C++ SDL_Mouse类代码示例

void
SDL_MouseQuit(void)
{
    SDL_Cursor *cursor, *next;
    SDL_Mouse *mouse = SDL_GetMouse();

    if (mouse->CaptureMouse) {
        SDL_CaptureMouse(SDL_FALSE);
    }
    SDL_SetRelativeMouseMode(SDL_FALSE);
    SDL_ShowCursor(1);

    cursor = mouse->cursors;
    while (cursor) {
        next = cursor->next;
        SDL_FreeCursor(cursor);
        cursor = next;
    }

    if (mouse->def_cursor && mouse->FreeCursor) {
        mouse->FreeCursor(mouse->def_cursor);
    }

    if (mouse->clickstate) {
        SDL_free(mouse->clickstate);
    }

    SDL_zerop(mouse);
}

int
SDL_CaptureMouse(SDL_bool enabled)
{
    SDL_Mouse *mouse = SDL_GetMouse();
    SDL_Window *focusWindow;
    SDL_bool isCaptured;

    if (!mouse->CaptureMouse) {
        return SDL_Unsupported();
    }

    focusWindow = SDL_GetKeyboardFocus();

    isCaptured = focusWindow && (focusWindow->flags & SDL_WINDOW_MOUSE_CAPTURE);
    if (isCaptured == enabled) {
        return 0;  /* already done! */
    }

    if (enabled) {
        if (!focusWindow) {
            return SDL_SetError("No window has focus");
        } else if (mouse->CaptureMouse(focusWindow) == -1) {
            return -1;  /* CaptureMouse() should call SetError */
        }
        focusWindow->flags |= SDL_WINDOW_MOUSE_CAPTURE;
    } else {
        if (mouse->CaptureMouse(NULL) == -1) {
            return -1;  /* CaptureMouse() should call SetError */
        }
        focusWindow->flags &= ~SDL_WINDOW_MOUSE_CAPTURE;
    }

    return 0;
}

/* SDL_SetCursor(NULL) can be used to force the cursor redraw,
   if this is desired for any reason.  This is used when setting
   the video mode and when the SDL window gains the mouse focus.
 */
void
SDL_SetCursor(SDL_Cursor * cursor)
{
    SDL_Mouse *mouse = &SDL_mouse;

    /* Set the new cursor */
    if (cursor) {
        /* Make sure the cursor is still valid for this mouse */
        SDL_Cursor *found;
        for (found = mouse->cursors; found; found = found->next) {
            if (found == cursor) {
                break;
            }
        }
        if (!found) {
            SDL_SetError("Cursor not associated with the current mouse");
            return;
        }
        mouse->cur_cursor = cursor;
    } else {
        cursor = mouse->cur_cursor;
    }

    if (cursor && mouse->cursor_shown && !mouse->relative_mode) {
        if (mouse->ShowCursor) {
            mouse->ShowCursor(cursor);
        }
    } else {
        if (mouse->ShowCursor) {
            mouse->ShowCursor(NULL);
        }
    }
}

void
SDL_MouseQuit(void)
{
    SDL_Cursor *cursor, *next;
    SDL_Mouse *mouse = SDL_GetMouse();

    if (mouse->CaptureMouse) {
        SDL_CaptureMouse(SDL_FALSE);
    }
    SDL_SetRelativeMouseMode(SDL_FALSE);
    SDL_ShowCursor(1);

    cursor = mouse->cursors;
    while (cursor) {
        next = cursor->next;
        SDL_FreeCursor(cursor);
        cursor = next;
    }

    if (mouse->def_cursor && mouse->FreeCursor) {
        mouse->FreeCursor(mouse->def_cursor);
    }

    if (mouse->clickstate) {
        SDL_free(mouse->clickstate);
    }

    SDL_zerop(mouse);

    SDL_DelHintCallback(SDL_HINT_MOUSE_NORMAL_SPEED_SCALE,
                        SDL_MouseNormalSpeedScaleChanged, mouse);

