mutter/common/cogl-matrix-stack.c
Robert Bragg fffcf579d5 [cogl matrix stack] Create a client side matrix stack for the projection matrix
The cost of glGetFloatv with Mesa is still representing a majority of our
time in OpenGL for some applications, and the last thing left using this is
the current-matrix API when getting the projection matrix.

This adds a matrix stack for the projection matrix, so all getting, setting
and modification of the projection matrix is now managed by Cogl and it's only
when we come to draw that we flush changes to the matrix to OpenGL.

This also brings us closer to being able to drop internal use of the
deprecated OpenGL matrix functions, re: commit 54159f5a1d
2009-07-07 10:32:56 +01:00

364 lines
8.4 KiB
C

/*
* Cogl
*
* An object oriented GL/GLES Abstraction/Utility Layer
*
* Copyright (C) 2009 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, write to the
* Free Software Foundation, Inc., 59 Temple Place - Suite 330,
* Boston, MA 02111-1307, USA.
*
* Authors:
* Havoc Pennington <hp@pobox.com> for litl
*/
#ifdef HAVE_CONFIG_H
#include "config.h"
#endif
#include "cogl.h"
#include "cogl-context.h"
#include "cogl-internal.h"
#include "cogl-matrix-stack.h"
typedef struct {
CoglMatrix matrix;
/* count of pushes with no changes; when a change is
* requested, we create a new state and decrement this
*/
int push_count;
} CoglMatrixState;
/**
* CoglMatrixStack:
*
* Stores a cogl-side matrix stack, which we use as a cache
* so we can get the matrix efficiently when using indirect
* rendering.
*/
struct _CoglMatrixStack
{
GSList *stack;
/* which state does GL have, NULL if unknown */
CoglMatrixState *flushed_state;
};
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 */
return state;
}
static void
_cogl_matrix_state_destroy (CoglMatrixState *state)
{
g_slice_free (CoglMatrixState, state);
}
static CoglMatrixState*
_cogl_matrix_stack_top (CoglMatrixStack *stack)
{
return stack->stack->data;
}
static CoglMatrixState*
_cogl_matrix_stack_top_mutable (CoglMatrixStack *stack)
{
CoglMatrixState *state;
CoglMatrixState *new_top;
state = _cogl_matrix_stack_top (stack);
if (state->push_count == 0)
return state;
state->push_count -= 1;
new_top = _cogl_matrix_state_new ();
new_top->matrix = state->matrix;
if (stack->flushed_state == state)
{
stack->flushed_state = new_top;
}
stack->stack =
g_slist_prepend (stack->stack,
new_top);
return new_top;
}
CoglMatrixStack*
_cogl_matrix_stack_new (void)
{
CoglMatrixStack *stack;
CoglMatrixState *state;
stack = g_slice_new0 (CoglMatrixStack);
state = _cogl_matrix_state_new ();
stack->stack =
g_slist_prepend (stack->stack,
state);
return stack;
}
void
_cogl_matrix_stack_destroy (CoglMatrixStack *stack)
{
while (stack->stack)
{
CoglMatrixState *state;
state = stack->stack->data;
_cogl_matrix_state_destroy (state);
stack->stack =
g_slist_delete_link (stack->stack,
stack->stack);
}
g_slice_free (CoglMatrixStack, stack);
}
void
_cogl_matrix_stack_push (CoglMatrixStack *stack)
{
CoglMatrixState *state;
state = _cogl_matrix_stack_top (stack);
/* we lazily create a new stack top if someone changes the matrix
* while push_count > 0
*/
state->push_count += 1;
}
void
_cogl_matrix_stack_pop (CoglMatrixStack *stack)
{
CoglMatrixState *state;
state = _cogl_matrix_stack_top (stack);
if (state->push_count > 0)
{
state->push_count -= 1;
}
else
{
if (stack->stack->next == NULL)
{
g_warning ("Too many matrix pops");
