mutter/gl/cogl-fbo.c
Robert Bragg 82ef6b51b9 [cogl] cache the viewport width and height
This avoids some calls to glGetFloatv, which have at least proven to be very
in-efficient in mesa at this point in time, since it always updates all derived
state even when it may not relate to the state being requested.
2009-07-01 15:23:10 +01:00

319 lines
10 KiB
C

/*
* Cogl
*
* An object oriented GL/GLES Abstraction/Utility Layer
*
* Copyright (C) 2007,2008,2009 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.
*/
#ifdef HAVE_CONFIG_H
#include "config.h"
#endif
#include "cogl.h"
#include "cogl-internal.h"
#include "cogl-util.h"
#include "cogl-texture-private.h"
#include "cogl-fbo.h"
#include "cogl-context.h"
#include "cogl-handle.h"
/* Expecting EXT functions not to be defined - redirect to pointers in context */
#define glGenRenderbuffersEXT ctx->pf_glGenRenderbuffersEXT
#define glDeleteRenderbuffersEXT ctx->pf_glDeleteRenderbuffersEXT
#define glBindRenderbufferEXT ctx->pf_glBindRenderbufferEXT
#define glRenderbufferStorageEXT ctx->pf_glRenderbufferStorageEXT
#define glGenFramebuffersEXT ctx->pf_glGenFramebuffersEXT
#define glBindFramebufferEXT ctx->pf_glBindFramebufferEXT
#define glFramebufferTexture2DEXT ctx->pf_glFramebufferTexture2DEXT
#define glFramebufferRenderbufferEXT ctx->pf_glFramebufferRenderbufferEXT
#define glCheckFramebufferStatusEXT ctx->pf_glCheckFramebufferStatusEXT
#define glDeleteFramebuffersEXT ctx->pf_glDeleteFramebuffersEXT
#define glBlitFramebufferEXT ctx->pf_glBlitFramebufferEXT
#define glRenderbufferStorageMultisampleEXT ctx->pf_glRenderbufferStorageMultisampleEXT
#ifndef GL_READ_FRAMEBUFFER_EXT
#define GL_READ_FRAMEBUFFER_EXT 0x8CA8
#endif
#ifndef GL_DRAW_FRAMEBUFFER_EXT
#define GL_DRAW_FRAMEBUFFER_EXT 0x8CA9
#endif
static void _cogl_offscreen_free (CoglFbo *fbo);
COGL_HANDLE_DEFINE (Fbo, offscreen);
CoglHandle
cogl_offscreen_new_to_texture (CoglHandle texhandle)
{
CoglTexture *tex;
CoglFbo *fbo;
CoglTexSliceSpan *x_span;
CoglTexSliceSpan *y_span;
GLuint tex_gl_handle;
GLuint fbo_gl_handle;
GLuint gl_stencil_handle;
GLenum status;
_COGL_GET_CONTEXT (ctx, COGL_INVALID_HANDLE);
if (!cogl_features_available (COGL_FEATURE_OFFSCREEN))
return COGL_INVALID_HANDLE;
/* Make texhandle is a valid texture object */
if (!cogl_is_texture (texhandle))
return COGL_INVALID_HANDLE;
tex = _cogl_texture_pointer_from_handle (texhandle);
/* The texture must not be sliced */
if (tex->slice_gl_handles == NULL)
return COGL_INVALID_HANDLE;
if (tex->slice_gl_handles->len != 1)
return COGL_INVALID_HANDLE;
/* Pick the single texture slice width, height and GL id */
x_span = &g_array_index (tex->slice_x_spans, CoglTexSliceSpan, 0);
y_span = &g_array_index (tex->slice_y_spans, CoglTexSliceSpan, 0);
tex_gl_handle = g_array_index (tex->slice_gl_handles, GLuint, 0);
/* Create a renderbuffer for stenciling */
GE( glGenRenderbuffersEXT (1, &gl_stencil_handle) );
GE( glBindRenderbufferEXT (GL_RENDERBUFFER_EXT, gl_stencil_handle) );
