void
_cogl_flush_clip_state (CoglClipStackState *clip_state)
{
CoglClipStack *stack;
int has_clip_planes;
gboolean using_clip_planes = FALSE;
gboolean using_stencil_buffer = FALSE;
GList *node;
int scissor_x0 = 0;
int scissor_y0 = 0;
int scissor_x1 = G_MAXINT;
int scissor_y1 = G_MAXINT;
CoglMatrixStack *modelview_stack =
_cogl_framebuffer_get_modelview_stack (_cogl_get_framebuffer ());
if (!clip_state->stack_dirty)
return;
/* The current primitive journal does not support tracking changes to the
* clip stack... */
_cogl_journal_flush ();
/* XXX: the handling of clipping is quite complex. It may involve use of
* the Cogl Journal or other Cogl APIs which may end up recursively
* wanting to ensure the clip state is flushed. We need to ensure we
* don't recurse infinitely...
*/
clip_state->stack_dirty = FALSE;
has_clip_planes = cogl_features_available (COGL_FEATURE_FOUR_CLIP_PLANES);
stack = clip_state->stacks->data;
clip_state->stencil_used = FALSE;
disable_clip_planes ();
disable_stencil_buffer ();
GE (glDisable (GL_SCISSOR_TEST));
/* If the stack is empty then there's nothing else to do */
if (stack->stack_top == NULL)
return;
/* Find the bottom of the stack */
for (node = stack->stack_top; node->next; node = node->next);
/* Re-add every entry from the bottom of the stack up */
for (; node; node = node->prev)
{
gpointer entry = node->data;
CoglClipStackEntryType type = *(CoglClipStackEntryType *) entry;
if (type == COGL_CLIP_STACK_PATH)
{
CoglClipStackEntryPath *path = (CoglClipStackEntryPath *) entry;
_cogl_matrix_stack_push (modelview_stack);
_cogl_matrix_stack_set (modelview_stack, &path->matrix);
_cogl_add_path_to_stencil_buffer (path->path_nodes_min,
path->path_nodes_max,
path->path_size,
path->path,
using_stencil_buffer,
TRUE);
_cogl_matrix_stack_pop (modelview_stack);
using_stencil_buffer = TRUE;
/* We can't use clip planes any more */
has_clip_planes = FALSE;
}
else if (type == COGL_CLIP_STACK_RECT)
{
CoglClipStackEntryRect *rect = (CoglClipStackEntryRect *) entry;
_cogl_matrix_stack_push (modelview_stack);
_cogl_matrix_stack_set (modelview_stack, &rect->matrix);
/* If this is the first entry and we support clip planes then use
that instead */
if (has_clip_planes)
{
set_clip_planes (rect->x0,
rect->y0,
rect->x1,
rect->y1);
using_clip_planes = TRUE;
/* We can't use clip planes a second time */
has_clip_planes = FALSE;
}
else
{
add_stencil_clip_rectangle (rect->x0,
rect->y0,
rect->x1,
rect->y1,
!using_stencil_buffer);
using_stencil_buffer = TRUE;
}
_cogl_matrix_stack_pop (modelview_stack);
}
else
{
/* Get the intersection of all window space rectangles in the clip
* stack */
CoglClipStackEntryWindowRect *window_rect = entry;
scissor_x0 = MAX (scissor_x0, window_rect->x0);
scissor_y0 = MAX (scissor_y0, window_rect->y0);
scissor_x1 = MIN (scissor_x1, window_rect->x1);
scissor_y1 = MIN (scissor_y1, window_rect->y1);
}
}
/* Enabling clip planes is delayed to now so that they won't affect
setting up the stencil buffer */
if (using_clip_planes)
enable_clip_planes ();
if (scissor_x0 >= scissor_x1 || scissor_y0 >= scissor_y1)
scissor_x0 = scissor_y0 = scissor_x1 = scissor_y1 = 0;
if (!(scissor_x0 == 0 && scissor_y0 == 0 &&
scissor_x1 == G_MAXINT && scissor_y1 == G_MAXINT))
{
GE (glEnable (GL_SCISSOR_TEST));
GE (glScissor (scissor_x0, scissor_y0,
scissor_x1 - scissor_x0,
scissor_y1 - scissor_y0));
}
clip_state->stencil_used = using_stencil_buffer;
}
void
_cogl_clip_stack_gl_flush (CoglClipStack *stack,
CoglFramebuffer *framebuffer)
{
CoglContext *ctx = framebuffer->context;
int has_clip_planes;
CoglBool using_clip_planes = FALSE;
CoglBool using_stencil_buffer = FALSE;
int scissor_x0;
int scissor_y0;
int scissor_x1;
int scissor_y1;
CoglClipStack *entry;
int scissor_y_start;
/* If we have already flushed this state then we don't need to do
anything */
if (ctx->current_clip_stack_valid)
{
if (ctx->current_clip_stack == stack &&
(ctx->needs_viewport_scissor_workaround == FALSE ||
(framebuffer->viewport_age ==
framebuffer->viewport_age_for_scissor_workaround &&
ctx->viewport_scissor_workaround_framebuffer ==
framebuffer)))
return;
_cogl_clip_stack_unref (ctx->current_clip_stack);
}
ctx->current_clip_stack_valid = TRUE;
ctx->current_clip_stack = _cogl_clip_stack_ref (stack);
has_clip_planes =
_cogl_has_private_feature (ctx, COGL_PRIVATE_FEATURE_FOUR_CLIP_PLANES);
if (has_clip_planes)
disable_clip_planes (ctx);
GE( ctx, glDisable (GL_STENCIL_TEST) );
/* If the stack is empty then there's nothing else to do
*
* See comment below about ctx->needs_viewport_scissor_workaround
*/
if (stack == NULL && !ctx->needs_viewport_scissor_workaround)
{
COGL_NOTE (CLIPPING, "Flushed empty clip stack");
GE (ctx, glDisable (GL_SCISSOR_TEST));
return;
}
/* Calculate the scissor rect first so that if we eventually have to
clear the stencil buffer then the clear will be clipped to the
intersection of all of the bounding boxes. This saves having to
clear the whole stencil buffer */
_cogl_clip_stack_get_bounds (stack,
&scissor_x0, &scissor_y0,
&scissor_x1, &scissor_y1);
/* XXX: ONGOING BUG: Intel viewport scissor
*
* Intel gen6 drivers don't correctly handle offset viewports, since
* primitives aren't clipped within the bounds of the viewport. To
* workaround this we push our own clip for the viewport that will
* use scissoring to ensure we clip as expected.
