Question

当我编译我的opengl代码时，我正面临这个错误。如何删除它？

all: sample2D

sample2D: Sample_GL3_2D.cpp glad.c
        g++ -o sample2D Sample_GL3_2D.cpp glad.c -lGL -lglfw -ldl -std=c++11

clean:
        rm sample2D

这是我的Makefile内容和我的渲染字体的代码

const char* fontfile = "Monaco.ttf";
GL3Font.font = new FTExtrudeFont(fontfile); // 3D extrude style rendering

if(GL3Font.font->Error())
{
    cout << "Error: Could not load font `" << fontfile << "'" << endl;
    glfwTerminate();
    exit(EXIT_FAILURE);
}

// Create and compile our GLSL program from the font shaders
fontProgramID = LoadShaders( "fontrender.vert", "fontrender.frag" );
GLint fontVertexCoordAttrib, fontVertexNormalAttrib, fontVertexOffsetUniform;
fontVertexCoordAttrib = glGetAttribLocation(fontProgramID, "vertexPosition");
fontVertexNormalAttrib = glGetAttribLocation(fontProgramID, "vertexNormal");
fontVertexOffsetUniform = glGetUniformLocation(fontProgramID, "pen");
GL3Font.fontMatrixID = glGetUniformLocation(fontProgramID, "MVP");
GL3Font.fontColorID = glGetUniformLocation(fontProgramID, "fontColor");

GL3Font.font->ShaderLocations(fontVertexCoordAttrib, fontVertexNormalAttrib, fontVertexOffsetUniform);
GL3Font.font->FaceSize(1);
GL3Font.font->Depth(0);
GL3Font.font->Outset(0, 0);
GL3Font.font->CharMap(ft_encoding_unicode);

Answer 1

查找FTExtrudeFont它似乎是ftgl库中的一个函数 http://ftgl.sourceforge.net/docs/html/classFTExtrudeFont.html 但是你没有链接那个库。所以你可能需要-lftgl（假设它是库的名称）。

根据库的安装位置（或者您是否自己构建了它），您可能还需要使用-L标志告诉链接器在哪里查找库，即您的编译行将类似于

g++ -o sample2D Sample_GL3_2D.cpp glad.c -L <path-to-dir-with-ftgl-library> -lftgl -lglfw -lGL -ldl -std=c++11

错误未定义引用`FTExtrudeFont :: FTExtrudeFont（char const *）＆＃39;

1 个答案: