/*
  Simple DirectMedia Layer
  Copyright (C) 1997-2016 Sam Lantinga <slouken@libsdl.org>

  This software is provided 'as-is', without any express or implied
  warranty.  In no event will the authors be held liable for any damages
  arising from the use of this software.

  Permission is granted to anyone to use this software for any purpose,
  including commercial applications, and to alter it and redistribute it
  freely, subject to the following restrictions:

  1. The origin of this software must not be misrepresented; you must not
     claim that you wrote the original software. If you use this software
     in a product, an acknowledgment in the product documentation would be
     appreciated but is not required.
  2. Altered source versions must be plainly marked as such, and must not be
     misrepresented as being the original software.
  3. This notice may not be removed or altered from any source distribution.
*/
#include "../../SDL_internal.h"
#include "../SDL_sysvideo.h"
#define INCL_WIN
#define INCL_GPI
#include <os2.h>
#define  _MEERROR_H_
#include <mmioos2.h>
#include <os2me.h>
#define INCL_MM_OS2
#include <dive.h>
#include <fourcc.h>
#include "SDL_os2output.h"

typedef struct _VODATA {
  HDIVE      hDive;
  PVOID      pBuffer;
  ULONG      ulDIVEBufNum;
  FOURCC     fccColorEncoding;
  ULONG      ulWidth;
  ULONG      ulHeight;
  BOOL       fBlitterReady;
} VODATA;

static BOOL voQueryInfo(PVIDEOOUTPUTINFO pInfo);
static PVODATA voOpen();
static VOID voClose(PVODATA pVOData);
static BOOL voSetVisibleRegion(PVODATA pVOData, HWND hwnd,
                               SDL_DisplayMode *pSDLDisplayMode,
                               HRGN hrgnShape, BOOL fVisible);
static PVOID voVideoBufAlloc(PVODATA pVOData, ULONG ulWidth, ULONG ulHeight,
                             ULONG ulBPP, ULONG fccColorEncoding,
                             PULONG pulScanLineSize);
static VOID voVideoBufFree(PVODATA pVOData);
static BOOL voUpdate(PVODATA pVOData, HWND hwnd, SDL_Rect *pSDLRects,
                     ULONG cSDLRects);

OS2VIDEOOUTPUT voDive = {
  voQueryInfo,
  voOpen,
  voClose,
  voSetVisibleRegion,
  voVideoBufAlloc,
  voVideoBufFree,
  voUpdate
};


static BOOL voQueryInfo(PVIDEOOUTPUTINFO pInfo)
{
  DIVE_CAPS            sDiveCaps = { 0 };
  FOURCC               fccFormats[100] = { 0 };

  // Query information about display hardware from DIVE.

  sDiveCaps.pFormatData    = &fccFormats;
  sDiveCaps.ulFormatLength = 100;
  sDiveCaps.ulStructLen    = sizeof(DIVE_CAPS);

  if ( DiveQueryCaps( &sDiveCaps, DIVE_BUFFER_SCREEN ) )
  {
    debug( "DiveQueryCaps() failed." );
    return FALSE;
  }

  if ( sDiveCaps.ulDepth < 8 )
  {
    debug( "Not enough screen colors to run DIVE. "
           "Must be at least 256 colors." );
    return FALSE;
  }

  pInfo->ulBPP             = sDiveCaps.ulDepth;
  pInfo->fccColorEncoding  = sDiveCaps.fccColorEncoding;
  pInfo->ulScanLineSize    = sDiveCaps.ulScanLineBytes;
  pInfo->ulHorizResolution = sDiveCaps.ulHorizontalResolution;
  pInfo->ulVertResolution  = sDiveCaps.ulVerticalResolution;

  return TRUE;
}

PVODATA voOpen()
{
  PVODATA    pVOData = SDL_calloc( 1, sizeof(VODATA) );

  if ( pVOData == NULL )
  {
    SDL_OutOfMemory();
    return NULL;
  }

  if ( DiveOpen( &pVOData->hDive, FALSE, NULL ) != DIVE_SUCCESS )
  {
    SDL_free( pVOData );
    SDL_SetError( "DIVE: A display engine instance open failed" );
    return NULL;
  }

  return pVOData;
}

static VOID voClose(PVODATA pVOData)
{
  voVideoBufFree( pVOData );
  DiveClose( pVOData->hDive );
  SDL_free( pVOData );
}

static BOOL voSetVisibleRegion(PVODATA pVOData, HWND hwnd,
                               SDL_DisplayMode *pSDLDisplayMode,
                               HRGN hrgnShape, BOOL fVisible)
{
  HPS        hps;
  HRGN       hrgn;
  RGNRECT    rgnCtl;
  PRECTL     prectl = NULL;
  ULONG      ulRC;

  if ( !fVisible )
  {
    if ( pVOData->fBlitterReady )
    {
      pVOData->fBlitterReady = FALSE;
      DiveSetupBlitter( pVOData->hDive, 0 );
      debug( "DIVE blitter is tuned off" );
    }
    return TRUE;
  }

