Speed enhancements; Write savefiles

src/cpu.rs

@@ -1,5 +1,8 @@
 use super::interconnect;
 
+use std::time::{Duration, Instant};
+use std::thread::sleep;
+
 const REG_A: usize = 6;
 
 const REG_N_B: usize = 0;
@@ -46,7 +49,7 @@ impl CPU {
             ip: 0,
             sp: 0xFFFE,
             interconnect: interconnect,
-            ime: false,  // Is this correct?
+            ime: false,
             debug: false,
             halted: false,
         }
@@ -861,39 +864,58 @@ impl CPU {
         self.halted = false;
     }
 
-    pub fn run_instruction(&mut self) {
+    pub fn run(&mut self) {
-        // self.debug = !self.interconnect.is_boot_rom();
+        loop {
-        /*
+            let mut cycles: i32 = 0;
-        if self.ip == 0x553 {
+            let start = Instant::now();
-            self.debug = true;
+            for _ in 0 .. 1000 {
+                cycles += self.run_instruction() as i32;
             }
-        */
+
-        // Check for interrupts.
+            let gb_dur = cycles * 238;
-        // TODO: Make this right
+            let our_dur = start.elapsed().subsec_nanos() as i32;
-        if self.ime {
+            let delta = gb_dur - our_dur;
+            if delta > (20 * 238) { // We're at least 20 cycles faster.
+                sleep(Duration::new(0, delta as u32));
+            } else if delta < 0 {
+                print!("-");
+            }
+        }
+    }
+
+    fn check_interrupts(&mut self) {
         // read pending interrupts
         let pending = self.interconnect.read_byte(0xFF0F);
         let enabled = self.interconnect.read_byte(0xFFFF);
         let e_pending = pending & enabled;
 
         if e_pending & interconnect::INTERRUPT_DISPLAY_VBLANK > 0 {
-                // println!("Handling vblank interrupt");
             self.handle_interrupt(0x40, interconnect::INTERRUPT_DISPLAY_VBLANK);
         } else if e_pending & interconnect::INTERRUPT_DISPLAY_STAT > 0 {
-                // println!("Handling display stat interrupt");
             self.handle_interrupt(0x48, interconnect::INTERRUPT_DISPLAY_STAT);
-            } else if e_pending & interconnect::INTERRUPT_TIMER_OVERFLOW > 0{
+        } else if e_pending & interconnect::INTERRUPT_TIMER_OVERFLOW > 0 {
-                println!("Handling timer interrupt");
             self.handle_interrupt(0x50, interconnect::INTERRUPT_TIMER_OVERFLOW);
+        } else if e_pending & interconnect::INTERRUPT_SERIAL > 0 {
+            self.handle_interrupt(0x58, interconnect::INTERRUPT_SERIAL);
+        } else if e_pending & interconnect::INTERRUPT_INPUT > 0 {
+            self.handle_interrupt(0x60, interconnect::INTERRUPT_INPUT);
         } else if e_pending > 0 {
             panic!("Unknown pending interrupt: {:02X}", e_pending);
         }
     }
 
+    pub fn run_instruction(&mut self) -> u8 {
+        // self.debug = !self.interconnect.is_boot_rom();
+        // Check for interrupts.
+        if self.ime {
+            self.check_interrupts();
+        }
+
         let mut cycles: u8 = 1;
+        let instruction: u8;
         if !self.halted {
             // We need to double-check the flags
-            let instruction = self.read_byte(self.ip);
+            instruction = self.read_byte(self.ip);
             if self.debug {
                 print!("{:#06x}: [SP: {:#04X}] i={:02X}. ", &self.ip, &self.sp, &instruction);
                 for i in 0 .. 6 {
@@ -1647,5 +1669,6 @@ impl CPU {
             };
         }
         self.interconnect.tick(cycles);
+        cycles
     }
 }

src/display.rs

@@ -45,12 +45,20 @@ const SPRITE_PALETTE_NO: u8 = 1 << 4; // NonCGB only
 // const SPRITE_TILE_VRAM_BANK: u8 = 1 << 3; // CGB only
 
 // Display color
+/*
 const MONOCHROME_PALETTE: &'static [[f64; 3]; 4] = &[
     [0.605, 0.734, 0.059],
     [0.543, 0.672, 0.059],
     [0.188, 0.383, 0.188],
     [0.059, 0.219, 0.059],
 ];
+*/
+const MONOCHROME_PALETTE: &'static [[u8; 3]; 4] = &[
+    [255, 255, 255],
+    [200, 200, 200],
+    [125, 125, 12],
+    [50, 50, 50],
+];
 
 #[derive(Debug, Copy, Clone)]
 enum PixelOrigin {
@@ -150,6 +158,9 @@ pub struct Display {
     stat_interrupt: bool,
 
     pixels: [Pixel; GB_PIXELS_X * GB_PIXELS_Y],
+
+    frameskip: u8,
+    frame_no: u8,
 }
 
 impl Display {
@@ -185,6 +196,8 @@ impl Display {
             vblank_interrupt: false,
             stat_interrupt: false,
             pixels: pixels,
+            frameskip: 0,
+            frame_no: 0,
         }
     }
 
@@ -328,7 +341,9 @@ impl Display {
                 if self.current_ticks > TICKS_END_READMODE {
                     self.current_ticks = 0;
                     self.current_mode = DisplayMode::HBlank;
+                    if self.frameskip < self.frame_no {
                         self.renderscan();
+                    }
                     if self.status & STAT_MODE_HBLANK_INT > 0 {
                         self.stat_interrupt = true;
                     }
@@ -365,10 +380,15 @@ impl Display {
                     }
                     if self.curline > 153 {
                         self.current_mode = DisplayMode::ReadOAMMemory; // Mode 2, scanline.
+                        if self.frameskip < self.frame_no {
                             self.render_screen();
                             self.renderer.present();
                             self.renderer.set_draw_color(sdl2::pixels::Color::RGB(255, 255, 255));
                             self.renderer.clear();
+                            self.frame_no = 0;
+                        } else {
+                            self.frame_no += 1;
+                        }
                         self.curline = 0;
                         if self.status & STAT_MODE_OAM_INT > 0 {
                             self.stat_interrupt = true;
@@ -423,10 +443,11 @@ impl Display {
                     let tile_offset_y: usize = render_y as usize - y_o as usize;
                     let tile_base_addr: usize = sprite.tile as usize * 16; // Should this be twice as wide in wide mode?
 
-                    let tile_line_1 = self.vram[tile_base_addr + tile_offset_y * 2 + 1];
+                    let tile_addr = tile_base_addr + tile_offset_y * 2;
-                    let tile_line_2 = self.vram[tile_base_addr + tile_offset_y * 2 + 1];
+                    let tile_line_1 = self.vram[tile_addr + 0];
-                    let tile_line_3 = self.vram[tile_base_addr + tile_offset_y * 2 + 2];
+                    let tile_line_2 = self.vram[tile_addr + 1];
-                    let tile_line_4 = self.vram[tile_base_addr + tile_offset_y * 2 + 3];
+                    let tile_line_3 = self.vram[tile_addr + 2];
+                    let tile_line_4 = self.vram[tile_addr + 3];
 
                     // We need to draw this.
                     let wide_mode = self.control & CTRL_BG_SPRITE_SIZE > 0;
@@ -488,7 +509,7 @@ impl Display {
                         let entry = MONOCHROME_PALETTE[lookup[c as usize] as usize];
 
                         // Draw stuff. We're currently only in monochrome mode
-                        self.set_pixel(x.wrapping_add(x_o), render_y, sdl2::pixels::Color::RGB((entry[0]*255.0) as u8, (entry[1]*255.0) as u8, (entry[2]*255.0) as u8), PixelOrigin::Sprite);
+                        self.set_pixel(x.wrapping_add(x_o), render_y, sdl2::pixels::Color::RGB(entry[0], entry[1], entry[2]), PixelOrigin::Sprite);
                     }
                 }
             }
@@ -499,11 +520,11 @@ impl Display {
     fn get_bg_window_tile_addr(&self, tile_id: u8) -> usize {
         if (self.control & CTRL_BG_WINDOW_TILE_DATA_SELECT) == CTRL_BG_WINDOW_TILE_DATA_SELECT {
             let base_addr = 0x0000;
-            base_addr + (tile_id as usize) * 16
+            base_addr + ((tile_id as usize) << 4)
         } else {
             let base_addr = 0x0800;
             let tile_id = (128u8 as i8).wrapping_add(tile_id as i8) as u8;
-            base_addr + (tile_id as usize) * 16
+            base_addr + ((tile_id as usize) << 4)
         }
     }
 
