I’m trying to use opencv withing the zig programming language, I tried to follow what I read on this stackoverflow post to use the opencv c++ library in the zig language, I created a opencv_binding.h file that contains a simple function called doSomething that only just calls imread function
opencv_binding.h:
void doSomething(void);
opencv_binding.cpp:
#include <opencv2/core/core.hpp>
#include <opencv2/imgcodecs/imgcodecs.hpp>
#include <opencv2/imgproc/imgproc.hpp>
#include <opencv2/highgui/highgui.hpp>
extern "C" void doSomething(void) {
cv::Mat image = cv::imread("sample.png", cv::IMREAD_COLOR);
}
build.zig:
const std = @import("std");
// Although this function looks imperative, note that its job is to
// declaratively construct a build graph that will be executed by an external
// runner.
pub fn build(b: *std.Build) void {
// Standard target options allows the person running `zig build` to choose
// what target to build for. Here we do not override the defaults, which
// means any target is allowed, and the default is native. Other options
// for restricting supported target set are available.
const target = b.standardTargetOptions(.{});
// Standard optimization options allow the person running `zig build` to select
// between Debug, ReleaseSafe, ReleaseFast, and ReleaseSmall. Here we do not
// set a preferred release mode, allowing the user to decide how to optimize.
const optimize = b.standardOptimizeOption(.{});
const exe = b.addExecutable(.{
.name = "opencv_test",
// In this case the main source file is merely a path, however, in more
// complicated build scripts, this could be a generated file.
.root_source_file = .{ .path = "src/main.zig" },
.target = target,
.optimize = optimize,
});
exe.linkLibC();
exe.linkLibCpp();
exe.addIncludePath("C:/OpenCV/build/include");
exe.addLibraryPath("C:/OpenCV/build/x64/vc16/lib");
exe.linkSystemLibrary("opencv_world470");
exe.addIncludePath("src");
exe.addCSourceFile("src/opencv_binding.cpp", &.{});
// This declares intent for the executable to be installed into the
// standard location when the user invokes the "install" step (the default
// step when running `zig build`).
b.installArtifact(exe);
// This *creates* a Run step in the build graph, to be executed when another
// step is evaluated that depends on it. The next line below will establish
// such a dependency.
const run_cmd = b.addRunArtifact(exe);
// By making the run step depend on the install step, it will be run from the
// installation directory rather than directly from within the cache directory.
// This is not necessary, however, if the application depends on other installed
// files, this ensures they will be present and in the expected location.
run_cmd.step.dependOn(b.getInstallStep());
// This allows the user to pass arguments to the application in the build
// command itself, like this: `zig build run -- arg1 arg2 etc`
if (b.args) |args| {
run_cmd.addArgs(args);
}
// This creates a build step. It will be visible in the `zig build --help` menu,
// and can be selected like this: `zig build run`
// This will evaluate the `run` step rather than the default, which is "install".
const run_step = b.step("run", "Run the app");
run_step.dependOn(&run_cmd.step);
// Creates a step for unit testing. This only builds the test executable
// but does not run it.
const unit_tests = b.addTest(.{
.root_source_file = .{ .path = "src/main.zig" },
.target = target,
.optimize = optimize,
});
const run_unit_tests = b.addRunArtifact(unit_tests);
// Similar to creating the run step earlier, this exposes a `test` step to
// the `zig build --help` menu, providing a way for the user to request
// running the unit tests.
const test_step = b.step("test", "Run unit tests");
test_step.dependOn(&run_unit_tests.step);
}
NOTE: these are the lines I added to the build.zig file:
exe.linkLibC();
exe.linkLibCpp();
exe.addIncludePath("C:/OpenCV/build/include");
exe.addLibraryPath("C:/OpenCV/build/x64/vc16/lib");
exe.linkSystemLibrary("opencv_world470");
exe.addIncludePath("src");
exe.addCSourceFile("src/opencv_binding.cpp", &.{});
in the build.zig file I am linking the opencv_world.lib library however when compiling I get some errors:
error: lld-link: undefined symbol: cv::imread(std::__1::basic_string<char, std::__1::char_traits<char>, std::__1::allocator<char>> const&, int)
error: lld-link: undefined symbol: cv::Mat::~Mat()
how can I fix this?