  // Query visible rectangles

  hps = WinGetPS( hwnd );
  hrgn = GpiCreateRegion( hps, 0, NULL );
  if ( hrgn == NULLHANDLE )
  {
    WinReleasePS( hps );
    SDL_SetError( "GpiCreateRegion() failed" );
  }
  else
  {
    WinQueryVisibleRegion( hwnd, hrgn );
    if ( hrgnShape != NULLHANDLE )
      GpiCombineRegion( hps, hrgn, hrgn, hrgnShape, CRGN_AND );

    rgnCtl.ircStart     = 1;
    rgnCtl.crc          = 0;
    rgnCtl.ulDirection  = 1;
    GpiQueryRegionRects( hps, hrgn, NULL, &rgnCtl, NULL );
    if ( rgnCtl.crcReturned != 0 )
    {
      prectl = SDL_malloc( rgnCtl.crcReturned * sizeof(RECTL) );
      if ( prectl != NULL )
      {
        rgnCtl.ircStart     = 1;
        rgnCtl.crc          = rgnCtl.crcReturned;
        rgnCtl.ulDirection  = 1;
        GpiQueryRegionRects( hps, hrgn, NULL, &rgnCtl, prectl );
      }
      else
        SDL_OutOfMemory();
    }
    GpiDestroyRegion( hps, hrgn );
    WinReleasePS( hps );

    if ( prectl != NULL )
    {
      // Setup DIVE blitter.
      SETUP_BLITTER      sSetupBlitter;
      SWP                swp;
      POINTL             pointl = { 0 };

      WinQueryWindowPos( hwnd, &swp );
      WinMapWindowPoints( hwnd, HWND_DESKTOP, &pointl, 1 );

      sSetupBlitter.ulStructLen       = sizeof(SETUP_BLITTER);
      sSetupBlitter.fccSrcColorFormat = pVOData->fccColorEncoding;
      sSetupBlitter.fInvert           = FALSE;
      sSetupBlitter.ulSrcWidth        = pVOData->ulWidth;
      sSetupBlitter.ulSrcHeight       = pVOData->ulHeight;
      sSetupBlitter.ulSrcPosX         = 0;
      sSetupBlitter.ulSrcPosY         = 0;
      sSetupBlitter.ulDitherType      = 0;
      sSetupBlitter.fccDstColorFormat = FOURCC_SCRN;
      sSetupBlitter.ulDstWidth        = swp.cx;
      sSetupBlitter.ulDstHeight       = swp.cy;
      sSetupBlitter.lDstPosX          = 0;
      sSetupBlitter.lDstPosY          = 0;
      sSetupBlitter.lScreenPosX       = pointl.x;
      sSetupBlitter.lScreenPosY       = pointl.y;

      sSetupBlitter.ulNumDstRects     = rgnCtl.crcReturned;
      sSetupBlitter.pVisDstRects      = prectl;

      ulRC = DiveSetupBlitter( pVOData->hDive, &sSetupBlitter );
      SDL_free( prectl );

      if ( ulRC == DIVE_SUCCESS )
      {
        pVOData->fBlitterReady = TRUE;
        WinInvalidateRect( hwnd, NULL, TRUE );
        debug( "DIVE blitter is ready now." );
        return TRUE;
      }

      SDL_SetError( "DiveSetupBlitter(), rc = 0x%X", ulRC );
    } // if ( prectl != NULL )
  } // if ( hrgn == NULLHANDLE ) else

  pVOData->fBlitterReady = FALSE;
  DiveSetupBlitter( pVOData->hDive, 0 );
  return FALSE;
}

static PVOID voVideoBufAlloc(PVODATA pVOData, ULONG ulWidth, ULONG ulHeight,
                             ULONG ulBPP, FOURCC fccColorEncoding,
                             PULONG pulScanLineSize)
{
  ULONG      ulRC;
  ULONG      ulScanLineSize = ulWidth * (ulBPP >> 3);

