From 8b0ac6a400cf1fd67552670dde430f7ef35d228e Mon Sep 17 00:00:00 2001
From: BryanHeBY <1319212443@qq.com>
Date: Fri, 25 Feb 2022 16:21:26 +0800
Subject: [PATCH] Add: vga_cycles control api

---
 include/configs.h | 4 +---
 include/nvboard.h | 1 +
 include/vga.h     | 1 +
 src/nvboard.cpp   | 8 +++++++-
 src/vga.cpp       | 8 +++++++-
 5 files changed, 17 insertions(+), 5 deletions(-)

diff --git a/include/configs.h b/include/configs.h
index ec72e2b..c872da8 100644
--- a/include/configs.h
+++ b/include/configs.h
@@ -34,9 +34,7 @@
 
 //#define VSYNC
 
-#define SHOW_FRAME_UPDATE
-
-#define CALCULATE_CLOCK_FREQUENCY
+//#define DEBUG
 #define CALCULATE_CLOCK_FREQUENCY_INTERVAL 1
 
 #endif
\ No newline at end of file
diff --git a/include/nvboard.h b/include/nvboard.h
index 33141cd..e11aa86 100644
--- a/include/nvboard.h
+++ b/include/nvboard.h
@@ -9,3 +9,4 @@ void nvboard_init();
 void nvboard_quit();
 void nvboard_bind_pin(void *signal, bool is_rt, bool is_output, int len, ...);
 void nvboard_update();
+void nvboard_set_vga_cycles(int cycles); //default: 1
diff --git a/include/vga.h b/include/vga.h
index b063355..abab7ee 100644
--- a/include/vga.h
+++ b/include/vga.h
@@ -24,6 +24,7 @@ private:
   int vga_pos;
   int vga_pre_clk, vga_pre_vsync, vga_pre_hsync;
   int vga_vaddr, vga_haddr;
+  int vga_clk_cnt;
 public:
   VGA(SDL_Renderer *rend, int cnt, int init_val, int it, int ct);
   ~VGA();
diff --git a/src/nvboard.cpp b/src/nvboard.cpp
index 371b05f..a1f244b 100644
--- a/src/nvboard.cpp
+++ b/src/nvboard.cpp
@@ -103,7 +103,7 @@ static void nvboard_update_output(PinMap *p) {
 }
 
 void nvboard_update() {
-#ifdef CALCULATE_CLOCK_FREQUENCY
+#ifdef DEBUG
   calculate_clock_frequency();
 #endif
 
@@ -195,3 +195,9 @@ void nvboard_bind_pin(void *signal, bool is_rt, bool is_output, int len, ...) {
   if (is_rt) { p->next = rt_pin_map; rt_pin_map = p; }
   else { p->next = pin_map; pin_map = p; }
 }
+
+int vga_cycles = 1;
+
+void nvboard_set_vga_cycles(int cycles) {
+  vga_cycles = cycles;
+}
diff --git a/src/vga.cpp b/src/vga.cpp
index 7f714ef..114c17a 100644
--- a/src/vga.cpp
+++ b/src/vga.cpp
@@ -20,7 +20,7 @@ VGA::VGA(SDL_Renderer *rend, int cnt, int init_val, int it, int ct):
     Component(rend, cnt, init_val, it, ct), 
     vga_screen_width(VGA_DEFAULT_WIDTH), vga_screen_height(VGA_DEFAULT_HEIGHT),
     vga_pre_clk(0), vga_pre_hsync(0), vga_pre_vsync(0),
-    vga_pos(0), vga_vaddr(0), vga_haddr(0) {
+    vga_pos(0), vga_vaddr(0), vga_haddr(0), vga_clk_cnt(1) {
   SDL_Texture *temp_texture = SDL_CreateTexture(rend, SDL_PIXELFORMAT_ARGB8888,
     SDL_TEXTUREACCESS_STATIC, vga_screen_width, vga_screen_height);
   set_texture(temp_texture, 0);
@@ -48,6 +48,12 @@ void VGA::update_gui() {
 }
 
 void VGA::update_state() {
+  extern int vga_cycles;
+  if(vga_clk_cnt != vga_cycles){
+    vga_clk_cnt ++;
+    return;
+  }
+  vga_clk_cnt = 1;
   int vga_vsync = output_map[VGA_VSYNC];
   int vga_hsync = output_map[VGA_HSYNC];
   int vga_blank_n = output_map[VGA_BLANK_N];