GE( glRenderbufferStorageEXT (GL_RENDERBUFFER_EXT, GL_STENCIL_INDEX8_EXT,
cogl_texture_get_width (texhandle),
cogl_texture_get_height (texhandle)) );
GE( glBindRenderbufferEXT (GL_RENDERBUFFER_EXT, 0) );
/* Generate framebuffer */
glGenFramebuffersEXT (1, &fbo_gl_handle);
GE( glBindFramebufferEXT (GL_FRAMEBUFFER_EXT, fbo_gl_handle) );
GE( glFramebufferTexture2DEXT (GL_FRAMEBUFFER_EXT, GL_COLOR_ATTACHMENT0_EXT,
tex->gl_target, tex_gl_handle, 0) );
GE( glFramebufferRenderbufferEXT (GL_FRAMEBUFFER_EXT,
GL_STENCIL_ATTACHMENT_EXT,
GL_RENDERBUFFER_EXT, gl_stencil_handle) );
/* Make sure it's complete */
status = glCheckFramebufferStatusEXT (GL_FRAMEBUFFER_EXT);
if (status != GL_FRAMEBUFFER_COMPLETE_EXT)
{
/* Stencil renderbuffers aren't always supported. Try again
without the stencil buffer */
GE( glFramebufferRenderbufferEXT (GL_FRAMEBUFFER_EXT,
GL_STENCIL_ATTACHMENT_EXT,
GL_RENDERBUFFER_EXT,
0) );
GE( glDeleteRenderbuffersEXT (1, &gl_stencil_handle) );
gl_stencil_handle = 0;
status = glCheckFramebufferStatusEXT (GL_FRAMEBUFFER_EXT);
if (status != GL_FRAMEBUFFER_COMPLETE_EXT)
{
/* Still failing, so give up */
GE( glDeleteFramebuffersEXT (1, &fbo_gl_handle) );
GE( glBindFramebufferEXT (GL_FRAMEBUFFER_EXT, 0) );
return COGL_INVALID_HANDLE;
}
}
GE( glBindFramebufferEXT (GL_FRAMEBUFFER_EXT, 0) );
/* Allocate and init a CoglFbo object (store non-wasted size
for subsequent blits and viewport setup) */
fbo = (CoglFbo*) g_malloc (sizeof (CoglFbo));
fbo->width = x_span->size - x_span->waste;
fbo->height = y_span->size - y_span->waste;
fbo->gl_handle = fbo_gl_handle;
fbo->gl_stencil_handle = gl_stencil_handle;
return _cogl_offscreen_handle_new (fbo);
}
static void
_cogl_offscreen_free (CoglFbo *fbo)
{
_COGL_GET_CONTEXT (ctx, NO_RETVAL);
/* Frees FBO resources but its handle is not
released! Do that separately before this! */
if (fbo->gl_stencil_handle)
GE( glDeleteRenderbuffersEXT (1, &fbo->gl_stencil_handle) );
GE( glDeleteFramebuffersEXT (1, &fbo->gl_handle) );
g_free (fbo);
}
void
cogl_set_draw_buffer (CoglBufferTarget target, CoglHandle offscreen)
{
CoglFbo *fbo = NULL;
CoglDrawBufferState *draw_buffer;
_COGL_GET_CONTEXT (ctx, NO_RETVAL);
_cogl_journal_flush ();
g_assert (ctx->draw_buffer_stack != NULL);
draw_buffer = ctx->draw_buffer_stack->data;
if (target == COGL_OFFSCREEN_BUFFER)
{
/* Make sure it is a valid fbo handle */
if (!cogl_is_offscreen (offscreen))
return;
fbo = _cogl_offscreen_pointer_from_handle (offscreen);
/* Check current draw buffer target */
if (draw_buffer->target != COGL_OFFSCREEN_BUFFER)
{
/* Push the viewport and matrix setup if redirecting
from a non-screen buffer */
GE( glPushAttrib (GL_VIEWPORT_BIT) );
_cogl_set_current_matrix (COGL_MATRIX_PROJECTION);
_cogl_current_matrix_push ();
_cogl_current_matrix_identity ();
_cogl_set_current_matrix (COGL_MATRIX_MODELVIEW);
_cogl_current_matrix_push ();
_cogl_current_matrix_identity ();
}
else
{
/* Override viewport and matrix setup if redirecting
from another offscreen buffer */
_cogl_set_current_matrix (COGL_MATRIX_PROJECTION);