*
* TODO: file a bug upstream!
*/
if (ctx->needs_viewport_scissor_workaround)
{
_cogl_util_scissor_intersect (framebuffer->viewport_x,
framebuffer->viewport_y,
framebuffer->viewport_x +
framebuffer->viewport_width,
framebuffer->viewport_y +
framebuffer->viewport_height,
&scissor_x0, &scissor_y0,
&scissor_x1, &scissor_y1);
framebuffer->viewport_age_for_scissor_workaround =
framebuffer->viewport_age;
ctx->viewport_scissor_workaround_framebuffer =
framebuffer;
}
/* Enable scissoring as soon as possible */
if (scissor_x0 >= scissor_x1 || scissor_y0 >= scissor_y1)
scissor_x0 = scissor_y0 = scissor_x1 = scissor_y1 = scissor_y_start = 0;
else
{
/* We store the entry coordinates in Cogl coordinate space
* but OpenGL requires the window origin to be the bottom
* left so we may need to convert the incoming coordinates.
*
* NB: Cogl forces all offscreen rendering to be done upside
* down so in this case no conversion is needed.
*/
if (cogl_is_offscreen (framebuffer))
scissor_y_start = scissor_y0;
else
{
int framebuffer_height =
cogl_framebuffer_get_height (framebuffer);
scissor_y_start = framebuffer_height - scissor_y1;
}
}
COGL_NOTE (CLIPPING, "Flushing scissor to (%i, %i, %i, %i)",
scissor_x0, scissor_y0,
scissor_x1, scissor_y1);
GE (ctx, glEnable (GL_SCISSOR_TEST));
GE (ctx, glScissor (scissor_x0, scissor_y_start,
scissor_x1 - scissor_x0,
scissor_y1 - scissor_y0));
/* Add all of the entries. This will end up adding them in the
reverse order that they were specified but as all of the clips
are intersecting it should work out the same regardless of the
order */
for (entry = stack; entry; entry = entry->parent)
{
switch (entry->type)
{
case COGL_CLIP_STACK_PRIMITIVE:
{
CoglClipStackPrimitive *primitive_entry =
(CoglClipStackPrimitive *) entry;
COGL_NOTE (CLIPPING, "Adding stencil clip for primitive");
add_stencil_clip_primitive (framebuffer,
primitive_entry->matrix_entry,
primitive_entry->primitive,
primitive_entry->bounds_x1,
primitive_entry->bounds_y1,
primitive_entry->bounds_x2,
primitive_entry->bounds_y2,
using_stencil_buffer,
TRUE);
using_stencil_buffer = TRUE;
break;
}
case COGL_CLIP_STACK_RECT:
{
CoglClipStackRect *rect = (CoglClipStackRect *) entry;
/* We don't need to do anything extra if the clip for this
rectangle was entirely described by its scissor bounds */
if (!rect->can_be_scissor)
{
/* If we support clip planes and we haven't already used
them then use that instead */
if (has_clip_planes)
{
COGL_NOTE (CLIPPING,
"Adding clip planes clip for rectangle");
set_clip_planes (framebuffer,
rect->matrix_entry,
rect->x0,
rect->y0,
rect->x1,
rect->y1);
using_clip_planes = TRUE;
/* We can't use clip planes a second time */
has_clip_planes = FALSE;
}
else
{
COGL_NOTE (CLIPPING, "Adding stencil clip for rectangle");
add_stencil_clip_rectangle (framebuffer,
rect->matrix_entry,
rect->x0,
rect->y0,
rect->x1,
rect->y1,
!using_stencil_buffer);
using_stencil_buffer = TRUE;
}
}
break;
}
case COGL_CLIP_STACK_WINDOW_RECT:
break;
/* We don't need to do anything for window space rectangles because
* their functionality is entirely implemented by the entry bounding
* box */
}
}
/* Enabling clip planes is delayed to now so that they won't affect
setting up the stencil buffer */
if (using_clip_planes)
enable_clip_planes (ctx);
}