@@ -570,19 +591,20 @@ impl Display {
                 let tile_index_y: u8 = render_abs_y >> 3;
                 let tile_offset_y: u8 = render_abs_y & 7;
 
-                let vram_offset: usize = background_map + (tile_index_y as usize) * 32 + tile_index_x as usize;
+                let vram_offset: usize = background_map + ((tile_index_y as usize) * 32) + tile_index_x as usize;
 
                 // Obtain tile ID in this area
                 let tile_id = self.vram[vram_offset];
 
                 // Obtain tile information
                 let tile_base_addr: usize = self.get_bg_window_tile_addr(tile_id);
-                let tile_line_1 = self.vram[tile_base_addr + (tile_offset_y as usize) * 2];
+                let addr = tile_base_addr + (tile_offset_y as usize) * 2;
-                let tile_line_2 = self.vram[tile_base_addr + (tile_offset_y as usize) * 2 + 1];
+                let tile_line_1 = self.vram[addr];
+                let tile_line_2 = self.vram[addr + 1];
 
                 // Get the correct bit
-                let b1: bool = (tile_line_1 & 1 << (7 - tile_offset_x)) > 0;
+                let b1: bool = (tile_line_1 & 1 << (7 - tile_offset_x)) != 0;
-                let b2: bool = (tile_line_2 & 1 << (7 - tile_offset_x)) > 0;
+                let b2: bool = (tile_line_2 & 1 << (7 - tile_offset_x)) != 0;
 
                 // Lookup the color
                 let c = (b1 as u8) * 2 + b2 as u8;
@@ -598,11 +620,7 @@ impl Display {
                     0 => PixelOrigin::Empty, // Hack so that objects will be in front of it.
                     _ => PixelOrigin::Background,
                 };
-                self.set_pixel(render_x, render_y, sdl2::pixels::Color::RGB((entry[0]*255.0) as u8, (entry[1]*255.0) as u8, (entry[2]*255.0) as u8), origin);
+                self.set_pixel(render_x, render_y, sdl2::pixels::Color::RGB(entry[0], entry[1], entry[2]), origin);
-            }
-
-            if (self.control & CTRL_BG_SPRITE_ENABLE) == CTRL_BG_SPRITE_ENABLE {
-                self.render_sprites(&queue);
             }
         }
 
@@ -628,8 +646,9 @@ impl Display {
 
                     // Obtain tile information
                     let tile_base_addr: usize = self.get_bg_window_tile_addr(tile_id);
-                    let tile_line_1 = self.vram[tile_base_addr + (tile_offset_y as usize) * 2];
+                    let tile_addr = tile_base_addr + (tile_offset_y as usize) * 2;
-                    let tile_line_2 = self.vram[tile_base_addr + (tile_offset_y as usize) * 2 + 1];
+                    let tile_line_1 = self.vram[tile_addr];
+                    let tile_line_2 = self.vram[tile_addr + 1];
 
                     // Get the correct bit
                     let b1: bool = (tile_line_1 & 1 << (7 - tile_offset_x)) > 0;
@@ -649,9 +668,12 @@ impl Display {
                         0 => PixelOrigin::Empty, // Hack so that objects will be in front of it.
                         _ => PixelOrigin::Window,
                     };
-                    self.set_pixel(render_x, render_y, sdl2::pixels::Color::RGB((entry[0]*255.0) as u8, (entry[1]*255.0) as u8, (entry[2]*255.0) as u8), origin);
+                    self.set_pixel(render_x, render_y, sdl2::pixels::Color::RGB(entry[0], entry[1], entry[2]), origin);
                 }
             }
         }
+        if (self.control & CTRL_BG_SPRITE_ENABLE) == CTRL_BG_SPRITE_ENABLE {
+            self.render_sprites(&queue);
+        }
     }
 }

src/interconnect.rs

@@ -2,6 +2,8 @@
 const WRAM_SIZE: usize = 0x8000;
 const HIRAM_SIZE: usize = (0xFFFE - 0xFF80) + 1;
 
