  gtk_widget_show_all((GtkWidget*)g_cairo_gtk.window);
+  gtk_main();
+
+  return NULL;
+}
+
+static gboolean on_draw(GtkWidget* widget,
+                        cairo_t* cr,
+                        gpointer data)
+{
+  g_mutex_lock (&g_cairo_gtk.draw_mutex);
+
+  scenic_cairo_ctx_t* p_ctx = (scenic_cairo_ctx_t*)data;
+  cairo_set_source_surface(cr, p_ctx->surface, 0, 0);
+  cairo_paint(cr);
+
+  g_cond_signal(&g_cairo_gtk.draw_finished);
+  g_mutex_unlock(&g_cairo_gtk.draw_mutex);
+
+  return FALSE;
+}
+
+static gboolean
+on_delete_event(GtkWidget* widget,
+                GdkEvent* event,
+                gpointer data)
+{
+  send_close(0);
+  return TRUE;
+}
+
+int device_init(const device_opts_t* p_opts,
+                device_info_t* p_info,
+                driver_data_t* p_data)
+{
+  if (g_opts.debug_mode) {
+    log_error("cairo %s", __func__);
+  }
+
+  scenic_cairo_ctx_t* p_ctx = scenic_cairo_init(p_opts, p_info);
+  if (!p_ctx) {
+    log_error("cairo %s failed", __func__);
+    return -1;
+  }
+
+  gtk_init(NULL, NULL);
+
+  g_cairo_gtk.window = gtk_window_new(GTK_WINDOW_TOPLEVEL);
+  gtk_window_set_title(GTK_WINDOW(g_cairo_gtk.window), "scenic_driver_local: cairo");
+  gtk_window_set_default_size(GTK_WINDOW(g_cairo_gtk.window), p_info->width, p_info->height);
+  gtk_window_set_resizable(GTK_WINDOW(g_cairo_gtk.window), FALSE);
+
+  g_signal_connect(G_OBJECT(g_cairo_gtk.window), "delete-event", G_CALLBACK(on_delete_event), NULL);
+
+  GtkDrawingArea* drawing_area = (GtkDrawingArea*)gtk_drawing_area_new();
+  gtk_container_add(GTK_CONTAINER(g_cairo_gtk.window), (GtkWidget*)drawing_area);
+  g_signal_connect((GtkWidget*)drawing_area, "draw", G_CALLBACK(on_draw), p_ctx);
+
+  g_cairo_gtk.main = g_thread_new("gtk_main", cairo_gtk_main, NULL);
+
+  return 0;
+}
+
+int device_close(device_info_t* p_info)
+{
+  if (g_opts.debug_mode) {
+    log_info("cairo %s", __func__);
+  }
+
+  scenic_cairo_ctx_t* p_ctx = (scenic_cairo_ctx_t*)p_info->v_ctx;
+  gtk_main_quit();
+  g_thread_join(g_cairo_gtk.main);
+  scenic_cairo_fini(p_ctx);
+}
+
+void device_poll()
+{
+}
+
+void device_begin_render(driver_data_t* p_data)
+{
+  if (g_opts.debug_mode) {
+    log_info("cairo %s", __func__);
+  }
+
+  scenic_cairo_ctx_t* p_ctx = (scenic_cairo_ctx_t*)p_data->v_ctx;
+
+  // Paint surface to clear color
+  cairo_set_source_rgba(p_ctx->cr,
+                        p_ctx->clear_color.red,
+                        p_ctx->clear_color.green,
+                        p_ctx->clear_color.blue,
+                        p_ctx->clear_color.alpha);
+  cairo_paint(p_ctx->cr);
+}
+
+void device_end_render(driver_data_t* p_data)
+{
+  if (g_opts.debug_mode) {
+    log_info("cairo %s", __func__);
+  }
+
+  scenic_cairo_ctx_t* p_ctx = (scenic_cairo_ctx_t*)p_data->v_ctx;
+
+  g_mutex_lock(&g_cairo_gtk.draw_mutex);
+
+  g_cond_clear(&g_cairo_gtk.draw_finished);
+  gtk_widget_queue_draw((GtkWidget*)g_cairo_gtk.window);
+  g_cond_wait(&g_cairo_gtk.draw_finished, &g_cairo_gtk.draw_mutex);
+
+  g_mutex_unlock(&g_cairo_gtk.draw_mutex);
+}