/*

    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

	 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;

}