Question

我正在寻找一种方法，使用PHP将文本包装到特定宽度的框中。我有动态文本字符串，可变字体大小。

我找到了一种很好的方法来从我想要的方式剪切文本： Smarter word-wrap in PHP for long words?

使用这段代码：

function smart_wordwrap($string, $width = 10, $break = "\n") {
// split on problem words over the line length
$pattern = sprintf('/([^ ]{%d,})/', $width);
$output = '';
$words = preg_split($pattern, $string, -1, PREG_SPLIT_NO_EMPTY | PREG_SPLIT_DELIM_CAPTURE);

foreach ($words as $word) {
    if (false !== strpos($word, ' ')) {
        // normal behaviour, rebuild the string
        $output .= $word;
    } else {
        // work out how many characters would be on the current line
        $wrapped = explode($break, wordwrap($output, $width, $break));
        $count = $width - (strlen(end($wrapped)) % $width);

        // fill the current line and add a break
        $output .= substr($word, 0, $count) . $break;

        // wrap any remaining characters from the problem word
        $output .= wordwrap(substr($word, $count), $width, $break, true);
    }
}

// wrap the final output
return wordwrap($output, $width, $break);

}

这很好用，但我需要找到一种方法来将设置的像素尺寸（约束框）和字体大小输入上面。上面的函数使用字符数 - 如果字体大小非常小，显然字符数需要更大，反之亦然。

如果我有以下变量，我还能做到吗？

$boxWidth = 200(px);
$text = (dynamic string);
$font = 'customfont.ttf'
$fontSize = (dynamic size);

我在考虑另一个循环到自动换行功能。或者也许有一种方法来编辑“爆炸”，因为我不完全确定该功能是如何工作的。

Answer 1

作为suggested的@Mark Baker，我已经使用imagettfbbox()

实现了此行为

可以找到完整的带有帮助功能的代码段here
我正在发布相关的代码位以供参考

//实用程序功能可帮助在图像上渲染文本

// Returns expected width of rendered text in pixels
public static function getWidthPixels(string $text, string $font, int $font_size): int {
    // https://www.php.net/manual/en/function.imageftbbox.php#refsect1-function.imageftbbox-returnvalues
    $bbox = imageftbbox($font_size, 0, $font, " " . $text);
    return $bbox[2] - $bbox[0];
}

// Returns wrapped format (with newlines) of a piece of text (meant to be rendered on an image)
// using the width of rendered bounding box of text
public static function wrapTextByPixels(
    string $text,
    int $line_max_pixels,
    int $font_size,
    string $font
): string {
    $words = explode(' ', $text);   // tokenize the text into words
    $lines = [];                             // Array[Array[string]]: array to store lines of words
    $crr_line_idx = 0;                       // (zero-based) index of current lines in which words are being added
    $crr_line_pixels = 0;                    // width of current line (in which words are being added) in pixels

    foreach ($words as $word) {
        // determine the new width of current line (in pixels) if the current word is added to it (including space)
        $crr_line_new_pixels = $crr_line_pixels + ImageTextRenderUtils::getWidthPixels(' ' . $word, $font, $font_size);
        // determine the width of current word in pixels
        $crr_word_pixels = ImageTextRenderUtils::getWidthPixels($word, $font, $font_size);


        if ($crr_word_pixels > $line_max_pixels) {
            // if the current word itself is too long to fit in single line
            // then we have no option: it must still be put in oneline only
            if ($crr_line_pixels == 0) {
                // but it is put into current line only if current line is empty
                $lines[$crr_line_idx] = array($word);
                $crr_line_idx++;
            } else {
                // otherwise if current line is non-empty, then the extra long word is put into a newline
                $crr_line_idx++;
                $lines[$crr_line_idx] = array($word);
                $crr_line_idx++;
                $crr_line_pixels = 0;
            }
        } else if ($crr_line_new_pixels > $line_max_pixels) {
            // otherwise if new width of current line (including current word and space)
            // exceeds the maximum permissible width, then force the current word into newline
            $crr_line_idx++;
            $lines[$crr_line_idx] = array($word);
            $crr_line_pixels = $crr_word_pixels;
        } else {
            // else if the current word (including space) can fit in the current line, then put it there
            $lines[$crr_line_idx][] = $word;
            $crr_line_pixels = $crr_line_new_pixels;
        }
    }

    // after the above foreach loop terminates, the $lines 2-d array Array[Array[string]]
    // would contain words segregated into lines to preserve the $line_max_pixels

    // now we just need to stitch together lines (array of word strings) into a single continuous piece of text with
    $concatenated_string = array_reduce(
        $lines,
        static function (string $wrapped_text, array $crr_line): string {
            return $wrapped_text . PHP_EOL . implode(' ', $crr_line);
        },
        ''
    );

    // the above process of concatenating lines into single piece of text will inadvertently
    // add an extra newline '\n' character in the beginning; so we must remove that
    return StringUtils::removeFirstOccurrence($concatenated_string, "\n");
}

带有像素尺寸的PHP自动换行

1 个答案: