matrix-stack: more optimization for load_identity case
This goes a bit further than the previous patch, and as a special case we now simply represent identity matrices using a boolean, and only lazily initialize them when they need to be modified.
This commit is contained in:
Robert Bragg
parent
d153316045
commit
43f8032a7f
1 changed files with 71 additions and 11 deletions
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@ -35,6 +35,7 @@
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typedef struct {
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CoglMatrix matrix;
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gboolean is_identity;
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/* count of pushes with no changes; when a change is
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* requested, we create a new state and decrement this
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*/
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@ -54,6 +55,7 @@ struct _CoglMatrixStack
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/* which state does GL have, NULL if unknown */
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CoglMatrixState *flushed_state;
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gboolean flushed_identity;
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};
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/* XXX: this doesn't initialize the matrix! */
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@ -64,6 +66,7 @@ _cogl_matrix_state_new (void)
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state = g_slice_new (CoglMatrixState);
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state->push_count = 0;
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state->is_identity = FALSE;
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return state;
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}
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@ -71,7 +74,6 @@ _cogl_matrix_state_new (void)
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static void
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_cogl_matrix_state_destroy (CoglMatrixState *state)
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{
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g_slice_free (CoglMatrixState, state);
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}
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@ -81,6 +83,18 @@ _cogl_matrix_stack_top (CoglMatrixStack *stack)
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return stack->stack->data;
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}
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/* XXX:
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* Operations like scale, translate, rotate etc need to have an
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* initialized state->matrix to work with, so they will pass
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* initialize = TRUE.
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*
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* _cogl_matrix_stack_load_identity and _cogl_matrix_stack_set on the
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* other hand don't so they will pass initialize = FALSE
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*
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* NB: Identity matrices are represented by setting
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* state->is_identity=TRUE in which case state->matrix will be
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* uninitialized.
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*/
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static CoglMatrixState *
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_cogl_matrix_stack_top_mutable (CoglMatrixStack *stack,
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gboolean initialize)
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@ -91,7 +105,11 @@ _cogl_matrix_stack_top_mutable (CoglMatrixStack *stack,
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state = _cogl_matrix_stack_top (stack);
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if (state->push_count == 0)
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return state;
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{
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if (state->is_identity && initialize)
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cogl_matrix_init_identity (&state->matrix);
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return state;
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}
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state->push_count -= 1;
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@ -99,7 +117,10 @@ _cogl_matrix_stack_top_mutable (CoglMatrixStack *stack,
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if (initialize)
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{
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new_top->matrix = state->matrix;
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if (state->is_identity)
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cogl_matrix_init_identity (&new_top->matrix);
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else
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new_top->matrix = state->matrix;
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if (stack->flushed_state == state)
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stack->flushed_state = new_top;
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@ -119,7 +140,7 @@ _cogl_matrix_stack_new (void)
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stack = g_slice_new0 (CoglMatrixStack);
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state = _cogl_matrix_state_new ();
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cogl_matrix_init_identity (&state->matrix);
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state->is_identity = TRUE;
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stack->stack = g_slist_prepend (stack->stack, state);
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@ -192,12 +213,22 @@ _cogl_matrix_stack_load_identity (CoglMatrixStack *stack)
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{
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CoglMatrixState *state;
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/* XXX: In this case an uninitialized top is acceptable */
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state = _cogl_matrix_stack_top_mutable (stack, FALSE);
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cogl_matrix_init_identity (&state->matrix);
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/* mark dirty */
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stack->flushed_state = NULL;
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/* NB: Identity matrices are represented by setting
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* state->is_identity = TRUE and leaving state->matrix
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* uninitialized.
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*
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* This is done to optimize the heavy usage of
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* _cogl_matrix_stack_load_identity by the Cogl Journal.
