done with imperative shell/ffi aspect of sending KEY_ESC to update thread when that action has occurred

ffi/export.h

@@ -159,6 +159,7 @@ extern "C" {
 
 MLLIB_PUBLIC(void mltonFramebufferSizeCallback (Int32 x0, Int32 x1);)
 MLLIB_PUBLIC(void mltonCharCallback (Word32 x0);)
+MLLIB_PUBLIC(void mltonKeyCallback (Int32 x0, Int32 x1, Int32 x2, Int32 x3);)
 
 #undef MLLIB_PRIVATE
 #undef MLLIB_PUBLIC

ffi/glfw-input.c

@@ -6,6 +6,7 @@
 int PRESS = GLFW_PRESS;
 int REPEAT = GLFW_REPEAT;
 int RELEASE = GLFW_RELEASE;
+int KEY_ESC = GLFW_KEY_ESCAPE;
 
 void framebufferSizeCallback(GLFWwindow* window, int width, int height) {
   glViewport(0, 0, width, height);
@@ -24,3 +25,11 @@ void setCharCallback(GLFWwindow* window) {
   glfwSetCharCallback(window, charCallback);
 }
 
+void keyCallback(GLFWwindow *window, int key, int scancode, int action, int mods) {
+  mltonKeyCallback(key, scancode, action, mods);
+}
+
+void setKeyCallback(GLFWwindow *window) {
+  glfwSetKeyCallback(window, keyCallback);
+}
+

ffi/glfw-input.sml

@@ -24,4 +24,13 @@ struct
     _export "mltonCharCallback" public : (Word32.word -> unit) -> unit;
   val setCharCallback =
     _import "setCharCallback" public : window -> unit;
+
+  val exportKeyCallback =
+    _export "mltonKeyCallback" public : (int * int * int * int -> unit) -> unit;
+  val setKeyCallback =
+    _import "setKeyCallback" public : window -> unit;
+
+  val (KEY_ESC, _) =
+    _symbol "KEY_ESC" public : ( unit -> int ) * ( int -> unit );
+  val KEY_ESC = KEY_ESC ()
 end