nsmryan / minifb

MiniFB is a small cross platform library to create a frame buffer that you can draw pixels in

MiniFB

MiniFB (Mini FrameBuffer) is a small cross platform library that makes it easy to render (32-bit) pixels in a window.

An example is the best way to show how it works:

struct mfb_window *window = mfb_open_ex("my display", 800, 600, WF_RESIZABLE);
if (!window)
    return 0;

buffer = (uint32_t *) malloc(800 * 600 * 4);

do {
    int state;

    // TODO: add some fancy rendering to the buffer of size 800 * 600

    state = mfb_update_ex(buffer, 800, 600);

    if (state < 0) {
        window = NULL;
        break;
    }
} while(mfb_wait_sync(window));

1. First the application creates a window calling mfb_open or mfb_open_ex.
2. Next it's the application responsibility to allocate a buffer to work with.
3. Next calling mfb_update or mfb_update_ex the buffer will be copied over to the window and displayed. If this function return a value lower than 0 the window will have been destroyed internally and cannot be used anymore.
4. Last the code waits to synchronize with the monitor calling mfb_wait_sync.

Note that, by default, if ESC key is pressed mfb_update / mfb_update_ex will return -1 (and the window will have been destroyed internally).

See https://github.com/emoon/minifb/blob/master/tests/noise.c for a complete example.

MiniFB has been tested on Windows, Mac OS X, Linux and iOS but may of course have trouble depending on your setup. Currently the code will not do any converting of data if not a proper 32-bit display can be created.

More features:

You can add callbacks to the windows:

void active(struct mfb_window *window, bool isActive) {
    ...
}

void resize(struct mfb_window *window, int width, int height) {
    ...
    // Optionally you can also change the viewport size
    mfb_set_viewport(window, x, y, width, height);
}

void keyboard(struct mfb_window *window, mfb_key key, mfb_key_mod mod, bool isPressed) {
    ...
    // Remember to close the window in some way
    if(key == KB_KEY_ESCAPE) {
        mfb_close(window);
    }

    fprintf(stdout, "%s > keyboard: key: %s (pressed: %d) [key_mod: %x]\n", window_title, mfb_get_key_name(key), isPressed, mod);

}

void char_input(struct mfb_window *window, unsigned int charCode) {
    ...
}

void mouse_btn(struct mfb_window *window, mfb_mouse_button button, mfb_key_mod mod, bool isPressed) {
    ...
}

// Use wisely this event. It can be sent too often
void mouse_move(struct mfb_window *window, int x, int y) {
    ...
}

// Mouse wheel
void mouse_scroll(struct mfb_window *window, mfb_key_mod mod, float deltaX, float deltaY) {
    ...
}

struct mfb_window *window = mfb_open_ex("my display", 800, 600, WF_RESIZABLE);
if (!window)
    return 0;

mfb_set_active_callback(window, active);
mfb_set_resize_callback(window, resize);
mfb_set_keyboard_callback(window, keyboard);
mfb_set_char_input_callback(window, char_input);
mfb_set_mouse_button_callback(window, mouse_btn);
mfb_set_mouse_move_callback(window, mouse_move);
mfb_set_mouse_scroll_callback(window, mouse_scroll);

Or you can get information about the window events directly:

bool                mfb_is_window_active(struct mfb_window *window);

unsigned            mfb_get_window_width(struct mfb_window *window);
unsigned            mfb_get_window_height(struct mfb_window *window);

int                 mfb_get_mouse_x(struct mfb_window *window);             // Last mouse pos X
int                 mfb_get_mouse_y(struct mfb_window *window);             // Last mouse pos Y

float               mfb_get_mouse_scroll_x(struct mfb_window *window);      // Mouse wheel X as a sum. When you call this function it resets.
float               mfb_get_mouse_scroll_y(struct mfb_window *window);      // Mouse wheel Y as a sum. When you call this function it resets.

const uint8_t *     mfb_get_mouse_button_buffer(struct mfb_window *window); // One byte for every button. Press (1), Release 0. (up to 8 buttons)

const uint8_t *     mfb_get_key_buffer(struct mfb_window *window);          // One byte for every key. Press (1), Release 0.

