mutter/cogl/cogl-matrix-stack.c
Emmanuele Bassi 72f4ddf532 Remove mentions of the FSF address
Since using addresses that might change is something that finally
the FSF acknowledge as a plausible scenario (after changing address
twice), the license blurb in the source files should use the URI
for getting the license in case the library did not come with it.

Not that URIs cannot possibly change, but at least it's easier to
set up a redirection at the same place.

As a side note: this commit closes the oldes bug in Clutter's bug
report tool.

http://bugzilla.openedhand.com/show_bug.cgi?id=521
2010-03-01 12:56:10 +00:00

472 lines
12 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, see <http://www.gnu.org/licenses/>.
*
*
*
* Authors:
* Havoc Pennington <hp@pobox.com> for litl
* Robert Bragg <robert@linux.intel.com>
*/
#ifdef HAVE_CONFIG_H
#include "config.h"
#endif
#include "cogl.h"
#include "cogl-context.h"
#include "cogl-internal.h"
#include "cogl-matrix-stack.h"
#include "cogl-framebuffer-private.h"
typedef struct {
CoglMatrix matrix;
gboolean is_identity;
/* 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;
gboolean flushed_identity;
};
/* XXX: this doesn't initialize the matrix! */
static CoglMatrixState*
_cogl_matrix_state_new (void)
{
CoglMatrixState *state;
state = g_slice_new (CoglMatrixState);
state->push_count = 0;
state->is_identity = FALSE;
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;
}
/* XXX:
* Operations like scale, translate, rotate etc need to have an
* initialized state->matrix to work with, so they will pass
* initialize = TRUE.
*
* _cogl_matrix_stack_load_identity and _cogl_matrix_stack_set on the
* other hand don't so they will pass initialize = FALSE
*
* NB: Identity matrices are represented by setting
* state->is_identity=TRUE in which case state->matrix will be
* uninitialized.
*/
static CoglMatrixState *
_cogl_matrix_stack_top_mutable (CoglMatrixStack *stack,
gboolean initialize)
{
CoglMatrixState *state;
CoglMatrixState *new_top;
state = _cogl_matrix_stack_top (stack);
if (state->push_count == 0)
{
if (state->is_identity && initialize)
cogl_matrix_init_identity (&state->matrix);
return state;
}
state->push_count -= 1;
new_top = _cogl_matrix_state_new ();
if (initialize)
{
if (state->is_identity)
cogl_matrix_init_identity (&new_top->matrix);
else
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 ();
state->is_identity = TRUE;
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, FALSE);
/* NB: Identity matrices are represented by setting
* state->is_identity = TRUE and leaving state->matrix
* uninitialized.
*
* This is done to optimize the heavy usage of
* _cogl_matrix_stack_load_identity by the Cogl Journal.
*/
if (!state->is_identity)
{
state->is_identity = TRUE;
/* 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, TRUE);
cogl_matrix_scale (&state->matrix, x, y, z);
/* mark dirty */
stack->flushed_state = NULL;
state->is_identity = FALSE;
}
void
_cogl_matrix_stack_translate (CoglMatrixStack *stack,
float x,
float y,
float z)
{
CoglMatrixState *state;
state = _cogl_matrix_stack_top_mutable (stack, TRUE);
cogl_matrix_translate (&state->matrix, x, y, z);
/* mark dirty */
stack->flushed_state = NULL;
state->is_identity = FALSE;
}
void
_cogl_matrix_stack_rotate (CoglMatrixStack *stack,
float angle,
float x,
float y,
float z)
{
CoglMatrixState *state;
state = _cogl_matrix_stack_top_mutable (stack, TRUE);
cogl_matrix_rotate (&state->matrix, angle, x, y, z);
