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| -rw-r--r-- | src/fl_draw.cxx | 16 |
1 files changed, 16 insertions, 0 deletions
diff --git a/src/fl_draw.cxx b/src/fl_draw.cxx index 4c13a5657..657ee05ec 100644 --- a/src/fl_draw.cxx +++ b/src/fl_draw.cxx @@ -383,9 +383,25 @@ void fl_draw( Measure how wide and tall the string will be when printed by the fl_draw() function with \p align parameter. If the incoming \p w is non-zero it will wrap to that width. + + The 'current font' is used to do the width/height calculations, + so unless its value is known at the time fl_measure() is called, + it is advised to first set the current font with fl_font(). + + \b Note: In the general use case, it's a common error to forget to set + \p w to 0 before calling fl_measure() when wrap behavior isn't needed. + \param[in] str nul-terminated string \param[out] w,h width and height of string in current font \param[in] draw_symbols non-zero to enable @@symbol handling [default=1] + + \code + // Example: Common use case for fl_measure() + const char *s = "This is a test"; + int wi=0, hi=0; // initialize to zero before calling fl_measure() + fl_font(FL_HELVETICA, 14); // set current font face/size to be used for measuring + fl_measure(s, wi, hi); // returns pixel width/height of string in current font + \endcode */ void fl_measure(const char* str, int& w, int& h, int draw_symbols) { if (!str || !*str) {w = 0; h = 0; return;} |