/*

     SDL - Simple DirectMedia Layer

     Copyright (C) 1997, 1998, 1999, 2000, 2001  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@devolution.com

 */

 /*

      File added by Alan Buckley (alan_baa@hotmail.com) for RISCOS compatability

 	 27 March 2003

      Implements RISCOS wimp display.

 */

 #include <stdio.h>

 #include <stdlib.h>

 #include <string.h>

 #include "SDL.h"

 #include "SDL_error.h"

 #include "SDL_video.h"

 #include "SDL_mouse.h"

 #include "SDL_sysvideo.h"

 #include "SDL_pixels_c.h"

 #include "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) 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);

     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;

 	strncpy(this->hidden->title, title, 255);

 	this->hidden->title[255] = 0;

 	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;

       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);

       riscos_backbuffer = 1;

       if (buffer && old_alloc_bank) 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) free(buffer);

       RISCOS_StoreWimpMode();

       FULLSCREEN_SetMode(width, height, bpp);

    }

    return 0;

 }