Additionally you can set per window data and recover it:

mfb_set_user_data(window, (void *) myData);
...
myData = (someCast *) mfb_get_user_data(window);

Extra: Timers and target FPS

You can create timers for your own purposes.

struct mfb_timer *  mfb_timer_create();
void                mfb_timer_destroy(struct mfb_timer *tmr);

void                mfb_timer_reset(struct mfb_timer *tmr);
double              mfb_timer_now(struct mfb_timer *tmr);
double              mfb_timer_delta(struct mfb_timer *tmr);

double              mfb_timer_get_frequency();
double              mfb_timer_get_resolution();

Furthermore you can set a target fps for the application. The default is 60 frames per second.

void                mfb_set_target_fps(uint32_t fps);

This avoid the problem of update too fast the window collapsing the redrawing in fast processors.

To use this you need to call the function:

bool                mfb_wait_sync(struct mfb_window *window);

Note that if you have several windows running on the same thread it makes no sense to wait them all...

Build instructions

The current build system is CMake.

Initially MiniFB used tundra https://github.com/deplinenoise/tundra as build system and it was required to build the code (but now is not maintained).

In any case, not many changes should be needed if you want to use MiniFB directly in your own code.

Mac

Cocoa and clang is assumed to be installed on the system (downloading latest XCode + installing the command line tools should do the trick).

Note that MacOS X Mojave+ does not support Cocoa framework as expected. For that reason you can switch to Metal API. To enable it just compile defining the preprocessor macro USE_METAL_API.

If you use CMake just enable the flag:

mkdir build
cd build
cmake .. -DUSE_METAL_API=ON

or if you don't want to use Metal API:

mkdir build
cd build
cmake .. -DUSE_METAL_API=OFF

if you use tundra:

tundra2 macosx-clang-debug

and you should be able to run the noise example (t2-output/macosx-clang-debug-default/noise).

iOS (beta)

It works with and without an UIWindow created. If you want to create the UIWindow through an Story Board, remember to set the UIViewController as iOSViewController and the UIView as iOSView.

Issues:

• It seems that you have to manually set 'tvOS Deployment Target' to less than 13.
• It seems that you have to manually set 'Launch Screen File' in project > executable > general to be able to get the real device height.
• You need to manually set the 'Signing Team' and 'Bundle Identifier'.
• No multitouch is available yet.
• As this version uses Metal API it cannot be run in the emulator.

Functions:

Some of the MiniFB functions don't make sense on mobile. The available functions for iOS are:

struct mfb_window * mfb_open(const char *title, unsigned width, unsigned height);
struct mfb_window * mfb_open_ex(const char *title, unsigned width, unsigned height, unsigned flags);    // flags ignored

mfb_update_state    mfb_update(struct mfb_window *window, void *buffer);

void                mfb_close(struct mfb_window *window);

void                mfb_set_user_data(struct mfb_window *window, void *user_data);
void *              mfb_get_user_data(struct mfb_window *window);

bool                mfb_set_viewport(struct mfb_window *window, unsigned offset_x, unsigned offset_y, unsigned width, unsigned height);

void                mfb_set_mouse_button_callback(struct mfb_window *window, mfb_mouse_button_func callback);
void                mfb_set_mouse_move_callback(struct mfb_window *window, mfb_mouse_move_func callback);
void                mfb_set_resize_callback(struct mfb_window *window, mfb_resize_func callback);

unsigned            mfb_get_window_width(struct mfb_window *window);
unsigned            mfb_get_window_height(struct mfb_window *window);
int                 mfb_get_mouse_x(struct mfb_window *window);             // Last mouse pos X
int                 mfb_get_mouse_y(struct mfb_window *window);             // Last mouse pos Y

