Win32 API process messages

win32_process_messages.c

// basic version
void process_messages1() {
    MSG message;
    BOOL result;
    // GetMessage() blocks and waits for a message
    // returns 0 when it sees WM_QUIT
    // returns -1 when something goes wrong
    // returns a nonzero when there is a valid message to dispatch
    while (result = GetMessage(&message, 0, 0, 0)) {
        if (result != -1) {
            // There is no TranslateMessage() here
            // TranslateMessage() converts virtual-key (WM_KEYDOWN) 
            // messages to character messages (WM_CHAR)
            DispatchMessage(&message);
        }
        // Use GetLastError() to get errors
    }
}

// Another (useless) version, equivalent to above
// using PeekMessage for illustration purpose only
void process_messages2() {
    MSG message;
    BOOL result;
    while (1) {
        // PeekMessage() returns TRUE (1) or FALSE (0)
        // takes a message structure
        // the second parameter is a window handle, if NULL
        // (or 0, which is allowed here), the function polls 
        // any window belonging to current thread
        // the last parameter specifies how processed messages are handled
        // the third and fourth parameters are for filtering
        while (PeekMessage(&message, 0, 0, 0, PM_REMOVE) == FALSE) {}
        if (message.message == WM_QUIT)
            break;
        DispatchMessage(&message);
    }
}

#define LEN(array) (sizeof(array) / sizeof((array)[0]))
// A version processes available messages but does not wait 
// for any with PeekMessages
void process_messages3() {
    MSG message;
    while (1) {
        BOOL result = FALSE;

        // Skipping code idea (and buggy value) from Handmade Hero
        DWORD skip_these[] = {
            // 0x738 is a buggy message sent on Windows 10 -- is that fixed?
            0x738,
            // 0xffffffff is max DWORD
            0xffffffff
        };
        DWORD range_start = 0;

        for (u32 index; index < LEN(skip_these); index++) {
            DWORD skip = skip_these[index];
            if ((result = PeekMessage(&message, 0, range_start, skip - 1, PM_REMOVE)) == TRUE)
                break;
            range_start = skip + 1;
        }

        if (result == FALSE)
            break;
        
        switch (message.message) {
            // processing code goes here, keyboard, mouse, input recording etc...
            // Should handle WM_QUIT one way or another 
            case WM_QUIT: { /* global_quit = TRUE; */ } break;
            default: { DispatchMessage(&message); } break;
        }
    }
}

// THOUGHT: another version is keeping the message loop in a separate thread