render: texture: Add texture-null? procedure.

* sly/render/texture.scm (texture-null?): New procedure.

1 files changed, 5 insertions, 0 deletions

diff --git a/sly/render/texture.scm b/sly/render/texture.scm
index d9c9267..df786b6 100644
--- a/sly/render/texture.scm
+++ b/sly/render/texture.scm
@@ -39,6 +39,7 @@
             load-texture
             texture?
             texture-region?
+            texture-null?
             texture-id
             texture-parent
             texture-width
@@ -75,6 +76,10 @@
 
 (define null-texture (%make-texture 0 #f 0 0 0 0 0 0))
 
+(define (texture-null? texture)
+  "Return #t if TEXTURE is the null texture."
+  (eq? texture null-texture))
+
 (define (texture-region? texture)
   "Return #t if TEXTURE has a parent texture."
   (texture? (texture-parent texture)))