From d15331604501dae4d6071de4092b91e88c02b3f8 Mon Sep 17 00:00:00 2001 From: Robert Bragg Date: Tue, 6 Oct 2009 10:52:07 +0100 Subject: [PATCH] [matrix-stack] avoid redundant clearing of matrix when using load_identity The journal always uses an identity matrix since it uses software transformation. Currently it manually uses glLoadMatrix since previous experimentation showed that the cogl-matrix-stack gave bad performance, but it would be nice to fix performance so we only have to care about one path for loading matrices. For the common case where we do: cogl_matrix_stack_push() cogl_matrix_stack_load_identity() we were effectively initializing the matrix 3 times. Once due to use of g_slice_new0, then we had a cogl_matrix_init_identity in _cogl_matrix_state_new for good measure, and then finally in cogl_matrix_stack_load_identity we did another cogl_matrix_init_identity. We don't use g_slice_new0 anymore, _cogl_matrix_state_new is documented as not initializing the matrix (instead _cogl_matrix_stack_top_mutable now takes a boolean to choose if new stack entries should be initialised) and so we now only initialize once in cogl_matrix_stack_load_identity. --- cogl/cogl-matrix-stack.c | 54 +++++++++++++++++++--------------------- 1 file changed, 26 insertions(+), 28 deletions(-) diff --git a/cogl/cogl-matrix-stack.c b/cogl/cogl-matrix-stack.c index 39e4e8476..c581b2d2b 100644 --- a/cogl/cogl-matrix-stack.c +++ b/cogl/cogl-matrix-stack.c @@ -56,18 +56,14 @@ struct _CoglMatrixStack CoglMatrixState *flushed_state; }; - +/* XXX: this doesn't initialize the matrix! */ static CoglMatrixState* _cogl_matrix_state_new (void) { CoglMatrixState *state; - state = g_slice_new0 (CoglMatrixState); - - /* load identity */ - cogl_matrix_init_identity (&state->matrix); - - /* state->push_count defaults to 0 */ + state = g_slice_new (CoglMatrixState); + state->push_count = 0; return state; } @@ -85,8 +81,9 @@ _cogl_matrix_stack_top (CoglMatrixStack *stack) return stack->stack->data; } -static CoglMatrixState* -_cogl_matrix_stack_top_mutable (CoglMatrixStack *stack) +static CoglMatrixState * +_cogl_matrix_stack_top_mutable (CoglMatrixStack *stack, + gboolean initialize) { CoglMatrixState *state; CoglMatrixState *new_top; @@ -100,16 +97,15 @@ _cogl_matrix_stack_top_mutable (CoglMatrixStack *stack) new_top = _cogl_matrix_state_new (); - new_top->matrix = state->matrix; - - if (stack->flushed_state == state) + if (initialize) { - stack->flushed_state = new_top; + new_top->matrix = state->matrix; + + if (stack->flushed_state == state) + stack->flushed_state = new_top; } - stack->stack = - g_slist_prepend (stack->stack, - new_top); + stack->stack = g_slist_prepend (stack->stack, new_top); return new_top; } @@ -121,10 +117,11 @@ _cogl_matrix_stack_new (void) CoglMatrixState *state; stack = g_slice_new0 (CoglMatrixStack); + state = _cogl_matrix_state_new (); - stack->stack = - g_slist_prepend (stack->stack, - state); + cogl_matrix_init_identity (&state->matrix); + + stack->stack = g_slist_prepend (stack->stack, state); return stack; } @@ -195,7 +192,8 @@ _cogl_matrix_stack_load_identity (CoglMatrixStack *stack) { CoglMatrixState *state; - state = _cogl_matrix_stack_top_mutable (stack); + /* XXX: In this case an uninitialized top is acceptable */ + state = _cogl_matrix_stack_top_mutable (stack, FALSE); cogl_matrix_init_identity (&state->matrix); /* mark dirty */ @@ -210,7 +208,7 @@ _cogl_matrix_stack_scale (CoglMatrixStack *stack, { CoglMatrixState *state; - state = _cogl_matrix_stack_top_mutable (stack); + state = _cogl_matrix_stack_top_mutable (stack, TRUE); cogl_matrix_scale (&state->matrix, x, y, z); /* mark dirty */ stack->flushed_state = NULL; @@ -224,7 +222,7 @@ _cogl_matrix_stack_translate (CoglMatrixStack *stack, { CoglMatrixState *state; - state = _cogl_matrix_stack_top_mutable (stack); + state = _cogl_matrix_stack_top_mutable (stack, TRUE); cogl_matrix_translate (&state->matrix, x, y, z); /* mark dirty */ stack->flushed_state = NULL; @@ -239,7 +237,7 @@ _cogl_matrix_stack_rotate (CoglMatrixStack *stack, { CoglMatrixState *state; - state = _cogl_matrix_stack_top_mutable (stack); + state = _cogl_matrix_stack_top_mutable (stack, TRUE); cogl_matrix_rotate (&state->matrix, angle, x, y, z); /* mark dirty */ stack->flushed_state = NULL; @@ -251,7 +249,7 @@ _cogl_matrix_stack_multiply (CoglMatrixStack *stack, { CoglMatrixState *state; - state = _cogl_matrix_stack_top_mutable (stack); + state = _cogl_matrix_stack_top_mutable (stack, TRUE); cogl_matrix_multiply (&state->matrix, &state->matrix, matrix); /* mark dirty */ stack->flushed_state = NULL; @@ -268,7 +266,7 @@ _cogl_matrix_stack_frustum (CoglMatrixStack *stack, { CoglMatrixState *state; - state = _cogl_matrix_stack_top_mutable (stack); + state = _cogl_matrix_stack_top_mutable (stack, TRUE); cogl_matrix_frustum (&state->matrix, left, right, bottom, top, z_near, z_far); @@ -285,7 +283,7 @@ _cogl_matrix_stack_perspective (CoglMatrixStack *stack, { CoglMatrixState *state; - state = _cogl_matrix_stack_top_mutable (stack); + state = _cogl_matrix_stack_top_mutable (stack, TRUE); cogl_matrix_perspective (&state->matrix, fov_y, aspect, z_near, z_far); /* mark dirty */ @@ -303,7 +301,7 @@ _cogl_matrix_stack_ortho (CoglMatrixStack *stack, { CoglMatrixState *state; - state = _cogl_matrix_stack_top_mutable (stack); + state = _cogl_matrix_stack_top_mutable (stack, TRUE); cogl_matrix_ortho (&state->matrix, left, right, bottom, top, z_near, z_far); /* mark dirty */ @@ -327,7 +325,7 @@ _cogl_matrix_stack_set (CoglMatrixStack *stack, { CoglMatrixState *state; - state = _cogl_matrix_stack_top_mutable (stack); + state = _cogl_matrix_stack_top_mutable (stack, TRUE); state->matrix = *matrix; /* mark dirty */ stack->flushed_state = NULL;