nes-emu/ppu/renderers/tables/FramePalette.js

A NES emulator

"use strict";

Object.defineProperty(exports, "__esModule", {
  value: true
});
exports.default = void 0;
var _palette = _interopRequireDefault(require("../../constants/palette"));
var _constants = _interopRequireDefault(require("../../../constants"));
var _helpers = require("../../../helpers");
function _interopRequireDefault(e) { return e && e.__esModule ? e : { default: e }; }
/**
 * An area of memory which defines eight 4-color palettes (4 for backgrounds, 4 for sprites).
 * It's located at $3F00 (Palette RAM), and its total size is 32 bytes.
 * Each byte is an index to the system palette (0x00 ~ 0x3f).
 */
class FramePalette {
  constructor() {
    _helpers.WithContext.apply(this);
  }

  /** Returns the BGR color of `paletteIndex` from `paletteId`. */
  getColorOf(paletteId, paletteIndex) {
    const startAddress = _constants.default.PPU_ADDRESSED_PALETTE_RAM_START_ADDRESS + paletteId * _constants.default.PALETTE_SIZE;
    const colorIndex = this.context.ppu.memory.readAt(startAddress + paletteIndex);
    return _palette.default[colorIndex];
  }
}
exports.default = FramePalette;