Allow bits to be NULL when bit images are created

diff --git a/pixman/pixman-image.c b/pixman/pixman-image.c
index a719f3a8dde38cc3d873880f6b81ad9ed4a87ce6..e6d366a1af2decf678998bdb87bc37f7dffc2cf0 100644 (file)
--- a/pixman/pixman-image.c
+++ b/pixman/pixman-image.c
@@ -263,6 +263,26 @@ pixman_image_create_conical_gradient (pixman_point_fixed_t *center,
     return image;
 }
 
+static uint32_t *
+create_bits (pixman_format_code_t format,
+            int                  width,
+            int                  height,
+            int                 *rowstride_bytes)
+{
+    int stride;
+    int buf_size;
+    int bpp;
+    
+    bpp = PIXMAN_FORMAT_BPP (format);
+    stride = ((width * bpp + FB_MASK) >> FB_SHIFT) * sizeof (uint32_t);
+    buf_size = height * stride;
+
+    if (rowstride_bytes)
+       *rowstride_bytes = stride;
+    
+    return calloc (buf_size, 1);
+}
+
 pixman_image_t *
 pixman_image_create_bits (pixman_format_code_t  format,
                          int                   width,
@@ -276,6 +296,13 @@ pixman_image_create_bits (pixman_format_code_t  format,
      */
     return_val_if_fail ((rowstride_bytes % sizeof (uint32_t)) == 0, NULL); 
 
+    if (!bits)
+    {
+       bits = create_bits (format, width, height, &rowstride_bytes);
+       if (!bits)
+           return NULL;
+    }
+    
     image = allocate_image();
 
     if (!image)