view src/video/riscos/SDL_riscosvideo.c @ 2042:3908e1f808e1

Fixed bug #292 I might be on crack here. It looks like SDL_ConvertMono() in src/audio/SDL_audiocvt.c adds the left and right channels of a stereo stream together, and clamps the new mono channel if it would overflow. Shouldn't it be dividing by 2 to average the two sample points instead of clamping? Otherwise the mono sample point's volume doubles in the conversion. This would also make the conversion faster, as it replaces two branches per sample frame with a bitwise shift. --ryan.
author Sam Lantinga <slouken@libsdl.org>
date Sun, 24 Sep 2006 15:56:36 +0000
parents c121d94672cb
children e1da92da346c
line wrap: on
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/*
    SDL - Simple DirectMedia Layer
    Copyright (C) 1997-2004 Sam Lantinga

    This library is free software; you can redistribute it and/or
    modify it under the terms of the GNU Library General Public
    License as published by the Free Software Foundation; either
    version 2 of the License, or (at your option) any later version.

    This library 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
    Library General Public License for more details.

    You should have received a copy of the GNU Library General Public
    License along with this library; if not, write to the Free
    Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA

    Sam Lantinga
    slouken@libsdl.org
*/
#include "SDL_config.h"

/*
     File added by Alan Buckley (alan_baa@hotmail.com) for RISC OS compatability
	 23 March 2003

     Implements RISC OS display device management.
	 Routines for full screen and wimp modes are split
	 into other source files.
*/

#include "SDL_video.h"
#include "SDL_mouse.h"
#include "SDL_syswm.h"
#include "../SDL_sysvideo.h"
#include "../SDL_pixels_c.h"
#include "../../events/SDL_events_c.h"

#include "SDL_riscostask.h"
#include "SDL_riscosvideo.h"
#include "SDL_riscosevents_c.h"
#include "SDL_riscosmouse_c.h"

#include "kernel.h"
#include "swis.h"

#define RISCOSVID_DRIVER_NAME "riscos"

/* Initialization/Query functions */
static int RISCOS_VideoInit(_THIS, SDL_PixelFormat * vformat);
static void RISCOS_VideoQuit(_THIS);

static SDL_Rect **RISCOS_ListModes(_THIS, SDL_PixelFormat * format,
                                   Uint32 flags);
static SDL_Surface *RISCOS_SetVideoMode(_THIS, SDL_Surface * current,
                                        int width, int height, int bpp,
                                        Uint32 flags);

int RISCOS_GetWmInfo(_THIS, SDL_SysWMinfo * info);

int RISCOS_ToggleFullScreen(_THIS, int fullscreen);
/* Mouse checking */
void RISCOS_CheckMouseMode(_THIS);
extern SDL_GrabMode RISCOS_GrabInput(_THIS, SDL_GrabMode mode);

/* Fullscreen mode functions */
extern SDL_Surface *FULLSCREEN_SetVideoMode(_THIS, SDL_Surface * current,
                                            int width, int height, int bpp,
                                            Uint32 flags);
extern void FULLSCREEN_BuildModeList(_THIS);
extern void FULLSCREEN_SetDeviceMode(_THIS);
extern int FULLSCREEN_ToggleFromWimp(_THIS);

/* Wimp mode functions */
extern SDL_Surface *WIMP_SetVideoMode(_THIS, SDL_Surface * current,
                                      int width, int height, int bpp,
                                      Uint32 flags);
extern void WIMP_DeleteWindow(_THIS);
extern int WIMP_ToggleFromFullScreen(_THIS);

/* Hardware surface functions - common to WIMP and FULLSCREEN */
static int RISCOS_AllocHWSurface(_THIS, SDL_Surface * surface);
static int RISCOS_LockHWSurface(_THIS, SDL_Surface * surface);
static void RISCOS_UnlockHWSurface(_THIS, SDL_Surface * surface);
static void RISCOS_FreeHWSurface(_THIS, SDL_Surface * surface);

/* RISC OS driver bootstrap functions */

static int
RISCOS_Available(void)
{
    return (1);
}

static void
RISCOS_DeleteDevice(SDL_VideoDevice * device)
{
    SDL_free(device->hidden);
    SDL_free(device);
}

static SDL_VideoDevice *
RISCOS_CreateDevice(int devindex)
{
    SDL_VideoDevice *device;

    /* Initialize all variables that we clean on shutdown */
    device = (SDL_VideoDevice *) SDL_malloc(sizeof(SDL_VideoDevice));
    if (device) {
        SDL_memset(device, 0, (sizeof *device));
        device->hidden = (struct SDL_PrivateVideoData *)
            SDL_malloc((sizeof *device->hidden));
    }
    if ((device == NULL) || (device->hidden == NULL)) {
        SDL_OutOfMemory();
        if (device) {
            SDL_free(device);
        }
        return (0);
    }
    SDL_memset(device->hidden, 0, (sizeof *device->hidden));

    /* Set the function pointers */
    device->VideoInit = RISCOS_VideoInit;
    device->VideoQuit = RISCOS_VideoQuit;

    device->ListModes = RISCOS_ListModes;
    device->SetVideoMode = RISCOS_SetVideoMode;
    device->CreateYUVOverlay = NULL;
    device->AllocHWSurface = RISCOS_AllocHWSurface;
    device->CheckHWBlit = NULL;
    device->FillHWRect = NULL;
    device->SetHWColorKey = NULL;
    device->SetHWAlpha = NULL;
    device->LockHWSurface = RISCOS_LockHWSurface;
    device->UnlockHWSurface = RISCOS_UnlockHWSurface;
    device->FreeHWSurface = RISCOS_FreeHWSurface;

    device->FreeWMCursor = RISCOS_FreeWMCursor;
    device->CreateWMCursor = RISCOS_CreateWMCursor;
    device->CheckMouseMode = RISCOS_CheckMouseMode;
    device->GrabInput = RISCOS_GrabInput;

    device->InitOSKeymap = RISCOS_InitOSKeymap;

    device->GetWMInfo = RISCOS_GetWmInfo;

    device->free = RISCOS_DeleteDevice;

