文本的自动字体大小(通过PHP的GD)

时间:2008-11-14 11:36:48

标签: php gd

对于$ im(GD图像资源)上的文本,有一个x * y的空格如何选择字体大小(或写入文本),它不会溢出该区域?

2 个答案:

答案 0 :(得分:4)

我认为您正在寻找imagettfbbox功能。

几年前我用它来生成一个为Web界面生成本地化按钮的脚本。实际上,如果文本不适合模板,我会调整按钮大小,以保持文本大小一致,但您可以尝试减小文本大小,直到文本适合。

如果您有兴趣,我可以粘贴我的代码的一些片段(或立即给它)。

[编辑]好的,这是我的代码的一些摘录,有一天我会清理它(使其独立于目标应用程序,提供样本)并将其作为一个整体公开。
我希望这些片段有意义。

// Bounding boxes: ImageTTFBBox, ImageTTFText:
// Bottom-Left: $bb[0], $bb[1]
// Bottom-Right: $bb[2], $bb[3]
// Top-Right: $bb[4]; $bb[5]
// Top-Left: $bb[6], $bb[7]
define('GDBB_TOP', 5);
define('GDBB_LEFT', 0);
define('GDBB_BOTTOM', 1);
define('GDBB_RIGHT', 2);

#[ In class constructor ]#
// Get size in pixels, must convert to points for GD2.
// Because GD2 assumes 96 pixels per inch and we use more "standard" 72.
$this->textSize *= 72/96;
$this->ComputeTextDimensions($this->textSize, FONT, $this->text);

#[ Remainder of the class (extract) ]
/**
 * Compute the dimensions of the text.
 */
function ComputeTextDimensions($textSize, $fontFile, $text)
{
    $this->textAreaWidth = $this->imageHSize - $this->marginL - $this->marginR;
    $this->textAreaHeight = $this->imageVSize - $this->marginT - $this->marginB;

    // Handle text on several lines
    $this->lines = explode(NEWLINE_CHAR, $text);
    $this->lineNb = count($this->lines);
    if ($this->lineNb == 1)
    {
        $bb = ImageTTFBBox($textSize, 0, $fontFile, $text);
        $this->textWidth[0] = $bb[GDBB_RIGHT] - $bb[GDBB_LEFT];
        $this->maxTextWidth = $this->textWidth[0];
        $this->textHeight[0] = $bb[GDBB_BOTTOM] - $bb[GDBB_TOP];
    }
    else
    {
        for ($i = 0; $i < $this->lineNb; $i++)
        {
            $bb = ImageTTFBBox($textSize, 0, $fontFile, $this->lines[$i]);
            $this->textWidth[$i] = $bb[GDBB_RIGHT] - $bb[GDBB_LEFT];
            $this->maxTextWidth = max($this->maxTextWidth, $this->textWidth[$i]);
            $this->textHeight[$i] = $bb[GDBB_BOTTOM] - $bb[GDBB_TOP];
        }
    }
    // Is the given text area width too small for asked text?
    if ($this->maxTextWidth > $this->textAreaWidth)
    {
        // Yes! Increase button size
        $this->textAreaWidth = $this->maxTextWidth;
        $this->imageHSize = $this->textAreaWidth + $this->marginL + $this->marginR;
    }
    // Now compute the text positions given the new (?) text area width
    if ($this->lineNb == 1)
    {
        $this->ComputeTextPosition(0, $textSize, $fontFile, $text, false);
    }
    else
    {
        for ($i = 0; $i < $this->lineNb; $i++)
        {
            $this->ComputeTextPosition($i, $textSize, $fontFile, $this->lines[$i], false);
        }
    }
}

/**
 * Compute xText and yText (text position) for the given text.
 */
function ComputeTextPosition($index, $textSize, $fontFile, $text, $centerAscDesc)
{
    switch ($this->textAlign)
    {
    case 'L':
        $this->xText[$index] = $this->marginL;
        break;
    case 'R':
        $this->xText[$index] = $this->marginL + 
                $this->textAreaWidth - $this->textWidth[$index];
        break;
    case 'C':
    default:
        $this->xText[$index] = $this->marginL + 
                ($this->textAreaWidth - $this->textWidth[$index]) / 2;
        break;
    }

