GHOST_DisplayManagerSDL.cpp

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/*
 * ***** BEGIN GPL LICENSE BLOCK *****
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License
 * as published by the Free Software Foundation; either version 2
 * of the License, or (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software Foundation,
 * Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
 *
 * Contributor(s): Campbell Barton
 *
 * Mode switching
 * Copyright (C) 1997-2001 Id Software, Inc.
 * Copyright (c) 1993-2011 Tim Riker
 * Copyright (C) 2012 Alex Fraser
 *
 * ***** END GPL LICENSE BLOCK *****
 */

#include "GHOST_SystemSDL.h"
#include "GHOST_DisplayManagerSDL.h"

GHOST_DisplayManagerSDL::GHOST_DisplayManagerSDL(GHOST_SystemSDL *system)
    :
      GHOST_DisplayManager(),
      m_system(system)
{
    /* do nothing */
}

GHOST_TSuccess
GHOST_DisplayManagerSDL::getNumDisplays(GHOST_TUns8& numDisplays) const
{
    numDisplays=  SDL_GetNumVideoDisplays();
    return GHOST_kSuccess;
}


GHOST_TSuccess GHOST_DisplayManagerSDL::getNumDisplaySettings(GHOST_TUns8 display,
                                                              GHOST_TInt32& numSettings) const
{
    GHOST_ASSERT(display < 1, "Only single display systems are currently supported.\n");
    int i;
    SDL_Rect **vidmodes;

    vidmodes = SDL_ListModes(NULL, SDL_HWSURFACE | SDL_OPENGL |
            SDL_FULLSCREEN | SDL_HWPALETTE);
    if (!vidmodes) {
        fprintf(stderr, "Could not get available video modes: %s.\n",
                SDL_GetError());
        return GHOST_kFailure;
    }
    for (i = 0; vidmodes[i]; i++);
    numSettings = GHOST_TInt32(i);

    return GHOST_kSuccess;
}

GHOST_TSuccess
GHOST_DisplayManagerSDL::getDisplaySetting(GHOST_TUns8 display,
                                           GHOST_TInt32 index,
                                           GHOST_DisplaySetting& setting) const
{
    GHOST_ASSERT(display < 1, "Only single display systems are currently supported.\n");

    int i;
    SDL_Rect **vidmodes;
    /* NULL is passed in here to get the modes for the current bit depth.
     * Other bit depths may be possible; in that case, an SDL_PixelFormat struct
     * should be passed in. To get a complete profile, all possible bit depths
     * would need to be iterated over. - z0r */
    vidmodes = SDL_ListModes(NULL, SDL_HWSURFACE | SDL_OPENGL |
            SDL_FULLSCREEN | SDL_HWPALETTE);
    if (!vidmodes) {
        fprintf(stderr, "Could not get available video modes: %s.\n",
                SDL_GetError());
        return GHOST_kFailure;
    }
    for (i = 0; vidmodes[i]; i++);
    GHOST_ASSERT(index < i, "Requested setting outside of valid range.\n");

    setting.xPixels = vidmodes[index]->w;
    setting.yPixels = vidmodes[index]->h;

    SDL_Surface *surf;
    surf = SDL_GetVideoSurface();
    if (surf == NULL) {
        fprintf(stderr, "Getting display setting: %s\n", SDL_GetError());
        /* Just guess the bit depth */
        setting.bpp = 32;
    } else {
        setting.bpp = surf->format->BitsPerPixel;
    }
    /* Just guess the frequency :( */
    setting.frequency = 60;

    return GHOST_kSuccess;
}

GHOST_TSuccess
GHOST_DisplayManagerSDL::getCurrentDisplaySetting(GHOST_TUns8 display,
                                                  GHOST_DisplaySetting& setting) const
{
    SDL_Surface *surf;
    const SDL_VideoInfo *info;

    /* Note: not using SDL_GetDesktopDisplayMode because that does not return
     * the current mode. Try to use GetVideoSurface first, as it seems more
     * accurate. If that fails, try other methods. - z0r */
    surf = SDL_GetVideoSurface();

    if (surf != NULL) {
        setting.xPixels = surf->w;
        setting.yPixels = surf->h;
        setting.bpp = surf->format->BitsPerPixel;
        /* Just guess the frequency :( */
        setting.frequency = 60;
    } else {
        /* This may happen if the surface hasn't been created yet, e.g. on
         * application startup. */
        info = SDL_GetVideoInfo();
        setting.xPixels = info->current_w;
        setting.yPixels = info->current_h;
        setting.bpp = info->vfmt->BitsPerPixel;
        /* Just guess the frequency :( */
        setting.frequency = 60;
    }

    return GHOST_kSuccess;
}

GHOST_TSuccess
GHOST_DisplayManagerSDL:: setCurrentDisplaySetting(GHOST_TUns8 display,
                                                   const GHOST_DisplaySetting& setting)
{

    /*
     * Mode switching code ported from Quake 2 version 3.21 and bzflag version
     * 2.4.0:
     * ftp://ftp.idsoftware.com/idstuff/source/q2source-3.21.zip
     * See linux/gl_glx.c:GLimp_SetMode
     * http://wiki.bzflag.org/BZFlag_Source
     * See src/platform/SDLDisplay.cxx:SDLDisplay and createWindow
     */
    SDL_Surface *surf;
    int best_fit, best_dist, dist, x, y;

    SDL_Rect **vidmodes = SDL_ListModes(NULL, SDL_HWSURFACE | SDL_OPENGL |
            SDL_FULLSCREEN | SDL_HWPALETTE);
    if (!vidmodes) {
        fprintf(stderr, "Could not get available video modes: %s.\n",
                SDL_GetError());
    }

    best_dist = 9999999;
    best_fit = -1;

    if (vidmodes == (SDL_Rect **) -1) {
        /* Any mode is OK. */
        x = setting.xPixels;
        y = setting.yPixels;
    } else {
        for (int i = 0; vidmodes[i]; i++) {
            if (setting.xPixels > vidmodes[i]->w ||
                setting.yPixels > vidmodes[i]->h)
                continue;

            x = setting.xPixels - vidmodes[i]->w;
            y = setting.yPixels - vidmodes[i]->h;
            dist = (x * x) + (y * y);
            if (dist < best_dist) {
                best_dist = dist;
                best_fit = i;
            }
        }

        if (best_fit == -1)
            return GHOST_kFailure;

        x = vidmodes[best_fit]->w;
        y = vidmodes[best_fit]->h;
    }

#  ifdef _DEBUG
    printf("Switching to video mode %dx%d\n", x, y);
#  endif

    // limit us to the main display
    static char singleDisplayEnv[] = "SDL_SINGLEDISPLAY=1";
    putenv(singleDisplayEnv);

    // change to the mode
    surf = SDL_SetVideoMode(x, y, setting.bpp, SDL_OPENGL | SDL_FULLSCREEN);
    if (surf == NULL) {
        fprintf(stderr, "Could not set video mode: %s.\n", SDL_GetError());
        return GHOST_kFailure;
    }

    return GHOST_kSuccess;
}