render: sprite: Fix sprite batch resizing.

* chickadee/render/sprite.scm (double-sprite-batch-size!): Get
  reference to bytevectors before unmapping old buffers.

1 files changed, 11 insertions, 8 deletions

diff --git a/chickadee/render/sprite.scm b/chickadee/render/sprite.scm
index 1291687..5c4ecb4 100644
--- a/chickadee/render/sprite.scm
+++ b/chickadee/render/sprite.scm
@@ -174,9 +174,12 @@ void main (void) {
   (= (sprite-batch-capacity batch) (sprite-batch-size batch)))
 
 (define (double-sprite-batch-size! batch)
-  (let ((old-index (sprite-batch-index-buffer batch))
-        (old-verts (sprite-batch-position-buffer batch))
-        (old-tex (sprite-batch-texture-buffer batch)))
+  (let* ((old-index (sprite-batch-index-buffer batch))
+         (old-verts (sprite-batch-position-buffer batch))
+         (old-tex (sprite-batch-texture-buffer batch))
+         (old-index-data (typed-buffer-data old-index))
+         (old-verts-data (typed-buffer-data old-verts))
+         (old-tex-data (typed-buffer-data old-tex)))
     (unmap-typed-buffer! old-index)
     (unmap-typed-buffer! old-verts)
     (unmap-typed-buffer! old-tex)
@@ -186,12 +189,12 @@ void main (void) {
           (new-verts (sprite-batch-position-buffer batch))
           (new-tex (sprite-batch-texture-buffer batch)))
       (define (copy from to)
-        (bytevector-copy! (typed-buffer-data from) 0
+        (bytevector-copy! from 0
                           (typed-buffer-data to) 0
-                          (bytevector-length (typed-buffer-data from))))
-      (copy old-index new-index)
-      (copy old-verts new-verts)
-      (copy old-tex new-tex))))
+                          (bytevector-length from)))
+      (copy old-index-data new-index)
+      (copy old-verts-data new-verts)
+      (copy old-tex-data new-tex))))
 
 (define (sprite-batch-reset! batch)
   "Reset BATCH to size 0."