Print debug spew when given invalid trapezoids.trapdebug

1 files changed, 32 insertions, 0 deletions

diff --git a/pixman/pixman-trap.c b/pixman/pixman-trap.c
index c99f03ec..1ed75b82 100644
--- a/pixman/pixman-trap.c
+++ b/pixman/pixman-trap.c
@@ -314,6 +314,33 @@ dump_image (pixman_image_t *image,
 }
 #endif
 
+void __attribute__((__noinline__))
+print_trap (const pixman_trapezoid_t *trap)
+{
+    fprintf (stderr, "  top:      %x\n", trap->top);
+    fprintf (stderr, "  bottom:   %x\n", trap->bottom);
+    fprintf (stderr, "  left.p1:  %x, %x\n", trap->left.p1.x, trap->left.p1.y);
+    fprintf (stderr, "  left.p2:  %x, %x\n", trap->left.p2.x, trap->left.p2.y);
+    fprintf (stderr, "  right.p1: %x, %x\n", trap->right.p1.x, trap->right.p1.y);
+    fprintf (stderr, "  right.p2: %x, %x\n", trap->right.p2.x, trap->right.p2.y);
+}
+
+static void
+check_trapezoids (const pixman_trapezoid_t *traps, int n_traps)
+{
+    int i;
+
+    for (i = 0; i < n_traps; ++i)
+    {
+	const pixman_trapezoid_t *trap = &(traps[i]);
+	if (!(pixman_trapezoid_valid (trap)))
+	{
+	    fprintf (stderr, "Invalid trapezoid detected\n");
+	    print_trap (trap);
+	}
+    }
+}
+
 PIXMAN_EXPORT void
 pixman_add_trapezoids (pixman_image_t *          image,
                        int16_t                   x_off,
@@ -323,6 +350,7 @@ pixman_add_trapezoids (pixman_image_t *          image,
 {
     int i;
 
+    check_trapezoids (traps, ntraps);
 #if 0
     dump_image (image, "before");
 #endif
@@ -357,6 +385,8 @@ pixman_rasterize_trapezoid (pixman_image_t *          image,
 
     return_if_fail (image->type == BITS);
 
+    check_trapezoids (trap, 1);
+
     _pixman_image_validate (image);
     
     if (!pixman_trapezoid_valid (trap))
@@ -417,6 +447,8 @@ pixman_composite_trapezoids (pixman_op_t		op,
     if (n_traps <= 0)
 	return;
 
+    check_trapezoids (traps, n_traps);
+
     _pixman_image_validate (src);
     _pixman_image_validate (dst);