gtk2/gsk/gskcairorenderer.c
Emmanuele Bassi 7afdd3fdb5 Initial implementation of GSK rendering pipeline
GSK is conceptually split into two scene graphs:

 * a simple rendering tree of operations
 * a complex set of logical layers

The latter is built on the former, and adds convenience and high level
API for application developers.

The lower layer, though, is what gets transformed into the rendering
pipeline, as it's simple and thus can be transformed into appropriate
rendering commands with minimal state changes.

The lower layer is also suitable for reuse from more complex higher
layers, like the CSS machinery in GTK, without necessarily port those
layers to the GSK high level API.

This lower layer is based on GskRenderNode instances, which represent
the tree of rendering operations; and a GskRenderer instance, which
takes the render nodes and submits them (after potentially reordering
and transforming them to a more appropriate representation) to the
underlying graphic system.
2016-10-18 11:29:34 +01:00

196 lines
5.5 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);
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 %p at %g, %g\n",
gsk_render_node_get_surface (node),
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);
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_resize_viewport (GskRenderer *renderer,
const graphene_rect_t *viewport)
{
GskCairoRenderer *self = GSK_CAIRO_RENDERER (renderer);
self->viewport = *viewport;
}
static void
gsk_cairo_renderer_render (GskRenderer *renderer)
{
GskCairoRenderer *self = GSK_CAIRO_RENDERER (renderer);
cairo_surface_t *target = gsk_renderer_get_surface (renderer);
GskRenderNode *root = gsk_renderer_get_root_node (renderer);
cairo_t *cr = cairo_create (target);
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);
cairo_destroy (cr);
}
static void
gsk_cairo_renderer_clear (GskRenderer *renderer)
{
cairo_surface_t *surface = gsk_renderer_get_surface (renderer);
cairo_t *cr = cairo_create (surface);
cairo_set_operator (cr, CAIRO_OPERATOR_OVER);
if (gsk_renderer_get_use_alpha (renderer))
cairo_set_source_rgba (cr, 0, 0, 0, 0);
else
cairo_set_source_rgb (cr, 0, 0, 0);
cairo_paint (cr);
cairo_destroy (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->resize_viewport = gsk_cairo_renderer_resize_viewport;
renderer_class->clear = gsk_cairo_renderer_clear;
renderer_class->render = gsk_cairo_renderer_render;
}
static void
gsk_cairo_renderer_init (GskCairoRenderer *self)
{
}