render: shader: Convert camel case uniform names to lispy snake case.

1 files changed, 11 insertions, 1 deletions

diff --git a/chickadee/render/shader.scm b/chickadee/render/shader.scm
index 9d5bc51..5442097 100644
--- a/chickadee/render/shader.scm
+++ b/chickadee/render/shader.scm
@@ -532,13 +532,23 @@ them into a GPU shader program."
      ((= type (version-2-0 sampler-2d)) sampler-2d)
      (else
       (error "unsupported OpenGL type" type))))
+  (define (camel->snake str)
+    (list->string
+     (let loop ((i 0))
+       (if (< i (string-length str))
+           (let ((c (string-ref str i)))
+             (if (char-set-contains? char-set:upper-case c)
+                 (cons* #\- (char-downcase c) (loop (+ i 1)))
+                 (cons c (loop (+ i 1)))))
+           '()))))
   (define (uniform-name->symbol name)
     ;; array uniform names have a suffix like "[0]" that needs to be
     ;; removed to produce the actual uniform variable name that our
     ;; shader interface will recognize.
     (string->symbol
      (let ((i (string-contains name "[")))
-       (if i (substring name 0 i) name))))
+       (camel->snake
+        (if i (substring name 0 i) name)))))
   (define (parse-array-index name)
     (let* ((start (string-contains name "["))
            (end (- (string-length name) 1)))