From e47b19822510344e4cae854e99a5ef0a76304980 Mon Sep 17 00:00:00 2001
From: Havoc Pennington <hp@pobox.com>
Date: Thu, 19 Feb 2009 22:37:08 -0500
Subject: [PATCH] add cogl_push_draw_buffer() and cogl_pop_draw_buffer()
These are necessary if nesting redirections to an fbo,
otherwise there's no way to know how to restore
previous state.
glPushAttrib(GL_COLOR_BUFFER_BIT) would save draw buffer
state, but also saves a lot of other stuff, and
cogl_draw_buffer() relies on knowing about all draw
buffer state changes. So we have to implement a
draw buffer stack ourselves.
Signed-off-by: Robert Bragg <robert@linux.intel.com>
---
clutter/cogl/cogl-offscreen.h | 14 ++++++
clutter/cogl/gl/cogl-context.c | 7 ++-
clutter/cogl/gl/cogl-context.h | 8 +++-
clutter/cogl/gl/cogl-fbo.c | 75 ++++++++++++++++++++++++++++++--
clutter/cogl/gles/cogl-context.c | 7 ++-
clutter/cogl/gles/cogl-context.h | 8 +++-
clutter/cogl/gles/cogl-fbo.c | 75 ++++++++++++++++++++++++++++++--
7 files changed, 184 insertions(+), 10 deletions(-)
diff --git a/clutter/cogl/cogl-offscreen.h b/clutter/cogl/cogl-offscreen.h
index 17d2e54d6..6be6cf0f2 100644
--- a/clutter/cogl/cogl-offscreen.h
+++ b/clutter/cogl/cogl-offscreen.h
@@ -128,6 +128,20 @@ void cogl_offscreen_blit_region (CoglHandle src_buffer,
void cogl_draw_buffer (CoglBufferTarget target,
CoglHandle offscreen);
+/**
+ * cogl_push_draw_buffer:
+ *
+ * Save cogl_draw_buffer() state.
+ */
+void cogl_push_draw_buffer (void);
+
+/**
+ * cogl_pop_draw_buffer:
+ *
+ * Restore cogl_draw_buffer() state.
+ */
+void cogl_pop_draw_buffer (void);
+
G_END_DECLS
#endif /* __COGL_OFFSCREEN_H__ */
diff --git a/clutter/cogl/gl/cogl-context.c b/clutter/cogl/gl/cogl-context.c
index 7f757f45e..986da8aa8 100644
--- a/clutter/cogl/gl/cogl-context.c
+++ b/clutter/cogl/gl/cogl-context.c
@@ -42,6 +42,7 @@ cogl_create_context ()
{
GLubyte default_texture_data[] = { 0xff, 0xff, 0xff, 0x0 };
gulong enable_flags = 0;
+ CoglDrawBufferState *draw_buffer;
if (_context != NULL)
return FALSE;
@@ -78,7 +79,11 @@ cogl_create_context ()
sizeof (CoglLayerInfo));
_context->n_texcoord_arrays_enabled = 0;
- _context->draw_buffer = COGL_WINDOW_BUFFER;
+ draw_buffer = g_slice_new0 (CoglDrawBufferState);
+ draw_buffer->target = COGL_WINDOW_BUFFER;
+ draw_buffer->offscreen = COGL_INVALID_HANDLE;
+ _context->draw_buffer_stack =
+ g_slist_prepend (NULL, draw_buffer);
_context->path_nodes = g_array_new (FALSE, FALSE, sizeof (CoglPathNode));
_context->last_path = 0;
diff --git a/clutter/cogl/gl/cogl-context.h b/clutter/cogl/gl/cogl-context.h
index 602240793..2660ed812 100644
--- a/clutter/cogl/gl/cogl-context.h
+++ b/clutter/cogl/gl/cogl-context.h
@@ -36,6 +36,12 @@ typedef struct
GLubyte c[4];
} CoglTextureGLVertex;
+typedef struct
+{
+ CoglBufferTarget target;
+ CoglHandle offscreen;
+} CoglDrawBufferState;
+
typedef struct
{
/* Features cache */
@@ -82,7 +88,7 @@ typedef struct
guint n_texcoord_arrays_enabled;
/* Framebuffer objects */
- CoglBufferTarget draw_buffer;
+ GSList *draw_buffer_stack;
/* Clip stack */
CoglClipStackState clip;
diff --git a/clutter/cogl/gl/cogl-fbo.c b/clutter/cogl/gl/cogl-fbo.c
index ce703d9a6..a5f6e22fd 100644
--- a/clutter/cogl/gl/cogl-fbo.c
+++ b/clutter/cogl/gl/cogl-fbo.c
@@ -242,9 +242,13 @@ void
cogl_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)
{
/* Make sure it is a valid fbo handle */
@@ -254,7 +258,7 @@ cogl_draw_buffer (CoglBufferTarget target, CoglHandle offscreen)
fbo = _cogl_offscreen_pointer_from_handle (offscreen);
/* Check current draw buffer target */
- if (ctx->draw_buffer != COGL_OFFSCREEN_BUFFER)
+ if (draw_buffer->target != COGL_OFFSCREEN_BUFFER)
{
/* Push the viewport and matrix setup if redirecting
from a non-screen buffer */
@@ -303,7 +307,7 @@ cogl_draw_buffer (CoglBufferTarget target, CoglHandle offscreen)
(target & COGL_MASK_BUFFER))
{
/* Check current draw buffer target */
- if (ctx->draw_buffer == COGL_OFFSCREEN_BUFFER)
+ if (draw_buffer->target == COGL_OFFSCREEN_BUFFER)
{
/* Pop viewport and matrices if redirecting back
from an offscreen buffer */
@@ -338,5 +342,70 @@ cogl_draw_buffer (CoglBufferTarget target, CoglHandle offscreen)
}
/* Store new target */
- ctx->draw_buffer = 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_draw_buffer() only works if
+ * to_pop is still on top of the stack, because
+ * cogl_draw_buffer() needs to know the previous
+ * state.
