From 99c46f263e98dcb1e3c97ab97b8768b29a5ca754 Mon Sep 17 00:00:00 2001
From: Alexander Larsson <alexl@redhat.com>
Date: Tue, 24 Apr 2018 14:31:49 +0200
Subject: [PATCH] broadway: Add basic GdkCairoContext implementation

---
 gdk/broadway/gdkcairocontext-broadway.c | 109 +++++++++++++++++++++++-
 gdk/broadway/gdkcairocontext-broadway.h |   2 +
 2 files changed, 110 insertions(+), 1 deletion(-)

diff --git a/gdk/broadway/gdkcairocontext-broadway.c b/gdk/broadway/gdkcairocontext-broadway.c
index 245e33551a..bc45b5094a 100644
--- a/gdk/broadway/gdkcairocontext-broadway.c
+++ b/gdk/broadway/gdkcairocontext-broadway.c
@@ -21,16 +21,123 @@
 #include "gdkconfig.h"
 
 #include "gdkcairocontext-broadway.h"
+#include "gdktextureprivate.h"
+#include "gdkprivate-broadway.h"
 
 G_DEFINE_TYPE (GdkBroadwayCairoContext, gdk_broadway_cairo_context, GDK_TYPE_CAIRO_CONTEXT)
 
+static void
+gdk_broadway_cairo_context_dispose (GObject *object)
+{
+  G_OBJECT_CLASS (gdk_broadway_cairo_context_parent_class)->dispose (object);
+}
+
+static void
+gdk_broadway_cairo_context_begin_frame (GdkDrawContext *draw_context,
+                                        cairo_region_t *region)
+{
+  GdkBroadwayCairoContext *self = GDK_BROADWAY_CAIRO_CONTEXT (draw_context);
+  GdkSurface *surface = gdk_draw_context_get_surface (GDK_DRAW_CONTEXT (self));
+  cairo_t *cr;
+  cairo_region_t *repaint_region;
+  int width, height, scale;
+
+  width = gdk_surface_get_width (surface);
+  height = gdk_surface_get_height (surface);
+  scale = gdk_surface_get_scale_factor (surface);
+  self->paint_surface = cairo_image_surface_create (CAIRO_FORMAT_ARGB32,
+                                                    width * scale, height * scale);
+  cairo_surface_set_device_scale (self->paint_surface, scale, scale);
+
+  repaint_region = cairo_region_create_rectangle (&(cairo_rectangle_int_t) { 0, 0, width, height });
+  cairo_region_union (region, repaint_region);
+  cairo_region_destroy (repaint_region);
+
+  /* clear the repaint area */
+  cr = cairo_create (self->paint_surface);
+  cairo_set_operator (cr, CAIRO_OPERATOR_CLEAR);
+  cairo_fill (cr);
+  cairo_destroy (cr);
+}
+
+static void
+add_uint32 (GArray *nodes, guint32 v)
+{
+  g_array_append_val (nodes, v);
+}
+
+static void
+add_float (GArray *nodes, float f)
+{
+  gint32 i = (gint32) (f * 256.0f);
+  guint u = (guint32) i;
+  g_array_append_val (nodes, u);
+}
+
+static void
+gdk_broadway_cairo_context_end_frame (GdkDrawContext *draw_context,
+                                      cairo_region_t *painted)
+{
+  GdkBroadwayCairoContext *self = GDK_BROADWAY_CAIRO_CONTEXT (draw_context);
+  GdkDisplay *display = gdk_draw_context_get_display (draw_context);
+  GdkSurface *surface = gdk_draw_context_get_surface (draw_context);
+  GdkTexture *texture;
+  GPtrArray *node_textures;
+  GArray *nodes;
+  guint32 texture_id;
+
+  nodes = g_array_new (FALSE, FALSE, sizeof(guint32));
+  node_textures = g_ptr_array_new_with_free_func (g_object_unref);
+
+  texture = gdk_texture_new_for_surface ((cairo_surface_t *)self->paint_surface);
+  g_ptr_array_add (node_textures, g_object_ref (texture)); /* Transfers ownership to node_textures */
+  texture_id = gdk_broadway_display_ensure_texture (display, texture);
+
+  add_uint32 (nodes, BROADWAY_NODE_TEXTURE);
+  add_float (nodes, 0);
+  add_float (nodes, 0);
+  add_float (nodes, cairo_image_surface_get_width (self->paint_surface));
+  add_float (nodes, cairo_image_surface_get_height (self->paint_surface));
+  add_uint32 (nodes, texture_id);
+
+  gdk_broadway_surface_set_nodes (surface, nodes, node_textures);
+  g_array_unref (nodes);
+  g_ptr_array_unref (node_textures);
+
+  cairo_surface_destroy (self->paint_surface);
+  self->paint_surface = NULL;
+}
+
+static void
+gdk_broadway_cairo_context_surface_resized (GdkDrawContext *draw_context)
+{
+}
+
+static cairo_t *
+gdk_broadway_cairo_context_cairo_create (GdkCairoContext *context)
+{
+  GdkBroadwayCairoContext *self = GDK_BROADWAY_CAIRO_CONTEXT (context);
+
+  return cairo_create (self->paint_surface);
+}
+
 static void
 gdk_broadway_cairo_context_class_init (GdkBroadwayCairoContextClass *klass)
 {
+  GObjectClass *gobject_class = G_OBJECT_CLASS (klass);
+  GdkDrawContextClass *draw_context_class = GDK_DRAW_CONTEXT_CLASS (klass);
+  GdkCairoContextClass *cairo_context_class = GDK_CAIRO_CONTEXT_CLASS (klass);
+
+  gobject_class->dispose = gdk_broadway_cairo_context_dispose;
+
+  draw_context_class->begin_frame = gdk_broadway_cairo_context_begin_frame;
+  draw_context_class->end_frame = gdk_broadway_cairo_context_end_frame;
+  draw_context_class->surface_resized = gdk_broadway_cairo_context_surface_resized;
+
+  cairo_context_class->cairo_create = gdk_broadway_cairo_context_cairo_create;
 }
 
 static void
 gdk_broadway_cairo_context_init (GdkBroadwayCairoContext *self)
 {
 }
-
diff --git a/gdk/broadway/gdkcairocontext-broadway.h b/gdk/broadway/gdkcairocontext-broadway.h
index a5b9368f58..fb607f9c8a 100644
--- a/gdk/broadway/gdkcairocontext-broadway.h
+++ b/gdk/broadway/gdkcairocontext-broadway.h
@@ -38,6 +38,8 @@ typedef struct _GdkBroadwayCairoContextClass GdkBroadwayCairoContextClass;
 struct _GdkBroadwayCairoContext
 {
   GdkCairoContext parent_instance;
+
+  cairo_surface_t *paint_surface;
 };
 
 struct _GdkBroadwayCairoContextClass
-- 
2.30.2