_cogl_current_matrix_identity ();
_cogl_set_current_matrix (COGL_MATRIX_MODELVIEW);
_cogl_current_matrix_identity ();
}
/* Setup new viewport and matrices */
cogl_viewport (fbo->width, fbo->height);
_cogl_current_matrix_translate (-1.0f, -1.0f, 0.0f);
_cogl_current_matrix_scale (2.0f / fbo->width, 2.0f / fbo->height, 1.0f);
/* Bind offscreen framebuffer object */
GE( glBindFramebufferEXT (GL_FRAMEBUFFER_EXT, fbo->gl_handle) );
GE( glColorMask (GL_TRUE, GL_TRUE, GL_TRUE, GL_TRUE) );
/* Some implementation require a clear before drawing
to an fbo. Luckily it is affected by scissor test. */
/* FIXME: test where exactly this is needed end whether
a glClear with 0 argument is enough */
GE( glPushAttrib (GL_SCISSOR_BIT) );
GE( glScissor (0,0,0,0) );
GE( glEnable (GL_SCISSOR_TEST) );
GE( glClear (GL_COLOR_BUFFER_BIT) );
GE( glPopAttrib () );
}
else if (target & COGL_WINDOW_BUFFER)
{
/* Check current draw buffer target */
if (draw_buffer->target == COGL_OFFSCREEN_BUFFER)
{
/* Pop viewport and matrices if redirecting back
from an offscreen buffer */
GE( glPopAttrib () );
_cogl_set_current_matrix (COGL_MATRIX_PROJECTION);
_cogl_current_matrix_pop ();
_cogl_set_current_matrix (COGL_MATRIX_MODELVIEW);
_cogl_current_matrix_pop ();
}
/* Bind window framebuffer object */
GE( glBindFramebufferEXT (GL_FRAMEBUFFER_EXT, 0) );
}
/* Store new target */
draw_buffer->target = target;
if (draw_buffer->offscreen != offscreen)
{
if (draw_buffer->offscreen != COGL_INVALID_HANDLE)
cogl_handle_unref (draw_buffer->offscreen);
if (offscreen != COGL_INVALID_HANDLE)
cogl_handle_ref (offscreen);
draw_buffer->offscreen = offscreen;
}
}
void
cogl_push_draw_buffer(void)
{
CoglDrawBufferState *old;
CoglDrawBufferState *draw_buffer;
_COGL_GET_CONTEXT (ctx, NO_RETVAL);
g_assert (ctx->draw_buffer_stack != NULL);
old = ctx->draw_buffer_stack->data;
draw_buffer = g_slice_new0 (CoglDrawBufferState);
*draw_buffer = *old;
ctx->draw_buffer_stack =
g_slist_prepend (ctx->draw_buffer_stack, draw_buffer);
}
void
cogl_pop_draw_buffer(void)
{
CoglDrawBufferState *to_pop;
CoglDrawBufferState *to_restore;
_COGL_GET_CONTEXT (ctx, NO_RETVAL);
g_assert (ctx->draw_buffer_stack != NULL);
if (ctx->draw_buffer_stack->next == NULL)
{
g_warning ("1 more cogl_pop_draw_buffer() than cogl_push_draw_buffer()");
return;
}
to_pop = ctx->draw_buffer_stack->data;
to_restore = ctx->draw_buffer_stack->next->data;
/* the logic in cogl_set_draw_buffer() only works if
* to_pop is still on top of the stack, because
* cogl_set_draw_buffer() needs to know the previous
* state.
*/
cogl_set_draw_buffer (to_restore->target, to_restore->offscreen);
/* cogl_set_draw_buffer() should have set top of stack
* to to_restore
*/
g_assert (to_restore->target == to_pop->target);
g_assert (to_restore->offscreen == to_pop->offscreen);
g_assert (ctx->draw_buffer_stack->data == to_pop);
ctx->draw_buffer_stack =
g_slist_remove_link (ctx->draw_buffer_stack,
ctx->draw_buffer_stack);
g_slice_free (CoglDrawBufferState, to_pop);
}