/*
    SDL - Simple DirectMedia Layer
    Copyright (C) 1997-2010 Sam Lantinga

    This library is free software; you can redistribute it and/or
    modify it under the terms of the GNU Lesser General Public
    License as published by the Free Software Foundation; either
    version 2.1 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
    Lesser General Public License for more details.

    You should have received a copy of the GNU Lesser General Public
    License along with this library; if not, write to the Free Software
    Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA

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

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

     Implements RISC OS Wimp display.
*/

#include "SDL_video.h"
#include "SDL_mouse.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"

/* Initialization/Query functions */
SDL_Rect **WIMP_ListModes(_THIS, SDL_PixelFormat * format, Uint32 flags);
SDL_Surface *WIMP_SetVideoMode(_THIS, SDL_Surface * current, int width,
                               int height, int bpp, Uint32 flags);
int WIMP_SetColors(_THIS, int firstcolor, int ncolors, SDL_Color * colors);
void WIMP_SetWMCaption(_THIS, const char *title, const char *icon);


extern unsigned char *WIMP_CreateBuffer(int width, int height, int bpp);
extern void WIMP_PumpEvents(_THIS);
extern void WIMP_PlotSprite(_THIS, int x, int y);
extern void WIMP_SetupPlotInfo(_THIS);
extern void WIMP_SetFocus(int win);

/* etc. */
static void WIMP_UpdateRects(_THIS, int numrects, SDL_Rect * rects);

/* RISC OS Wimp handling helpers */
void WIMP_ReadModeInfo(_THIS);
unsigned int WIMP_SetupWindow(_THIS, SDL_Surface * surface);
void WIMP_SetDeviceMode(_THIS);
void WIMP_DeleteWindow(_THIS);

/* FULLSCREEN function required for wimp/fullscreen toggling */
extern int FULLSCREEN_SetMode(int width, int height, int bpp);

/* Currently need to set this up here as it only works if you
   start up in a Wimp mode */
extern int RISCOS_ToggleFullScreen(_THIS, int fullscreen);

extern int riscos_backbuffer;
extern int mouseInWindow;
extern int riscos_closeaction;

/* Following needed to ensure window is shown immediately */
extern int hasFocus;
extern void WIMP_Poll(_THIS, int waitTime);

SDL_Surface *
WIMP_SetVideoMode(_THIS, SDL_Surface * current,
                  int width, int height, int bpp, Uint32 flags)
{
    Uint32 Rmask = 0;
    Uint32 Gmask = 0;
    Uint32 Bmask = 0;
    char *buffer = NULL;
    int bytesPerPixel = 1;

    /* Don't support double buffering in Wimp mode */
    flags &= ~SDL_DOUBLEBUF;
    flags &= ~SDL_HWSURFACE;

    switch (bpp) {
    case 8:
        /* Emulated palette using ColourTrans */
        flags |= SDL_HWPALETTE;
        break;

    case 15:
    case 16:
        Bmask = 0x00007c00;
        Gmask = 0x000003e0;
        Rmask = 0x0000001f;
        bytesPerPixel = 2;
        break;

    case 32:
        Bmask = 0x00ff0000;
        Gmask = 0x0000ff00;
        Rmask = 0x000000ff;
        bytesPerPixel = 4;
        break;

    default:
        SDL_SetError("Pixel depth not supported");
        return NULL;
        break;
    }

/* 	printf("Setting mode %dx%d\n", width, height);*/

    /* Allocate the new pixel format for the screen */
    if (!SDL_ReallocFormat(current, bpp, Rmask, Gmask, Bmask, 0)) {
        SDL_SetError("Couldn't allocate new pixel format for requested mode");
        return (NULL);
    }

