mutter/clutter/cogl/gles/cogl-fbo.c

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/*
* Cogl
*
* An object oriented GL/GLES Abstraction/Utility Layer
*
* Copyright (C) 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"
#include "cogl-gles2-wrapper.h"
#ifdef HAVE_COGL_GLES2
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( glGenRenderbuffers (1, &gl_stencil_handle) );
GE( glBindRenderbuffer (GL_RENDERBUFFER, gl_stencil_handle) );
GE( glRenderbufferStorage (GL_RENDERBUFFER, GL_STENCIL_INDEX8,
cogl_texture_get_width (texhandle),
cogl_texture_get_height (texhandle)) );
GE( glBindRenderbuffer (GL_RENDERBUFFER, 0) );
/* Generate framebuffer */
glGenFramebuffers (1, &fbo_gl_handle);
GE( glBindFramebuffer (GL_FRAMEBUFFER, fbo_gl_handle) );
GE( glFramebufferTexture2D (GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0,
tex->gl_target, tex_gl_handle, 0) );
GE( glFramebufferRenderbuffer (GL_FRAMEBUFFER,
GL_STENCIL_ATTACHMENT,
GL_RENDERBUFFER, gl_stencil_handle) );
/* Make sure it's complete */
status = glCheckFramebufferStatus (GL_FRAMEBUFFER);
if (status != GL_FRAMEBUFFER_COMPLETE)
{
/* Stencil renderbuffers aren't always supported. Try again
without the stencil buffer */
GE( glFramebufferRenderbuffer (GL_FRAMEBUFFER,
GL_STENCIL_ATTACHMENT,
GL_RENDERBUFFER,
0) );
GE( glDeleteRenderbuffers (1, &gl_stencil_handle) );
gl_stencil_handle = 0;
status = glCheckFramebufferStatus (GL_FRAMEBUFFER);
if (status != GL_FRAMEBUFFER_COMPLETE)
{
/* Still failing, so give up */
GE( glDeleteFramebuffers (1, &fbo_gl_handle) );
GE( glBindFramebuffer (GL_FRAMEBUFFER, 0) );
return COGL_INVALID_HANDLE;
}
}
GE( glBindFramebuffer (GL_FRAMEBUFFER, 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( glDeleteRenderbuffers (1, &fbo->gl_stencil_handle) );
GE( glDeleteFramebuffers (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);
g_assert (ctx->draw_buffer_stack != NULL);
draw_buffer = ctx->draw_buffer_stack->data;
if (target == COGL_OFFSCREEN_BUFFER)
{
GLboolean scissor_enabled;
GLint scissor_box[4];
/* 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( glGetIntegerv (GL_VIEWPORT, ctx->viewport_store) );
_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 */
GE( glViewport (0, 0, 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( glBindFramebuffer (GL_FRAMEBUFFER, 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 */
scissor_enabled = glIsEnabled (GL_SCISSOR_TEST);
GE( glGetIntegerv (GL_SCISSOR_BOX, scissor_box) );
GE( glScissor (0, 0, 0, 0) );
GE( glEnable (GL_SCISSOR_TEST) );
GE( glClear (GL_COLOR_BUFFER_BIT) );
if (!scissor_enabled)
glDisable (GL_SCISSOR_TEST);
glScissor (scissor_box[0], scissor_box[1],
scissor_box[2], scissor_box[3]);
}
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( glViewport (ctx->viewport_store[0], ctx->viewport_store[1],
ctx->viewport_store[2], ctx->viewport_store[3]) );
_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( glBindFramebuffer (GL_FRAMEBUFFER, 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);
}
#else /* HAVE_COGL_GLES2 */
/* No support on regular OpenGL 1.1 */
gboolean
cogl_is_offscreen (CoglHandle handle)
{
return FALSE;
}
CoglHandle
cogl_offscreen_new_to_texture (CoglHandle texhandle)
{
return COGL_INVALID_HANDLE;
}
CoglHandle
cogl_offscreen_ref (CoglHandle handle)
{
return COGL_INVALID_HANDLE;
}
void
cogl_offscreen_unref (CoglHandle handle)
{
}
void
cogl_set_draw_buffer (CoglBufferTarget target, CoglHandle offscreen)
{
}
#endif /* HAVE_COGL_GLES2 */