From 3fa91efea84c2c442fcc92e8ed0df711d7e67988 Mon Sep 17 00:00:00 2001
From: Neil Roberts <neil@linux.intel.com>
Date: Wed, 10 Nov 2010 14:02:31 +0000
Subject: [PATCH] Add a COGL_DEBUG option to disable software clipping

This adds a debug option called disable-software-clipping which causes
the journal to always log the clip stack state rather than trying to
manually clip rectangles.
---
 clutter/cogl/cogl/cogl-debug-options.h |  5 +++++
 clutter/cogl/cogl/cogl-debug.c         |  3 ++-
 clutter/cogl/cogl/cogl-debug.h         |  3 ++-
 clutter/cogl/cogl/cogl-journal.c       | 23 +++++++++++++----------
 4 files changed, 22 insertions(+), 12 deletions(-)

diff --git a/clutter/cogl/cogl/cogl-debug-options.h b/clutter/cogl/cogl/cogl-debug-options.h
index f1536020f..c93c301f3 100644
--- a/clutter/cogl/cogl/cogl-debug-options.h
+++ b/clutter/cogl/cogl/cogl-debug-options.h
@@ -143,6 +143,11 @@ OPT (DISABLE_NPOT_TEXTURES,
      "Disable non-power-of-two textures",
      "Makes Cogl think that the GL driver doesn't support NPOT textures "
      "so that it will create sliced textures or textures with waste instead.")
+OPT (DISABLE_SOFTWARE_CLIP,
+     "Root Cause",
+     "disable-software-clip",
+     "Disable software clipping",
+     "Disables Cogl's attempts to clip some rectangles in software.")
 OPT (SHOW_SOURCE,
      "Cogl Tracing",
      "show-source",
diff --git a/clutter/cogl/cogl/cogl-debug.c b/clutter/cogl/cogl/cogl-debug.c
index 34351d9e9..5cfa8339e 100644
--- a/clutter/cogl/cogl/cogl-debug.c
+++ b/clutter/cogl/cogl/cogl-debug.c
@@ -72,7 +72,8 @@ static const GDebugKey cogl_behavioural_debug_keys[] = {
   { "disable-glsl", COGL_DEBUG_DISABLE_GLSL},
   { "disable-blending", COGL_DEBUG_DISABLE_BLENDING},
   { "disable-npot-textures", COGL_DEBUG_DISABLE_NPOT_TEXTURES},
-  { "wireframe", COGL_DEBUG_WIREFRAME}
+  { "wireframe", COGL_DEBUG_WIREFRAME},
+  { "disable-software-clip", COGL_DEBUG_DISABLE_SOFTWARE_CLIP}
 };
 static const int n_cogl_behavioural_debug_keys =
   G_N_ELEMENTS (cogl_behavioural_debug_keys);
diff --git a/clutter/cogl/cogl/cogl-debug.h b/clutter/cogl/cogl/cogl-debug.h
index 6c9aee58f..4c49d7381 100644
--- a/clutter/cogl/cogl/cogl-debug.h
+++ b/clutter/cogl/cogl/cogl-debug.h
@@ -58,7 +58,8 @@ typedef enum {
   COGL_DEBUG_TEXTURE_PIXMAP   = 1 << 25,
   COGL_DEBUG_BITMAP           = 1 << 26,
   COGL_DEBUG_DISABLE_NPOT_TEXTURES = 1 << 27,
-  COGL_DEBUG_WIREFRAME        = 1 << 28
+  COGL_DEBUG_WIREFRAME        = 1 << 28,
+  COGL_DEBUG_DISABLE_SOFTWARE_CLIP = 1 << 29
 } CoglDebugFlags;
 
 #ifdef COGL_ENABLE_DEBUG
diff --git a/clutter/cogl/cogl/cogl-journal.c b/clutter/cogl/cogl/cogl-journal.c
index 210043b25..6a78d27bb 100644
--- a/clutter/cogl/cogl/cogl-journal.c
+++ b/clutter/cogl/cogl/cogl-journal.c
@@ -1155,16 +1155,19 @@ _cogl_journal_flush (void)
   state.modelview_stack = modelview_stack;
   state.projection_stack = _cogl_framebuffer_get_projection_stack (framebuffer);
 
-  /* We do an initial walk of the journal to analyse the clip stack
-     batches to see if we can do software clipping. We do this as a
-     separate walk of the journal because we can modify entries and
-     this may end up joining together clip stack batches in the next
-     iteration. */
-  batch_and_call ((CoglJournalEntry *)ctx->journal->data, /* first entry */
-                  ctx->journal->len, /* max number of entries to consider */
-                  compare_entry_clip_stacks,
-                  _cogl_journal_check_software_clip, /* callback */
-                  &state); /* data */
+  if (G_UNLIKELY ((cogl_debug_flags & COGL_DEBUG_DISABLE_SOFTWARE_CLIP) == 0))
+    {
+      /* We do an initial walk of the journal to analyse the clip stack
+         batches to see if we can do software clipping. We do this as a
+         separate walk of the journal because we can modify entries and
+         this may end up joining together clip stack batches in the next
+         iteration. */
+      batch_and_call ((CoglJournalEntry *)ctx->journal->data, /* first entry */
+                      ctx->journal->len, /* max number of entries to consider */
+                      compare_entry_clip_stacks,
+                      _cogl_journal_check_software_clip, /* callback */
+                      &state); /* data */
+    }
 
   /* We upload the vertices after the clip stack pass in case it
      modifies the entries */