/* Can't get Toggle screen to work if program starts up in Full screen mode so
   disable it here and re-enable it when a wimp screen is chosen */
    device->ToggleFullScreen = NULL;    /*RISCOS_ToggleFullScreen; */

    /* Set other entries for fullscreen mode */
    FULLSCREEN_SetDeviceMode(device);

    /* Mouse pointer needs to use the WIMP ShowCursor version so
       that it doesn't modify the pointer until the SDL Window is
       entered or the application goes full screen */
    device->ShowWMCursor = WIMP_ShowWMCursor;

    return device;
}

VideoBootStrap RISCOS_bootstrap = {
    RISCOSVID_DRIVER_NAME, "RISC OS video driver",
    RISCOS_Available, RISCOS_CreateDevice
};


int
RISCOS_VideoInit(_THIS, SDL_PixelFormat * vformat)
{
    _kernel_swi_regs regs;
    int vars[4], vals[3];

    if (RISCOS_InitTask() == 0) {
        SDL_SetError("Unable to start task");
        return 0;
    }

    vars[0] = 9;                /* Log base 2 bpp */
    vars[1] = 11;               /* XWndLimit - num x pixels -1 */
    vars[2] = 12;               /* YWndLimit - num y pixels -1 */
    vars[3] = -1;               /* Terminate list */
    regs.r[0] = (int) vars;
    regs.r[1] = (int) vals;

    _kernel_swi(OS_ReadVduVariables, &regs, &regs);
    vformat->BitsPerPixel = (1 << vals[0]);

    /* Determine the current screen size */
    this->info.current_w = vals[1] + 1;
    this->info.current_h = vals[2] + 1;

    /* Minimum bpp for SDL is 8 */
    if (vformat->BitsPerPixel < 8)
        vformat->BitsPerPixel = 8;


    switch (vformat->BitsPerPixel) {
    case 15:
    case 16:
        vformat->Bmask = 0x00007c00;
        vformat->Gmask = 0x000003e0;
        vformat->Rmask = 0x0000001f;
        vformat->BitsPerPixel = 16;     /* SDL wants actual number of bits used */
        vformat->BytesPerPixel = 2;
        break;

    case 24:
    case 32:
        vformat->Bmask = 0x00ff0000;
        vformat->Gmask = 0x0000ff00;
        vformat->Rmask = 0x000000ff;
        vformat->BytesPerPixel = 4;
        break;

    default:
        vformat->Bmask = 0;
        vformat->Gmask = 0;
        vformat->Rmask = 0;
        vformat->BytesPerPixel = 1;
        break;
    }

    /* Fill in some window manager capabilities */
    this->info.wm_available = 1;

    /* We're done! */
    return (0);
}

/* Note:  If we are terminated, this could be called in the middle of
   another SDL video routine -- notably UpdateRects.
*/
void
RISCOS_VideoQuit(_THIS)
{
    RISCOS_ExitTask();

    if (this->hidden->alloc_bank)
        SDL_free(this->hidden->alloc_bank);
    this->hidden->alloc_bank = 0;
}


SDL_Rect **
RISCOS_ListModes(_THIS, SDL_PixelFormat * format, Uint32 flags)
{
    if (flags & SDL_FULLSCREEN) {
        /* Build mode list when first required. */
        if (SDL_nummodes[0] == 0)
            FULLSCREEN_BuildModeList(this);

        return (SDL_modelist[((format->BitsPerPixel + 7) / 8) - 1]);
    } else
        return (SDL_Rect **) - 1;
}


/* Set up video mode */
SDL_Surface *
RISCOS_SetVideoMode(_THIS, SDL_Surface * current,
                    int width, int height, int bpp, Uint32 flags)
{
    if (flags & SDL_FULLSCREEN) {
        RISCOS_StoreWimpMode();
        /* Dump wimp window on switch to full screen */
        if (this->hidden->window_handle)
            WIMP_DeleteWindow(this);

        return FULLSCREEN_SetVideoMode(this, current, width, height, bpp,
                                       flags);
    } else {
        RISCOS_RestoreWimpMode();
        return WIMP_SetVideoMode(this, current, width, height, bpp, flags);
    }
}


/* We don't actually allow hardware surfaces other than the main one */
static int
RISCOS_AllocHWSurface(_THIS, SDL_Surface * surface)
{
    return (-1);
}
static void
RISCOS_FreeHWSurface(_THIS, SDL_Surface * surface)
{
    return;
}

/* We need to wait for vertical retrace on page flipped displays */
static int
RISCOS_LockHWSurface(_THIS, SDL_Surface * surface)
{
    return (0);
}

static void
RISCOS_UnlockHWSurface(_THIS, SDL_Surface * surface)
{
    return;
}


int
RISCOS_GetWmInfo(_THIS, SDL_SysWMinfo * info)
{
    SDL_VERSION(&(info->version));
    info->wimpVersion = RISCOS_GetWimpVersion();
    info->taskHandle = RISCOS_GetTaskHandle();
    info->window = this->hidden->window_handle;

    return 1;
}

/* Toggle full screen mode.
   Returns 1 if successful otherwise 0
*/

int
RISCOS_ToggleFullScreen(_THIS, int fullscreen)
{
    if (fullscreen) {
        return FULLSCREEN_ToggleFromWimp(this);
    } else {
        return WIMP_ToggleFromFullScreen(this);
    }

    return 0;
}

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