Skip to content

Instantly share code, notes, and snippets.

@esmitt

esmitt/transparency_glfw.cpp

Created June 4, 2021 15:09
Show Gist options

  • Select an option

    Learn more about clone URLs
  • Save esmitt/e722265936f0ebe96fc166bdf1fff41b to your computer and use it in GitHub Desktop.

Select an option

Learn more about clone URLs
Save esmitt/e722265936f0ebe96fc166bdf1fff41b to your computer and use it in GitHub Desktop.
Download ZIP

Revisions

  1. esmitt created this gist Jun 4, 2021.
    85 changes: 85 additions & 0 deletions transparency_glfw.cpp
    View file
    Original file line number Diff line number Diff line change
    @@ -0,0 +1,85 @@
    #include <windows.h>
    #include <GLFW/glfw3.h>
    #include <iostream>

    // change this to int main() to allow the console
    int WINAPI WinMain(HINSTANCE hInstance, HINSTANCE hPrevInstance, char*, int nShowCmd)
    {
    GLFWwindow* window;
    int windowSizeW = 640, windowSizeH = 480;
    // initialize the library
    if (!glfwInit())
    return -1;

    glfwWindowHint(GLFW_TRANSPARENT_FRAMEBUFFER, GLFW_TRUE);
    int count, windowWidth, windowHeight, monitorX, monitorY;

    // I am assuming that main monitor is in the 0 position
    GLFWmonitor** monitors = glfwGetMonitors(&count);
    const GLFWvidmode* videoMode = glfwGetVideoMode(monitors[0]);
    // width: 75% of the screen
    windowWidth = static_cast<int>(videoMode->width / 1.5);
    // aspect ratio 16 to 9
    windowHeight = static_cast<int>(videoMode->height / 16 * 9);

    glfwGetMonitorPos(monitors[0], &monitorX, &monitorY);

    // set the visibility window hint to false for subsequent window creation
    glfwWindowHint(GLFW_VISIBLE, GLFW_FALSE);

    // create a windowed mode window and its OpenGL context
    window = glfwCreateWindow(windowSizeW, windowSizeH, "Hello World", NULL, NULL);
    if (!window)
    {
    glfwTerminate();
    return -1;
    }

    // make the window's context current
    glfwMakeContextCurrent(window);

    // reset the window hints to default
    glfwDefaultWindowHints();

    glfwSetWindowPos(window,
    monitorX + (videoMode->width - windowWidth) / 2,
    monitorY + (videoMode->height - windowHeight) / 2);

    // show the window
    glfwShowWindow(window);

    // uncomment following line to see the border of window
    glfwSetWindowAttrib(window, GLFW_DECORATED, GLFW_FALSE);

    float fAngle = 0.0f;
    // Loop until the user closes the window
    while (!glfwWindowShouldClose(window))
    {
    // render
    glClearColor(0.0f, 0.0f, 0.0f, 0.0f);
    glClear(GL_COLOR_BUFFER_BIT);
    glLoadIdentity();
    glRotatef(fAngle, 0, 0, 1);
    glBegin(GL_QUADS);
    glColor3f(0, 0, 1);
    glVertex3f(-0.5, -0.5, -1);
    glColor3f(0, 1, 0);
    glVertex3f(0.5, -0.5, -1);
    glColor3f(1, 0, 1);
    glVertex3f(0.5, 0.5, -1);
    glColor3f(1, 1, 0);
    glVertex3f(-0.5, 0.5, -1);
    glEnd();

    fAngle += 0.01; // at some point this will explote! overflow: put the corresponding of

    // swap front and back buffers
    glfwSwapBuffers(window);

    // poll for and process events
    glfwPollEvents();
    }

    glfwTerminate();
    return 0;
    }