    if ($centerAscDesc)
    {
        // Must compute the difference between baseline and bottom of BB.
        // I have to use a temporary image, as ImageTTFBBox doesn't use coordinates
        // providing offset from the baseline.
        $tmpBaseline = 5;
        // Image size isn't important here, GD2 still computes correct BB
        $tmpImage = ImageCreate(5, 5);
        $bbt = ImageTTFText($tmpImage, $this->textSize, 0, 0, $tmpBaseline,
                $this->color, $fontFile, $text);
        // Bottom to Baseline
        $baselinePos = $bbt[GDBB_BOTTOM] - $tmpBaseline;
        ImageDestroy($tmpImage);
        $this->yText[$index] = $this->marginT + $this->textAreaHeight -
                ($this->textAreaHeight - $this->textHeight) / 2 - $baselinePos + 0.5;
    }
    else
    {
        // Actually, we want to center the x-height, ie. to keep the baseline at same pos.
        // whatever the text is really, ie. independantly of ascenders and descenders.
        // This provide better looking buttons, as they are more consistent.
        $bbt = ImageTTFBBox($textSize, 0, $fontFile, "moxun");
        $tmpHeight = $bbt[GDBB_BOTTOM] - $bbt[GDBB_TOP];
        $this->yText[$index] = $this->marginT + $this->textAreaHeight -
                ($this->textAreaHeight - $tmpHeight) / 2 + 0.5;
    }
}

/**
 * Add the text to the button.
 */
function DrawText()
{
    for ($i = 0; $i < $this->lineNb; $i++)
    {
        // Increase slightly line height
        $yText = $this->yText[$i] + $this->textHeight[$i] * 1.1 * 
                ($i - ($this->lineNb - 1) / 2);
        ImageTTFText($this->image, $this->textSize, 0,
                $this->xText[$i], $yText, $this->color, FONT, $this->lines[$i]);
    }
}

答案 1 :(得分:4)

我上面的PhiLho上课,并将其扩展为动态缩放单个文本行以适应边界框。我也打电话给你,这样你就可以看到它是如何运作的。这几乎是复制意大利面,只需改变你的变量,它应该开箱即用。

      <? 

header("Content-type: image/png"); 

define('GDBB_TOP', 5);
define('GDBB_LEFT', 0);
define('GDBB_BOTTOM', 1);
define('GDBB_RIGHT', 2);


class DrawFont {

    function DrawFont($details) {
    // Get size in pixels, must convert to points for GD2.
    // Because GD2 assumes 96 pixels per inch and we use more "standard" 72.
    $this->textSizeMax = $details['size'];
    $this->font = $details['font'];
    $this->text = $details['text'];
    $this->image = $details['image']; 
    $this->color = $details['color'];
    $this->shadowColor = $details['shadowColor'];
    $this->textAlign = "C";

    $this->imageHSize = $details['imageHSize'];
    $this->imageVSize = $details['imageVSize'];

    $this->marginL = $details['marginL'];
    $this->marginR = $details['marginR'];

    $this->marginT = $details['marginT'];
    $this->marginB = $details['marginB'];

    $this->ComputeTextDimensions($this->font, $this->text);

    }


    /**
     * Compute the dimensions of the text.
     */
    function ComputeTextDimensions($fontFile, $text)
    {
        $this->textAreaWidth = $this->imageHSize - $this->marginL - $this->marginR;
        $this->textAreaHeight = $this->imageVSize - $this->marginT - $this->marginB;

        // Handle text on several lines
        $this->lines = explode(' ', $text);
        $this->lineNb = count($this->lines);




        if ($this->lineNb == 1)
        {

            $this->textSize[0] = $this->textSizeMax;

            $bb = ImageTTFBBox($this->textSize[0], 0, $fontFile, $text);
            $this->textWidth[0] = $bb[GDBB_RIGHT] - $bb[GDBB_LEFT];
            $this->maxTextWidth = $this->textWidth[0];
            $this->textHeight[0] = $bb[GDBB_BOTTOM] - $bb[GDBB_TOP];


            $this->textSize[0] = $this->textSizeMax;
              while ($this->textWidth[0] > $this->textAreaWidth && $this->textSize[0] > 1) {

                $this->textSize[0]--;

                $bb = ImageTTFBBox($this->textWidth[$i], 0, $fontFile, $text);
                $this->textWidth[0] = $bb[GDBB_RIGHT] - $bb[GDBB_LEFT];
                $this->maxTextWidth = $this->textWidth[0];
                $this->textHeight[0] = $bb[GDBB_BOTTOM] - $bb[GDBB_TOP];    

              }


        }
        else
        {
            for ($i = 0; $i < $this->lineNb; $i++)
            {
                $this->textSize[$i] = $this->textSizeMax;

                $bb = ImageTTFBBox($this->textSize[$i], 0, $fontFile, $this->lines[$i]);
                $this->textWidth[$i] = $bb[GDBB_RIGHT] - $bb[GDBB_LEFT];
                $this->maxTextWidth = max($this->maxTextWidth, $this->textWidth[$i]);
                $this->textHeight[$i] = $bb[GDBB_BOTTOM] - $bb[GDBB_TOP];



                while ($this->textWidth[$i] > $this->textAreaWidth && $this->textSize[$i] > 1) {

                  $this->textSize[$i]--;

