Passing SDL_WINDOW_RESIZABLE when creating the window, instead of calling SDL_SetWindowResizable

[8Observer8]

It works:

    const int winW = 300;
    const int winH = 300;
    window = SDL_CreateWindow("OpenGL, SDL2, C++",
        SDL_WINDOWPOS_CENTERED,
        SDL_WINDOWPOS_CENTERED,
        winW,
        winH,
        SDL_WINDOW_OPENGL | SDL_WINDOW_RESIZABLE);

But SDL_SetWindowResizable does not work:

#define SDL_MAIN_HANDLED
#include <SDL2/SDL.h>

#include <glad/glad.h>
#include <iostream>

SDL_Window *window;
const float maxFPS = 5.f;

void fatalError(const std::string &message)
{
    std::cout << message << std::endl;
    if (window)
    {
        SDL_DestroyWindow(window);
    }
    SDL_Quit();
    exit(-1);
}

int main()
{
    if (SDL_Init(SDL_INIT_VIDEO) < 0)
    {
        fatalError("Failed to initialize");
    }
    
    SDL_GL_SetAttribute(SDL_GL_DOUBLEBUFFER, 1);

    const int winW = 300;
    const int winH = 300;
    window = SDL_CreateWindow("OpenGL, SDL2, C++",
        SDL_WINDOWPOS_CENTERED,
        SDL_WINDOWPOS_CENTERED,
        winW,
        winH,
        SDL_WINDOW_OPENGL);
    if (!window)
    {
        fatalError("Failed to create the SDL window");
    }
    
    SDL_SetWindowResizable(window, SDL_TRUE);

    SDL_GLContext glContext = SDL_GL_CreateContext(window);
    if (!glContext)
    {
        fatalError("Failed to create the SDL_GL context");
    }

    if (!gladLoadGL())
    {
        fatalError("Failed to initialize the GLAD library");
    }

    glViewport(0, 0, winW, winH);
    glClearColor(0.5f, 0.5f, 1.f, 1.f);
    
    SDL_Event event;
    bool running = true;
    while (running)
    {
        while (SDL_PollEvent(&event))
        {
            switch (event.type)
            {
            case SDL_QUIT:
                running = false;
                break;
            case SDL_WINDOWEVENT:
                switch (event.window.event)
                {
                case SDL_WINDOWEVENT_RESIZED:
                    glViewport(0, 0, event.window.data1, event.window.data2);
                    break;
                }
                break;
            }
        }
        float startTicks = SDL_GetTicks();

        glClear(GL_COLOR_BUFFER_BIT);

        SDL_GL_SwapWindow(window);

        // Limit FPS to the max FPS
        float frameTicks = SDL_GetTicks() - startTicks;
        if (1000.f / maxFPS > frameTicks)
        {
            SDL_Delay(1000.f / maxFPS - frameTicks);
        }
    }

    SDL_GL_DeleteContext(glContext);
    SDL_DestroyWindow(window);
    SDL_Quit();
    return 0;
}

[slouken]

That's odd, I copied your program and removed the glad OpenGL code (since I don't have that installed) and it worked for me:

#include <stdlib.h>
#include <SDL.h>
#include "SDL_opengl.h"

SDL_Window *window;
const float maxFPS = 5.f;

void
fatalError(const char *message)
{
    SDL_Log("%s", message);
    if (window) {
        SDL_DestroyWindow(window);
    }
    SDL_Quit();
    exit(-1);
}

int
main()
{
    if (SDL_Init(SDL_INIT_VIDEO) < 0) {
        fatalError("Failed to initialize");
    }

    SDL_GL_SetAttribute(SDL_GL_DOUBLEBUFFER, 1);

    const int winW = 300;
    const int winH = 300;
    window = SDL_CreateWindow("OpenGL, SDL2, C++",
                              SDL_WINDOWPOS_CENTERED,
                              SDL_WINDOWPOS_CENTERED,
                              winW,
                              winH,
                              SDL_WINDOW_OPENGL);
    if (!window) {
        fatalError("Failed to create the SDL window");
    }

    SDL_SetWindowResizable(window, SDL_TRUE);

    SDL_GLContext glContext = SDL_GL_CreateContext(window);
    if (!glContext) {
        fatalError("Failed to create the SDL_GL context");
    }

    glViewport(0, 0, winW, winH);
    glClearColor(0.5f, 0.5f, 1.f, 1.f);

    SDL_Event event;
    int running = 1;
    while (running) {
        while (SDL_PollEvent(&event)) {
            switch (event.type) {
            case SDL_QUIT:
                running = 0;
                break;
            case SDL_WINDOWEVENT:
                switch (event.window.event) {
                case SDL_WINDOWEVENT_RESIZED:
                    glViewport(0, 0, event.window.data1, event.window.data2);
                    break;
                }
                break;
            }
        }
        float startTicks = SDL_GetTicks();

        glClear(GL_COLOR_BUFFER_BIT);

        SDL_GL_SwapWindow(window);

        // Limit FPS to the max FPS
        float frameTicks = SDL_GetTicks() - startTicks;
        if (1000.f / maxFPS > frameTicks) {
            SDL_Delay(1000.f / maxFPS - frameTicks);
        }
    }

    SDL_GL_DeleteContext(glContext);
    SDL_DestroyWindow(window);
    SDL_Quit();
    return 0;
}

[8Observer8]

HolyBlackCat wrote here:

It appears to be a SDL bug, though for me the effect was different (the window wasn't resizable at all).

Instead of calling SDL_SetWindowResizable(window, SDL_TRUE);, pass SDL_WINDOW_RESIZABLE when creating the window.

Whoever reads this, please, test it on your computer too. It would be nice if my example tested at least 2-3 people. I use Windows 10 64-bit.

[slouken]

SDL 2.0 is now in maintenance mode, and all inactive issues are being closed. If this issue is impacting you, please feel free to reopen it with additional information.