[gegl] tests: Add test case for cow-copy pyramid handling

[Daniel Sabo <daniels src gnome org>]

commit 05b8ecf173cb41d456c01ec4f415680b378e061f
Author: Daniel Sabo <DanielSabo gmail com>
Date:   Mon Oct 7 09:10:32 2013 -0700

    tests: Add test case for cow-copy pyramid handling

 tests/simple/.gitignore                 |    3 +-
 tests/simple/Makefile.am                |    1 +
 tests/simple/test-buffer-tile-voiding.c |  182 +++++++++++++++++++++++++++++++
 3 files changed, 185 insertions(+), 1 deletions(-)
---
diff --git a/tests/simple/.gitignore b/tests/simple/.gitignore
index 675cf63..d44873f 100644
--- a/tests/simple/.gitignore
+++ b/tests/simple/.gitignore
@@ -19,4 +19,5 @@
 /test-buffer-changes
 /test-format-sensing
 /test-scaled-blit
-/test-svg-abyss
\ No newline at end of file
+/test-svg-abyss
+/test-buffer-tile-voiding
\ No newline at end of file
diff --git a/tests/simple/Makefile.am b/tests/simple/Makefile.am
index 2bf0d56..131d88b 100644
--- a/tests/simple/Makefile.am
+++ b/tests/simple/Makefile.am
@@ -16,6 +16,7 @@ noinst_PROGRAMS = \
        test-buffer-extract \
        test-buffer-cast  \
        test-buffer-changes \
+       test-buffer-tile-voiding \
        test-proxynop-processing \
        test-format-sensing \
        test-scaled-blit \
diff --git a/tests/simple/test-buffer-tile-voiding.c b/tests/simple/test-buffer-tile-voiding.c
new file mode 100644
index 0000000..01abdae
--- /dev/null
+++ b/tests/simple/test-buffer-tile-voiding.c
@@ -0,0 +1,182 @@
+/*
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program 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 General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, see <http://www.gnu.org/licenses/>.
+ *
+ * Copyright (C) 2013 Daniel Sabo
+ */
+#include "gegl.h"
+#include "gegl-buffer-backend.h"
+#include "gegl-utils.h"
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+static gboolean
+test_buffer_copy ()
+{
+  gboolean result = TRUE;
+
+  GeglBuffer *bufferA, *bufferB;
+  const Babl *format = babl_format ("Y u8");
+  const gint bpp = babl_format_get_bytes_per_pixel (format);
+  GeglColor *white = gegl_color_new("white");
+  GeglColor *black = gegl_color_new("black");
+  GeglRectangle full_extent = {0, 0, 0, 0};
+  GeglRectangle scaled_extent = {0, 0, 0, 0};
+
+  int i, j;
+
+  gint output_buffer_size;
+
+  guchar *output_buffer_a, *output_buffer_b;
+
+  bufferA = gegl_buffer_new (NULL, format);
+  bufferB = gegl_buffer_new (NULL, format);
+
+  g_object_get (bufferA,
+                "tile-width", &full_extent.width,
+                "tile-height", &full_extent.height,
+                NULL);
+
+  full_extent.width *= 2;
+  full_extent.height *= 2;
+
+  scaled_extent.width = full_extent.width / 4;
+  scaled_extent.height = full_extent.height / 4;
+
+  output_buffer_size = scaled_extent.width * scaled_extent.height * bpp;
+
+  output_buffer_a = gegl_malloc (output_buffer_size);
+  output_buffer_b   = gegl_malloc (output_buffer_size);
+
+  gegl_buffer_set_extent (bufferA, &full_extent);
+  gegl_buffer_set_extent (bufferB, &full_extent);
+
+  gegl_buffer_set_color (bufferA, NULL, white);
+  gegl_buffer_set_color (bufferB, NULL, black);
+
+  /* Assert that the buffers differ before the copy, and cause the mipmaps to generate */
+  gegl_buffer_get (bufferA,
+                   &scaled_extent,
+                   0.25,
+                   format,
+                   output_buffer_a,
+                   GEGL_AUTO_ROWSTRIDE,
+                   GEGL_ABYSS_NONE);
+
+  gegl_buffer_get (bufferB,
+                   &scaled_extent,
+                   0.25,
+                   format,
+                   output_buffer_b,
+                   GEGL_AUTO_ROWSTRIDE,
+                   GEGL_ABYSS_NONE);
+
+  if (0 == memcmp (output_buffer_a, output_buffer_b, output_buffer_size))
+    {
+      printf ("%s: buffers are already identical!\n", G_STRFUNC);
+      result = FALSE;
+    }
+
+  /* Copy-on-write copy from B to A */
+  gegl_buffer_copy (bufferA, NULL, bufferB, NULL);
+
+  /* Assert that the copy-on-write actually happened */
+  for (i = 0; i < 2; ++i)
+    for (j = 0; j < 2; ++j)
+      {
+        GeglTile *tile_a = gegl_tile_source_get_tile ((GeglTileSource *) bufferA, i, j, 0);
+        GeglTile *tile_b = gegl_tile_source_get_tile ((GeglTileSource *) bufferB, i, j, 0);
+
+        if (gegl_tile_get_data (tile_a) != gegl_tile_get_data (tile_b))
+          {
+            printf ("%s: tile %d, %d not coppied!\n", G_STRFUNC, i, j);
+            result = FALSE;
+          }
+
+        gegl_tile_unref (tile_a);
+        gegl_tile_unref (tile_b);
+      }
+
+  /* Assert the buffers are the same after the copy */
+  gegl_buffer_get (bufferA,
+                   &scaled_extent,
+                   0.25,
+                   format,
+                   output_buffer_a,
+                   GEGL_AUTO_ROWSTRIDE,
+                   GEGL_ABYSS_NONE);
+
+  gegl_buffer_get (bufferB,
+                   &scaled_extent,
+                   0.25,
+                   format,
+                   output_buffer_b,
+                   GEGL_AUTO_ROWSTRIDE,
+                   GEGL_ABYSS_NONE);
+
+  if (0 != memcmp (output_buffer_a, output_buffer_b, output_buffer_size))
+    {
+      printf ("%s: buffers don't match!\n", G_STRFUNC);
+      result = FALSE;
+    }
+
+  gegl_free (output_buffer_a);
+  gegl_free (output_buffer_b);
+
+  g_object_unref (bufferA);
+  g_object_unref (bufferB);
+  g_object_unref (white);
+  g_object_unref (black);
+
+  return result;
+}
+
+#define RUN_TEST(test_name) \
+{ \
+  if (test_name()) \
+    { \
+      printf ("" #test_name " ... PASS\n"); \
+      tests_passed++; \
+    } \
+  else \
+    { \
+      printf ("" #test_name " ... FAIL\n"); \
+      tests_failed++; \
+    } \
+  tests_run++; \
+}
+
+int main(int argc, char **argv)
+{
+  gint tests_run    = 0;
+  gint tests_passed = 0;
+  gint tests_failed = 0;
+
+  gegl_init(0, NULL);
+  g_object_set(G_OBJECT(gegl_config()),
+               "swap", "RAM",
+               "use-opencl", FALSE,
+               NULL);
+
+  RUN_TEST (test_buffer_copy)
+
+  gegl_exit();
+
+  if (tests_passed == tests_run)
+    return 0;
+  return -1;
+
+  return 0;
+}
\ No newline at end of file