C++ cogl_get_draw_framebuffer函数代码示例

void
cogl_begin_gl (void)
{
  CoglPipeline *pipeline;

  _COGL_GET_CONTEXT (ctx, NO_RETVAL);

  if (ctx->in_begin_gl_block)
    {
      static CoglBool shown = FALSE;
      if (!shown)
        g_warning ("You should not nest cogl_begin_gl/cogl_end_gl blocks");
      shown = TRUE;
      return;
    }
  ctx->in_begin_gl_block = TRUE;

  /* Flush all batched primitives */
  cogl_flush ();

  /* Flush framebuffer state, including clip state, modelview and
   * projection matrix state
   *
   * NB: _cogl_framebuffer_flush_state may disrupt various state (such
   * as the pipeline state) when flushing the clip stack, so should
   * always be done first when preparing to draw. */
  _cogl_framebuffer_flush_state (cogl_get_draw_framebuffer (),
                                 _cogl_get_read_framebuffer (),
                                 COGL_FRAMEBUFFER_STATE_ALL);

  /* Setup the state for the current pipeline */

  /* We considered flushing a specific, minimal pipeline here to try and
   * simplify the GL state, but decided to avoid special cases and second
   * guessing what would be actually helpful.
   *
   * A user should instead call cogl_set_source_color4ub() before
   * cogl_begin_gl() to simplify the state flushed.
   *
   * XXX: note defining n_tex_coord_attribs using
   * cogl_pipeline_get_n_layers is a hack, but the problem is that
   * n_tex_coord_attribs is usually defined when drawing a primitive
   * which isn't happening here.
   *
   * Maybe it would be more useful if this code did flush the
   * opaque_color_pipeline and then call into cogl-pipeline-opengl.c to then
   * restore all state for the material's backend back to default OpenGL
   * values.
   */
  pipeline = cogl_get_source ();
  _cogl_pipeline_flush_gl_state (ctx,
                                 pipeline,
                                 cogl_get_draw_framebuffer (),
                                 FALSE,
                                 FALSE);

  /* Disable any cached vertex arrays */
  _cogl_gl_disable_all_attributes (ctx);
}

static void _capture_desktop(MetaSwitcher* self)
{
    MetaSwitcherPrivate* priv = self->priv;
    MetaScreen* screen = meta_plugin_get_screen(priv->plugin);
    ClutterActor* stage = meta_get_stage_for_screen(screen);

    gfloat tx, ty, w, h;
    clutter_actor_get_position(priv->top, &tx, &ty);
    clutter_actor_get_size(priv->top, &w, &h);

    g_debug("%s: %f, %f, %f, %f", __func__, tx, ty, w, h);
    if (priv->snapshot) {
        cairo_surface_destroy(priv->snapshot);
        priv->snapshot = NULL;
    }
    priv->snapshot_offset = 20.0;
    w += priv->snapshot_offset*3;
    clutter_stage_ensure_redraw(CLUTTER_STAGE(stage));

    guchar* data = g_malloc(w*h*4);
    cogl_framebuffer_read_pixels(cogl_get_draw_framebuffer(),
            tx-priv->snapshot_offset, ty, w, h,
            CLUTTER_CAIRO_FORMAT_ARGB32, data);

    /*guchar* data = clutter_stage_read_pixels(CLUTTER_STAGE(stage), */
            /*tx-priv->snapshot_offset, ty, w, h);*/
    priv->snapshot = cairo_image_surface_create_for_data(data,
            CAIRO_FORMAT_ARGB32, w, h, w*4);
    g_free(data);
}

static void
_cogl_path_fill_nodes_with_clipped_rectangle (CoglPath *path)
{
  CoglFramebuffer *fb;

  _COGL_GET_CONTEXT (ctx, NO_RETVAL);

  if (!(ctx->private_feature_flags & COGL_PRIVATE_FEATURE_STENCIL_BUFFER))
    {
      static gboolean seen_warning = FALSE;

      if (!seen_warning)
        {
          g_warning ("Paths can not be filled using materials with "
                     "sliced textures unless there is a stencil "
                     "buffer");
          seen_warning = TRUE;
        }
    }

  fb = cogl_get_draw_framebuffer ();
  cogl_framebuffer_push_path_clip (fb, path);
  cogl_rectangle (path->data->path_nodes_min.x,
                  path->data->path_nodes_min.y,
                  path->data->path_nodes_max.x,
                  path->data->path_nodes_max.y);
  cogl_framebuffer_pop_clip (fb);
}

void
_cogl_path_fill_nodes (CoglPath *path, CoglDrawFlags flags)
{
  gboolean needs_fallback = FALSE;
  CoglPipeline *pipeline = cogl_get_source ();