return;
}
if (stack->flushed_state == state)
{
stack->flushed_state = NULL;
}
stack->stack =
g_slist_delete_link (stack->stack,
stack->stack);
_cogl_matrix_state_destroy (state);
}
}
void
_cogl_matrix_stack_load_identity (CoglMatrixStack *stack)
{
CoglMatrixState *state;
state = _cogl_matrix_stack_top_mutable (stack);
cogl_matrix_init_identity (&state->matrix);
/* mark dirty */
stack->flushed_state = NULL;
}
void
_cogl_matrix_stack_scale (CoglMatrixStack *stack,
float x,
float y,
float z)
{
CoglMatrixState *state;
state = _cogl_matrix_stack_top_mutable (stack);
cogl_matrix_scale (&state->matrix, x, y, z);
/* mark dirty */
stack->flushed_state = NULL;
}
void
_cogl_matrix_stack_translate (CoglMatrixStack *stack,
float x,
float y,
float z)
{
CoglMatrixState *state;
state = _cogl_matrix_stack_top_mutable (stack);
cogl_matrix_translate (&state->matrix, x, y, z);
/* mark dirty */
stack->flushed_state = NULL;
}
void
_cogl_matrix_stack_rotate (CoglMatrixStack *stack,
float angle,
float x,
float y,
float z)
{
CoglMatrixState *state;
state = _cogl_matrix_stack_top_mutable (stack);
cogl_matrix_rotate (&state->matrix, angle, x, y, z);
/* mark dirty */
stack->flushed_state = NULL;
}
void
_cogl_matrix_stack_multiply (CoglMatrixStack *stack,
const CoglMatrix *matrix)
{
CoglMatrixState *state;
state = _cogl_matrix_stack_top_mutable (stack);
cogl_matrix_multiply (&state->matrix, &state->matrix, matrix);
/* mark dirty */
stack->flushed_state = NULL;
}
void
_cogl_matrix_stack_frustum (CoglMatrixStack *stack,
float left,
float right,
float bottom,
float top,
float z_near,
float z_far)
{
CoglMatrixState *state;
state = _cogl_matrix_stack_top_mutable (stack);
cogl_matrix_frustum (&state->matrix,
left, right, bottom, top,
z_near, z_far);
/* mark dirty */
stack->flushed_state = NULL;
}
void
_cogl_matrix_stack_perspective (CoglMatrixStack *stack,
float fov_y,
float aspect,
float z_near,
float z_far)
{
CoglMatrixState *state;
state = _cogl_matrix_stack_top_mutable (stack);
cogl_matrix_perspective (&state->matrix,
fov_y, aspect, z_near, z_far);
/* mark dirty */
stack->flushed_state = NULL;
}
void
_cogl_matrix_stack_ortho (CoglMatrixStack *stack,
float left,
float right,
float bottom,
float top,
float z_near,
float z_far)
{
CoglMatrixState *state;
state = _cogl_matrix_stack_top_mutable (stack);
cogl_matrix_ortho (&state->matrix,
left, right, bottom, top, z_near, z_far);
/* mark dirty */
stack->flushed_state = NULL;
}
void
_cogl_matrix_stack_get (CoglMatrixStack *stack,
CoglMatrix *matrix)
{
CoglMatrixState *state;
state = _cogl_matrix_stack_top (stack);
*matrix = state->matrix;
}
void
_cogl_matrix_stack_set (CoglMatrixStack *stack,
const CoglMatrix *matrix)
{
CoglMatrixState *state;
state = _cogl_matrix_stack_top_mutable (stack);
state->matrix = *matrix;
/* mark dirty */
stack->flushed_state = NULL;
}
void
_cogl_matrix_stack_flush_to_gl (CoglMatrixStack *stack,
GLenum gl_mode)
{
CoglMatrixState *state;
state = _cogl_matrix_stack_top (stack);
if (stack->flushed_state == state)
return;
GE (glMatrixMode (gl_mode));
/* In theory it might help the GL implementation if we used our
* local analysis of the matrix and called Translate/Scale rather
* than LoadMatrix to send a 2D matrix
*/
GE (glLoadMatrixf (cogl_matrix_get_array (&state->matrix)));
stack->flushed_state = state;
}
void
_cogl_matrix_stack_dirty (CoglMatrixStack *stack)
{
stack->flushed_state = NULL;
}