OpenGL自制游戏引擎-着色器

const char* vertexShaderSource =
"#version 330 core                                       \n"
"layout (location = 0) in vec3 aPos;                     \n"
"out vec4 vertexColor; \n"
"void main()                                             \n"
"{                                                       \n"
"    gl_Position = vec4(aPos.x, aPos.y, aPos.z, 1.0);\n"
"    vertexColor = vec4(1.0,1.0,0,1.0); \n"
"}   \n";

const char* fragmentShaderSource =
"#version 330 core                               \n"
"in vec4 vertexColor; \n"
"out vec4 FragColor;                             \n"
"void main(){                                    \n"
"    FragColor =vertexColor;}  \n";

const char* fragmentShaderSource =
"#version 330 core                               \n"
"in vec4 vertexColor; \n"
"uniform vec4 ourColor; \n"
"out vec4 FragColor;                             \n"
"void main(){                                    \n"
"    FragColor =ourColor;}  \n";

        float timeValue = glfwGetTime();
        float greenValue = (sin(timeValue) / 2.0f) + 0.5f;
        int vertexColorLocation = glGetUniformLocation(shaderProgram, "ourColor"); 
        

        //glBindVertexArray(VAO);
        glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, EBO);
        glUseProgram(shaderProgram);

        glUniform4f(vertexColorLocation, 0, greenValue, 0, 1.0f);
        //glDrawArrays(GL_TRIANGLES, 0, 6);
        glDrawElements(GL_TRIANGLES, 6, GL_UNSIGNED_INT, 0);