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*/
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if (!state->is_identity)
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{
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state->is_identity = TRUE;
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/* mark dirty */
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stack->flushed_state = NULL;
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}
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}
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void
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@ -212,6 +243,7 @@ _cogl_matrix_stack_scale (CoglMatrixStack *stack,
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cogl_matrix_scale (&state->matrix, x, y, z);
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/* mark dirty */
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stack->flushed_state = NULL;
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state->is_identity = FALSE;
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}
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void
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@ -226,6 +258,7 @@ _cogl_matrix_stack_translate (CoglMatrixStack *stack,
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cogl_matrix_translate (&state->matrix, x, y, z);
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/* mark dirty */
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stack->flushed_state = NULL;
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state->is_identity = FALSE;
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}
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void
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@ -241,6 +274,7 @@ _cogl_matrix_stack_rotate (CoglMatrixStack *stack,
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cogl_matrix_rotate (&state->matrix, angle, x, y, z);
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/* mark dirty */
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stack->flushed_state = NULL;
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state->is_identity = FALSE;
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}
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void
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@ -253,6 +287,7 @@ _cogl_matrix_stack_multiply (CoglMatrixStack *stack,
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cogl_matrix_multiply (&state->matrix, &state->matrix, matrix);
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/* mark dirty */
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stack->flushed_state = NULL;
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state->is_identity = FALSE;
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}
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void
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@ -272,6 +307,7 @@ _cogl_matrix_stack_frustum (CoglMatrixStack *stack,
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z_near, z_far);
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/* mark dirty */
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stack->flushed_state = NULL;
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state->is_identity = FALSE;
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}
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void
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@ -288,6 +324,7 @@ _cogl_matrix_stack_perspective (CoglMatrixStack *stack,
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fov_y, aspect, z_near, z_far);
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/* mark dirty */
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stack->flushed_state = NULL;
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state->is_identity = FALSE;
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}
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void
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@ -306,6 +343,7 @@ _cogl_matrix_stack_ortho (CoglMatrixStack *stack,
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left, right, bottom, top, z_near, z_far);
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/* mark dirty */
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stack->flushed_state = NULL;
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state->is_identity = FALSE;
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}
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void
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@ -316,7 +354,17 @@ _cogl_matrix_stack_get (CoglMatrixStack *stack,
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state = _cogl_matrix_stack_top (stack);
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*matrix = state->matrix;
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/* NB: identity matrices are lazily initialized because we can often avoid
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* initializing them at all if nothing is pushed on top of them since we
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* load them using glLoadIdentity()
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*
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* The Cogl journal typically loads an identiy matrix because it performs
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* software transformations, which is why we have optimized this case.
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*/
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if (state->is_identity)
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cogl_matrix_init_identity (matrix);
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else
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*matrix = state->matrix;
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}
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void
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@ -325,10 +373,11 @@ _cogl_matrix_stack_set (CoglMatrixStack *stack,
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{
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CoglMatrixState *state;
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state = _cogl_matrix_stack_top_mutable (stack, TRUE);
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state = _cogl_matrix_stack_top_mutable (stack, FALSE);
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state->matrix = *matrix;
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/* mark dirty */
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stack->flushed_state = NULL;
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state->is_identity = FALSE;
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}
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void
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@ -362,7 +411,17 @@ _cogl_matrix_stack_flush_to_gl (CoglMatrixStack *stack,
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* than LoadMatrix to send a 2D matrix
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*/
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GE (glLoadMatrixf (cogl_matrix_get_array (&state->matrix)));
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if (state->is_identity)
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{
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if (!stack->flushed_identity)
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GE (glLoadIdentity ());
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stack->flushed_identity = TRUE;
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}
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else
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{
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GE (glLoadMatrixf (cogl_matrix_get_array (&state->matrix)));
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stack->flushed_identity = FALSE;
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}
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stack->flushed_state = state;
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}
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@ -370,5 +429,6 @@ void
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_cogl_matrix_stack_dirty (CoglMatrixStack *stack)
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{
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stack->flushed_state = NULL;
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stack->flushed_identity = FALSE;
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}
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