    SDL_DelHintCallback(SDL_HINT_MOUSE_RELATIVE_SPEED_SCALE,
                        SDL_MouseRelativeSpeedScaleChanged, mouse);
}

void
SDL_FreeCursor(SDL_Cursor * cursor)
{
    SDL_Mouse *mouse = SDL_GetMouse();
    SDL_Cursor *curr, *prev;

    if (!cursor) {
        return;
    }

    if (cursor == mouse->def_cursor) {
        return;
    }
    if (cursor == mouse->cur_cursor) {
        SDL_SetCursor(mouse->def_cursor);
    }

    for (prev = NULL, curr = mouse->cursors; curr;
         prev = curr, curr = curr->next) {
        if (curr == cursor) {
            if (prev) {
                prev->next = curr->next;
            } else {
                mouse->cursors = curr->next;
            }

            if (mouse->FreeCursor) {
                mouse->FreeCursor(curr);
            }
            return;
        }
    }
}

void
SDL_WarpMouseGlobal(int x, int y)
{
    SDL_Mouse *mouse = SDL_GetMouse();

    if (mouse->WarpMouseGlobal) {
        mouse->WarpMouseGlobal(x, y);
    }
}

void
SDL_WarpMouseInWindow(SDL_Window * window, int x, int y)
{
    SDL_Mouse *mouse = &SDL_mouse;

    if (mouse->WarpMouse) {
        mouse->WarpMouse(mouse, window, x, y);
    } else {
        SDL_SendMouseMotion(window, 0, x, y);
    }
}

int
SDL_WarpMouseGlobal(int x, int y)
{
    SDL_Mouse *mouse = SDL_GetMouse();

    if (mouse->WarpMouseGlobal) {
        return mouse->WarpMouseGlobal(x, y);
    }

    return SDL_Unsupported();
}

int
SDL_SetRelativeMouseMode(SDL_bool enabled)
{
    SDL_Mouse *mouse = SDL_GetMouse();
    SDL_Window *focusWindow = SDL_GetKeyboardFocus();

    if (enabled == mouse->relative_mode) {
        return 0;
    }

    if (enabled && focusWindow) {
        /* Center it in the focused window to prevent clicks from going through
         * to background windows.
         */
        SDL_SetMouseFocus(focusWindow);
        SDL_WarpMouseInWindow(focusWindow, focusWindow->w/2, focusWindow->h/2);
    }

    /* Set the relative mode */
    if (!enabled && mouse->relative_mode_warp) {
        mouse->relative_mode_warp = SDL_FALSE;
    } else if (enabled && ShouldUseRelativeModeWarp(mouse)) {
        mouse->relative_mode_warp = SDL_TRUE;
    } else if (mouse->SetRelativeMouseMode(enabled) < 0) {
        if (enabled) {
            /* Fall back to warp mode if native relative mode failed */
            if (!mouse->WarpMouse) {
                return SDL_SetError("No relative mode implementation available");
            }
            mouse->relative_mode_warp = SDL_TRUE;
        }
    }
    mouse->relative_mode = enabled;
    mouse->scale_accum_x = 0.0f;
    mouse->scale_accum_y = 0.0f;

    if (mouse->focus) {
        SDL_UpdateWindowGrab(mouse->focus);

        /* Put the cursor back to where the application expects it */
        if (!enabled) {
            SDL_WarpMouseInWindow(mouse->focus, mouse->x, mouse->y);
        }
    }

    /* Flush pending mouse motion - ideally we would pump events, but that's not always safe */
    SDL_FlushEvent(SDL_MOUSEMOTION);

    /* Update cursor visibility */
    SDL_SetCursor(NULL);

    return 0;
}

void
SDL_WarpMouseInWindow(SDL_Window * window, int x, int y)
{
    SDL_Mouse *mouse = SDL_GetMouse(SDL_current_mouse);

    if (!mouse) {
        return;
    }

    if (mouse->WarpMouse) {
        mouse->WarpMouse(mouse, window, x, y);
    } else {
        SDL_SetMouseFocus(SDL_current_mouse, window);
        SDL_SendMouseMotion(SDL_current_mouse, 0, x, y, 0);
    }
}