+pub const INTERRUPT_INPUT: u8 = 1 << 4;
+pub const INTERRUPT_SERIAL: u8 = 1 << 3;
 pub const INTERRUPT_TIMER_OVERFLOW: u8 = 1 << 2;
 pub const INTERRUPT_DISPLAY_STAT: u8 = 1 << 1;
 pub const INTERRUPT_DISPLAY_VBLANK: u8 = 1 << 0;
@@ -92,11 +94,13 @@ impl Interconnect {
             joy_regular_keys: 0x0F,
             joy_special_keys: 0x0F,
             joy_switch: 0x30,
+
+            cycles: 0,
         }
     }
 
     fn press_key(&mut self, key: Key) {
-        println!("Press key {:?}", &key);
+        // println!("Press key {:?}", &key);
         match key {
             Key::UP => self.joy_regular_keys &= !KEY_UP,
             Key::DOWN => self.joy_regular_keys &= !KEY_DOWN,
@@ -107,10 +111,11 @@ impl Interconnect {
             Key::A => self.joy_special_keys &= !KEY_A,
             Key::B => self.joy_special_keys &= !KEY_B,
         }
+        self.interrupt_request_flags |= INTERRUPT_INPUT;
     }
 
     fn release_key(&mut self, key: Key) {
-        println!("Release key {:?}", &key);
+        // println!("Release key {:?}", &key);
         match key {
             Key::UP => self.joy_regular_keys |= KEY_UP,
             Key::DOWN => self.joy_regular_keys |= KEY_DOWN,
@@ -121,6 +126,7 @@ impl Interconnect {
             Key::A => self.joy_special_keys |= KEY_A,
             Key::B => self.joy_special_keys |= KEY_B,
         }
+        self.interrupt_request_flags |= INTERRUPT_INPUT;
     }
 
     // Somehow we need different timers for this.
@@ -140,11 +146,17 @@ impl Interconnect {
             self.interrupt_request_flags |= INTERRUPT_TIMER_OVERFLOW;
         }
 
+        if self.serial.serial_interrupt() {
+            self.interrupt_request_flags |= INTERRUPT_SERIAL;
+        }
+
         // Make sure the window is responsive:
+        if self.cycles > 500 {
             loop {
                 if let Some(event) = self.display.event_pump.poll_event(){
                     match event {
                         Event::Quit {..} | Event::KeyDown { keycode: Some(Keycode::Escape), .. } => {
+                            self.cartridge.save();
                             panic!("TODO: Proper shutdown");
                         },
                         Event::KeyDown { keycode: Some(Keycode::Left), .. } => self.press_key(Key::LEFT),
@@ -170,6 +182,10 @@ impl Interconnect {
                     break;
                 }
             }
+            self.cycles = 0;
+        } else {
+            self.cycles += cycles as u16;
+        }
     }
 
     #[inline]

src/serial.rs

@@ -11,7 +11,10 @@ impl Serial {
 
     pub fn write_byte(&mut self, addr: u16, val: u8) {
         match addr {
-            0xFF01 => self.data = val,
+            0xFF01 => {
+                println!("Serial: Write {:02X}", val);
+                self.data = val;
+            }
             0xFF02 => self.control = val,
             _ => panic!("Serial: Write {:02X} to {:04X} unsupported", val, addr),
         }
@@ -24,4 +27,9 @@ impl Serial {
             _ => panic!("Serial: Read from {:04X} unsupported", addr),
         }
     }
+
+    pub fn serial_interrupt(&self) -> bool {
+        // TODO
+        false
+    }
 }