  _cogl_pipeline_foreach_layer_internal (pipeline,
                                         validate_layer_cb, &needs_fallback);
  if (needs_fallback)
    {
      _cogl_path_fill_nodes_with_clipped_rectangle (path);
      return;
    }

  _cogl_path_build_fill_attribute_buffer (path);

  _cogl_framebuffer_draw_indexed_attributes (cogl_get_draw_framebuffer (),
                                             pipeline,
                                             COGL_VERTICES_MODE_TRIANGLES,
                                             0, /* first_vertex */
                                             path->data->fill_vbo_n_indices,
                                             path->data->fill_vbo_indices,
                                             path->data->fill_attributes,
                                             COGL_PATH_N_ATTRIBUTES,
                                             flags);
}

void
_st_paint_shadow_with_opacity (StShadow        *shadow_spec,
                               CoglPipeline    *shadow_pipeline,
                               ClutterActorBox *box,
                               guint8           paint_opacity)
{
    CoglFramebuffer *fb = cogl_get_draw_framebuffer ();
    ClutterActorBox shadow_box;
    CoglColor color;

    g_return_if_fail (shadow_spec != NULL);
    g_return_if_fail (shadow_pipeline != NULL);

    st_shadow_get_box (shadow_spec, box, &shadow_box);

    cogl_color_init_from_4ub (&color,
                              shadow_spec->color.red   * paint_opacity / 255,
                              shadow_spec->color.green * paint_opacity / 255,
                              shadow_spec->color.blue  * paint_opacity / 255,
                              shadow_spec->color.alpha * paint_opacity / 255);
    cogl_color_premultiply (&color);
    cogl_pipeline_set_layer_combine_constant (shadow_pipeline, 0, &color);
    cogl_framebuffer_draw_rectangle (fb, shadow_pipeline,
                                     shadow_box.x1, shadow_box.y1,
                                     shadow_box.x2, shadow_box.y2);
}

CoglClipState *
_cogl_get_clip_state (void)
{
    CoglFramebuffer *framebuffer;

    framebuffer = cogl_get_draw_framebuffer ();
    return _cogl_framebuffer_get_clip_state (framebuffer);
}

static void
meta_surface_actor_pick (ClutterActor       *actor,
                         const ClutterColor *color)
{
  MetaSurfaceActor *self = META_SURFACE_ACTOR (actor);
  MetaSurfaceActorPrivate *priv =
    meta_surface_actor_get_instance_private (self);
  ClutterActorIter iter;
  ClutterActor *child;

  if (!clutter_actor_should_pick_paint (actor))
    return;

  /* If there is no region then use the regular pick */
  if (priv->input_region == NULL)
    CLUTTER_ACTOR_CLASS (meta_surface_actor_parent_class)->pick (actor, color);
  else
    {
      int n_rects;
      float *rectangles;
      int i;
      CoglPipeline *pipeline;
      CoglContext *ctx;
      CoglFramebuffer *fb;
      CoglColor cogl_color;

      n_rects = cairo_region_num_rectangles (priv->input_region);
      rectangles = g_alloca (sizeof (float) * 4 * n_rects);

      for (i = 0; i < n_rects; i++)
        {
          cairo_rectangle_int_t rect;
          int pos = i * 4;

          cairo_region_get_rectangle (priv->input_region, i, &rect);

          rectangles[pos + 0] = rect.x;
          rectangles[pos + 1] = rect.y;
          rectangles[pos + 2] = rect.x + rect.width;
          rectangles[pos + 3] = rect.y + rect.height;
        }

      ctx = clutter_backend_get_cogl_context (clutter_get_default_backend ());
      fb = cogl_get_draw_framebuffer ();

      cogl_color_init_from_4ub (&cogl_color, color->red, color->green, color->blue, color->alpha);

      pipeline = cogl_pipeline_new (ctx);
      cogl_pipeline_set_color (pipeline, &cogl_color);
      cogl_framebuffer_draw_rectangles (fb, pipeline, rectangles, n_rects);
      cogl_object_unref (pipeline);
    }

  clutter_actor_iter_init (&iter, actor);

  while (clutter_actor_iter_next (&iter, &child))
    clutter_actor_paint (child);
}

