Makefile and linking libraries

[ryan1117001]

Hello

I'm having a problem with linking the libraries. From what I have, I've linked the libraries to OpenCV correctly, but not the one's for rpi-rgb-led-matrix. How do I link the libraries? Makefile:

led: minimal-example.cc g++ -o led minimal-example.cc -lopencv_core -lopencv_imgproc -lopencv_imgcodecs

Errors:

/tmp/ccYPtyMS.o: In function main': minimal-example.cc:(.text+0x1c0): undefined reference torgb_matrix::RGBMatrix::Options::Options()' minimal-example.cc:(.text+0x204): undefined reference to `rgb_matrix::CreateMatrixFromFlags(int*, char, rgb_matrix::RGBMatrix::Options, rgb_matrix::RuntimeOptions, bool)' collect2: error: ld returned 1 exit status Makefile:2: recipe for target 'led' failed make: [led] Error 1

Code:

include "led-matrix.h"

include

include

include

include

include <opencv2/core.hpp>

include <opencv2/imgproc.hpp>

include <opencv2/imgcodecs.hpp>

using rgb_matrix::GPIO; using rgb_matrix::RGBMatrix; using rgb_matrix::Canvas; using namespace cv;

volatile bool interrupt_received = false; static void InterruptHandler(int signo) { interrupt_received = true; }

static void DrawOnCanvas(Canvas *canvas) { Mat input_image = cv::imread("snapshot.png"); for (int y = 0; y < 32; y++) { for (int x = 0; x < 32; x++) { Vec3b color = input_image.at(Point(x,y)); canvas->setPixel(x,y,color[0],color[1],color[2]); } } }

int main(int argc, char argv[]) { RGBMatrix::Options defaults; defaults.hardware_mapping = "regular"; // or e.g. "adafruit-hat" defaults.rows = 32; defaults.chain_length = 1; defaults.parallel = 1; defaults.show_refresh_rate = true; Canvas canvas = rgb_matrix::CreateMatrixFromFlags(&argc, &argv, &defaults); if (canvas == NULL) return 1;

// It is always good to set up a signal handler to cleanly exit when we // receive a CTRL-C for instance. The DrawOnCanvas() routine is looking // for that. signal(SIGTERM, InterruptHandler); signal(SIGINT, InterruptHandler);

DrawOnCanvas(canvas); // Using the canvas.

// Animation finished. Shut down the RGB matrix. canvas->Clear(); delete canvas;

return 0; }

[stefandz]

Have you tried adding these lines to your Makefile (or linker options) and modifying the library path to suit where it is on your system?