                  $bb = ImageTTFBBox($this->textSize[$i], 0, $fontFile, $this->lines[$i]);
                  $this->textWidth[$i] = $bb[GDBB_RIGHT] - $bb[GDBB_LEFT];
                  $this->maxTextWidth = max($this->maxTextWidth, $this->textWidth[$i]);
                  $this->textHeight[$i] = $bb[GDBB_BOTTOM] - $bb[GDBB_TOP];      


                }




            }
        }

        /*
        // Is the given text area width too small for asked text?
        if ($this->maxTextWidth > $this->textAreaWidth)
        {
            // Yes! Increase button size
            $this->textAreaWidth = $this->maxTextWidth;
            $this->imageHSize = $this->textAreaWidth + $this->marginL + $this->marginR;


        }
        */

        // Now compute the text positions given the new (?) text area width
        if ($this->lineNb == 1)
        {
            $this->ComputeTextPosition(0, $this->textSize[0], $fontFile, $text, false);
        }
        else
        {
            for ($i = 0; $i < $this->lineNb; $i++)
            {
                $this->ComputeTextPosition($i, $this->textSize[$i], $fontFile, $this->lines[$i], false);
            }
        }
    }

    /**
     * Compute xText and yText (text position) for the given text.
     */
    function ComputeTextPosition($index, $textSize, $fontFile, $text, $centerAscDesc)
    {
        switch ($this->textAlign)
        {
        case 'L':
            $this->xText[$index] = $this->marginL;
            break;
        case 'R':
            $this->xText[$index] = $this->marginL + 
                    $this->textAreaWidth - $this->textWidth[$index];
            break;
        case 'C':
        default:
            $this->xText[$index] = $this->marginL + 
                    ($this->textAreaWidth - $this->textWidth[$index]) / 2;
            break;
        }

        if ($centerAscDesc)
        {
            // Must compute the difference between baseline and bottom of BB.
            // I have to use a temporary image, as ImageTTFBBox doesn't use coordinates
            // providing offset from the baseline.
            $tmpBaseline = 5;
            // Image size isn't important here, GD2 still computes correct BB
            $tmpImage = ImageCreate(5, 5);
            $bbt = ImageTTFText($tmpImage, $this->textSizeMax, 0, 0, $tmpBaseline,
                    $this->color, $fontFile, $text);
            // Bottom to Baseline
            $baselinePos = $bbt[GDBB_BOTTOM] - $tmpBaseline;
            ImageDestroy($tmpImage);
            $this->yText[$index] = $this->marginT + $this->textAreaHeight -
                    ($this->textAreaHeight - $this->textHeight) / 2 - $baselinePos + 0.5;
        }
        else
        {
            // Actually, we want to center the x-height, ie. to keep the baseline at same pos.
            // whatever the text is really, ie. independantly of ascenders and descenders.
            // This provide better looking buttons, as they are more consistent.
            $bbt = ImageTTFBBox($textSize, 0, $fontFile, "moxun");
            $tmpHeight = $bbt[GDBB_BOTTOM] - $bbt[GDBB_TOP];
            $this->yText[$index] = $this->marginT + $this->textAreaHeight -
                    ($this->textAreaHeight - $tmpHeight) / 2 + 0.5;
        }
    }

    /**
     * Add the text to the button.
     */
    function DrawText()
    {

        $this->maxTextHeight = 0;

        // find maxTextHeight
        for ($i = 0; $i < $this->lineNb; $i++)
        {
          if ($this->textHeight[$i] > $this->maxTextHeight) {
            $this->maxTextHeight = $this->textHeight[$i];
          }
        }

        for ($i = 0; $i < $this->lineNb; $i++)
        {
            // Increase slightly line height
            $yText = $this->yText[$i] + $this->maxTextHeight * 1.1 * 
                    ($i - ($this->lineNb - 1) / 2);

            ImageTTFText($this->image, $this->textSize[$i], 0,
                    $this->xText[$i]+2, $yText+2, $this->shadowColor, $this->font, $this->lines[$i]);

            ImageTTFText($this->image, $this->textSize[$i], 0,
                    $this->xText[$i], $yText, $this->color, $this->font, $this->lines[$i]);


        }
    }

}





// Script starts here

$im = imagecreatefromjpeg("/home/cvgcfjpq/public_html/fb/img/page_template.jpg"); 

$color = imagecolorallocate($im, 235, 235, 235);
$shadowColor = imagecolorallocate($im, 90, 90, 90);

$details = array("image" => $im, 
                 "font" => "OldSansBlack.ttf", 
                 "text" => $_GET['name'],
                 "color" => $color,
                 "shadowColor" => $shadowColor,
                 "size" => 40,
                 "imageHSize" => 200,
                 "imageVSize" =>  250,
                 "marginL" => 5,
                 "marginR" => 5,
                 "marginT" => 5,
                 "marginB" => 5);

$dofontobj =& new DrawFont($details);
$dofontobj->DrawText();

imagepng($im); 
imagedestroy($im); 
unset($px); 

?>