Fix keypad and drawing bugs, add drawing refresh wait

chip-8.fln

@@ -29,6 +29,7 @@ class State
   audio-stream: rl/AudioStream
   font: rl/Font
   page: int
+  fullscreen: bool
   step-mode: bool
   clear-screen: bool
   pending-key: u8?
@@ -122,11 +123,13 @@ fn parse-instruction(pc: u16) -> Instruction
 fn reset() -> ()
   cpu = Cpu{}
   machine = Machine{}
-  ;; load-rom("./IBM Logo.ch8")
+  load-rom("./IBM Logo.ch8")
   ;; load-rom("./vendor/chip8-test-suite/bin/1-chip8-logo.ch8")
   ;; load-rom("./vendor/chip8-test-suite/bin/2-ibm-logo.ch8")
   ;; load-rom("./vendor/chip8-test-suite/bin/3-corax+.ch8")
-  load-rom("./vendor/chip8-test-suite/bin/4-flags.ch8")
+  ;; load-rom("./vendor/chip8-test-suite/bin/4-flags.ch8")
+  ;; load-rom("./roms/Breakout [Carmelo Cortez, 1979].ch8")
+  load-rom("./roms/Brix [Andreas Gustafsson, 1990].ch8")
   cpu.pc = 0x200
 
 fn decode-instruction(inst: Instruction) -> str
@@ -182,18 +185,15 @@ fn decode-instruction(inst: Instruction) -> str
 
 ;; You should extract the execution from the other stuff here so you can manually
 ;; run an instruction when needed, all it needs is a parsed instruction
-fn step() -> ()
+fn step(inst: Instruction) -> ()
   if cpu.pc >= length(machine.memory) - 2
     cpu.pc = 0
     return
 
-  let inst = parse-instruction(cpu.pc)
-
   cpu.pc += 2
   match inst.op
     0x0 ->
       match inst.nn
-        ;; TODO: Maybe this can be a draw command that clears the screen rather than special cased
         0xE0 -> state.clear-screen = true
         0xEE ->
           cpu.sp -= 1
@@ -253,12 +253,12 @@ fn step() -> ()
         loop bit in reverse(0..8)
           if byte >> bit & 0x1 == 1 and idx < length(machine.vbuffer)
             if machine.vbuffer[idx] then collision = true
-            machine.vbuffer[idx] = true
+            machine.vbuffer[idx] = not machine.vbuffer[idx]
           idx += 1
 
       cpu.v[0xF] = if collision then 1 else 0
     0xE ->
-      let pressed = machine.keypad[inst.x]
+      let pressed = machine.keypad[cpu.v[inst.x]]
       match inst.nn
         0x9E -> if pressed then cpu.pc += 2
         0xA1 -> if not pressed then cpu.pc += 2
@@ -295,8 +295,7 @@ fn step() -> ()
 
 fn run-update() -> ()
   loop i, key in keypad-keymap
-    if rl/is-key-down(key) and not state.step-mode
-      machine.keypad[keypad-mapping[i]] = true
+    machine.keypad[keypad-mapping[i]] = rl/is-key-down(key)
     if state.pending-key as reg
       cpu.v[reg] = u8(i)
       state.pending-key = nil
@@ -306,10 +305,11 @@ fn run-update() -> ()
   if rl/is-key-pressed(:key-equal)
     state.page = min(5, state.page + 1)
 
-  if rl/is-key-pressed(:key-r)
+  if rl/is-key-pressed(:key-period)
     reset()
     return
-
+  if rl/is-key-pressed(:key-enter)
+    state.fullscreen = not state.fullscreen
   if rl/is-key-pressed(:key-space)
     state.step-mode = not state.step-mode
 
@@ -325,23 +325,28 @@ fn run-update() -> ()
     return
 
   if state.step-mode
-    if rl/is-key-pressed(:key-n)
-      step()
-    if rl/is-key-pressed-repeat(:key-n)
-      step()
+    if rl/is-key-pressed(:key-n) or rl/is-key-pressed-repeat(:key-n)
+      let inst = parse-instruction(cpu.pc)
+      step(inst)
   else
     cycles += f64(rl/get-frame-time()) * ips
-
     loop cycles >= 1.0
-      step()
+      let inst = parse-instruction(cpu.pc)
+      step(inst)
+      ;; Apparently on the COSMAC VIP and other devices, drawing would wait for the next scree
+      ;; refresh which ran at 60hz
+      if inst.op == 0xD
+        cycles = 0.0
+        break
       cycles -= 1.0
 
+  fill(state.screen-pixels, rl/black)
   if state.clear-screen
     state.clear-screen = false
-    fill(state.screen-pixels, rl/black)
   else
     loop i,pixel in machine.vbuffer
-      state.screen-pixels[i] = if pixel then rl/white else rl/black
+      if pixel
+        state.screen-pixels[i] = rl/white
 
   ;; loop i,pixel in machine.vbuffer
   ;;   if i % 2 == 0 and i / pixels-width % 2 == 0 or i % 2 == 1 and i / pixels-width % 2 == 1
@@ -357,6 +362,16 @@ fn draw-text-normal(text: str, x: $t, y: $t, color: rl/Color) -> () where is-num
 fn run-drawing() -> ()
   rl/clear-background(rl/black)
 
+  ;; Texture
+  let scale: f32 = if state.fullscreen then 14 else 5
+      src = rl/Rectangle(0, 0, f32(pixels-width), f32(pixels-height))
+      dst = rl/Rectangle(10, 10, f32(pixels-width) * scale, f32(pixels-height) * scale)
+  rl/draw-texture-pro(state.screen-texture, src, dst, rl/Vector2(0.0, 0.0), 0.0, rl/white)
+  rl/draw-rectangle-lines(i32(dst.x), i32(dst.y), i32(dst.width), i32(dst.height), rl/white)
+
+  if state.fullscreen
+    return
+
   draw-text-normal("Keypad", 10, 200, rl/white)
   let key-size = 25
   loop i, key in keypad-keymap
@@ -394,13 +409,6 @@ fn run-drawing() -> ()
     let reg-val = format("V{:X}=0x{:02X}", i, cpu.v[i])
     draw-text-normal(reg-val, reg-x, 200 + 21 * i, rl/white)
 
-  ;; Texture
-  let scale: f32 = 5.5
-      src = rl/Rectangle(0, 0, f32(pixels-width), f32(pixels-height))
-      dst = rl/Rectangle(10, 10, f32(pixels-width) * scale, f32(pixels-height) * scale)
-  rl/draw-texture-pro(state.screen-texture, src, dst, rl/Vector2(0.0, 0.0), 0.0, rl/white)
-  rl/draw-rectangle-lines(i32(dst.x), i32(dst.y), i32(dst.width), i32(dst.height), rl/white)
-
   ;; Stack
   loop i in 0..16
     let row = i % 8