From ef885890c1bda92d97e3aeb6153184015f649105 Mon Sep 17 00:00:00 2001
From: Yanyan Jiang <jiangyy@outlook.com>
Date: Wed, 12 Aug 2020 22:06:06 +0800
Subject: [PATCH] much better user interface for litenes

---
 kernels/litenes/src/fce.c  | 10 ++++++----
 kernels/litenes/src/fce.h  |  7 ++++---
 kernels/litenes/src/main.c |  6 ++++--
 3 files changed, 14 insertions(+), 9 deletions(-)

diff --git a/kernels/litenes/src/fce.c b/kernels/litenes/src/fce.c
index 28b2cbd..b4ffac7 100644
--- a/kernels/litenes/src/fce.c
+++ b/kernels/litenes/src/fce.c
@@ -6,7 +6,7 @@
 #include <klib.h>
 
 static int frame_cnt;
-bool candraw() { return frame_cnt % 3 == 0; }
+static inline bool candraw() { return frame_cnt % (1 + FRAME_SKIP) == 0; }
 
 static uint32_t canvas[SCR_W * SCR_H];
 
@@ -112,9 +112,11 @@ void fce_run() {
     }
 
     nr_draw ++;
-    if (uptime_ms() - last > 1000) {
-      last = uptime_ms();
-      printf("FPS = %d\n", nr_draw);
+    int upt = uptime_ms();
+    if (upt - last > 1000) {
+      last = upt;
+      for (int i = 0; i < 80; i++) putch('\b');
+      printf("(System time: %ds) FPS = %d", upt / 1000, nr_draw);
       nr_draw = 0;
     }
   }
diff --git a/kernels/litenes/src/fce.h b/kernels/litenes/src/fce.h
index 4109ebd..4795874 100644
--- a/kernels/litenes/src/fce.h
+++ b/kernels/litenes/src/fce.h
@@ -3,9 +3,10 @@
 
 #include "common.h"
 
-#define FPS    60
-#define SCR_W 256
-#define SCR_H 240
+#define FPS          60
+#define SCR_W       256
+#define SCR_H       240
+#define FRAME_SKIP    1
 
 void fce_update_screen();
 int fce_load_rom(char *rom);
diff --git a/kernels/litenes/src/main.c b/kernels/litenes/src/main.c
index 4139e97..491f155 100644
--- a/kernels/litenes/src/main.c
+++ b/kernels/litenes/src/main.c
@@ -7,11 +7,13 @@ extern char rom_mario_nes[];
 int main() {
   ioe_init();
 
-  printf("Play:      [%s]         SELECT [%s] START [%s]\n"
-         "       [%s] [%s] [%s]          A [%s] B     [%s]\n",
+  printf("==================== LiteNES Emulator ====================\n\n");
+  printf("Control:      [%s]         SELECT [%s]   START [%s]\n"
+         "          [%s] [%s] [%s]          A [%s]   B     [%s]\n\n",
         TOSTRING(KEY_UP),   TOSTRING(KEY_SELECT), TOSTRING(KEY_START),
         TOSTRING(KEY_LEFT), TOSTRING(KEY_DOWN),   TOSTRING(KEY_RIGHT),
         TOSTRING(KEY_A),    TOSTRING(KEY_B));
+  printf("==========================================================\n");
 
   fce_load_rom((void *)rom_mario_nes);
   fce_init();