[Pixman] [PATCH 1/2] pixman_composite_trapezoids(): Factor out extents computation

[Søren Sandmann]

From: Søren Sandmann Pedersen <ssp at redhat.com>

The computation of the extents rectangle is moved to its own
function.
---
 pixman/pixman-trap.c |   93 ++++++++++++++++++++++++++++---------------------
 1 files changed, 53 insertions(+), 40 deletions(-)

diff --git a/pixman/pixman-trap.c b/pixman/pixman-trap.c
index 35128ee..f633738 100644
--- a/pixman/pixman-trap.c
+++ b/pixman/pixman-trap.c
@@ -387,6 +387,56 @@ pixman_rasterize_trapezoid (pixman_image_t *          image,
     }
 }
 
+static pixman_bool_t
+get_trap_extents (pixman_op_t op, const pixman_trapezoid_t *traps, int n_traps,
+		  pixman_box32_t *box)
+{
+    int i;
+
+    box->x1 = INT32_MAX;
+    box->y1 = INT32_MAX;
+    box->x2 = INT32_MIN;
+    box->y2 = INT32_MIN;
+	
+    for (i = 0; i < n_traps; ++i)
+    {
+	const pixman_trapezoid_t *trap = &(traps[i]);
+	int y1, y2;
+	    
+	if (!pixman_trapezoid_valid (trap))
+	    continue;
+	    
+	y1 = pixman_fixed_to_int (trap->top);
+	if (y1 < box->y1)
+	    box->y1 = y1;
+	    
+	y2 = pixman_fixed_to_int (pixman_fixed_ceil (trap->bottom));
+	if (y2 > box->y2)
+	    box->y2 = y2;
+	    
+#define EXTEND_MIN(x)							\
+	if (pixman_fixed_to_int ((x)) < box->x1)			\
+	    box->x1 = pixman_fixed_to_int ((x));
+#define EXTEND_MAX(x)							\
+	if (pixman_fixed_to_int (pixman_fixed_ceil ((x))) > box->x2)	\
+	    box->x2 = pixman_fixed_to_int (pixman_fixed_ceil ((x)));
+	    
+#define EXTEND(x)							\
+	EXTEND_MIN(x);							\
+	EXTEND_MAX(x);
+	    
+	EXTEND(trap->left.p1.x);
+	EXTEND(trap->left.p2.x);
+	EXTEND(trap->right.p1.x);
+	EXTEND(trap->right.p2.x);
+    }
+	
+    if (box->x1 >= box->x2 || box->y1 >= box->y2)
+	return FALSE;
+
+    return TRUE;
+}
+
 /*
  * pixman_composite_trapezoids()
  *
@@ -439,46 +489,9 @@ pixman_composite_trapezoids (pixman_op_t		op,
     {
 	pixman_image_t *tmp;
 	pixman_box32_t box;
-	
-	box.x1 = INT32_MAX;
-	box.y1 = INT32_MAX;
-	box.x2 = INT32_MIN;
-	box.y2 = INT32_MIN;
-	
-	for (i = 0; i < n_traps; ++i)
-	{
-	    const pixman_trapezoid_t *trap = &(traps[i]);
-	    int y1, y2;
-	    
-	    if (!pixman_trapezoid_valid (trap))
-		continue;
-	    
-	    y1 = pixman_fixed_to_int (trap->top);
-	    if (y1 < box.y1)
-		box.y1 = y1;
-	    
-	    y2 = pixman_fixed_to_int (pixman_fixed_ceil (trap->bottom));
-	    if (y2 > box.y2)
-		box.y2 = y2;
-	    
-#define EXTEND_MIN(x)							\
-	    if (pixman_fixed_to_int ((x)) < box.x1)			\
-		box.x1 = pixman_fixed_to_int ((x));
-#define EXTEND_MAX(x)							\
-	    if (pixman_fixed_to_int (pixman_fixed_ceil ((x))) > box.x2)	\
-		box.x2 = pixman_fixed_to_int (pixman_fixed_ceil ((x)));
-	    
-#define EXTEND(x)							\
-	    EXTEND_MIN(x);						\
-	    EXTEND_MAX(x);
-	    
-	    EXTEND(trap->left.p1.x);
-	    EXTEND(trap->left.p2.x);
-	    EXTEND(trap->right.p1.x);
-	    EXTEND(trap->right.p2.x);
-	}
-	
-	if (box.x1 >= box.x2 || box.y1 >= box.y2)
+	int i;
+
+	if (!get_trap_extents (op, traps, n_traps, &box))
 	    return;
 	
 	tmp = pixman_image_create_bits (
-- 
1.7.4