[debug] Adds a COGL_DEBUG=matrices debug option

This adds a COGL_DEBUG=matrices debug option that can be used to trace all
matrix manipulation done using the Cogl API.  This can be handy when you
break something in such a way that a trace is still comparable with a
previous working version since you can simply diff a log of the broken
version vs the working version to home in on the bug.

clutter/cogl/cogl/cogl-debug.c

@@ -46,7 +46,8 @@ static const GDebugKey cogl_debug_keys[] = {
   { "disable-vbos", COGL_DEBUG_DISABLE_VBOS },
   { "journal", COGL_DEBUG_JOURNAL },
   { "batching", COGL_DEBUG_BATCHING },
-  { "disable-software-transform", COGL_DEBUG_DISABLE_SOFTWARE_TRANSFORM }
+  { "disable-software-transform", COGL_DEBUG_DISABLE_SOFTWARE_TRANSFORM },
+  { "matrices", COGL_DEBUG_MATRICES }
 };
 
 static const gint n_cogl_debug_keys = G_N_ELEMENTS (cogl_debug_keys);

clutter/cogl/cogl/cogl-debug.h

@@ -44,7 +44,8 @@ typedef enum {
   COGL_DEBUG_DISABLE_VBOS     = 1 << 12,
   COGL_DEBUG_JOURNAL          = 1 << 13,
   COGL_DEBUG_BATCHING         = 1 << 14,
-  COGL_DEBUG_DISABLE_SOFTWARE_TRANSFORM = 1 << 15
+  COGL_DEBUG_DISABLE_SOFTWARE_TRANSFORM = 1 << 15,
+  COGL_DEBUG_MATRICES = 1 << 16
 } CoglDebugFlags;
 
 #ifdef COGL_ENABLE_DEBUG

clutter/cogl/cogl/cogl-matrix-private.h

@@ -0,0 +1,47 @@
+/*
+ * 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.
+ *
+ * Authors:
+ *   Robert Bragg <robert@linux.intel.com>
+ */
+
+#ifndef __COGL_MATRIX_PRIVATE_H
+#define __COGL_MATRIX_PRIVATE_H
+
+#include <glib.h>
+
+G_BEGIN_DECLS
+
+#define _COGL_MATRIX_DEBUG_PRINT(MATRIX) \
+  if (G_UNLIKELY (cogl_debug_flags & COGL_DEBUG_MATRICES)) \
+    { \
+      g_print ("%s:\n", G_STRFUNC); \
+      _cogl_matrix_print (MATRIX); \
+    }
+
+void
+_cogl_matrix_print (CoglMatrix *matrix);
+
+G_END_DECLS
+
+#endif /* __COGL_MATRIX_PRIVATE_H */
+

clutter/cogl/cogl/cogl-matrix.c

@@ -28,6 +28,7 @@
 
 #include <cogl.h>
 #include <cogl-matrix.h>
+#include <cogl-matrix-private.h>
 #ifdef USE_MESA_MATRIX_API
 #include <cogl-matrix-mesa.h>
 #endif
@@ -36,6 +37,16 @@
 #include <math.h>
 #include <string.h>
 
+void
+_cogl_matrix_print (CoglMatrix *matrix)
+{
+  float *m = (float *)matrix;
+  int y;
+
+  for (y = 0; y < 4; y++)
+    g_print ("\t%6.4f %6.4f %6.4f %6.4f\n", m[y], m[4+y], m[8+y], m[12+y]);
+}
+
 void
 cogl_matrix_init_identity (CoglMatrix *matrix)
 {
@@ -47,6 +58,7 @@ cogl_matrix_init_identity (CoglMatrix *matrix)
 #else
   _math_matrix_init_identity (matrix);
 #endif
+  _COGL_MATRIX_DEBUG_PRINT (matrix);
 }
 
 void
@@ -90,6 +102,7 @@ cogl_matrix_multiply (CoglMatrix *result,
 #else
   _math_matrix_multiply (result, a, b);
 #endif
+  _COGL_MATRIX_DEBUG_PRINT (result);
 }
 