void
SDL_WarpMouseInWindow(SDL_Window * window, int x, int y)
{
    SDL_Mouse *mouse = SDL_GetMouse();

    if (mouse->WarpMouse) {
        mouse->WarpMouse(window, x, y);
        // Urho3D: update the internal position
        mouse->x = x;
        mouse->y = y;
        mouse->last_x = x;
        mouse->last_y = y;
    } else {
        SDL_SendMouseMotion(window, 0, x, y);
    }
}

int
SDL_SetRelativeMouseMode(SDL_bool enabled)
{
    SDL_Mouse *mouse = SDL_GetMouse();
    SDL_Window *focusWindow = SDL_GetKeyboardFocus();
    int original_x = mouse->x, original_y = mouse->y;

    if (enabled == mouse->relative_mode) {
        return 0;
    }

    if (!mouse->SetRelativeMouseMode) {
        return SDL_Unsupported();
    }

    if (enabled && focusWindow) {
        /* Center it in the focused window to prevent clicks from going through
         * to background windows.
         */
        SDL_SetMouseFocus(focusWindow);
        SDL_WarpMouseInWindow(focusWindow, focusWindow->w/2, focusWindow->h/2);
    }

    if (mouse->SetRelativeMouseMode(enabled) < 0) {
        return -1;
    }

    /* Set the relative mode */
    mouse->relative_mode = enabled;

    if (enabled) {
        /* Save the expected mouse position */
        mouse->original_x = original_x;
        mouse->original_y = original_y;
    } else if (mouse->focus) {
        /* Restore the expected mouse position */
        SDL_WarpMouseInWindow(mouse->focus, mouse->original_x, mouse->original_y);
    }

    /* Flush pending mouse motion */
    SDL_FlushEvent(SDL_MOUSEMOTION);

    /* Update cursor visibility */
    SDL_SetCursor(NULL);

    return 0;
}

void
SDL_WarpMouseInWindow(SDL_Window * window, int x, int y)
{
    SDL_Mouse *mouse = SDL_GetMouse();

    if ( window == NULL )
        window = mouse->focus;

    if ( window == NULL )
        return;

    if (mouse->WarpMouse) {
        mouse->WarpMouse(window, x, y);
    } else {
        SDL_SendMouseMotion(window, mouse->mouseID, 0, x, y);
    }
}

SDL_Cursor *
SDL_CreateColorCursor(SDL_Surface *surface, int hot_x, int hot_y)
{
    SDL_Mouse *mouse = SDL_GetMouse();
    SDL_Surface *temp = NULL;
    SDL_Cursor *cursor;

    if (!surface) {
        SDL_SetError("Passed NULL cursor surface");
        return NULL;
    }

    if (!mouse->CreateCursor) {
        SDL_SetError("Cursors are not currently supported");
        return NULL;
    }

    /* Sanity check the hot spot */
    if ((hot_x < 0) || (hot_y < 0) ||
        (hot_x >= surface->w) || (hot_y >= surface->h)) {
        SDL_SetError("Cursor hot spot doesn't lie within cursor");
        return NULL;
    }

    if (surface->format->format != SDL_PIXELFORMAT_ARGB8888) {
        temp = SDL_ConvertSurfaceFormat(surface, SDL_PIXELFORMAT_ARGB8888, 0);
        if (!temp) {
            return NULL;
        }
        surface = temp;
    }

    cursor = mouse->CreateCursor(surface, hot_x, hot_y);
    if (cursor) {
        cursor->next = mouse->cursors;
        mouse->cursors = cursor;
    }

    if (temp) {
        SDL_FreeSurface(temp);
    }

    return cursor;
}

SDL_Cursor *
SDL_CreateSystemCursor(SDL_SystemCursor id)
{
    SDL_Mouse *mouse = SDL_GetMouse();
    SDL_Cursor *cursor;

    if (!mouse->CreateSystemCursor) {
        SDL_SetError("CreateSystemCursor is not currently supported");
        return NULL;
    }

    cursor = mouse->CreateSystemCursor(id);
    if (cursor) {
        cursor->next = mouse->cursors;
        mouse->cursors = cursor;
    }

    return cursor;
}