    /* Set up the new mode framebuffer */
    current->w = width;
    this->hidden->height = current->h = height;

    if (bpp == 15)
        bpp = 16;
    buffer = WIMP_CreateBuffer(width, height, bpp);
    if (buffer == NULL) {
        SDL_SetError("Couldn't create sprite for video memory");
        return (NULL);
    }

    this->hidden->bank[0] = buffer + 60;        /* Start of sprite data */
    if (bpp == 8)
        this->hidden->bank[0] += 2048;  /* 8bpp sprite have palette first */

    this->hidden->bank[1] = buffer;     /* Start of buffer */

    /* Remember sprite buffer so it can be freed later */
    if (this->hidden->alloc_bank)
        SDL_free(this->hidden->alloc_bank);
    this->hidden->alloc_bank = buffer;

    current->pitch = width * bytesPerPixel;
    if ((current->pitch & 3)) {
        /* Sprites are 32bit word aligned */
        current->pitch += (4 - (current->pitch & 3));
    }

    current->flags = flags | SDL_PREALLOC;

    WIMP_ReadModeInfo(this);

    SDL_memset(this->hidden->bank[0], 0, height * current->pitch);

    this->hidden->current_bank = 0;
    current->pixels = this->hidden->bank[0];


    if (WIMP_SetupWindow(this, current) == 0) {
        SDL_SetError("Unable to create window to display surface");
        return NULL;
    }

    /* Reset device functions for the wimp */
    WIMP_SetDeviceMode(this);

    /* Needs to set up plot info after window has been created */
    /* Not sure why, but plots don't work if I do it earlier */
    WIMP_SetupPlotInfo(this);

    /* Poll until window is shown */
    {
        /* We wait until it gets the focus, but give up after 5 seconds
           in case the focus is prevented in any way.
         */
        Uint32 now = SDL_GetTicks();
        while (!hasFocus && SDL_GetTicks() - now < 5000) {
            WIMP_Poll(this, 0);
        }
    }

    /* We're done */
    return (current);
}


void
WIMP_ReadModeInfo(_THIS)
{
    _kernel_swi_regs regs;
    int vars[6];
    int vals[5];

    vars[0] = 4;                /* XEig */
    vars[1] = 5;                /* YEig */
    vars[2] = 9;                /* Log base 2 bpp */
    vars[3] = 11;               /* Screen Width - 1 */
    vars[4] = 12;               /* Screen Depth - 1 */
    vars[5] = -1;               /* Terminate list */

    regs.r[0] = (int) vars;
    regs.r[1] = (int) vals;
    _kernel_swi(OS_ReadVduVariables, &regs, &regs);
    this->hidden->xeig = vals[0];
    this->hidden->yeig = vals[1];
    this->hidden->screen_bpp = 1 << vals[2];
    this->hidden->screen_width = vals[3] + 1;
    this->hidden->screen_height = vals[4] + 1;
}

/* Set device function to call the correct versions for running
   in a wimp window */

void
WIMP_SetDeviceMode(_THIS)
{
    if (this->UpdateRects == WIMP_UpdateRects)
        return;                 /* Already set up */

    this->SetColors = WIMP_SetColors;
    this->UpdateRects = WIMP_UpdateRects;

    this->FlipHWSurface = NULL;

    this->SetCaption = WIMP_SetWMCaption;
    this->SetIcon = NULL;
    this->IconifyWindow = NULL;

    this->ShowWMCursor = WIMP_ShowWMCursor;
    this->WarpWMCursor = WIMP_WarpWMCursor;

    this->ToggleFullScreen = RISCOS_ToggleFullScreen;

    this->PumpEvents = WIMP_PumpEvents;
}

/* Setup the Window to display the surface */
unsigned int
WIMP_SetupWindow(_THIS, SDL_Surface * surface)
{
    _kernel_swi_regs regs;
    int window_data[23];
    int *window_block = window_data + 1;
    int x = (this->hidden->screen_width - surface->w) / 2;
    int y = (this->hidden->screen_height - surface->h) / 2;
    int xeig = this->hidden->xeig;
    int yeig = this->hidden->yeig;

    mouseInWindow = 0;

    /* Always delete the window and recreate on a change */
    if (this->hidden->window_handle)
        WIMP_DeleteWindow(this);

    /* Setup window co-ordinates */
    window_block[0] = x << xeig;
    window_block[1] = y << yeig;
    window_block[2] = window_block[0] + (surface->w << xeig);
    window_block[3] = window_block[1] + (surface->h << yeig);


    window_block[4] = 0;        /* Scroll offsets */
    window_block[5] = 0;
    window_block[6] = -1;       /* Open on top of window stack */

    window_block[7] = 0x85040042;       /* Window flags */
    if (riscos_closeaction != 0)
        window_block[7] |= 0x2000000;

