I'm using FreeType2 for font rendering, and I need to get a global bounding box for all fonts, so I can align them in a nice grid. I call FT_Set_Char_Size followed by extracting the global bounds using
int pixels_x = ::FT_MulFix((face->bbox.xMax - face->bbox.xMin), face->size->metrics.x_scale );
int pixels_y = ::FT_MulFix((face->bbox.yMax - face->bbOx.yMin), face->size->metrics.y_scale );
return Size (pixels_x / 64, pixels_y / 64);
which works, but it's quite a bit too large. I also tried to compute using doubles (as described in the FreeType2 tutorial), but the results are practically the same. Even using just face->bbox.xMax results in bounding boxes which are too wide. Am I doing the right thing, or is there simply some huge glyph in my font (Arial.ttf in this case?) Any way to check which glyph is supposedly that big?
Why not calculate the min/max from the characters that you are using in the string that you want to align? Just loop through the characters and store the maximum and minimum from the characters that you are using. You can store these values after you rendered them so you don't need to look it up every time you render the glyphs.
I have a similar problem using freetype to render a bunch of text elements that will appear in a grid. Not all of the text elements are the same size, and I need to prerender them before I know where they would be laid out. The different sizes were the biggest problem when the heights changed, such as for letters with descending portions (like "j" or "Q").
I ended up using the height that is on the face (kind of like you did with the bbox). But like you mentioned, that value was much to big. It's supposed to be the baseline to baseline distance, but it appeared to be about twice that distance. So, I took the easy way out and divided the reported height by 2 and used that as a general height value. Most likely, the height is too big because there are some characters in the font that go way high or way low.
I suppose a better way might be to loop through all the characters expected to be used, get their glyph metrics and store the largest height found. But that doesn't seem all that robust either.
Your code is right.
It's not too large.
Because there are so many special symbols that is vary large than ascii charater. . view special big symbol
it's easy to traverse all unicode charcode, to find those large symbol.
if you only need ascii, my hack method is
FT_MulFix(face_->units_per_EM, face_->size->metrics.x_scale ) >> 6
FT_MulFix(face_->units_per_EM, face_->size->metrics.y_scale ) >> 6
Related
I am drawing text in a PDF page using iTextSharp, and I have two requirements:
1) the text needs to be searchable by Adobe Reader and such
2) I need character-level control over where the text is drawn.
I can draw the text word-by-word using PdfContentByte.ShowText(), but I don't have control over where each character is drawn.
I can draw the text character-by-character using PdfContentByte.ShowText() but then it isn't searchable.
I'm now trying to create a PdfTextArray, which would seem to satisfy both of my requirements, but I'm having trouble calculating the correct offsets.
So my first question is: do you agree that PdfTextArray is what I need to do, in order to satisfy both of my original requirements?
If so, I have the PdfTextArray working correctly (in that it's outputting text) but I can't figure out how to accurately calculate the positioning offset that needs to get put between each pair of characters (right now I'm just using the fixed value -200 just to prove that the function works).
I believe the positioning offset is the distance from the right edge of the previous character to the left edge of the new character, expressed in "thousandths of a unit of text space". That leaves me two problems:
1) How wide is the previous character (in points), as drawn in the specified font & height? (I know where its left edge is, since I drew it there)
2) How do I convert from points to "units of text space"?
I'm not doing any fancy scaling or rotating, so my transformation matrices should all be identity matrices, which should simplify the calculations ...
Thanks,
Chris
I was using a JFace TreeViewer perfectly well for a while.
It has a bunch of branches of varying lengths, but at the end of the day, the entire tree stretched to the size of its longest string. This was great.
Recently, I decided that the TreeItems labels should have some style to them fonts and highlights.
The trouble, is that the new fonts are a bit larger and stretch the size of the overall string. It seems that the Tree or TreeViewer doesn't recognize this expansion and still judges the size of the label by the amount of small characters in it. The result is that I get a TreeViewer with a horizontal scrollbar, which is highly inconvenient because now my users will have to scroll across each tree, rather than just being to quickly glance at the data.
Does anyone know how to get the Tree to properly fit the length of the longest string, and take into account the added length of the styling, etc?
Thanks!
While this is not a complete answer, I hope it will help jogs someone's memory who has more advanced knowledge on this:
When I set the font to the ViewerCell object to a font that is wide, the entire row properly resizes. It seems that the Tree measures its width by checking the length of the text and the font, but disregards the Style Ranges.
I want to know how many characters I can fit in a single line, but the function window-width returns the same number regardless of the font size. Is there a workaround?
Thanks
In general there is no such thing as "how many characters I can fit in a single line" since a single line may contain characters using different fonts or different sizes, and also because of the fact that fonts can be proportional so even with a single font, the size of each char can change (and beyond that, there could be kerning issues, etc...).
I use iReport to create reports, and I would like to know if there is a way to set the width of "optically grouped fields". They should be set to the minimal size that still displays longest text. I have Static Text on left side and Text Field right of them. This Text Fields are set to the width 150 and alignment to right, but I'd like to set smaller size to wipe out white spaces.
Consider some thing like this
Name: Paul
Surname: Smither
And want automatically to
Name: Paul
Surname: Smither
etc. can be smaller then preset size but no bigger.
Is there a way?? even some component
You cannot change the element width dynamically without using Java frameworks.
The quote from JasperReports Ultimate Guide:
ELEMENT SIZE
The width and height attributes are mandatory and represent the size
of the report element measured in pixels. Other element stretching
settings may instruct the reporting engine to ignore the specified
element height. Even in this case, the attributes remain mandatory
since even when the height is calculated dynamically, the element will
not be smaller than the originally specified height.
You can read this article for better understanding the mechanism of changing the element size.
If it's genuinely just a couple of fields that come from the same row in the dataset, then you could hack something together.
Use a monospace font
Define your maximum field length with a String set to N spaces. For example:
$P{MaxLengthString} default value is 10 spaces: " "
Change your field text from $F{FirstName} to this:
$P{MaxLengthString}.substring(
$P{MaxLengthString}.length() + $F{FirstName}.length() - java.lang.Math.max($F{FirstName}.length(), $F{LastName}.length())
) + $F{FirstName}
That is... er... a bit more complex. And it only works with monospace fonts. And I can't believe I really suggested this. Don't do it. (But it ought to work.)
Look at this UILabel. It's center-aligned:
Now look at this UILabel. Although it is technically center-aligned, it really doesn't look that way:
The reason why it looks like this is because the center-alignment considers the degree symbol a third character, thus bumping the other two off to the left a bit. My question is: is there any way to ignore certain characters whilst center-aligning a label?
Interesting question. The only solution that comes to mind for me is to pad the text string with spaces on the front to cancel out the ignored characters on the back.
That is, to center #"60d" as if it were #"60", set the text to #" 60d". This works well with a fixed width font, but otherwise is only a rough approximation.
If you like this idea and want to get fancy with it, then you can use NSStrings method
– stringByPaddingToLength:withString:startingAtIndex:
perhaps in conjunction with – rangeOfCharacterFromSet: or some such method to determine how many spaces to pad with.
You could of course measure the text string(s) and compute your own positioning, rather than using text alignment in a larger field.
Assuming you don't want to do that, another idea that comes to mind is to display the string “°60°” with the first character styled with a color of opacity 0 and no shadow.
I don't do iOS development so I don't know how practical these are.