static void
set_clip_planes (CoglFramebuffer *framebuffer,
CoglMatrixEntry *modelview_entry,
float x_1,
float y_1,
float x_2,
float y_2)
{
CoglMatrix modelview_matrix;
CoglMatrixStack *projection_stack =
_cogl_framebuffer_get_projection_stack (framebuffer);
CoglMatrix projection_matrix;
CoglMatrix modelview_projection;
float signed_area;
float vertex_tl[4] = { x_1, y_1, 0, 1.0 };
float vertex_tr[4] = { x_2, y_1, 0, 1.0 };
float vertex_bl[4] = { x_1, y_2, 0, 1.0 };
float vertex_br[4] = { x_2, y_2, 0, 1.0 };
cogl_matrix_stack_get (projection_stack, &projection_matrix);
cogl_matrix_entry_get (modelview_entry, &modelview_matrix);
cogl_matrix_multiply (&modelview_projection,
&projection_matrix,
&modelview_matrix);
project_vertex (&modelview_projection, vertex_tl);
project_vertex (&modelview_projection, vertex_tr);
project_vertex (&modelview_projection, vertex_bl);
project_vertex (&modelview_projection, vertex_br);
/* Calculate the signed area of the polygon formed by the four
vertices so that we can know its orientation */
signed_area = (vertex_tl[0] * (vertex_tr[1] - vertex_bl[1])
+ vertex_tr[0] * (vertex_br[1] - vertex_tl[1])
+ vertex_br[0] * (vertex_bl[1] - vertex_tr[1])
+ vertex_bl[0] * (vertex_tl[1] - vertex_br[1]));
/* Set the clip planes to form lines between all of the vertices
using the same orientation as we calculated */
if (signed_area > 0.0f)
{
/* counter-clockwise */
set_clip_plane (framebuffer, GL_CLIP_PLANE0, vertex_tl, vertex_bl);
set_clip_plane (framebuffer, GL_CLIP_PLANE1, vertex_bl, vertex_br);
set_clip_plane (framebuffer, GL_CLIP_PLANE2, vertex_br, vertex_tr);
set_clip_plane (framebuffer, GL_CLIP_PLANE3, vertex_tr, vertex_tl);
}
else
{
/* clockwise */
set_clip_plane (framebuffer, GL_CLIP_PLANE0, vertex_tl, vertex_tr);
set_clip_plane (framebuffer, GL_CLIP_PLANE1, vertex_tr, vertex_br);
set_clip_plane (framebuffer, GL_CLIP_PLANE2, vertex_br, vertex_bl);
set_clip_plane (framebuffer, GL_CLIP_PLANE3, vertex_bl, vertex_tl);
}
}
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 (projection_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;
}
void
_cogl_matrix_entry_flush_to_gl_builtins (CoglContext *ctx,
CoglMatrixEntry *entry,
CoglMatrixMode mode,
CoglFramebuffer *framebuffer,
CoglBool disable_flip)
{
g_assert (_cogl_has_private_feature (ctx, COGL_PRIVATE_FEATURE_GL_FIXED));
#if defined (HAVE_COGL_GL) || defined (HAVE_COGL_GLES)
{
CoglBool needs_flip;
CoglMatrixEntryCache *cache;
if (mode == COGL_MATRIX_PROJECTION)
{
/* Because Cogl defines texture coordinates to have a top left
* origin and because offscreen framebuffers may be used for
* rendering to textures we always render upside down to
* offscreen buffers. Also for some backends we need to render
* onscreen buffers upside-down too.
*/
if (disable_flip)
needs_flip = FALSE;
else
needs_flip = cogl_is_offscreen (framebuffer);
cache = &ctx->builtin_flushed_projection;
}
else
{
needs_flip = FALSE;
if (mode == COGL_MATRIX_MODELVIEW)
cache = &ctx->builtin_flushed_modelview;
else
cache = NULL;
}
/* We don't need to do anything if the state is the same */
if (!cache ||
_cogl_matrix_entry_cache_maybe_update (cache, entry, needs_flip))
{
CoglBool is_identity;
CoglMatrix matrix;
if (entry->op == COGL_MATRIX_OP_LOAD_IDENTITY)
is_identity = TRUE;
else
{
is_identity = FALSE;
cogl_matrix_entry_get (entry, &matrix);
}
if (needs_flip)
{
CoglMatrix flipped_matrix;
cogl_matrix_multiply (&flipped_matrix,
&ctx->y_flip_matrix,
is_identity ?