/* mark dirty */
stack->flushed_state = NULL;
state->is_identity = FALSE;
}
void
_cogl_matrix_stack_multiply (CoglMatrixStack *stack,
const CoglMatrix *matrix)
{
CoglMatrixState *state;
state = _cogl_matrix_stack_top_mutable (stack, TRUE);
cogl_matrix_multiply (&state->matrix, &state->matrix, matrix);
/* mark dirty */
stack->flushed_state = NULL;
state->is_identity = FALSE;
}
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, TRUE);
cogl_matrix_frustum (&state->matrix,
left, right, bottom, top,
z_near, z_far);
/* mark dirty */
stack->flushed_state = NULL;
state->is_identity = FALSE;
}
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, TRUE);
cogl_matrix_perspective (&state->matrix,
fov_y, aspect, z_near, z_far);
/* mark dirty */
stack->flushed_state = NULL;
state->is_identity = FALSE;
}
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, TRUE);
cogl_matrix_ortho (&state->matrix,
left, right, bottom, top, z_near, z_far);
/* mark dirty */
stack->flushed_state = NULL;
state->is_identity = FALSE;
}
gboolean
_cogl_matrix_stack_get_inverse (CoglMatrixStack *stack,
CoglMatrix *inverse)
{
CoglMatrixState *state;
state = _cogl_matrix_stack_top_mutable (stack, TRUE);
return cogl_matrix_get_inverse (&state->matrix, inverse);
}
void
_cogl_matrix_stack_get (CoglMatrixStack *stack,
CoglMatrix *matrix)
{
CoglMatrixState *state;
state = _cogl_matrix_stack_top (stack);
/* NB: identity matrices are lazily initialized because we can often avoid
* initializing them at all if nothing is pushed on top of them since we
* load them using glLoadIdentity()
*
* The Cogl journal typically loads an identiy matrix because it performs
* software transformations, which is why we have optimized this case.
*/
if (state->is_identity)
cogl_matrix_init_identity (matrix);
else
*matrix = state->matrix;
}
void
_cogl_matrix_stack_set (CoglMatrixStack *stack,
const CoglMatrix *matrix)
{
CoglMatrixState *state;
state = _cogl_matrix_stack_top_mutable (stack, FALSE);
state->matrix = *matrix;
/* mark dirty */
stack->flushed_state = NULL;
state->is_identity = FALSE;
}
void
_cogl_matrix_stack_flush_to_gl (CoglMatrixStack *stack,
CoglMatrixMode mode)
{
CoglMatrixState *state;
_COGL_GET_CONTEXT (ctx, NO_RETVAL);
state = _cogl_matrix_stack_top (stack);
if (stack->flushed_state == state)
return;
if (ctx->flushed_matrix_mode != mode)
{
GLenum gl_mode = 0;
switch (mode)
{
case COGL_MATRIX_MODELVIEW:
gl_mode = GL_MODELVIEW;
break;
case COGL_MATRIX_PROJECTION:
gl_mode = GL_PROJECTION;
break;
case COGL_MATRIX_TEXTURE:
gl_mode = GL_TEXTURE;
break;
}
GE (glMatrixMode (gl_mode));
ctx->flushed_matrix_mode = mode;
}
/* 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.
*/
if (mode == COGL_MATRIX_PROJECTION &&
cogl_is_offscreen (_cogl_get_framebuffer ()))
{
CoglMatrix flipped_projection;
CoglMatrix *projection =
state->is_identity ? &ctx->identity_matrix : &state->matrix;
cogl_matrix_multiply (&flipped_projection,
&ctx->y_flip_matrix, projection);
GE (glLoadMatrixf (cogl_matrix_get_array (&flipped_projection)));
stack->flushed_identity = FALSE;
}
else
{
if (state->is_identity)
{
if (!stack->flushed_identity)
GE (glLoadIdentity ());
stack->flushed_identity = TRUE;
}
else
{
GE (glLoadMatrixf (cogl_matrix_get_array (&state->matrix)));
stack->flushed_identity = FALSE;
}
}
stack->flushed_state = state;
}
void
_cogl_matrix_stack_dirty (CoglMatrixStack *stack)
{
stack->flushed_state = NULL;
stack->flushed_identity = FALSE;
}