Hyprland & GLFW: Window Shrinking Fix

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Hyprland and GLFW Framebuffer Size Issues: A Troubleshooting Guide

Hey guys, have you ever encountered a frustrating issue where your GLFW windows in Hyprland start shrinking automatically? I recently ran into this, and it was a real head-scratcher. Specifically, when I set GLFW_RESIZABLE to GLFW_FALSE, my window's height would progressively decrease, messing up the whole visual experience. Let's dive into this problem, explore potential causes, and hopefully, find a solution together.

The Core Problem: Framebuffer Size Reduction

So, the main issue is that the framebuffer size of the GLFW window keeps getting smaller over time. This happens on Arch Linux with Hyprland, and it's particularly noticeable when resizing is disabled (GLFW_RESIZABLE is GLFW_FALSE). You might have noticed this if you're working on a Vulkan project, like I was. Suddenly, your window's height just…shrinks. It's like the window is slowly collapsing in on itself. This is super annoying if you're trying to create a fixed-size window. The good news is that we'll explore some ways to fix this. Let's dig in.

When GLFW_RESIZABLE is set to GLFW_TRUE, the window behaves differently, with potential visual glitches like black offsets or stretched content. These aren't ideal either. But let's first focus on the shrinking issue, as it is the primary concern when GLFW_RESIZABLE is set to GLFW_FALSE.

Code Snippets and Setup

Here’s the relevant code snippet from my project that demonstrates the issue:

// [...] 
if (!glfwInit()) {
    LOG_ERROR_MSG("Couldn't initialize GLFW.");
    abort();
  }
  LOG_INFO_MSG("GLFW Initialized");

  if (!glfwVulkanSupported()) {
    glfwTerminate();
    LOG_ERROR_MSG("Vulkan not supported.");
    abort();
  }

  glfwWindowHint(GLFW_CLIENT_API, GLFW_NO_API);
  glfwWindowHint(GLFW_RESIZABLE, GLFW_FALSE);
  glfwWindowHint(GLFW_DECORATED, GLFW_FALSE);

  window = glfwCreateWindow(window_extent.width, window_extent.height,
                            "Vulkan Engine", NULL, NULL);

  glfwSetFramebufferSizeCallback(
      window, [](GLFWwindow *_ , int width, int height) {
        LOG_INFO_MSG("Framebuffer size: {}x{}", width, height);
      });

// [...]
  LOG_DEBUG_MSG("Creating window surface");
  VkSurfaceKHR c_surface;
  VkResult glfw_result = glfwCreateWindowSurface(
      implicit_cast<VkInstance>(instance), window, nullptr, &c_surface);
  if (glfw_result != VK_SUCCESS) {
    LOG_ERROR_MSG("Failed to create window surface. GLFW Error: {}",
                  std::to_string(glfw_result));
    glfwDestroyWindow(window);
    glfwTerminate();
    abort();
  }
  surface = vk::SurfaceKHR{c_surface};
  LOG_DEBUG_MSG("Window surface created successfully");
// [...]

In this example, I initialize GLFW, set GLFW_RESIZABLE to GLFW_FALSE, and create a window. I also set a glfwSetFramebufferSizeCallback to monitor the framebuffer size. The key part is that, despite setting a fixed size during window creation, the height of the window still decreases over time.

My Hyprland Configuration

In my Hyprland configuration, the relevant line is:

windowrule = float, title:^(Vulkan Engine)$

This rule makes the window float, but it shouldn't directly affect the window's size. However, any interaction between Hyprland's window management and GLFW could potentially lead to this behavior. We have to consider how Hyprland is interpreting and managing the window's properties.

Version Info

Here’s the version information for my setup:

$ hyprland --version
Hyprland 0.51.1 built from branch  at commit 71a1216abcc7031776630a6d88f105605c4dc1c9  ([gha] Nix: update inputs).
Date: Mon Sep 22 20:54:03 2025
Tag: v0.51.1, commits: 6436
built against:
 aquamarine 0.9.5
 hyprlang 0.6.3
 hyprutils 0.10.0
 hyprcursor 0.1.13
 hyprgraphics 0.2.0


no flags were set

This information can be crucial because software versions can play a role in compatibility issues. Sometimes, updates in either Hyprland or GLFW can introduce bugs.

Troubleshooting Steps and Potential Solutions

Okay, so what can we do to fix this annoying shrinking? Here are a few troubleshooting steps and potential solutions to try:

1. Check for Hyprland Conflicts

  • Window Rules: Double-check your Hyprland configuration (specifically, the hyprland.conf file) for any rules that might be unintentionally affecting the window size. Even though my rule made the window float, other rules might have been the culprit.
  • Hyprland Updates: It's possible that a recent Hyprland update introduced a bug. You might want to consider rolling back to a previous version to see if the problem disappears. This can help identify if it's a regression issue.
  • Hyprland Issues: Search the Hyprland issue tracker on GitHub for similar reports. Someone else might have already encountered the same issue and found a workaround or a fix.

