refactor: move screen rendering to separate file, add store_mem_listeners

orao.py

@@ -4,6 +4,7 @@
 import pygame, numpy, sys, datetime, wave, time
 from orao.cpu import CPU
 from orao.keyboard import listener as orao_kbd_listener
+from orao.video import mem_listener as video_mem_listener, terminal
 
 MEM_LOAD_PRG = None
 
@@ -21,13 +22,11 @@ pygame.time.set_timer(pygame.USEREVENT + 1, 40)
 # setup surfaces
 screen = pygame.display.set_mode((800, 900))
 background = pygame.image.load("pozadina.png").convert_alpha()
-terminal = pygame.Surface((256, 256), pygame.SRCALPHA, depth=32)
-terminal.fill((255, 255, 255))
 
 # create CPU
 cpu = CPU(bytearray([0xFF]*0xC000) + bytearray(open('ORAO13.ROM', 'rb').read()))
-cpu.alphaarray = pygame.surfarray.pixels_alpha(terminal)
 cpu.channel = pygame.mixer.Channel(0)
+cpu.store_mem_listeners.append(video_mem_listener)
 
 while running:
     before, previous_loop_cycles = datetime.datetime.now(), cpu.cycles

orao/cpu.py

@@ -5,6 +5,7 @@ import wave
 class CPU(object):
     CARRY, ZERO, INTERRUPT, DECIMAL, BREAK, UNUSED, OVERFLOW, NEGATIVE = [2**i for i in range(8)]
     alphaarray = None
+    store_mem_listeners = []
 
     def __init__(self, memory):
         s, self.tape_out, self.filename, self.samples = self, None, None, 0
@@ -98,14 +99,12 @@ class CPU(object):
             return
 
         if addr == 0x8800: self.speaker()                           # Zvucnik
-        if 0x6000 <= addr <= 0x7FFF:                                # Video RAM
-            if self.alphaarray is not None:
-                y, x = divmod((addr - 0x6000) * 8, 256)
-                for i in range(8):
-                    self.alphaarray[x+i, y] = 255 if (val>>i) & 1 else 0    # Transparency mask
 
         self.memory[addr] = val & 0xFF
 
+        for listener in self.store_mem_listeners:
+            listener(addr, val)
+
     def stack_push(self, value):
         self.store_byte(256 + self.sp, value & 0xFF)
         self.sp = (self.sp - 1) & 0xFF

orao/video.py

@@ -0,0 +1,11 @@
+import pygame
+
+terminal = pygame.Surface((256, 256), pygame.SRCALPHA, depth=32)
+terminal.fill((255, 255, 255))
+alphaarray = pygame.surfarray.pixels_alpha(terminal)
+
+def mem_listener(addr, val):
+	if 0x6000 <= addr <= 0x7FFF:  # Video RAM
+		y, x = divmod((addr - 0x6000) * 8, 256)
+		for i in range(8):
+			alphaarray[x + i, y] = 255 if (val >> i) & 1 else 0  # Transparency mask