[portability] Use existing cv::putText

[ebachard]

Hello,

I recently discovered cvui, and I'm extremely interested. The idea is great, and I'm all for avoiding Qt to write a software.

For portability reasons, I think you should replace cvui::printf, with something from cv, even when writing the 2 + 3.2 = 5.2 example (in main-app.cpp), associated to two helpers, named intToString and floatToString (see below).

I'm not used to github, but I'll try to attach several patches. Waiting, you'll find a wild copy-paste. Apologies in advance.

@@ -43,11 +49,20 @@ int main(int argc, const char *argv[])
        // You can also specify the size of the text and its color
        // using hex 0xRRGGBB CSS-like style.
        cvui::text(frame, 200, 30, "Use hex 0xRRGGBB colors easily", 0.4, 0xff0000);
-       
-       // Sometimes you want to show text that is not that simple, e.g. strings + numbers.
-       // You can use cvui::printf for that. It accepts a variable number of parameter, pretty
-       // much like printf does.
-       cvui::printf(frame, 200, 50, 0.4, 0x00ff00, "Use printf formatting: %d + %.2f = %f", 2, 3.2, 5.2);
+
+                // cv::putText() signature, from opencv2/imgproc.hpp:
+                // putText(img, text, textOrg, fontFace, fontScale, Scalar::all(255),
+                //              thickness, LINE_TYPE /* default value = 8 */);
+
+                cv::Scalar aColor = CV_RGB(0, 255, 0);
+       cv::putText(frame,
+                            "Using cv::putText() : "+intToString(2)+" + "+floatToString(3.2)+" = "+floatToString(5.2),
+                            cv::Point(200,56),
+                            fontFace,
+                            0.4,
+                            aColor,
+                            1.5,
+                            8);

        // Buttons will return true if they were clicked, which makes
        // handling clicks a breeze.
@@ -88,7 +103,17 @@ int main(int argc, const char *argv[])
        cvui::checkbox(frame, 200, 190, "A checked checkbox", &checked2);

        // Display the lib version at the bottom of the screen
-       cvui::printf(frame, frame.cols - 80, frame.rows - 20, 0.4, 0xCECECE, "cvui v.%s", cvui::VERSION);
+//     cvui::printf(frame, frame.cols - 80, frame.rows - 20, 0.4, 0xCECECE, "cvui v.%s", cvui::VERSION);
+
+                aColor = CV_RGB(206, 206, 206);  /* 0xCE = 206 */
+                cv::putText(frame,
+                            "cvui v"+intToString(VERSION_MAJOR)+"."+intToString(VERSION_MINOR)+"."+intToString(VERSION_MICRO),
+                            cv::Point(frame.cols - 80,frame.rows - 10 /*FIXME : use font height instead of a magic */),
+                            fontFace,
+                            0.4,
+                            aColor,
+                            1.5,
+                            8);

        // This function must be called *AFTER* all UI components. It does
        // all the behind the scenes magic to handle mouse clicks, etc.

For intToString and floatToString, I propose to add the declarations in cvui.h like follow:

(in cvui.h)

+std::string intToString(int);
+std::string floatToString(double);

 namespace cvui
 {

in cvui.cpp:

+/* helpers */
+
+std::string intToString(int number)
+{
+   std::ostringstream ss;
+   ss << number;
+   return ss.str();
+}
+
+std::string floatToString(double aFloat)
+{
+   std::ostringstream ss;
+   ss << aFloat;
+   return ss.str();
+}
+
+

[ebachard]

ooops, looks like something was wrong with the code instertion ... apologies :-/

[ebachard]

Apologies, I'll read how to send patch, because I'm more used to speak patch language than html things.

[Dovyski]

Hello! Don't worry about formatting nor any Github idiosyncrasy, your contribution is the valuable part.

I would like you to elaborate a bit more regarding cvui::printf portability. Is it not portable because of a misbehavior or compilation warning/error on Linux/Mac?

I see the benefit of using cv::putText, but the general idea of cvui is to abstract opencv drawing primities to provide a simpler and more powerful API. I think the methods you suggested (intToString() and floatToString()) could be replaced by the already existing std::to_string():

// ... 
cv::putText(frame,
 "cvuiv" + std::to_string(VERSION_MAJOR) + "." + std::to_string(VERSION_MINOR) + "." + std::to_string(VERSION_MICRO),
  cv::Point(frame.cols - 80,frame.rows - 10 /*FIXME : use font height instead of a magic */),
  fontFace,
  0.4,
  aColor,
  1.5,
  8);

//...   

[ebachard]

Le 31/10/2016 20:16, Fernando Bevilacqua a écrit :

Hello! Don't worry about formatting nor any Github idiosyncrasy, your contribution is the valuable part.

Hello Fernando,

Apologies for the loooong delay : several things made me away from
keyboard, and I hope I'll have more time this week.

(of course, I'll answer the other mails you sent me asap)

I would like you to elaborate a bit more regarding cvui::printf portability. Is it not portable because of a misbehavior or compilation warning/error on Linux/Mac?

The problem is most of the time Microsoft, deciding something, without
verify the portability is respected on other OS's, and what I read here
and there told me it's simply not possible to use this directly. As I
wrote, I was busy last week, but I'll try to propose another solution
-means something simly working on Unix'es- once I'll have the time to
work on that. e.g., currently, some strings displaying is broken, due to
the uggly workaround I used (first thing was to make it compile, per see
:-)

I see the benefit of using cv::putText, but the general idea of cvui is to abstract opencv drawing primities to provide a simpler and more powerful API. I think the methods you suggested (intToString() and floatToString()) could be replaced by the already existing std::to_string():

OOOops, my bad :-)

I was simply unaware such solution was existing. Of course it is more
simple to use that, under to condition to build adding "-std=c++11 " in
the command line.

// ...
cv::putText(frame,
  "cvuiv" + std::to_string(VERSION_MAJOR) + "." + std::to_string(VERSION_MINOR) + "." + std::to_string(VERSION_MICRO),
   cv::Point(frame.cols - 80,frame.rows - 10 /*FIXME : use font height instead of a magic */),
   fontFace,
   0.4,
   aColor,
   1.5,
   8);

Tested one minute ago => works as expected on Linux (not tested on Mac OS X)

Regards,
Eric Bachard

//...

[Dovyski]

I think all the issues reported here were fixed by 80f382f. If you face any problems, please open a new issue.