opengl_test

opengl.cpp

//#include <iostream>
//
//
//#include <cstdio>
//#include <cstdlib>
//#include <iostream>
//#include <fstream>
//#include <sstream>
//#include <glad/glad.h>

#include <GL/glew.h>
#include <GLFW/glfw3.h>
#include <iostream>

extern "C"
{
#include <libavutil/frame.h>
}

int showGLWindow(uint8_t *data) {
    GLFWwindow *window;

    /* Initialize the library */
    if (!glfwInit())
        return -1;

    /* Create buffer windowed mode window and its OpenGL context */
    window = glfwCreateWindow(800, 800, "Hello World", NULL, NULL);
    if (!window) {
        glfwTerminate();
        return -1;
    }

    /* Make the window's context current */
    glfwMakeContextCurrent(window);

    if (glewInit() != GLEW_OK)
        std::cout << "Error! Glew could not init\n";

    std::cout << "OpenGL using: " << glGetString(GL_VERSION) << std::endl;


    int h = 800, w = 800;

    GLuint g_texture = {};
    glGenTextures(1, &g_texture);

    //glPixelStorei(GL_UNPACK_ALIGNMENT, 1);
    glBindTexture(GL_TEXTURE_2D, g_texture);
    glTexImage2D(GL_TEXTURE_2D, 0, GL_RGB, w,
                 h, 0, GL_RGB, GL_UNSIGNED_BYTE,
                 data);
    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER,
                    GL_LINEAR); /* We will use linear interpolation for magnification filter */
    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER,
                    GL_LINEAR); /* We will use linear interpolation for minifying filter */


    /* Loop until the user closes the window */
    while (!glfwWindowShouldClose(window)) {
        /* Render here */
        // Clear color and depth buffers
        glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
        glMatrixMode(GL_MODELVIEW);     // Operate on model-view matrix

        glEnable(GL_TEXTURE_2D);
        GLuint texture = g_texture;
        glBindTexture(GL_TEXTURE_2D, texture);
        glTexSubImage2D(GL_TEXTURE_2D, 0, 0,0, 800, 800, GL_RGB, GL_UNSIGNED_BYTE, data);
        // Draw a quad
        glBegin(GL_QUADS);
        glTexCoord2f(0.0f, 0.0f); glVertex2f(-1.0f, 1.0f);
        glTexCoord2f(0.0f, 1.0f); glVertex2f(-1.0f, -1.0f);
        glTexCoord2f(1.0f, 1.0f); glVertex2f(1.0f, -1.0f);
        glTexCoord2f(1.0f, 0.0f); glVertex2f(1.0f, 1.0f);
        glEnd();

        glDisable(GL_TEXTURE_2D);
        glBindTexture(GL_TEXTURE_2D, 0);

        glFlush();


        /* Swap front and back buffers */
        glfwSwapBuffers(window);

        /* Poll for and process events */
        glfwPollEvents();
    }

    glfwTerminate();
    return 0;
}