Add loadGame & add few opcodes

main.go

@@ -3,6 +3,7 @@ package main
 import (
 	"flag"
 	"fmt"
+	"io/ioutil"
 )
 
 type chip8 struct {
@@ -67,6 +68,85 @@ func (c *chip8) emulateCycle() {
 		c.v[pos] = byte(c.opcode)
 		c.pc += 2
 		break
+	case 0x7000:
+		c.v[c.opcode&0x0F00>>8] += byte(c.opcode)
+		c.pc += 2
+		break
+	case 0x8000:
+		switch c.opcode & 0x000F {
+		case 0x0004: // 0x8XY4
+			if c.v[(c.opcode&0x00F0)>>4] > (0xFF - c.v[c.opcode&0x0F00]) {
+				c.v[0xF] = 1
+			} else {
+				c.v[0xF] = 0
+			}
+			c.v[(c.opcode&0x0F00)>>8] += c.v[(c.opcode&0x00F0)>>4]
+			c.pc += 2
+			break
+		default:
+			fmt.Printf("Unknown opcode [0x8000]: 0x%X\n", c.opcode)
+		}
+	case 0xA000:
+		// set index to NNN position
+		c.index = c.opcode & 0x0FFF
+		c.pc += 2
+		break
+	case 0xD000:
+		x := uint16(c.v[(c.opcode&0x0F00)>>8])
+		y := uint16(c.v[(c.opcode&0x00F0)>>4])
+		height := c.opcode & 0x000F
+
+		var pixel byte
+		c.v[0xF] = 0
+		for yline := uint16(0); yline < height; yline++ {
+			pixel = c.memory[c.index+yline]
+			for xline := uint16(0); xline < 8; xline++ {
+				if (pixel & (0x80 >> xline)) != 0 {
+					if c.gfx[(x+xline+((y+yline)*64))] == 1 {
+						c.v[0xF] = 1
+					}
+					c.gfx[x+xline+((y+yline)*64)] ^= 1
+				}
+			}
+
+		}
+		c.drawFlag = true
+		c.pc += 2
+		break
+	case 0xE000:
+		switch c.opcode & 0x00FF {
+		case 0x009E:
+			if c.key[c.v[(c.opcode&0x0F00)>>8]] != 0 {
+				c.pc += 4
+			} else {
+				c.pc += 2
+			}
+			break
+		}
+		break
+	case 0xF000:
+		x := (c.opcode & 0x0F00) >> 8
+		fmt.Printf("F: 0x%X\n", c.opcode)
+		switch c.opcode & 0x00FF {
+		case 0x0029:
+			// TODO
+			// c.index = uint16(c.v[x]) *
+			c.pc += 2
+			break
+		case 0x0033:
+			c.memory[c.index] = c.v[x] / 100
+			c.memory[c.index+1] = (c.v[x] / 10) % 10
+			c.memory[c.index+2] = (c.v[x] / 100) % 10
+			c.pc += 2
+			break
+		case 0x0065:
+			for i := uint16(0); i < x+1; i++ {
+				c.v[i] = c.memory[c.index+i]
+			}
+			c.pc += 2
+			break
+		}
+		break
 	default:
 		fmt.Printf("Unknown opcode: 0x%X\n", c.opcode)
 	}
@@ -84,9 +164,37 @@ func (c *chip8) emulateCycle() {
 }
 
 func (c *chip8) loadGame(filepath string) error {
+	buffer, err := ioutil.ReadFile(filepath)
+	if err != nil {
+		return err
+	}
+
+	for i := 0; i < len(buffer); i++ {
+		// 0x200 == 512
+		c.memory[512+i] = buffer[i]
+	}
 	return nil
 }
 
+var fontSet = [80]byte{
+	0xF0, 0x90, 0x90, 0x90, 0xF0, // 0
+	0x20, 0x60, 0x20, 0x20, 0x70, // 1
+	0xF0, 0x10, 0xF0, 0x80, 0xF0, // 2
+	0xF0, 0x10, 0xF0, 0x10, 0xF0, // 3
+	0x90, 0x90, 0xF0, 0x10, 0x10, // 4
+	0xF0, 0x80, 0xF0, 0x10, 0xF0, // 5
+	0xF0, 0x80, 0xF0, 0x90, 0xF0, // 6
+	0xF0, 0x10, 0x20, 0x40, 0x40, // 7
+	0xF0, 0x90, 0xF0, 0x90, 0xF0, // 8
+	0xF0, 0x90, 0xF0, 0x10, 0xF0, // 9
+	0xF0, 0x90, 0xF0, 0x90, 0x90, // A
+	0xE0, 0x90, 0xE0, 0x90, 0xE0, // B
+	0xF0, 0x80, 0x80, 0x80, 0xF0, // C
+	0xE0, 0x90, 0x90, 0x90, 0xE0, // D
+	0xF0, 0x80, 0xF0, 0x80, 0xF0, // E
+	0xF0, 0x80, 0xF0, 0x80, 0x80, // F
+}
+
 func (c *chip8) drawGraphics() {
 
 }