reduce number of type conversoins required for mouse move callback (and fix the other code which uses it too)

ffi/export.h

@@ -157,7 +157,7 @@ typedef Pointer Objptr;
 extern "C" {
 #endif
 
-MLLIB_PUBLIC(void mltonMouseMoveCallback (Int32 x0, Int32 x1);)
+MLLIB_PUBLIC(void mltonMouseMoveCallback (Real32 x0, Real32 x1);)
 MLLIB_PUBLIC(void mltonMouseClickCallback (Int32 x0, Int32 x1);)
 
 #undef MLLIB_PRIVATE

ffi/glfw-input.c

@@ -7,7 +7,7 @@ int LEFT_MOUSE_BUTTON = GLFW_MOUSE_BUTTON_1;
 
 // Calls function exported from SML 
 void mouseMoveCallback(GLFWwindow *window, double xpos, double ypos) {
-  mltonMouseMoveCallback((int)xpos, (int)ypos);
+  mltonMouseMoveCallback((float)xpos, (float)ypos);
 }
 
 void mouseClickCallback(GLFWwindow *window, int button, int action, int mods) {

ffi/glfw-input.sml

@@ -4,7 +4,7 @@ struct
 
   (* Export function to C. *)
   val exportMouseMoveCallback =
-    _export "mltonMouseMoveCallback" public : (int * int -> unit) -> unit;
+    _export "mltonMouseMoveCallback" public : (Real32.real * Real32.real -> unit) -> unit;
 
   (* Import function to set callback for GLFW. *)
   val setMouseMoveCallback = _import "setMouseMoveCallback" public reentrant : window -> unit;

functional-core/app-update.sml

@@ -90,7 +90,7 @@ struct
      *)
     fun getClickPos (mouseX, mouseY, r, g, b) =
       getHorizontalClickPos
-        (0, Real32.fromInt mouseX, Real32.fromInt mouseY, r, g, b)
+        (0, mouseX, mouseY, r, g, b)
   end
 
   fun getFirstTriangleStageVector (x1, y1, drawVec) =

imperative-shell/event-loop.sml

@@ -15,7 +15,7 @@ struct
       end
   in
     fun update (inputMailbox, drawMailbox) =
-      loop (inputMailbox, drawMailbox, 0, 0, AppType.initial)
+      loop (inputMailbox, drawMailbox, 0.0, 0.0, AppType.initial)
   end
 
   fun draw

message-types/input-msg.sml

@@ -1,7 +1,7 @@
 signature INPUT_MESSAGE =
 sig
   datatype t =
-    MOUSE_MOVE of {x: int, y: int}
+    MOUSE_MOVE of {x: Real32.real, y: Real32.real}
   | MOUSE_LEFT_CLICK
   | MOUSE_LEFT_RELEASE
 end
@@ -9,7 +9,7 @@ end
 structure InputMessage :> INPUT_MESSAGE =
 struct
   datatype t =
-    MOUSE_MOVE of {x: int, y: int}
+    MOUSE_MOVE of {x: Real32.real, y: Real32.real}
   | MOUSE_LEFT_CLICK
   | MOUSE_LEFT_RELEASE
 end