wcursor.cpp

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/* Copyright (c) 2012 Wildfire Games
 *
 * Permission is hereby granted, free of charge, to any person obtaining
 * a copy of this software and associated documentation files (the
 * "Software"), to deal in the Software without restriction, including
 * without limitation the rights to use, copy, modify, merge, publish,
 * distribute, sublicense, and/or sell copies of the Software, and to
 * permit persons to whom the Software is furnished to do so, subject to
 * the following conditions:
 * 
 * The above copyright notice and this permission notice shall be included
 * in all copies or substantial portions of the Software.
 * 
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
 * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
 * IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY
 * CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
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 */

#include "precompiled.h"
#include "lib/sysdep/cursor.h"

#include "lib/sysdep/gfx.h"
#include "lib/sysdep/os/win/win.h"
#include "lib/sysdep/os/win/wutil.h"

static sys_cursor cursor_from_HICON(HICON hIcon)
{
    return (sys_cursor)(uintptr_t)hIcon;
}

static sys_cursor cursor_from_HCURSOR(HCURSOR hCursor)
{
    return (sys_cursor)(uintptr_t)hCursor;
}

static HICON HICON_from_cursor(sys_cursor cursor)
{
    return (HICON)(uintptr_t)cursor;
}

static HCURSOR HCURSOR_from_cursor(sys_cursor cursor)
{
    return (HCURSOR)(uintptr_t)cursor;
}


static Status sys_cursor_create_common(int w, int h, void* bgra_img, void* mask_img, int hx, int hy, sys_cursor* cursor)
{
    *cursor = 0;

    // MSDN says selecting this HBITMAP into a DC is slower since we use
    // CreateBitmap; bpp/format must be checked against those of the DC.
    // this is the simplest way and we don't care about slight performance
    // differences because this is typically only called once.
    HBITMAP hbmColour = CreateBitmap(w, h, 1, 32, bgra_img);

    // CreateIconIndirect doesn't access this; we just need to pass
    // an empty bitmap.
    HBITMAP hbmMask = CreateBitmap(w, h, 1, 1, mask_img);

    // create the cursor (really an icon; they differ only in
    // fIcon and the hotspot definitions).
    ICONINFO ii;
    ii.fIcon = FALSE;  // cursor
    ii.xHotspot = (DWORD)hx;
    ii.yHotspot = (DWORD)hy;
    ii.hbmMask  = hbmMask;
    ii.hbmColor = hbmColour;
    HICON hIcon = CreateIconIndirect(&ii);

    // CreateIconIndirect makes copies, so we no longer need these.
    DeleteObject(hbmMask);
    DeleteObject(hbmColour);

    if(!wutil_IsValidHandle(hIcon))
        WARN_RETURN(ERR::FAIL);

    *cursor = cursor_from_HICON(hIcon);
    return INFO::OK;
}

Status sys_cursor_create(int w, int h, void* bgra_img, int hx, int hy, sys_cursor* cursor)
{
    // alpha-blended cursors do not work on a 16-bit display
    // (they get drawn as a black square), so refuse to load the
    // cursor in that case
    int bpp = 0;
    RETURN_STATUS_IF_ERR(gfx::GetVideoMode(NULL, NULL, &bpp, NULL));
    if (bpp <= 16)
        return ERR::FAIL;

    return sys_cursor_create_common(w, h, bgra_img, NULL, hx, hy, cursor);
}

Status sys_cursor_create_empty(sys_cursor* cursor)
{
    // the mask gets ignored on 32-bit displays, but is used on 16-bit displays;
    // setting it to 0xFF makes the cursor invisible (though I'm not quite
    // sure why it's that way round)
    u8 bgra_img[] = {0, 0, 0, 0};
    u8 mask_img[] = {0xFF};
    return sys_cursor_create_common(1, 1, bgra_img, mask_img, 0, 0, cursor);
}


Status sys_cursor_set(sys_cursor cursor)
{
    // restore default cursor.
    if(!cursor)
        cursor = cursor_from_HCURSOR(LoadCursor(0, MAKEINTRESOURCE(IDC_ARROW)));

    (void)SetCursor(HCURSOR_from_cursor(cursor));
    // return value (previous cursor) is useless.

    return INFO::OK;
}


Status sys_cursor_free(sys_cursor cursor)
{
    // bail now to prevent potential confusion below; there's nothing to do.
    if(!cursor)
        return INFO::OK;

    // if the cursor being freed is active, restore the default arrow
    // (just for safety).
    if(cursor_from_HCURSOR(GetCursor()) == cursor)
        WARN_IF_ERR(sys_cursor_set(0));

    if(!DestroyIcon(HICON_from_cursor(cursor)))
        WARN_RETURN(StatusFromWin());
    return INFO::OK;
}

Status sys_cursor_reset()
{
    return INFO::OK;
}