Added Gameboy Emulator

src/debug.js

@@ -0,0 +1,73 @@
+var GameboyJS;
+(function (GameboyJS) {
+"use strict";
+
+var Debug = {};
+// Output a range of 16 memory addresses
+Debug.view_memory = function(addr, gameboy) {
+    var memory = gameboy.cpu.memory;
+    addr = addr & 0xFFF0;
+    var pad = '00';
+    var str = addr.toString(16) + ':';
+    for (var i = addr; i < addr + 0x10; i++) {
+        if ((i & 0x1) == 0) {
+            str += ' ';
+        }
+        var val = memory[i] || 0;
+
+        val = val.toString(16);
+        str += pad.substring(val.length) + val;
+    }
+
+    return str;
+};
+
+Debug.view_tile = function(gameboy, index, dataStart) {
+    var memory = gameboy.cpu.memory;
+    var screen = gameboy.screen;
+    var LCDC = screen.deviceram(screen.LCDC);
+    if (typeof dataStart === 'undefined') {
+        dataStart = 0x8000;
+        if (!GameboyJS.Util.readBit(LCDC, 4)) {
+            dataStart = 0x8800;
+            index = GameboyJS.cpuOps._getSignedValue(index) + 128;
+        }
+    }
+
+    var tileData = screen.readTileData(index, dataStart);
+
+    var pixelData = new Array(8 * 8)
+    for (var line = 0; line < 8; line++) {
+        var b1 = tileData.shift();
+        var b2 = tileData.shift();
+
+        for (var pixel = 0; pixel < 8; pixel++) {
+            var mask = (1 << (7-pixel));
+            var colorValue = ((b1 & mask) >> (7-pixel)) + ((b2 & mask) >> (7-pixel))*2;
+            pixelData[line * 8 + pixel] = colorValue;
+        }
+    }
+
+    var i = 0;
+    while (pixelData.length) {
+        console.log(i++ + ' ' + pixelData.splice(0, 8).join(''));
+    }
+};
+
+Debug.list_visible_sprites = function(gameboy) {
+    var memory = gameboy.cpu.memory;
+    var indexes = new Array();
+    for (var i = 0xFE00; i < 0xFE9F; i += 4) {
+        var x = memory.oamram(i + 1);
+        var y = memory.oamram(i);
+        var tileIndex = memory.oamram(i + 2);
+        if (x == 0 || x >= 168) {
+            continue;
+        }
+        indexes.push({oamIndex:i, x:x, y:y, tileIndex:tileIndex});
+    }
+
+    return indexes;
+};
+GameboyJS.Debug = Debug;
+}(GameboyJS || (GameboyJS = {})));