/**
 * LCD subpixel rendering support
 *
 * LCD displays have RGB subpixels that can be individually addressed
 * to achieve higher effective resolution. This module provides:
 * 1. Subpixel rendering (3x horizontal resolution)
 * 2. FIR filtering to reduce color fringing
 */
import type { GlyphPath } from "../render/path.ts";
import type { Bitmap } from "./types.ts";
/**
 * LCD filter weights for reducing color fringing
 * These are based on FreeType's default LCD filter
 */
export declare const LCD_FILTER_LIGHT: number[];
export declare const LCD_FILTER_DEFAULT: number[];
export declare const LCD_FILTER_LEGACY: number[];
/**
 * LCD rendering mode
 */
export declare enum LcdMode {
    /** Horizontal RGB subpixels (most common) */
    RGB = 0,
    /** Horizontal BGR subpixels */
    BGR = 1,
    /** Vertical RGB subpixels */
    RGB_V = 2,
    /** Vertical BGR subpixels */
    BGR_V = 3
}
/**
 * Rasterize a glyph with LCD subpixel rendering
 *
 * The algorithm:
 * 1. Render at 3x horizontal resolution
 * 2. Apply FIR filter to reduce color fringing
 * 3. Output RGB values per pixel
 *
 * @param path Glyph path to rasterize
 * @param width Width in pixels
 * @param height Height in pixels
 * @param scale Scale factor from font units to pixels
 * @param offsetX X offset in pixels
 * @param offsetY Y offset in pixels
 * @param mode LCD subpixel mode (RGB, BGR, RGB_V, BGR_V)
 * @param filterWeights FIR filter coefficients for reducing color fringing
 * @returns Bitmap with LCD subpixel data (3 bytes per pixel)
 */
export declare function rasterizeLcd(path: GlyphPath, width: number, height: number, scale: number, offsetX: number, offsetY: number, mode?: LcdMode, filterWeights?: number[]): Bitmap;
/**
 * Convert LCD bitmap to RGBA for display
 * Uses gamma-corrected blending against a background color
 *
 * @param lcd LCD bitmap to convert
 * @param bgColor Background color as RGB (0-255 each)
 * @param fgColor Foreground color as RGB (0-255 each)
 * @returns RGBA pixel array (4 bytes per pixel)
 */
export declare function lcdToRGBA(lcd: Bitmap, bgColor?: [number, number, number], fgColor?: [number, number, number]): Uint8Array;