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mutter-performance-source/cogl/cogl-clip-stack.c
Robert Bragg 7365c3aa77 Separate out CoglPath api into sub-library
This splits out the cogl_path_ api into a separate cogl-path sub-library
like cogl-pango and cogl-gst. This enables developers to build Cogl with
this sub-library disabled if they don't need it which can be useful when
its important to keep the size of an application and its dependencies
down to a minimum. The functions cogl_framebuffer_{fill,stroke}_path
have been renamed to cogl_path_{fill,stroke}.

There were a few places in core cogl and cogl-gst that referenced the
CoglPath api and these have been decoupled by using the CoglPrimitive
api instead. In the case of cogl_framebuffer_push_path_clip() the core
clip stack no longer accepts path clips directly but it's now possible
to get a CoglPrimitive for the fill of a path and so the implementation
of cogl_framebuffer_push_path_clip() now lives in cogl-path and works as
a shim that first gets a CoglPrimitive and uses
cogl_framebuffer_push_primitive_clip instead.

We may want to consider renaming cogl_framebuffer_push_path_clip to
put it in the cogl_path_ namespace.

Reviewed-by: Neil Roberts <neil@linux.intel.com>

(cherry picked from commit 8aadfd829239534fb4ec8255cdea813d698c5a3f)

So as to avoid breaking the 1.x API or even the ABI since we are quite
late in the 1.16 development cycle the patch was modified to build
cogl-path as a noinst_LTLIBRARY before building cogl and link the code
directly into libcogl.so as it was previously. This way we can wait
until the start of the 1.18 cycle before splitting the code into a
separate libcogl-path.so.

This also adds shims for cogl_framebuffer_fill/stroke_path() to avoid
breaking the 1.x API/ABI.
2013-08-19 22:44:35 +01:00

