So, i have the following code, but the bounding box loop in CalculateFontPointSize iterates generally 7-8 times(may be less may be more) to find best font size so its too slow for big images. I am looking for an alternative with better performance.
Rectangle rect2 = new Rectangle(6163, 3049, 4321, 2433);
imgLabel = new MagickImage(Color.Transparent, rect2.Width, rect2.Height);
imgLabel.Font = "Arial";
imgLabel.BackgroundColor = white;
imgLabel.FillColor = black;
imgLabel.TextGravity = Gravity.Center;
CalculateFontPointSize(imgLabel, text2, 100);
imgLabel.Read("label:" + text2);
imgOrig.Composite(imgLabel, new MagickGeometry(rect2));
privatevoid CalculateFontPointSize(MagickImage image, string text, double initialFontPointSize)
{
double calculatedWidth = 0;
double calculatedHeight = 0;
var metrics = image.FontTypeMetrics(text);
double sizeInc = 500;
double fontPointsize = initialFontPointSize, prevFontPointsize = 0,
lastFitFontPointsize = initialFontPointSize;
while (true)
{
prevFontPointsize = fontPointsize;
fontPointsize += sizeInc;
image.FontPointsize = fontPointsize;
metrics = image.FontTypeMetrics(text);
calculatedWidth = metrics.TextWidth;
calculatedHeight = metrics.TextHeight;
// Height calculation by FontTypeMetrics is not accurate so just use width.if (calculatedWidth > image.Width)
{
fontPointsize = prevFontPointsize;
if (sizeInc > 100)
sizeInc -= 100;
elseif (sizeInc > 10)
sizeInc -= 10;
elseif (sizeInc > 1)
sizeInc--;
else// sizeInc = 1
{
image.FontPointsize = lastFitFontPointsize;
break;
}
}
if (calculatedWidth <= image.Width && calculatedHeight <= image.Height)
{
lastFitFontPointsize = fontPointsize;
}
}
int threshold = 10;
if (calculatedWidth >= image.Width - threshold && calculatedWidth <= image.Width &&
calculatedHeight >= image.Height - threshold && calculatedHeight <= image.Height)
return;
using (MagickImage tempImg = new MagickImage(image))
{
sizeInc = 200;
fontPointsize = image.FontPointsize;
prevFontPointsize = 0;
tempImg.BackgroundColor = Color.White;
tempImg.FillColor = Color.Black;
MagickGeometry boundingBox = new MagickGeometry(0, 0);
while (true)
{
prevFontPointsize = fontPointsize;
fontPointsize += sizeInc;
tempImg.FontPointsize = fontPointsize;
tempImg.Read("label:" + text);
boundingBox = tempImg.BoundingBox;
if (boundingBox.Width > image.Width - threshold || boundingBox.Height > image.Height - threshold)
{
tempImg.Draw(new DrawableFillColor(Color.White),
new DrawableRectangle(new Rectangle(0, 0, tempImg.Width, tempImg.Height)));
fontPointsize = prevFontPointsize;
if (sizeInc > 100)
sizeInc -= 100;
elseif (sizeInc > 50)
sizeInc -= 50;
else// sizeInc = 50
{
image.FontPointsize = lastFitFontPointsize;
break;
}
}
else
{
lastFitFontPointsize = fontPointsize;
}
}
}
}