 void
@@ -133,6 +146,7 @@ cogl_matrix_rotate (CoglMatrix *matrix,
 #else
   _math_matrix_rotate (matrix, angle, x, y, z);
 #endif
+  _COGL_MATRIX_DEBUG_PRINT (matrix);
 }
 
 void
@@ -149,6 +163,7 @@ cogl_matrix_translate (CoglMatrix *matrix,
 #else
   _math_matrix_translate (matrix, x, y, z);
 #endif
+  _COGL_MATRIX_DEBUG_PRINT (matrix);
 }
 
 void
@@ -165,6 +180,7 @@ cogl_matrix_scale (CoglMatrix *matrix,
 #else
   _math_matrix_scale (matrix, sx, sy, sz);
 #endif
+  _COGL_MATRIX_DEBUG_PRINT (matrix);
 }
 
 #if 0
@@ -223,6 +239,7 @@ cogl_matrix_frustum (CoglMatrix *matrix,
 #else
   _math_matrix_frustum (matrix, left, right, bottom, top, z_near, z_far);
 #endif
+  _COGL_MATRIX_DEBUG_PRINT (matrix);
 }
 
 void
@@ -241,6 +258,7 @@ cogl_matrix_perspective (CoglMatrix *matrix,
                        ymax,            /* top */
                        z_near,
                        z_far);
+  _COGL_MATRIX_DEBUG_PRINT (matrix);
 }
 
 void
@@ -283,6 +301,7 @@ cogl_matrix_ortho (CoglMatrix *matrix,
 #else
   _math_matrix_ortho (matrix, left, right, bottom, top, near_val, far_val);
 #endif
+  _COGL_MATRIX_DEBUG_PRINT (matrix);
 }
 
 void
@@ -293,6 +312,7 @@ cogl_matrix_init_from_array (CoglMatrix *matrix, const float *array)
 #else
   _math_matrix_init_from_array (matrix, array);
 #endif
+  _COGL_MATRIX_DEBUG_PRINT (matrix);
 }
 
 const float *

clutter/cogl/cogl/cogl.c

@@ -39,6 +39,7 @@
 #include "cogl-material-private.h"
 #include "cogl-winsys.h"
 #include "cogl-draw-buffer-private.h"
+#include "cogl-matrix-private.h"
 
 #if defined (HAVE_COGL_GLES2) || defined (HAVE_COGL_GLES)
 #include "cogl-gles2-wrapper.h"
@@ -1165,6 +1166,7 @@ cogl_get_modelview_matrix (CoglMatrix *matrix)
   CoglMatrixStack *modelview_stack =
     _cogl_draw_buffer_get_modelview_stack (_cogl_get_draw_buffer ());
   _cogl_matrix_stack_get (modelview_stack, matrix);
+  _COGL_MATRIX_DEBUG_PRINT (matrix);
 }
 
 void
@@ -1173,6 +1175,7 @@ cogl_set_modelview_matrix (CoglMatrix *matrix)
   CoglMatrixStack *modelview_stack =
     _cogl_draw_buffer_get_modelview_stack (_cogl_get_draw_buffer ());
   _cogl_matrix_stack_set (modelview_stack, matrix);
+  _COGL_MATRIX_DEBUG_PRINT (matrix);
 }
 
 void
@@ -1181,6 +1184,7 @@ cogl_get_projection_matrix (CoglMatrix *matrix)
   CoglMatrixStack *projection_stack =
     _cogl_draw_buffer_get_projection_stack (_cogl_get_draw_buffer ());
   _cogl_matrix_stack_get (projection_stack, matrix);
+  _COGL_MATRIX_DEBUG_PRINT (matrix);
 }
 
 void
@@ -1192,6 +1196,7 @@ cogl_set_projection_matrix (CoglMatrix *matrix)
 
   /* FIXME: Update the inverse projection matrix!! Presumably use
    * of clip planes must currently be broken if this API is used. */
+  _COGL_MATRIX_DEBUG_PRINT (matrix);
 }
 
 CoglClipStackState *