void
cogl_perspective (float fov_y,
		  float aspect,
		  float z_near,
		  float z_far)
{
  cogl_framebuffer_perspective (cogl_get_draw_framebuffer (),
                                fov_y, aspect, z_near, z_far);
}

static void
pre_paint_windows (MetaCompositor *compositor)
{
  GList *l;
  MetaWindowActor *top_window;

  if (compositor->onscreen == NULL)
    {
      compositor->onscreen = COGL_ONSCREEN (cogl_get_draw_framebuffer ());
      compositor->frame_closure = cogl_onscreen_add_frame_callback (compositor->onscreen,
                                                                    frame_callback,
                                                                    compositor,
                                                                    NULL);
    }

  if (compositor->windows == NULL)
    return;

  top_window = g_list_last (compositor->windows)->data;

  if (meta_window_actor_should_unredirect (top_window) &&
      compositor->disable_unredirect_count == 0)
    set_unredirected_window (compositor, meta_window_actor_get_meta_window (top_window));
  else
    set_unredirected_window (compositor, NULL);

  for (l = compositor->windows; l; l = l->next)
    meta_window_actor_pre_paint (l->data);

  if (compositor->frame_has_updated_xsurfaces)
    {
      /* We need to make sure that any X drawing that happens before
       * the XDamageSubtract() for each window above is visible to
       * subsequent GL rendering; the only standardized way to do this
       * is EXT_x11_sync_object, which isn't yet widely available. For
       * now, we count on details of Xorg and the open source drivers,
       * and hope for the best otherwise.
       *
       * Xorg and open source driver specifics:
       *
       * The X server makes sure to flush drawing to the kernel before
       * sending out damage events, but since we use
       * DamageReportBoundingBox there may be drawing between the last
       * damage event and the XDamageSubtract() that needs to be
       * flushed as well.
       *
       * Xorg always makes sure that drawing is flushed to the kernel
       * before writing events or responses to the client, so any
       * round trip request at this point is sufficient to flush the
       * GLX buffers.
       */
      XSync (compositor->display->xdisplay, False);

      compositor->frame_has_updated_xsurfaces = FALSE;
    }
}

/* TODO: Update to the protoype used in the Cogl master branch.
 * This is experimental API but not in sync with the cogl_path_fill()
 * api in Cogl master which takes explicit framebuffer and pipeline
 * arguments */
void
cogl2_path_fill (CoglPath *path)
{
  _COGL_RETURN_IF_FAIL (cogl_is_path (path));

  _cogl_path_fill_nodes (path,
                         cogl_get_draw_framebuffer (),
                         cogl_get_source (),
                         0 /* flags */);
}

/* XXX: This function should either be replaced with one returning
 * integers, or removed/deprecated and make the
 * _cogl_framebuffer_get_viewport* functions public.
 */
void
cogl_get_viewport (float viewport[4])
{
  CoglFramebuffer *framebuffer;

  _COGL_GET_CONTEXT (ctx, NO_RETVAL);

  framebuffer = cogl_get_draw_framebuffer ();
  cogl_framebuffer_get_viewport4fv (framebuffer, viewport);
}

void
cogl_frustum (float        left,
	      float        right,
	      float        bottom,
	      float        top,
	      float        z_near,
	      float        z_far)
{
  cogl_framebuffer_frustum (cogl_get_draw_framebuffer (),
                            left, right, bottom, top, z_near, z_far);
}

void
cogl_ortho (float left,
	    float right,
	    float bottom,
	    float top,
	    float near,
	    float far)
{
  cogl_framebuffer_orthographic (cogl_get_draw_framebuffer (),
                                 left, top, right, bottom, near, far);
}

static void
_cogl_rectangles_with_multitexture_coords (
                                        CoglMultiTexturedRect *rects,
                                        int n_rects)
{
  _cogl_framebuffer_draw_multitextured_rectangles (cogl_get_draw_framebuffer (),
                                                   cogl_get_source (),
                                                   rects,
                                                   n_rects,
                                                   FALSE);
}

/* TODO: Update to the protoype used in the Cogl master branch.
 * This is experimental API but not in sync with the cogl_path_fill()
 * api in Cogl master which takes explicit framebuffer and pipeline
 * arguments */
void
cogl2_path_stroke (CoglPath *path)
{
  _COGL_RETURN_IF_FAIL (cogl_is_path (path));

  if (path->data->path_nodes->len == 0)
    return;

  _cogl_path_stroke_nodes (path,
                           cogl_get_draw_framebuffer (),
                           cogl_get_source ());
}