    /* TODO: Take into account surface->flags */

    window_block[8] = 0xff070207;       /* Window colours */
    window_block[9] = 0x000c0103;
    window_block[10] = 0;       /* Work area minimum */
    window_block[11] = -surface->h << yeig;
    window_block[12] = surface->w << xeig;      /* Work area maximum */
    window_block[13] = 0;
    window_block[14] = 0x2700013d;      /* Title icon flags */
    window_block[15] = 0x00003000;      /* Work area flags - Mouse click down reported */
    window_block[16] = 1;       /* Sprite area control block pointer */
    window_block[17] = 0x00100010;      /* Minimum window size (width & height) (16x16) */
    window_block[18] = (int) this->hidden->title;       /* Title data */
    window_block[19] = -1;
    window_block[20] = 256;
    window_block[21] = 0;       /* Number of icons */

    regs.r[1] = (unsigned int) (window_block);

    /* Create the window */
    if (_kernel_swi(Wimp_CreateWindow, &regs, &regs) == NULL) {
        this->hidden->window_handle = window_data[0] = regs.r[0];

        /* Show the window on the screen */
        regs.r[1] = (unsigned int) window_data;
        if (_kernel_swi(Wimp_OpenWindow, &regs, &regs) == NULL) {
            WIMP_SetFocus(this->hidden->window_handle);
        } else {
            WIMP_DeleteWindow(this);
        }
    }

    return this->hidden->window_handle;
}

/* Destroy the Window */

void
WIMP_DeleteWindow(_THIS)
{
    _kernel_swi_regs regs;
    regs.r[1] = (unsigned int) &(this->hidden->window_handle);
    _kernel_swi(Wimp_DeleteWindow, &regs, &regs);
    this->hidden->window_handle = 0;
}


void
WIMP_UpdateRects(_THIS, int numrects, SDL_Rect * rects)
{
    _kernel_swi_regs regs;
    int update_block[12];
    int xeig = this->hidden->xeig;
    int yeig = this->hidden->yeig;
    int j;
    update_block[0] = this->hidden->window_handle;

    for (j = 0; j < numrects; j++) {
        update_block[1] = rects[j].x << xeig;   /* Min X */
        update_block[4] = -(rects[j].y << yeig);
        update_block[3] = update_block[1] + (rects[j].w << xeig);
        update_block[2] = update_block[4] - (rects[j].h << yeig);

        regs.r[1] = (int) update_block;
        /* Update window can fail if called before first poll */
        if (_kernel_swi(Wimp_UpdateWindow, &regs, &regs) == 0) {
            while (regs.r[0]) {
                WIMP_PlotSprite(this, update_block[1], update_block[2]);
                _kernel_swi(Wimp_GetRectangle, &regs, &regs);
            }
        }
    }
}


int
WIMP_SetColors(_THIS, int firstcolor, int ncolors, SDL_Color * colors)
{
    unsigned int *pal = (unsigned int *) (this->hidden->bank[1] + 60);
    int j;
    SDL_Rect update;

    pal += firstcolor * 2;
    for (j = 0; j < ncolors; j++) {
        *pal = (((unsigned int) colors->r) << 8)
            + (((unsigned int) colors->g) << 16)
            + (((unsigned int) colors->b) << 24);
        pal[1] = *pal;
        pal += 2;
        colors++;
    }

    WIMP_SetupPlotInfo(this);

    /* Need to refresh the window */
    update.x = 0;
    update.y = 0;
    update.w = SDL_VideoSurface->w;
    update.h = SDL_VideoSurface->h;
    WIMP_UpdateRects(this, 1, &update);

    return 1;
}

void
WIMP_SetWMCaption(_THIS, const char *title, const char *icon)
{
    _kernel_swi_regs regs;

