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？
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);
?>