functional text display

perfgraph.ml

@@ -0,0 +1,87 @@
+module NVG = Graphv_gles2_native
+
+type style = FPS | Ms | Percent
+
+type t = {
+  style : style;
+  name : string;
+  values : float array;
+  mutable head : int;
+  mutable last : float;
+}
+
+let init style name =
+  { name; style; values = Array.make 100 0.; head = 0; last = 0. }
+
+let average t =
+  let avg = ref 0. in
+  for i = 0 to Array.length t.values - 1 do
+    avg := !avg +. t.values.(i)
+  done;
+  !avg /. float (Array.length t.values)
+
+let update t dt =
+  t.head <- (t.head + 1) mod Array.length t.values;
+  t.values.(t.head) <- dt
+(*
+    t.last <- t.last +. dt;
+    if t.last > 1. then (
+        t.last <- 0.;
+        Printf.printf "FPS %.2f\n%!" (1. /. average t);
+    )
+    *)
+
+let render t (vg : NVG.t) x y =
+  let avg = average t in
+  let w = 200. in
+  let h = 35. in
+
+  let open NVG in
+  let open FloatOps in
+  Path.begin_ vg;
+  Path.rect vg ~x ~y ~w ~h;
+  set_fill_color vg ~color:(Color.rgba ~r:0 ~g:0 ~b:0 ~a:128);
+  fill vg;
+
+  Path.begin_ vg;
+  Path.move_to vg ~x ~y:(y + h);
+  let len = Array.length t.values in
+  (match t.style with
+  | FPS ->
+      for i = 0 to len -. 1 do
+        let v = 1. / (0.00001 + t.values.((t.head +. i) mod len)) in
+        let v = if v > 80. then 80. else v in
+        let vx = x + (float i / (float len - 1.) * w) in
+        let vy = y + h - (v / 80. * h) in
+        Path.line_to vg ~x:vx ~y:vy
+      done
+  | Percent -> ()
+  | Ms -> ());
+  Path.line_to vg ~x:(x + w) ~y:(y + h);
+  set_fill_color vg ~color:(Color.rgba ~r:255 ~g:192 ~b:0 ~a:128);
+  fill vg;
+
+  Text.set_font_face vg ~name:"mono";
+
+  Text.set_size vg ~size:12.;
+  Text.set_align vg ~align:Align.(left lor top);
+  set_fill_color vg ~color:(Color.rgba ~r:240 ~g:240 ~b:240 ~a:192);
+  Text.text vg ~x:(x + 3.) ~y:(y + 3.) t.name;
+
+  match t.style with
+  | FPS ->
+      Text.set_size vg ~size:15.;
+      Text.set_align vg ~align:Align.(right lor top);
+      set_fill_color vg
+        ~color:(Color.rgba ~r:240 ~g:240 ~b:240 ~a:255);
+      let s = Printf.sprintf "%.2f FPS" (1. / avg) in
+      Text.text vg ~x:(x + w - 3.) ~y:(y + 3.) s;
+
+      Text.set_size vg ~size:13.;
+      Text.set_align vg ~align:Align.(right lor baseline);
+      set_fill_color vg
+        ~color:(Color.rgba ~r:240 ~g:240 ~b:240 ~a:160);
+      let s = Printf.sprintf "%.2f ms" (avg * 1000.) in
+      Text.text vg ~x:(x + w - 3.) ~y:(y + h - 3.) s
+  | Percent -> ()
+  | Ms -> ()