    SDL_strlcpy(this->hidden->title, title,
                SDL_arraysize(this->hidden->title));

    if (RISCOS_GetWimpVersion() < 380) {
        int block[6];

        regs.r[1] = (int) block;
        _kernel_swi(Wimp_GetCaretPosition, &regs, &regs);
        if (block[0] == (int) this->hidden->window_handle) {
            regs.r[0] = -1;
            _kernel_swi(Wimp_SetCaretPosition, &regs, &regs);
        } else {
            regs.r[0] = this->hidden->window_handle;
            regs.r[1] = -1;
            regs.r[2] = -1;
            regs.r[3] = -1;
            _kernel_swi(Wimp_SetCaretPosition, &regs, &regs);
        }
        regs.r[0] = block[0];
        regs.r[1] = block[1];
        regs.r[2] = block[2];
        regs.r[3] = block[3];
        regs.r[4] = block[4];
        regs.r[5] = block[5];
        _kernel_swi(Wimp_SetCaretPosition, &regs, &regs);
    } else {
        regs.r[0] = this->hidden->window_handle;
        regs.r[1] = 0x4b534154; /* "TASK" */
        regs.r[2] = 3;          /* Redraw title */
        _kernel_swi(Wimp_ForceRedraw, &regs, &regs);
    }
}

void
WIMP_RefreshDesktop(_THIS)
{
    int width = this->hidden->screen_width << this->hidden->xeig;
    int height = this->hidden->screen_height << this->hidden->yeig;
    _kernel_swi_regs regs;
    regs.r[0] = -1;             /* Whole screen */
    regs.r[1] = 0;
    regs.r[2] = 0;
    regs.r[3] = width;
    regs.r[4] = height;
    _kernel_swi(Wimp_ForceRedraw, &regs, &regs);
}

/* Toggle to window from full screen */
int
WIMP_ToggleFromFullScreen(_THIS)
{
    int width = this->screen->w;
    int height = this->screen->h;
    int bpp = this->screen->format->BitsPerPixel;
    char *buffer = NULL;
    char *old_bank[2];
    char *old_alloc_bank;

    /* Ensure flags are OK */
    this->screen->flags &= ~(SDL_DOUBLEBUF | SDL_HWSURFACE);

    if (this->hidden->bank[0] == this->hidden->alloc_bank
        || riscos_backbuffer == 0) {
        /* Need to create a sprite for the screen and copy the data to it */
        char *data;
        buffer = WIMP_CreateBuffer(width, height, bpp);
        data = buffer + 60;     /* Start of sprite data */
        if (bpp == 8)
            data += 2048;       /* 8bpp sprite have palette first */

        if (buffer == NULL)
            return 0;
        SDL_memcpy(data, this->hidden->bank[0],
                   width * height * this->screen->format->BytesPerPixel);
    }
    /* else We've switch to full screen before so we already have a sprite */

    old_bank[0] = this->hidden->bank[0];
    old_bank[1] = this->hidden->bank[1];
    old_alloc_bank = this->hidden->alloc_bank;

    if (buffer != NULL)
        this->hidden->alloc_bank = buffer;

    this->hidden->bank[1] = this->hidden->alloc_bank;
    this->hidden->bank[0] = this->hidden->bank[1] + 60; /* Start of sprite data */
    if (bpp == 8)
        this->hidden->bank[0] += 2048;  /* 8bpp sprite have palette first */

    this->hidden->current_bank = 0;
    this->screen->pixels = this->hidden->bank[0];

    RISCOS_RestoreWimpMode();
    WIMP_ReadModeInfo(this);
    if (WIMP_SetupWindow(this, this->screen)) {
        WIMP_SetDeviceMode(this);
        WIMP_SetupPlotInfo(this);

        if (riscos_backbuffer == 0)
            riscos_backbuffer = 1;

        if (buffer && old_alloc_bank)
            SDL_free(old_alloc_bank);

        return 1;
    } else {
        /* Drop back to full screen mode on failure */
        this->hidden->bank[0] = old_bank[0];
        this->hidden->bank[1] = old_bank[1];
        this->hidden->alloc_bank = old_alloc_bank;
        if (buffer)
            SDL_free(buffer);

        RISCOS_StoreWimpMode();
        FULLSCREEN_SetMode(width, height, bpp);
    }

    return 0;
}

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