/** Create a page texture with clamp + linear filtering (no mipmaps — §8.3). */
export declare function createTexture(gl: WebGL2RenderingContext): WebGLTexture;
/**
 * Upload a decoded page raster (ImageBitmap or canvas) into `tex`, returning the dimensions actually
 * uploaded (which differ from the source when it was too big for the GPU).
 *
 * A raster larger than `gl.MAX_TEXTURE_SIZE` on either axis cannot be uploaded: `texImage2D` fails
 * and leaves the texture incomplete, which samples as solid black. A zoomed page on a high-DPR phone
 * (small MAX_TEXTURE_SIZE, e.g. 4096) hits this readily. Downscale over-large rasters to fit,
 * preserving aspect, so a slightly-softer page beats a black one.
 */
export declare function uploadTexture(gl: WebGL2RenderingContext, tex: WebGLTexture, source: TexImageSource): {
    width: number;
    height: number;
};