406 lines
12 KiB
C

/*
* Cogl
*
* An object oriented GL/GLES Abstraction/Utility Layer
*
* Copyright (C) 2007,2008,2009,2010 Intel Corporation.
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2 of the License, or (at your option) any later version.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this library. If not, see
* <http://www.gnu.org/licenses/>.
*
*
*/
#ifdef HAVE_CONFIG_H
#include "config.h"
#endif
#include <string.h>
#include <math.h>
#include <glib.h>
#include "cogl-clip-stack.h"
#include "cogl-primitives.h"
#include "cogl-context-private.h"
#include "cogl-framebuffer-private.h"
#include "cogl-journal-private.h"
#include "cogl-util.h"
#include "cogl-matrix-private.h"
#include "cogl-primitives-private.h"
#include "cogl-private.h"
#include "cogl-pipeline-opengl-private.h"
#include "cogl-attribute-private.h"
#include "cogl-primitive-private.h"
#include "cogl1-context.h"
#include "cogl-offscreen.h"
#include "cogl-matrix-stack.h"
static void *
_cogl_clip_stack_push_entry (CoglClipStack *clip_stack,
size_t size,
CoglClipStackType type)
{
CoglClipStack *entry = g_slice_alloc (size);
/* The new entry starts with a ref count of 1 because the stack
holds a reference to it as it is the top entry */
entry->ref_count = 1;
entry->type = type;
entry->parent = clip_stack;
/* We don't need to take a reference to the parent from the entry
because the we are stealing the ref in the new stack top */
return entry;
}
static void
get_transformed_corners (float x_1,
float y_1,
float x_2,
float y_2,
CoglMatrix *modelview,
CoglMatrix *projection,
const float *viewport,
float *transformed_corners)
{
int i;
transformed_corners[0] = x_1;
transformed_corners[1] = y_1;
transformed_corners[2] = x_2;
transformed_corners[3] = y_1;
transformed_corners[4] = x_2;
transformed_corners[5] = y_2;
transformed_corners[6] = x_1;
transformed_corners[7] = y_2;
/* Project the coordinates to window space coordinates */
for (i = 0; i < 4; i++)
{
float *v = transformed_corners + i * 2;
_cogl_transform_point (modelview, projection, viewport, v, v + 1);
}
}
/* Sets the window-space bounds of the entry based on the projected
coordinates of the given rectangle */
static void
_cogl_clip_stack_entry_set_bounds (CoglClipStack *entry,
float *transformed_corners)
{
float min_x = G_MAXFLOAT, min_y = G_MAXFLOAT;
float max_x = -G_MAXFLOAT, max_y = -G_MAXFLOAT;
int i;
for (i = 0; i < 4; i++)
{
float *v = transformed_corners + i * 2;
if (v[0] > max_x)
max_x = v[0];
if (v[0] < min_x)
min_x = v[0];
if (v[1] > max_y)
max_y = v[1];
if (v[1] < min_y)
min_y = v[1];
}
entry->bounds_x0 = floorf (min_x);
entry->bounds_x1 = ceilf (max_x);
entry->bounds_y0 = floorf (min_y);
entry->bounds_y1 = ceilf (max_y);
}
CoglClipStack *
_cogl_clip_stack_push_window_rectangle (CoglClipStack *stack,
int x_offset,
int y_offset,
int width,
int height)
{
CoglClipStack *entry;
entry = _cogl_clip_stack_push_entry (stack,
sizeof (CoglClipStackWindowRect),
COGL_CLIP_STACK_WINDOW_RECT);
entry->bounds_x0 = x_offset;
entry->bounds_x1 = x_offset + width;
entry->bounds_y0 = y_offset;
entry->bounds_y1 = y_offset + height;
return entry;
}
CoglClipStack *
_cogl_clip_stack_push_rectangle (CoglClipStack *stack,
float x_1,
float y_1,
float x_2,
float y_2,
CoglMatrixEntry *modelview_entry,
CoglMatrixEntry *projection_entry,
const float *viewport)
{
CoglClipStackRect *entry;
CoglMatrix modelview;
CoglMatrix projection;
CoglMatrix modelview_projection;
/* Corners of the given rectangle in an clockwise order:
* (0, 1) (2, 3)
*
*
*
* (6, 7) (4, 5)
*/
float rect[] = {
x_1, y_1,
x_2, y_1,
x_2, y_2,
x_1, y_2
};
/* Make a new entry */
entry = _cogl_clip_stack_push_entry (stack,
sizeof (CoglClipStackRect),
COGL_CLIP_STACK_RECT);
entry->x0 = x_1;
entry->y0 = y_1;
entry->x1 = x_2;
entry->y1 = y_2;
entry->matrix_entry = cogl_matrix_entry_ref (modelview_entry);
cogl_matrix_entry_get (modelview_entry, &modelview);
cogl_matrix_entry_get (projection_entry, &projection);
cogl_matrix_multiply (&modelview_projection,
&projection,
&modelview);
/* Technically we could avoid the viewport transform at this point
* if we want to make this a bit faster. */
_cogl_transform_point (&modelview, &projection, viewport, &rect[0], &rect[1]);
_cogl_transform_point (&modelview, &projection, viewport, &rect[2], &rect[3]);
_cogl_transform_point (&modelview, &projection, viewport, &rect[4], &rect[5]);
_cogl_transform_point (&modelview, &projection, viewport, &rect[6], &rect[7]);
/* If the fully transformed rectangle isn't still axis aligned we
* can't handle it using a scissor.
*
* We don't use an epsilon here since we only really aim to catch
