Adjustments to make emu core run faster when not paused

snes-core/src/emulator.rs

@@ -7,7 +7,6 @@ pub struct Emulator {
     pub cpu: CPU,
     pub bus: Bus,
     pub rom: Box<dyn ROM>,
-    pub is_frame_ending: bool,
 }
 
 impl Emulator {
@@ -16,7 +15,6 @@ impl Emulator {
             cpu: CPU::new(),
             bus: Bus::new(),
             rom: Box::new(LoROM::new()),
-            is_frame_ending: false,
         }
     }
 
@@ -25,8 +23,14 @@ impl Emulator {
         self.bus.ppu.tick(self.cpu.cycles);
 
         self.cpu.cycles = 0;
+    }
 
-        self.is_frame_ending = true;
+    pub fn is_frame_ending(&self) -> bool {
+        self.bus.ppu.registers.v_count == 0
+    }
+
+    pub fn is_frame_starting(&self) -> bool {
+        self.bus.ppu.registers.v_count == 1
     }
 
     pub fn reset(&mut self) {

snes-frontend/src/main.rs

@@ -452,11 +452,13 @@ fn main() {
                     if !state.emulation.is_paused {
                         // We want to keep the emulator running
                         // as long as we are not at the end of the frame
-                        while !emulator.is_frame_ending {
+                        while !emulator.is_frame_ending() {
+                            emulator.tick()
+                        }
+                        // It takes some amount of cycles to get out of 0 v-count
+                        while !emulator.is_frame_starting() {
                             emulator.tick()
                         }
-                        // Reset the flag because otherwise the emulator will never continue running
-                        emulator.is_frame_ending = false
                     }
 
                     // Render emulator framebuffer

snes-frontend/src/ppu.rs

@@ -129,6 +129,11 @@ pub fn registers_window(ppu_registers: &PPURegisters, show_registers: &mut bool,
         .size([230.0, 310.0], imgui::Condition::FirstUseEver)
         .opened(show_registers)
         .build(ui, || {
+            ui.text("H/V Counters:");
+            ui.text(format!("V: {}", ppu_registers.v_count));
+            ui.text(format!("H: {}", ppu_registers.h_count));
+            ui.text(format!("VBlanking: {}", ppu_registers.is_vblanking()));
+            ui.separator();
             ui.text("Registers:");
             for (index, register_value) in ppu_registers.registers().iter().enumerate() {
                 let register = (index as u16) + 0x2100;