2. GLFW Version and Compatibility

  • GLFW Updates: The problem might be with the GLFW version. Try updating to the latest GLFW release, or try an older stable version if you've recently updated.
  • GLFW Submodule: Since you're using GLFW as a submodule, ensure it's properly initialized and up-to-date within your project. Double-check your commit to see if it is the latest commit to eliminate any possibility of the submodule getting outdated.
  • GLFW Context Creation: Ensure your GLFW context is created correctly. Incorrect context settings can lead to unexpected behavior.

3. Framebuffer Size Callback Investigation

  • Logging: Carefully examine the output from glfwSetFramebufferSizeCallback. This callback should tell us what's happening to the framebuffer size. The logs should reveal if the framebuffer size is actually changing, and if so, how. This can provide valuable clues.
  • Callback Implementation: Verify that the callback function is implemented correctly. Make sure that it is not doing anything that might be inadvertently modifying the window size.
  • Synchronization: In Vulkan applications, there can be synchronization issues. Make sure there aren't any race conditions related to the frame buffer size that are occurring within the rendering pipeline.

4. Vulkan and Rendering Considerations

  • Swapchain Recreation: If the framebuffer size changes, you might need to recreate the Vulkan swapchain. Ensure that your application is correctly handling framebuffer size changes by recreating the swapchain if necessary.
  • Viewport and Scissor: Verify your viewport and scissor settings in your rendering code. Incorrect settings can cause the rendered content to be clipped or scaled incorrectly.
  • Presentation: Make sure your presentation code is handling the window size correctly, especially after any resize events. Presentation errors can manifest as display issues.

5. Debugging and Logging

  • Detailed Logging: Add more detailed logging to your code. Log window creation, context creation, and any errors. Print out the window dimensions at different points in your program. This can help pinpoint when the size change occurs.
  • Debug Mode: Compile and run your application in debug mode. Debug mode often provides more information and can help you trace the execution flow, especially within the GLFW and Vulkan calls.
  • Valgrind/Address Sanitizer: Utilize tools like Valgrind or Address Sanitizer to detect memory errors or other issues that might be contributing to the problem.

6. Minimal Reproducible Example

  • Simplify: Create a minimal, reproducible example (MRE). Strip down your code to the bare essentials that still demonstrate the problem. This makes it easier to isolate the issue and share it with others.
  • Share: Share your MRE with the Hyprland and GLFW communities. This allows others to test the code and help you to identify the bug.

Potential Causes and Workarounds

Let's brainstorm about the possible causes of this problem:

  • Hyprland's Window Management: Hyprland's window manager might be interfering with the window size, especially if there are any conflicts with your window rules. As we said before, carefully examine the windowrule configuration. Try temporarily disabling any window rules to see if that resolves the issue.
  • GLFW's Interaction with Wayland: Wayland has its own window management mechanisms. There could be an interaction between GLFW and Wayland that leads to size changes. Verify the way your GLFW application interacts with Wayland by reviewing relevant documentation.
  • Driver Issues: Graphics drivers can sometimes cause unexpected behavior. Ensure you have the latest drivers for your graphics card installed. Also, try downgrading if you recently updated your drivers.
  • Floating Windows and Hyprland: Since the window is floating, it is possible that there might be some interaction between floating windows and Hyprland which triggers this behavior. Try to remove the floating flag and test to see if the problem persists.
  • Double-Buffering or Rendering Errors: In Vulkan applications, double-buffering or rendering errors might lead to inconsistent display sizes. Carefully check your rendering pipeline for potential problems.

Further Steps and Community Help

If you've tried all the above steps and are still stuck, here are the next steps:

  • Search for Similar Issues: Search online forums, the Hyprland and GLFW GitHub issue trackers, and other communities to see if anyone else has reported a similar issue. You might find a workaround or a solution.
  • Ask for Help: If you can't find a solution, ask for help from the community. Provide a detailed description of the problem, including the code snippets, the version information, and the troubleshooting steps you've already taken. Be specific to get the best help.
  • Report the Bug: If you suspect a bug, report it to the Hyprland or GLFW developers. Provide as much information as possible, including a minimal reproducible example, version information, and steps to reproduce the issue. Reporting the bug can help fix it for everyone.

I hope these troubleshooting steps help you resolve the shrinking window issue in Hyprland! Let me know if you have any questions or if you find a solution. Let's get those windows working correctly! Good luck, and happy coding!