// Not working on Linux (X11 nor Wayland)
void                mfb_get_monitor_dpi(struct mfb_window *window, float *dpi_x, float *dpi_y)

Timers are also available.

struct mfb_timer *  mfb_timer_create(void);
void                mfb_timer_destroy(struct mfb_timer *tmr);
void                mfb_timer_reset(struct mfb_timer *tmr);
double              mfb_timer_now(struct mfb_timer *tmr);
double              mfb_timer_delta(struct mfb_timer *tmr);
double              mfb_timer_get_frequency(void);
double              mfb_timer_get_resolution(void);

For now, no multitouch is available.

Example:

- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions {
    if(g_window == 0x0) {
        g_width  = [UIScreen mainScreen].bounds.size.width;
        g_height = [UIScreen mainScreen].bounds.size.height;
        g_window = mfb_open("noise", g_width, g_height);
        if(g_window != 0x0) {
            g_buffer = malloc(g_width * g_height * 4);
        }
    }

    return YES;
}

- (void)applicationDidBecomeActive:(UIApplication *)application {
    mDisplayLink = [CADisplayLink displayLinkWithTarget:self selector:@selector(OnUpdateFrame)];
    [mDisplayLink addToRunLoop:[NSRunLoop currentRunLoop] forMode:NSDefaultRunLoopMode];
}

- (void)applicationWillTerminate:(UIApplication *)application {
    [mDisplayLink invalidate];
    mfb_close(g_window);
}

- (void) OnUpdateFrame {
    if(g_buffer != 0x0) {
        // Do your wonderful rendering stuff
    }

    mfb_update_state state = mfb_update(g_window, g_buffer);
    if (state != STATE_OK) {
        free(g_buffer);
        g_buffer = 0x0;
        g_width   = 0;
        g_height  = 0;
    }
}

CMake

mkdir build
cd build
cmake -G Xcode -DCMAKE_SYSTEM_NAME=iOS -DCMAKE_OSX_DEPLOYMENT_TARGET=11.0 ..

Windows

If you use CMake the Visual Studio project will be generated (2015, 2017 and 2019 have been tested).

Furthermore you can also use MinGW instead of Visual Studio.

if you use tundra:

Visual Studio (ver 2012 express has been tested) tools needed (using the vcvars32.bat (for 32-bit) will set up the enviroment) to build run:

tundra2 win32-msvc-debug

and you should be able to run noise in t2-output/win32-msvc-debug-default/noise.exe

NEW: OpenGL API backend

Now, by default, OpenGL backend is used, instead of Windows GDI, because it is faster. To maintain compatibility with old computers an OpenGL 1.5 context is created (no shaders needed).

To enable or disable OpenGL just use a CMake flag:

cmake .. -DUSE_OPENGL_API=ON
or
cmake .. -DUSE_OPENGL_API=OFF

x11 (FreeBSD, Linux, *nix)

gcc and x11-dev libs needs to be installed.

If you use CMake just disable the flag:

mkdir build
cd build
cmake .. -DUSE_WAYLAND_API=OFF

If you use tundra:

To build the code run:

tundra2 x11-gcc-debug

and you should be able to run t2-output/x11-gcc-debug-default/noise

NEW: OpenGL API backend

Now, by default, OpenGL backend is used instead of X11 XImages because it is faster. To maintain compatibility with old computers an OpenGL 1.5 context is created (no shaders needed).

To enable or disable OpenGL just use a CMake flag:

cmake .. -DUSE_OPENGL_API=ON -DUSE_WAYLAND_API=OFF
or
cmake .. -DUSE_OPENGL_API=OFF -DUSE_WAYLAND_API=OFF

Wayland (Linux)

Depends on gcc and wayland-client and wayland-cursor. Built using the wayland-gcc variants.

If you use CMake just enable the flag:

mkdir build
cd build
cmake .. -DUSE_WAYLAND_API=ON