main.cpp

#include <glad/glad.h>
#include <GLFW\glfw3.h>
#include "LoadS.h"
#include "Shader.h"

const unsigned int SCR_WIDTH = 800, SCR_HEIGHT = 600;

void framebuffer_size_callback(GLFWwindow* window, int width, int height) {
    glViewport(0, 0, width, height);
}
void processInput(GLFWwindow* window){
    if (glfwGetKey(window, GLFW_KEY_ESCAPE) == GLFW_PRESS)
        glfwSetWindowShouldClose(window, true);
}

int main() {
    // glfw: initialize and configure
    // ------------------------------
    if (!glfwInit()) {
        std::cout << "Failed to create GLFW window" << std::endl;
        return -1;
    }
    // settings properties window
    glfwWindowHint(GLFW_CONTEXT_VERSION_MAJOR, 3);
    glfwWindowHint(GLFW_CONTEXT_VERSION_MINOR, 3);
    glfwWindowHint(GLFW_OPENGL_PROFILE, GLFW_OPENGL_CORE_PROFILE);
    glfwWindowHint(GLFW_RESIZABLE, GLFW_FALSE);
    //glfwWindowHint(GLFW_SAMPLES, 5);
    // glfw window creation
    GLFWwindow* window = glfwCreateWindow(SCR_WIDTH, SCR_HEIGHT, "Test OpenGL", NULL, NULL);

    if (!window){
        std::cout << "Failed to create GLFW window" << std::endl;
        glfwTerminate();
        return -1;
    }
    glfwMakeContextCurrent(window);

    int width, height;
    //glfwGetFramebufferSize(window, &width, &height);
    //glViewport(0, 0, width, height);

    // glad: load all OpenGL function pointers
    // ---------------------------------------
    if (!gladLoadGLLoader((GLADloadproc)glfwGetProcAddress)){
        std::cout << "Failed to initialize GLAD" << std::endl;
        glfwTerminate();
        return -1;
    }


    // build and compile our shader program
    // ------------------------------------

    Shader triangleShader("go2.glsl", "go.glsl");

    // set up vertex data (and buffer(s)) and configure vertex attributes
    // ------------------------------------------------------------------
    float vertices[] = {
        // positions         // colors
         0.5f, -0.5f, 0.0f,  1.0f, 0.0f, 0.0f,   // bottom right
        -0.5f, -0.5f, 0.0f,  0.0f, 1.0f, 0.0f,   // bottom left
         0.0f,  0.5f, 0.0f,  0.0f, 0.0f, 1.0f    // top 
    };

    unsigned int VBO, VAO;
    glGenVertexArrays(1, &VAO);
    glGenBuffers(1, &VBO);
    // bind the Vertex Array Object first, then bind and set vertex buffer(s), and then configure vertex attributes(s).
    glBindVertexArray(VAO);

    glBindBuffer(GL_ARRAY_BUFFER, VBO);
    glBufferData(GL_ARRAY_BUFFER, sizeof(vertices), vertices, GL_STATIC_DRAW);

    glVertexAttribPointer(0, 3, GL_FLOAT, GL_FALSE, 6 * sizeof(float), (void*)0);
    glEnableVertexAttribArray(0);
    glVertexAttribPointer(1, 3, GL_FLOAT, GL_FALSE, 6 * sizeof(float), (void*)(3 * sizeof(float)));
    glEnableVertexAttribArray(1);

    // note that this is allowed, the call to glVertexAttribPointer registered VBO as the vertex attribute's bound vertex buffer object so afterwards we can safely unbind
    glBindBuffer(GL_ARRAY_BUFFER, 0);

    // You can unbind the VAO afterwards so other VAO calls won't accidentally modify this VAO, but this rarely happens. Modifying other
    // VAOs requires a call to glBindVertexArray anyways so we generally don't unbind VAOs (nor VBOs) when it's not directly necessary.
    glBindVertexArray(0);

    GLint bufs, samples;
    glGetIntegerv(GL_SAMPLE_BUFFERS, &bufs);
    glGetIntegerv(GL_SAMPLES, &samples);
    printf("MSAA: buffers = %d samples = %d\n", bufs, samples);

    // uncomment this call to draw in wireframe polygons.
    //glPolygonMode(GL_FRONT_AND_BACK, GL_LINE);

    // render loop
    // -----------        
    double position_x = 0, position_y = 0;            
    int x = glGetUniformLocation(triangleShader.ID, "x"), y = glGetUniformLocation(triangleShader.ID, "y"), vertexColorLocation = glGetUniformLocation(triangleShader.ID, "ourColor");
    //glEnable(GL_MULTISAMPLE);
    while (!glfwWindowShouldClose(window)) {
        // input
        // -----
        processInput(window);


        if (glfwGetWindowAttrib(window, GLFW_HOVERED)){
            glfwGetCursorPos(window, &position_x, &position_y);
            std::cout << position_x <<"  "<< position_y <<std::endl;
        }

        float timeValue = glfwGetTime();
        glUniform4f(vertexColorLocation, cos(timeValue) / 2.0f + 0.5f, sin(timeValue) / 2.0f + 0.5f, cos(timeValue) / 3.0f + 0.5f, 1.0f);

        if (glfwGetMouseButton(window, GLFW_MOUSE_BUTTON_LEFT) == GLFW_PRESS){
            glUniform1f(x, position_x);
            glUniform1f(y, position_y);
        }

        // render
        // ------
        glClearColor(0.2f, 0.3f, 0.3f, 1.0f);
        glClear(GL_COLOR_BUFFER_BIT);

        // draw our first triangle
        triangleShader.use();

        glBindVertexArray(VAO); // seeing as we only have a single VAO there's no need to bind it every time, but we'll do so to keep things a bit more organized
        if (glfwGetMouseButton(window, GLFW_MOUSE_BUTTON_LEFT) == GLFW_PRESS) {
            glDrawArrays(GL_TRIANGLES, 0, 3);
        }

        // glBindVertexArray(0); // no need to unbind it every time 

        // glfw: swap buffers and poll IO events (keys pressed/released, mouse moved etc.)
        // -------------------------------------------------------------------------------
        glfwSwapBuffers(window);//вывод заднего буффера
        glfwPollEvents();
    }

    // optional: de-allocate all resources once they've outlived their purpose:
    // ------------------------------------------------------------------------
    glDeleteVertexArrays(1, &VAO);
    glDeleteBuffers(1, &VBO);
    glDeleteProgram(triangleShader.ID);
    glfwDestroyWindow(window);
    // glfw: terminate, clearing all previously allocated GLFW resources.
    // ------------------------------------------------------------------
    glfwTerminate();
    return 0;
}