QtCreator with C 库中的链接器问题

我有一个具有以下结构的项目：

3rd_party
- heatmap.c
- heatmap.h
- lodepng.cpp
- lodepng.h
CMakeLists.txt
data.cpp
data.hpp
main.cpp

运行项目时出现以下错误：

error: Undefined symbols for architecture x86_64:
"_heatmap_add_weighted_point", referenced from:
Data::plotImage(int, int, std::__1::vector<short, std::__1::allocator<short> > const&, std::__1::vector<Spherical, std::__1::allocator<Spherical> > const&, int) in data.cpp.o
"_heatmap_free", referenced from:
Data::plotImage(int, int, std::__1::vector<short, std::__1::allocator<short> > const&, std::__1::vector<Spherical, std::__1::allocator<Spherical> > const&, int) in data.cpp.o
"_heatmap_new", referenced from:
Data::plotImage(int, int, std::__1::vector<short, std::__1::allocator<short> > const&, std::__1::vector<Spherical, std::__1::allocator<Spherical> > const&, int) in data.cpp.o
"_heatmap_render_default_to", referenced from:
Data::plotImage(int, int, std::__1::vector<short, std::__1::allocator<short> > const&, std::__1::vector<Spherical, std::__1::allocator<Spherical> > const&, int) in data.cpp.o

我data.cpp的一部分是：

#include "data.hpp"
#include <fstream>
#include <vector>
#include <iostream>
#include <algorithm>
#include <cmath>
#include <array>
#include "3rd_party/heatmap.h"
/**
* Create the heatmap PNG file,  suing the package in https://github.com/lucasb-eyer/libheatmap
* @param Nx Number of columns of data.
* @param Ny Number of rows of data.
* @param image Array with the data to be converted to PNG.
* @param counter To be included in the filename to distinguish between pictures.
*/
void Data::plotImage(int Nx, int Ny, const std::vector<short int>& image, const std::vector<Spherical> &sph, int counter){
heatmap_t* hm = heatmap_new(Nx, Ny); // auxiliar function
heatmap_add_weighted_point(hm, aprox_column, aprox_row, value); 
}

heatmap.c和heatmap.h是从 https://github.com/lucasb-eyer/libheatmap 复制的

我的项目以Visual Studio Code生成，但不使用QtCreator我的CMakeLists.txt：

cmake_minimum_required(VERSION 3.5)
project(trial LANGUAGES CXX)
set(ANDROID_NDK_ROOT "/Users/hectoresteban/Documents/C++/Qt/android-ndk-r21d")
set(CMAKE_INCLUDE_CURRENT_DIR ON)
set(CMAKE_AUTOUIC ON)
set(CMAKE_AUTOMOC ON)
set(CMAKE_AUTORCC ON)
set(CMAKE_CXX_STANDARD 17)
set(CMAKE_CXX_STANDARD_REQUIRED ON)
# search for pkg-config
include (FindPkgConfig)
if (NOT PKG_CONFIG_FOUND)
message (FATAL_ERROR "pkg-config not found")
endif ()
find_package(Qt5 COMPONENTS Core LinguistTools REQUIRED)
set(TS_FILES trial_en_DE.ts)
add_executable(trial
main.cpp
${TS_FILES}
data.cpp
3rd_party/lodepng.cpp
3rd_party/heatmap.c
)
target_link_libraries(trial Qt5::Core)