broken-neees
Version:
A really broken NEEES emulator that introduces glitches and random bugs on purpose!
103 lines (102 loc) • 6.06 kB
JavaScript
;
Object.defineProperty(exports, "__esModule", {
value: true
});
exports.default = void 0;
var _Tile = _interopRequireDefault(require("./Tile"));
var _byte = _interopRequireDefault(require("../lib/byte"));
function _interopRequireDefault(obj) { return obj && obj.__esModule ? obj : { default: obj }; }
function _typeof(obj) { "@babel/helpers - typeof"; return _typeof = "function" == typeof Symbol && "symbol" == typeof Symbol.iterator ? function (obj) { return typeof obj; } : function (obj) { return obj && "function" == typeof Symbol && obj.constructor === Symbol && obj !== Symbol.prototype ? "symbol" : typeof obj; }, _typeof(obj); }
function _classCallCheck(instance, Constructor) { if (!(instance instanceof Constructor)) { throw new TypeError("Cannot call a class as a function"); } }
function _defineProperties(target, props) { for (var i = 0; i < props.length; i++) { var descriptor = props[i]; descriptor.enumerable = descriptor.enumerable || false; descriptor.configurable = true; if ("value" in descriptor) descriptor.writable = true; Object.defineProperty(target, _toPropertyKey(descriptor.key), descriptor); } }
function _createClass(Constructor, protoProps, staticProps) { if (protoProps) _defineProperties(Constructor.prototype, protoProps); if (staticProps) _defineProperties(Constructor, staticProps); Object.defineProperty(Constructor, "prototype", { writable: false }); return Constructor; }
function _toPropertyKey(arg) { var key = _toPrimitive(arg, "string"); return _typeof(key) === "symbol" ? key : String(key); }
function _toPrimitive(input, hint) { if (_typeof(input) !== "object" || input === null) return input; var prim = input[Symbol.toPrimitive]; if (prim !== undefined) { var res = prim.call(input, hint || "default"); if (_typeof(res) !== "object") return res; throw new TypeError("@@toPrimitive must return a primitive value."); } return (hint === "string" ? String : Number)(input); }
var SCREEN_WIDTH = 256;
var SCREEN_HEIGHT = 240;
var TILE_SIZE_PIXELS = 8;
var TILES_PER_ROW = SCREEN_WIDTH / TILE_SIZE_PIXELS;
var MEM_NAME_TABLES = 0x2000;
var NAME_TABLE_SIZE_BYTES = 1024;
var ATTRIBUTE_TABLE_SIZE_BYTES = 64;
var ATTRIBUTE_TABLE_BLOCK_SIZE = 32;
var ATTRIBUTE_TABLE_REGION_SIZE = 16;
var ATTRIBUTE_TABLE_TOTAL_BLOCKS_X = SCREEN_WIDTH / ATTRIBUTE_TABLE_BLOCK_SIZE;
var ATTRIBUTE_TABLE_TOTAL_REGIONS_X = ATTRIBUTE_TABLE_BLOCK_SIZE / ATTRIBUTE_TABLE_REGION_SIZE;
var ATTRIBUTE_TABLE_REGION_SIZE_BITS = 2;
function xxx(time, period, radius) {
return radius + Math.round(radius * Math.cos(2 * Math.PI * time / period));
}
function yyy(time, period, radius) {
return radius + Math.round(radius * Math.sin(2 * Math.PI * time / period));
}
var PERIOD = 60;
var RADIUS = 6;
var BackgroundRenderer = /*#__PURE__*/function () {
function BackgroundRenderer(ppu) {
_classCallCheck(this, BackgroundRenderer);
this.ppu = ppu;
}
_createClass(BackgroundRenderer, [{
key: "renderScanline",
value: function renderScanline() {
var y = this.ppu.scanline;
var scrolledY;
if (this.ppu.cpu.unbroken) {
scrolledY = this.ppu.loopy.scrolledY();
} else {
// [!!!]
scrolledY = (this.ppu.loopy.scrolledY() + (y > 31 ? yyy(this.ppu.frame, PERIOD, RADIUS) : 0)) % 240;
}
var backgroundColor = this.ppu.getColor(0, 0);
for (var x = 0; x < SCREEN_WIDTH; x++) {
if (!this.ppu.registers.ppuMask.showBackgroundInFirst8Pixels && x < 8) {
this.ppu.plotBG(x, y, backgroundColor, 0);
continue;
}
var scrolledX = void 0;
if (this.ppu.cpu.unbroken) {
scrolledX = this.ppu.loopy.scrolledX(x);
} else {
// [!!!]
scrolledX = (this.ppu.loopy.scrolledX(x) + xxx(this.ppu.frame, PERIOD, RADIUS)) % 256;
}
var nameTableId = this.ppu.loopy.nameTableId(scrolledX);
var nameTableX = scrolledX % SCREEN_WIDTH;
var nameTableY = scrolledY % SCREEN_HEIGHT;
var tileX = Math.floor(nameTableX / TILE_SIZE_PIXELS);
var tileY = Math.floor(nameTableY / TILE_SIZE_PIXELS);
var tileIndex = tileY * TILES_PER_ROW + tileX;
var tileId = this.ppu.memory.read(MEM_NAME_TABLES + nameTableId * NAME_TABLE_SIZE_BYTES + tileIndex);
var paletteId = this._getBackgroundPaletteId(nameTableId, nameTableX, nameTableY);
var paletteColors = this.ppu.getPaletteColors(paletteId);
var patternTableId = this.ppu.registers.ppuCtrl.backgroundPatternTableId;
var tileStartX = nameTableX % TILE_SIZE_PIXELS;
var tileInsideY = nameTableY % TILE_SIZE_PIXELS;
var tile = new _Tile.default(this.ppu, patternTableId, tileId, tileInsideY);
var tilePixels = Math.min(TILE_SIZE_PIXELS - tileStartX, SCREEN_WIDTH - nameTableX);
for (var xx = 0; xx < tilePixels; xx++) {
var colorIndex = tile.getColorIndex(tileStartX + xx);
var color = colorIndex > 0 ? paletteColors[colorIndex] : backgroundColor;
this.ppu.plotBG(x + xx, y, color, colorIndex);
}
x += tilePixels - 1;
}
}
}, {
key: "_getBackgroundPaletteId",
value: function _getBackgroundPaletteId(nameTableId, x, y) {
var startAddress = MEM_NAME_TABLES + (nameTableId + 1) * NAME_TABLE_SIZE_BYTES - ATTRIBUTE_TABLE_SIZE_BYTES;
var blockX = Math.floor(x / ATTRIBUTE_TABLE_BLOCK_SIZE);
var blockY = Math.floor(y / ATTRIBUTE_TABLE_BLOCK_SIZE);
var blockIndex = blockY * ATTRIBUTE_TABLE_TOTAL_BLOCKS_X + blockX;
var regionX = Math.floor(x % ATTRIBUTE_TABLE_BLOCK_SIZE / ATTRIBUTE_TABLE_REGION_SIZE);
var regionY = Math.floor(y % ATTRIBUTE_TABLE_BLOCK_SIZE / ATTRIBUTE_TABLE_REGION_SIZE);
var regionIndex = regionY * ATTRIBUTE_TABLE_TOTAL_REGIONS_X + regionX;
var block = this.ppu.memory.read(startAddress + blockIndex);
return _byte.default.getBits(block, regionIndex * ATTRIBUTE_TABLE_REGION_SIZE_BITS, ATTRIBUTE_TABLE_REGION_SIZE_BITS);
}
}]);
return BackgroundRenderer;
}();
exports.default = BackgroundRenderer;