<?php
/** @noinspection PhpUnused */

namespace Cijber\GraphicsToolkit;

use Cijber\GraphicsToolkit\Consts\GLConsts;
use FFI;
use FFI\CData;
use RuntimeException;


class GL extends GLConsts {
    public static string $lastCall;
    public static FFI $ffi;

    /**
     * @var array|callable[]
     */
    public static array $calls;

    /**
     * @GLIgnore
     */
    public static function init() {
        static::$ffi = FFI::load(__DIR__ . "/../headers/gl_generated.h");
        include_once __DIR__ . "/gl_functions.php";
    }

    /**
     * @GLIgnore
     */
    public static function getProcAddress($name): CData {
        $funcname = 'gl' . ucfirst($name);
        $typename = 'FUNC_' . $funcname;

        $funcstring = static::$ffi->new(FFI::arrayType(static::$ffi->type('GLubyte'), [strlen($funcname) + 1]));
        FFI::memcpy($funcstring, $funcname, strlen($funcname));
        $funcstring[strlen($funcname)] = "\0";

        /** @var CData $proc */
        /** @noinspection PhpUndefinedMethodInspection */
        $proc = static::$ffi->glXGetProcAddress(
          static::$ffi->cast("GLubyte*", $funcstring)
        );

        /** @noinspection PhpUndefinedMethodInspection */
        if ($proc === null || FFI::isNull($proc)) {
            throw new RuntimeException("GL function $name doesn't exist");
        }

        return static::$ffi->cast($typename, $proc);
    }

    public static function shaderSource(int $shader, array $sources) {
        $lens    = [];
        $strings = [];
        foreach ($sources as $source) {
            $strings[] = Utils::string($source, false);
            $lens[]    = strlen($source);
        }

        $arrays  = Utils::arrayOf('char*', $strings);
        $lengths = Utils::arrayOf('int32_t', $lens);

        glShaderSource($shader, count($sources), $arrays, $lengths);
    }
}