gtk/gsk/gskcairorenderer.c
Emmanuele Bassi dace0791a9 gsk: Add the ability to create fallback renderers
While porting GTK to GskRenderer we noticed that the current fallback
code for widgets using Cairo to draw is not enough to cover all the
possible cases.

For instance, if a container widget still uses GtkWidget::draw to render
its children, and at least one of them has been ported to using render
nodes instead, the container won't know how to draw it.

For this reason we want to provide to layers above GSK the ability to
create a "fallback" renderer instance, created using a "parent"
GskRenderer instance, but using a Cairo context as the rendering target
instead of a GdkDrawingContext.

GTK will use this inside the gtk_widget_draw() implementation, if a
widget implements GtkWidgetClass.get_render_node().
2016-10-18 11:49:16 +01:00

186 lines
5.2 KiB
C

#include "config.h"
#include "gskcairorendererprivate.h"
#include "gskdebugprivate.h"
#include "gskrendererprivate.h"
#include "gskrendernodeiter.h"
#include "gskrendernodeprivate.h"
struct _GskCairoRenderer
{
GskRenderer parent_instance;
graphene_rect_t viewport;
};
struct _GskCairoRendererClass
{
GskRendererClass parent_class;
};
G_DEFINE_TYPE (GskCairoRenderer, gsk_cairo_renderer, GSK_TYPE_RENDERER)
static gboolean
gsk_cairo_renderer_realize (GskRenderer *renderer)
{
return TRUE;
}
static void
gsk_cairo_renderer_unrealize (GskRenderer *renderer)
{
}
static void
gsk_cairo_renderer_render_node (GskCairoRenderer *self,
GskRenderNode *node,
cairo_t *cr)
{
GskRenderNodeIter iter;
GskRenderNode *child;
gboolean pop_group = FALSE;
graphene_matrix_t mvp;
cairo_matrix_t ctm;
graphene_rect_t frame;
if (gsk_render_node_is_hidden (node))
return;
cairo_save (cr);
if (!gsk_render_node_has_surface (node))
goto out;
gsk_render_node_get_world_matrix (node, &mvp);
if (graphene_matrix_to_2d (&mvp, &ctm.xx, &ctm.yx, &ctm.xy, &ctm.yy, &ctm.x0, &ctm.y0))
{
GSK_NOTE (CAIRO, g_print ("CTM = { .xx = %g, .yx = %g, .xy = %g, .yy = %g, .x0 = %g, .y0 = %g }\n",
ctm.xx, ctm.yx,
ctm.xy, ctm.yy,
ctm.x0, ctm.y0));
cairo_transform (cr, &ctm);
}
else
g_critical ("Invalid non-affine transformation for node %p", node);
gsk_render_node_get_bounds (node, &frame);
GSK_NOTE (CAIRO, g_print ("CLIP = { .x = %g, .y = %g, .width = %g, .height = %g }\n",
frame.origin.x, frame.origin.y,
frame.size.width, frame.size.height));
if (!GSK_RENDER_MODE_CHECK (GEOMETRY))
{
cairo_rectangle (cr, frame.origin.x, frame.origin.y, frame.size.width, frame.size.height);
cairo_clip (cr);
}
if (!gsk_render_node_is_opaque (node) && gsk_render_node_get_opacity (node) != 1.0)
{
GSK_NOTE (CAIRO, g_print ("Pushing opacity group (opacity:%g)\n",
gsk_render_node_get_opacity (node)));
cairo_push_group (cr);
pop_group = TRUE;
}
GSK_NOTE (CAIRO, g_print ("Rendering surface %p for node %s[%p] at %g, %g\n",
gsk_render_node_get_surface (node),
node->name,
node,
frame.origin.x, frame.origin.y));
cairo_set_source_surface (cr, gsk_render_node_get_surface (node), frame.origin.x, frame.origin.y);
cairo_paint (cr);
if (GSK_RENDER_MODE_CHECK (GEOMETRY))
{
cairo_save (cr);
cairo_set_operator (cr, CAIRO_OPERATOR_OVER);
cairo_rectangle (cr, frame.origin.x - 1, frame.origin.y - 1, frame.size.width + 2, frame.size.height + 2);
cairo_set_line_width (cr, 2);
cairo_set_source_rgba (cr, 0, 0, 0, 0.5);
cairo_stroke (cr);
cairo_restore (cr);
}
cairo_matrix_invert (&ctm);
cairo_transform (cr, &ctm);
out:
if (gsk_render_node_get_n_children (node) != 0)
{
GSK_NOTE (CAIRO, g_print ("Drawing %d children of node [%p]\n",
gsk_render_node_get_n_children (node),
node));
gsk_render_node_iter_init (&iter, node);
while (gsk_render_node_iter_next (&iter, &child))
gsk_cairo_renderer_render_node (self, child, cr);
}
if (pop_group)
{
cairo_pop_group_to_source (cr);
cairo_set_operator (cr, CAIRO_OPERATOR_OVER);
cairo_paint_with_alpha (cr, gsk_render_node_get_opacity (node));
}
cairo_restore (cr);
}
static void
gsk_cairo_renderer_render (GskRenderer *renderer,
GskRenderNode *root)
{
GskCairoRenderer *self = GSK_CAIRO_RENDERER (renderer);
GdkDrawingContext *context = gsk_renderer_get_drawing_context (renderer);
cairo_t *cr;
if (context != NULL)
cr = gdk_drawing_context_get_cairo_context (context);
else
cr = gsk_renderer_get_cairo_context (renderer);
if (cr == NULL)
return;
gsk_renderer_get_viewport (renderer, &self->viewport);
cairo_save (cr);
cairo_set_operator (cr, CAIRO_OPERATOR_OVER);
cairo_set_source_rgba (cr, 0, 0, 0, 0);
cairo_paint (cr);
cairo_restore (cr);
if (GSK_RENDER_MODE_CHECK (GEOMETRY))
{
cairo_save (cr);
cairo_set_operator (cr, CAIRO_OPERATOR_OVER);
cairo_rectangle (cr,
self->viewport.origin.x,
self->viewport.origin.y,
self->viewport.size.width,
self->viewport.size.height);
cairo_set_source_rgba (cr, 0, 0, 0.85, 0.5);
cairo_stroke (cr);
cairo_restore (cr);
}
gsk_cairo_renderer_render_node (self, root, cr);
}
static void
gsk_cairo_renderer_class_init (GskCairoRendererClass *klass)
{
GskRendererClass *renderer_class = GSK_RENDERER_CLASS (klass);
renderer_class->realize = gsk_cairo_renderer_realize;
renderer_class->unrealize = gsk_cairo_renderer_unrealize;
renderer_class->render = gsk_cairo_renderer_render;
}
static void
gsk_cairo_renderer_init (GskCairoRenderer *self)
{
}