  // Destroy previous buffer.
  voVideoBufFree( pVOData );

  if ( ( ulWidth == 0 ) || ( ulHeight == 0 ) || ( ulBPP == 0 ) )
    return NULL;

  // Bytes per line.
  ulScanLineSize = ( ulScanLineSize + 3 ) & ~3;	/* 4-byte aligning */
  *pulScanLineSize = ulScanLineSize;

  ulRC = DosAllocMem( &pVOData->pBuffer,
                      (ulHeight * ulScanLineSize) + sizeof(ULONG),
                      PAG_COMMIT | PAG_EXECUTE | PAG_READ | PAG_WRITE );
  if ( ulRC != NO_ERROR )
  {
    debug( "DosAllocMem(), rc = %u", ulRC );
    return NULL;
  }

  ulRC = DiveAllocImageBuffer( pVOData->hDive, &pVOData->ulDIVEBufNum,
                               fccColorEncoding, ulWidth, ulHeight,
                               ulScanLineSize, pVOData->pBuffer );
  if ( ulRC != DIVE_SUCCESS )
  {
    debug( "DiveAllocImageBuffer(), rc = 0x%X", ulRC );
    DosFreeMem( pVOData->pBuffer );
    pVOData->pBuffer = NULL;
    pVOData->ulDIVEBufNum = 0;
    return NULL;
  }

  pVOData->fccColorEncoding = fccColorEncoding;
  pVOData->ulWidth = ulWidth;
  pVOData->ulHeight = ulHeight;

  debug( "buffer: 0x%P, DIVE buffer number: %u",
         pVOData->pBuffer, pVOData->ulDIVEBufNum );

  return pVOData->pBuffer;
}

static VOID voVideoBufFree(PVODATA pVOData)
{
  ULONG      ulRC;

  if ( pVOData->ulDIVEBufNum != 0 )
  {
    ulRC = DiveFreeImageBuffer( pVOData->hDive, pVOData->ulDIVEBufNum );
    if ( ulRC != DIVE_SUCCESS )
      debug( "DiveFreeImageBuffer(,%u), rc = %u", pVOData->ulDIVEBufNum, ulRC );
    else
      debug( "DIVE buffer %u destroyed", pVOData->ulDIVEBufNum );

    pVOData->ulDIVEBufNum = 0;
  }

  if ( pVOData->pBuffer != NULL )
  {
    ulRC = DosFreeMem( pVOData->pBuffer );
    if ( ulRC != NO_ERROR )
      debug( "DosFreeMem(), rc = %u", ulRC );

    pVOData->pBuffer = NULL;
  }
}

static BOOL voUpdate(PVODATA pVOData, HWND hwnd, SDL_Rect *pSDLRects,
                     ULONG cSDLRects)
{
  ULONG                ulRC;

  if ( !pVOData->fBlitterReady || ( pVOData->ulDIVEBufNum == 0 ) )
  {
    debug( "DIVE blitter is not ready" );
    return FALSE;
  }

  if ( pSDLRects != 0 )
  {
    PBYTE              pbLineMask;

    pbLineMask = SDL_stack_alloc( BYTE, pVOData->ulHeight );
    if ( pbLineMask == NULL )
    {
      debug( "Not enough stack size" );
      return FALSE;
    }
    memset( pbLineMask, 0, pVOData->ulHeight );

    for( ; ((LONG)cSDLRects) > 0; cSDLRects--, pSDLRects++ )
      memset( &pbLineMask[pSDLRects->y], 1, pSDLRects->h );

    ulRC = DiveBlitImageLines( pVOData->hDive, pVOData->ulDIVEBufNum,
                               DIVE_BUFFER_SCREEN, pbLineMask );
    SDL_stack_free( pbLineMask );

    if ( ulRC != DIVE_SUCCESS )
      debug( "DiveBlitImageLines(), rc = 0x%X", ulRC );
  }
  else
  {
    ulRC = DiveBlitImage( pVOData->hDive, pVOData->ulDIVEBufNum,
                          DIVE_BUFFER_SCREEN );
    if ( ulRC != DIVE_SUCCESS )
      debug( "DiveBlitImage(), rc = 0x%X", ulRC );
  }

  return ulRC == DIVE_SUCCESS;
}