[f] Make interupt work

lib/chip_8/interpreter.rb

@@ -0,0 +1,231 @@
+module Chip8
+  class Interpreter
+    def initialize(chip)
+      @chip = chip
+    end
+
+    def run
+      chip.step += 1
+
+      if chip.step % 2 == 0 && chip.delay_timer > 0
+        chip.delay_timer -= 1
+      end
+
+      if chip.program_counter >= 0x1000
+        chip.running = false
+        return
+      end
+      opcode = (chip.memory[chip.program_counter] << 8) | chip.memory[chip.program_counter + 1]
+      increase_program_counter
+
+      sub_routine_pointer = opcode & 0x0FFF
+      compared_value = opcode & 0x00FF
+      register_index_1 = (opcode & 0x0F00) >> 8
+      register_index_2 = (opcode & 0x00F0) >> 4
+
+      case opcode & 0xF000
+      when 0x0000
+        case opcode
+        when 0x00E0
+          chip.display = chip.new_matrix
+          chip.draw_flag = true
+        when 0x00EE
+          chip.program_counter = chip.stack.pop
+        end
+
+      when 0x1000 # JMP
+        chip.program_counter = sub_routine_pointer
+
+      when 0x2000 # CALL
+        chip.stack.push(chip.program_counter)
+        chip.program_counter = sub_routine_pointer
+
+      when 0x3000 # SE - skip if equal
+        if chip.registers[register_index_1] == compared_value
+          increase_program_counter
+        end
+
+      when 0x4000 # SNE - skip if not equal
+        if chip.registers[register_index_1] != compared_value
+          increase_program_counter
+        end
+
+      when 0x5000 # SE Vx Vy - skip if registry equal
+        if chip.registers[register_index_1] == chip.registers[register_index_2]
+          increase_program_counter
+        end
+
+      when 0x6000 # load to register
+        chip.registers[register_index_1] = compared_value
+
+      when 0x7000 # add value
+        chip.registers[register_index_1] = (chip.registers[register_index_1] + compared_value) % 256
+
+      when 0x8000
+        case opcode & 0x000F
+        when 0x0000
+          chip.registers[register_index_1] = chip.registers[register_index_2]
+
+        when 0x0001
+          chip.registers[register_index_1] |= chip.registers[register_index_2]
+
+        when 0x0002
+          chip.registers[register_index_1] &= chip.registers[register_index_2]
+
+        when 0x0003
+          chip.registers[register_index_1] ^= chip.registers[register_index_2]
+
+        when 0x0004
+          chip.registers[register_index_1] += chip.registers[register_index_2]
+
+          if chip.registers[register_index_1] > 255
+            chip.registers[0xF] = 1
+            chip.registers[register_index_1] %= 256
+          else
+            chip.registers[0xF] = 0
+          end
+
+        when 0x0005
+          if chip.registers[register_index_1] > chip.registers[register_index_2]
+            chip.registers[0xF] = 1
+          else
+            chip.registers[0xF] = 0
+          end
+
+          chip.registers[register_index_1] -= chip.registers[register_index_2]
+          chip.registers[register_index_1] %= 256
+
+        when 0x0006
+          chip.registers[0xF] = chip.registers[register_index_1] % 2
+          chip.registers[register_index_1] /= 2
+
+        when 0x0007
+          if chip.registers[register_index_2] > chip.registers[register_index_1]
+            chip.registers[0xF] = 1
+          else
+            chip.registers[0xF] = 0
+          end
+
+          chip.registers[register_index_1] = chip.registers[register_index_2] - chip.registers[register_index_1]
+          chip.registers[register_index_1] %= 256
+
+        when 0x000E
+          chip.registers[register_index_1] *= 2
+          chip.registers[0xF] = chip.registers[register_index_1] / 256
+          chip.registers[register_index_1] %= 256
+        end
+      when 0x9000 # skip if not equal with register
+        if chip.registers[register_index_1] != chip.registers[register_index_2]
+          increase_program_counter
+        end
+
+      when 0xA000 # LD I, addr
+        chip.register_i = sub_routine_pointer
+
+      when 0xB000
+        chip.program_counter = sub_routine_pointer + chip.registers[0]
+
+      when 0xC000
+        chip.registers[register_index_1] = rand(0..255) & compared_value
+      when 0xD000
+        chip.registers[0xF] = 0
+        height = opcode & 0x000F
+        x = chip.registers[register_index_1]
+        y = chip.registers[register_index_2]
+
+        (0..height-1).each do |i|
+          data = chip.memory[chip.register_i + i]
+
+          (0..7).each do |j|
+            if (data & 0x80) > 0
+              # set pixel
+              a = x + j
+              b = y + i
+
+              if a >= Chip8::Main::WIDTH
+                a -= Chip8::Main::WIDTH
+              elsif a < 0
+                a += Chip8::Main::WIDTH
+              end
+
+              if b >= Chip8::Main::HEIGHT
+                b -= Chip8::Main::HEIGHT
+              elsif b < 0
+                b += Chip8::Main::HEIGHT
+              end
+
+              value = chip.display[a, b] ^ 1
+              chip.display.send(:'[]=', a, b, value)
+
+              if chip.display[a, b] == 0
+                chip.registers[0xF] = 1
+              end
+            end
+            data <<= 1
+          end
+
+          chip.draw_flag = true
+        end
+
+      when 0xE000
+        key = chip.registers[(opcode & 0x0F00) >> 8]
+
+        case opcode & 0x00FF
+        when 0x009E
+          if chip.keys[key] != 0
+            increase_program_counter
+          end
+        when 0x00A1
+          if chip.keys[key] == 0
+            increase_program_counter
+          end
+        end
+
+      when 0xF000
+        case opcode & 0x00FF
+        when 0x0007
+          chip.registers[register_index_1] = chip.delay_timer
+
+        when 0x000A
+          # not handle yet
+
+        when 0x0015
+          chip.delay_timer = chip.registers[register_index_1]
+        when 0x0018
+          # not handle yet
+
+        when 0x001E
+          chip.register_i += chip.registers[register_index_1]
+
+        when 0x0029
+          chip.register_i = chip.registers[register_index_1] * 5
+
+        when 0x0033
+          value = chip.registers[register_index_1]
+
+          (2..0).each do |i|
+            chip.memory[chip.register_i + i] = value % 10
+            value /= 10
+          end
+
+        when 0x0055
+          (0..register_index_1).each do |i|
+            chip.memory[chip.register_i + i] = chip.registers[i]
+          end
+        when 0x0065
+          (0..register_index_1).each do |i|
+            chip.registers[i] = chip.memory[chip.register_i + i]
+          end
+        end
+      end
+    end
+
+    private
+
+    attr_reader :chip
+
+    def increase_program_counter
+      chip.program_counter += 2
+    end
+  end
+end