+ */
+ cogl_draw_buffer (to_restore->target, to_restore->offscreen);
+
+ /* cogl_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);
}
diff --git a/clutter/cogl/gles/cogl-context.c b/clutter/cogl/gles/cogl-context.c
index c5bc2e3c6..d70d59d35 100644
--- a/clutter/cogl/gles/cogl-context.c
+++ b/clutter/cogl/gles/cogl-context.c
@@ -44,6 +44,7 @@ cogl_create_context ()
{
GLubyte default_texture_data[] = { 0xff, 0xff, 0xff, 0x0 };
gulong enable_flags = 0;
+ CoglDrawBufferState *draw_buffer;
if (_context != NULL)
return FALSE;
@@ -81,7 +82,11 @@ cogl_create_context ()
sizeof (CoglLayerInfo));
_context->n_texcoord_arrays_enabled = 0;
- _context->draw_buffer = COGL_WINDOW_BUFFER;
+ draw_buffer = g_slice_new0 (CoglDrawBufferState);
+ draw_buffer->target = COGL_WINDOW_BUFFER;
+ draw_buffer->offscreen = COGL_INVALID_HANDLE;
+ _context->draw_buffer_stack =
+ g_slist_prepend (NULL, draw_buffer);
_context->path_nodes = g_array_new (FALSE, FALSE, sizeof (CoglPathNode));
_context->last_path = 0;
diff --git a/clutter/cogl/gles/cogl-context.h b/clutter/cogl/gles/cogl-context.h
index 994b100ff..3542e038d 100644
--- a/clutter/cogl/gles/cogl-context.h
+++ b/clutter/cogl/gles/cogl-context.h
@@ -38,6 +38,12 @@ typedef struct
GLubyte c[4];
} CoglTextureGLVertex;
+typedef struct
+{
+ CoglBufferTarget target;
+ CoglHandle offscreen;
+} CoglDrawBufferState;
+
typedef struct
{
/* Features cache */
@@ -84,7 +90,7 @@ typedef struct
guint n_texcoord_arrays_enabled;
/* Framebuffer objects */
- CoglBufferTarget draw_buffer;
+ GSList *draw_buffer_stack;
/* Clip stack */
CoglClipStackState clip;
diff --git a/clutter/cogl/gles/cogl-fbo.c b/clutter/cogl/gles/cogl-fbo.c
index 6f2aef569..2b8aa46fa 100644
--- a/clutter/cogl/gles/cogl-fbo.c
+++ b/clutter/cogl/gles/cogl-fbo.c
@@ -180,9 +180,13 @@ void
cogl_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;
@@ -195,7 +199,7 @@ cogl_draw_buffer (CoglBufferTarget target, CoglHandle offscreen)
fbo = _cogl_offscreen_pointer_from_handle (offscreen);
/* Check current draw buffer target */
- if (ctx->draw_buffer != COGL_OFFSCREEN_BUFFER)
+ if (draw_buffer->target != COGL_OFFSCREEN_BUFFER)
{
/* Push the viewport and matrix setup if redirecting
from a non-screen buffer */
@@ -249,7 +253,7 @@ cogl_draw_buffer (CoglBufferTarget target, CoglHandle offscreen)
(target & COGL_MASK_BUFFER))
{
/* Check current draw buffer target */
- if (ctx->draw_buffer == COGL_OFFSCREEN_BUFFER)
+ if (draw_buffer->target == COGL_OFFSCREEN_BUFFER)
{
/* Pop viewport and matrices if redirecting back
from an offscreen buffer */
@@ -285,7 +289,72 @@ cogl_draw_buffer (CoglBufferTarget target, CoglHandle offscreen)
}
/* Store new target */
- ctx->draw_buffer = 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_draw_buffer() only works if
+ * to_pop is still on top of the stack, because
+ * cogl_draw_buffer() needs to know the previous
+ * state.
+ */
+ cogl_draw_buffer (to_restore->target, to_restore->offscreen);
+
+ /* cogl_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 */