* simple cases where the transform doesn't leave the rectangle screen
* aligned and don't mind some false positives.
*/
if (rect[0] != rect[6] ||
rect[1] != rect[3] ||
rect[2] != rect[4] ||
rect[7] != rect[5])
{
entry->can_be_scissor = FALSE;
_cogl_clip_stack_entry_set_bounds ((CoglClipStack *) entry,
rect);
}
else
{
CoglClipStack *base_entry = (CoglClipStack *) entry;
x_1 = rect[0];
y_1 = rect[1];
x_2 = rect[4];
y_2 = rect[5];
/* Consider that the modelview matrix may flip the rectangle
* along the x or y axis... */
#define SWAP(A,B) do { float tmp = B; B = A; A = tmp; } while (0)
if (x_1 > x_2)
SWAP (x_1, x_2);
if (y_1 > y_2)
SWAP (y_1, y_2);
#undef SWAP
base_entry->bounds_x0 = COGL_UTIL_NEARBYINT (x_1);
base_entry->bounds_y0 = COGL_UTIL_NEARBYINT (y_1);
base_entry->bounds_x1 = COGL_UTIL_NEARBYINT (x_2);
base_entry->bounds_y1 = COGL_UTIL_NEARBYINT (y_2);
entry->can_be_scissor = TRUE;
}
return (CoglClipStack *) entry;
}
CoglClipStack *
_cogl_clip_stack_push_primitive (CoglClipStack *stack,
CoglPrimitive *primitive,
float bounds_x1,
float bounds_y1,
float bounds_x2,
float bounds_y2,
CoglMatrixEntry *modelview_entry,
CoglMatrixEntry *projection_entry,
const float *viewport)
{
CoglClipStackPrimitive *entry;
CoglMatrix modelview;
CoglMatrix projection;
float transformed_corners[8];
entry = _cogl_clip_stack_push_entry (stack,
sizeof (CoglClipStackPrimitive),
COGL_CLIP_STACK_PRIMITIVE);
entry->primitive = cogl_object_ref (primitive);
entry->matrix_entry = cogl_matrix_entry_ref (modelview_entry);
entry->bounds_x1 = bounds_x1;
entry->bounds_y1 = bounds_y1;
entry->bounds_x2 = bounds_x2;
entry->bounds_y2 = bounds_y2;
cogl_matrix_entry_get (modelview_entry, &modelview);
cogl_matrix_entry_get (modelview_entry, &projection);
get_transformed_corners (bounds_x1, bounds_y1, bounds_x2, bounds_y2,
&modelview,
&projection,
viewport,
transformed_corners);
/* NB: this is referring to the bounds in window coordinates as opposed
* to the bounds above in primitive local coordinates. */
_cogl_clip_stack_entry_set_bounds ((CoglClipStack *) entry,
transformed_corners);
return (CoglClipStack *) entry;
}
CoglClipStack *
_cogl_clip_stack_ref (CoglClipStack *entry)
{
/* A NULL pointer is considered a valid stack so we should accept
that as an argument */
if (entry)
entry->ref_count++;
return entry;
}
void
_cogl_clip_stack_unref (CoglClipStack *entry)
{
/* Unref all of the entries until we hit the root of the list or the
entry still has a remaining reference */
while (entry && --entry->ref_count <= 0)
{
CoglClipStack *parent = entry->parent;
switch (entry->type)
{
case COGL_CLIP_STACK_RECT:
{
CoglClipStackRect *rect = (CoglClipStackRect *) entry;
cogl_matrix_entry_unref (rect->matrix_entry);
g_slice_free1 (sizeof (CoglClipStackRect), entry);
break;
}
case COGL_CLIP_STACK_WINDOW_RECT:
g_slice_free1 (sizeof (CoglClipStackWindowRect), entry);
break;
case COGL_CLIP_STACK_PRIMITIVE:
{
CoglClipStackPrimitive *primitive_entry =
(CoglClipStackPrimitive *) entry;
cogl_matrix_entry_unref (primitive_entry->matrix_entry);
cogl_object_unref (primitive_entry->primitive);
g_slice_free1 (sizeof (CoglClipStackPrimitive), entry);
break;
}
default:
g_assert_not_reached ();
}
entry = parent;
}
}
CoglClipStack *
_cogl_clip_stack_pop (CoglClipStack *stack)
{
CoglClipStack *new_top;
_COGL_RETURN_VAL_IF_FAIL (stack != NULL, NULL);
/* To pop we are moving the top of the stack to the old top's parent
node. The stack always needs to have a reference to the top entry
so we must take a reference to the new top. The stack would have
previously had a reference to the old top so we need to decrease
the ref count on that. We need to ref the new head first in case
this stack was the only thing referencing the old top. In that
case the call to _cogl_clip_stack_entry_unref will unref the
parent. */
new_top = stack->parent;
_cogl_clip_stack_ref (new_top);
_cogl_clip_stack_unref (stack);
return new_top;
}
void
_cogl_clip_stack_get_bounds (CoglClipStack *stack,
int *scissor_x0,
int *scissor_y0,
int *scissor_x1,
int *scissor_y1)
{
CoglClipStack *entry;
*scissor_x0 = 0;
*scissor_y0 = 0;
*scissor_x1 = G_MAXINT;
*scissor_y1 = G_MAXINT;
for (entry = stack; entry; entry = entry->parent)
{
/* Get the intersection of the current scissor and the bounding
box of this clip */
_cogl_util_scissor_intersect (entry->bounds_x0,
entry->bounds_y0,
entry->bounds_x1,
entry->bounds_y1,
scissor_x0,
scissor_y0,
scissor_x1,
scissor_y1);
}
}
void
_cogl_clip_stack_flush (CoglClipStack *stack,
CoglFramebuffer *framebuffer)
{
CoglContext *ctx = framebuffer->context;
ctx->driver_vtable->clip_stack_flush (stack, framebuffer);
}