&ctx->identity_matrix :
&matrix);
_cogl_matrix_flush_to_gl_builtin (ctx,
/* not identity */
FALSE,
&flipped_matrix,
mode);
}
else
{
_cogl_matrix_flush_to_gl_builtin (ctx,
is_identity,
&matrix,
mode);
}
}
}
#endif
}
/* In addition to writing the stack matrix into the give @matrix
* argument this function *may* sometimes also return a pointer
* to a matrix too so if we are querying the inverse matrix we
* should query from the return matrix so that the result can
* be cached within the stack. */
CoglMatrix *
cogl_matrix_stack_get (CoglMatrixStack *stack,
CoglMatrix *matrix)
{
return cogl_matrix_entry_get (stack->last_entry, matrix);
}
/* In addition to writing the stack matrix into the give @matrix
* argument this function *may* sometimes also return a pointer
* to a matrix too so if we are querying the inverse matrix we
* should query from the return matrix so that the result can
* be cached within the stack. */
CoglMatrix *
cogl_matrix_entry_get (CoglMatrixEntry *entry,
CoglMatrix *matrix)
{
int depth;
CoglMatrixEntry *current;
CoglMatrixEntry **children;
int i;
for (depth = 0, current = entry;
current;
current = current->parent, depth++)
{
switch (current->op)
{
case COGL_MATRIX_OP_LOAD_IDENTITY:
cogl_matrix_init_identity (matrix);
goto initialized;
case COGL_MATRIX_OP_LOAD:
{
CoglMatrixEntryLoad *load = (CoglMatrixEntryLoad *)current;
*matrix = *load->matrix;
goto initialized;
}
case COGL_MATRIX_OP_SAVE:
{
CoglMatrixEntrySave *save = (CoglMatrixEntrySave *)current;
if (!save->cache_valid)
{
CoglMagazine *matrices_magazine =
cogl_matrix_stack_matrices_magazine;
save->cache = _cogl_magazine_chunk_alloc (matrices_magazine);
cogl_matrix_entry_get (current->parent, save->cache);
save->cache_valid = TRUE;
}
*matrix = *save->cache;
goto initialized;
}
default:
continue;
}
}
initialized:
if (depth == 0)
{
switch (entry->op)
{
case COGL_MATRIX_OP_LOAD_IDENTITY:
case COGL_MATRIX_OP_TRANSLATE:
case COGL_MATRIX_OP_ROTATE:
case COGL_MATRIX_OP_ROTATE_QUATERNION:
case COGL_MATRIX_OP_ROTATE_EULER:
case COGL_MATRIX_OP_SCALE:
case COGL_MATRIX_OP_MULTIPLY:
return NULL;
case COGL_MATRIX_OP_LOAD:
{
CoglMatrixEntryLoad *load = (CoglMatrixEntryLoad *)entry;
return load->matrix;
}
case COGL_MATRIX_OP_SAVE:
{
CoglMatrixEntrySave *save = (CoglMatrixEntrySave *)entry;
return save->cache;
}
}
g_warn_if_reached ();
return NULL;
}
#ifdef COGL_ENABLE_DEBUG
if (!current)
{
g_warning ("Inconsistent matrix stack");
return NULL;
}
entry->composite_gets++;
#endif
children = g_alloca (sizeof (CoglMatrixEntry) * depth);
/* We need walk the list of entries from the init/load/save entry
* back towards the leaf node but the nodes don't link to their
* children so we need to re-walk them here to add to a separate
* array. */
for (i = depth - 1, current = entry;
i >= 0 && current;
i--, current = current->parent)
{
children[i] = current;
}
#ifdef COGL_ENABLE_DEBUG
if (COGL_DEBUG_ENABLED (COGL_DEBUG_PERFORMANCE) &&
entry->composite_gets >= 2)
{
COGL_NOTE (PERFORMANCE,
"Re-composing a matrix stack entry multiple times");
}
#endif
for (i = 0; i < depth; i++)
{
switch (children[i]->op)
{
case COGL_MATRIX_OP_TRANSLATE:
{
CoglMatrixEntryTranslate *translate =
(CoglMatrixEntryTranslate *)children[i];
cogl_matrix_translate (matrix,
translate->x,
translate->y,
translate->z);
continue;
}
case COGL_MATRIX_OP_ROTATE:
{
CoglMatrixEntryRotate *rotate=
(CoglMatrixEntryRotate *)children[i];
cogl_matrix_rotate (matrix,
rotate->angle,
rotate->x,
rotate->y,
rotate->z);
continue;
}
case COGL_MATRIX_OP_ROTATE_EULER:
{
CoglMatrixEntryRotateEuler *rotate =
(CoglMatrixEntryRotateEuler *)children[i];
CoglEuler euler;
cogl_euler_init (&euler,
rotate->heading,
rotate->pitch,
rotate->roll);
cogl_matrix_rotate_euler (matrix,
&euler);
continue;
}
case COGL_MATRIX_OP_ROTATE_QUATERNION:
{
CoglMatrixEntryRotateQuaternion *rotate =
(CoglMatrixEntryRotateQuaternion *)children[i];
CoglQuaternion quaternion;
cogl_quaternion_init_from_array (&quaternion, rotate->values);
cogl_matrix_rotate_quaternion (matrix, &quaternion);
continue;
}
case COGL_MATRIX_OP_SCALE:
{
CoglMatrixEntryScale *scale =
(CoglMatrixEntryScale *)children[i];
cogl_matrix_scale (matrix,
scale->x,
scale->y,
scale->z);
continue;
}
case COGL_MATRIX_OP_MULTIPLY:
{
CoglMatrixEntryMultiply *multiply =
(CoglMatrixEntryMultiply *)children[i];
cogl_matrix_multiply (matrix, matrix, multiply->matrix);
continue;
}
case COGL_MATRIX_OP_LOAD_IDENTITY:
case COGL_MATRIX_OP_LOAD:
case COGL_MATRIX_OP_SAVE:
g_warn_if_reached ();
continue;
}
}
return NULL;
}
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;
}