/*
 * COPYRIGHT:        See COPYING in the top level directory
 * PROJECT:          ReactOS kernel
 * PURPOSE:          GDI TransparentBlt Function
 * FILE:             win32ss/gdi/eng/transblt.c
 * PROGRAMER:        Thomas Weidenmueller (w3seek@users.sourceforge.net)
 */

#include <win32k.h>

#define NDEBUG
#include <debug.h>

BOOL
APIENTRY
EngTransparentBlt(
    SURFOBJ *psoDest,
    SURFOBJ *psoSource,
    CLIPOBJ *Clip,
    XLATEOBJ *ColorTranslation,
    PRECTL DestRect,
    PRECTL SourceRect,
    ULONG iTransColor,
    ULONG Reserved)
{
    BOOL Ret = TRUE;
    BYTE ClippingType;
    INTENG_ENTER_LEAVE EnterLeaveSource, EnterLeaveDest;
    SURFOBJ *InputObj, *OutputObj;
    RECTL OutputRect, InputRect;
    POINTL Translate;

    LONG DstHeight;
    LONG DstWidth;
    LONG SrcHeight;
    LONG SrcWidth;

    InputRect = *SourceRect;

    if (!IntEngEnter(&EnterLeaveSource, psoSource, &InputRect, TRUE, &Translate, &InputObj))
    {
        return FALSE;
    }
    InputRect.left += Translate.x;
    InputRect.right += Translate.x;
    InputRect.top += Translate.y;
    InputRect.bottom += Translate.y;

    OutputRect = *DestRect;
    if (OutputRect.right < OutputRect.left)
    {
        OutputRect.left = DestRect->right;
        OutputRect.right = DestRect->left;
    }
    if (OutputRect.bottom < OutputRect.top)
    {
        OutputRect.top = DestRect->bottom;
        OutputRect.bottom = DestRect->top;
    }

    if (Clip)
    {
        if (OutputRect.left < Clip->rclBounds.left)
        {
            InputRect.left += Clip->rclBounds.left - OutputRect.left;
            OutputRect.left = Clip->rclBounds.left;
        }
        if (Clip->rclBounds.right < OutputRect.right)
        {
            InputRect.right -=  OutputRect.right - Clip->rclBounds.right;
            OutputRect.right = Clip->rclBounds.right;
        }
        if (OutputRect.top < Clip->rclBounds.top)
        {
            InputRect.top += Clip->rclBounds.top - OutputRect.top;
            OutputRect.top = Clip->rclBounds.top;
        }
        if (Clip->rclBounds.bottom < OutputRect.bottom)
        {
            InputRect.bottom -=  OutputRect.bottom - Clip->rclBounds.bottom;
            OutputRect.bottom = Clip->rclBounds.bottom;
        }
    }

    /* Check for degenerate case: if height or width of OutputRect is 0 pixels there's
       nothing to do */
    if (OutputRect.right <= OutputRect.left || OutputRect.bottom <= OutputRect.top)
    {
        IntEngLeave(&EnterLeaveSource);
        return TRUE;
    }

    if (!IntEngEnter(&EnterLeaveDest, psoDest, &OutputRect, FALSE, &Translate, &OutputObj))
    {
        IntEngLeave(&EnterLeaveSource);
        return FALSE;
    }

    OutputRect.left = DestRect->left + Translate.x;
    OutputRect.right = DestRect->right + Translate.x;
    OutputRect.top = DestRect->top + Translate.y;
    OutputRect.bottom = DestRect->bottom + Translate.y;

    ClippingType = (Clip ? Clip->iDComplexity : DC_TRIVIAL);

    DstHeight = OutputRect.bottom - OutputRect.top;
    DstWidth = OutputRect.right - OutputRect.left;
    SrcHeight = InputRect.bottom - InputRect.top;
    SrcWidth = InputRect.right - InputRect.left;
    switch (ClippingType)
    {
        case DC_TRIVIAL:
        {
            Ret = DibFunctionsForBitmapFormat[psoDest->iBitmapFormat].DIB_TransparentBlt(
                      OutputObj, InputObj, &OutputRect, &InputRect, ColorTranslation, iTransColor);
            break;
        }
        case DC_RECT:
        {
            RECTL ClipRect, CombinedRect;
            RECTL InputToCombinedRect;

            ClipRect.left = Clip->rclBounds.left + Translate.x;
            ClipRect.right = Clip->rclBounds.right + Translate.x;
            ClipRect.top = Clip->rclBounds.top + Translate.y;
            ClipRect.bottom = Clip->rclBounds.bottom + Translate.y;
            if (RECTL_bIntersectRect(&CombinedRect, &OutputRect, &ClipRect))
            {
                InputToCombinedRect.top = InputRect.top + (CombinedRect.top - OutputRect.top) * SrcHeight / DstHeight;
                InputToCombinedRect.bottom = InputRect.top + (CombinedRect.bottom - OutputRect.top) * SrcHeight / DstHeight;
                InputToCombinedRect.left = InputRect.left + (CombinedRect.left - OutputRect.left) * SrcWidth / DstWidth;
                InputToCombinedRect.right = InputRect.left + (CombinedRect.right - OutputRect.left) * SrcWidth / DstWidth;
                Ret = DibFunctionsForBitmapFormat[psoDest->iBitmapFormat].DIB_TransparentBlt(
                          OutputObj, InputObj, &CombinedRect, &InputToCombinedRect, ColorTranslation, iTransColor);
            }
            break;
        }
        case DC_COMPLEX:
        {
            ULONG Direction, i;
            RECT_ENUM RectEnum;
            BOOL EnumMore;

            if (OutputObj == InputObj)
            {
                if (OutputRect.top < InputRect.top)
                {
                    Direction = OutputRect.left < (InputRect.left ? CD_RIGHTDOWN : CD_LEFTDOWN);
                }
                else
                {
                    Direction = OutputRect.left < (InputRect.left ? CD_RIGHTUP : CD_LEFTUP);
                }
            }
            else
            {
                Direction = CD_ANY;
            }

            CLIPOBJ_cEnumStart(Clip, FALSE, CT_RECTANGLES, Direction, 0);
            do
            {
                EnumMore = CLIPOBJ_bEnum(Clip, sizeof(RectEnum), (PVOID)&RectEnum);
                for (i = 0; i < RectEnum.c; i++)
                {
                    RECTL ClipRect, CombinedRect;
                    RECTL InputToCombinedRect;

                    ClipRect.left = RectEnum.arcl[i].left + Translate.x;
                    ClipRect.right = RectEnum.arcl[i].right + Translate.x;
                    ClipRect.top = RectEnum.arcl[i].top + Translate.y;
                    ClipRect.bottom = RectEnum.arcl[i].bottom + Translate.y;
                    if (RECTL_bIntersectRect(&CombinedRect, &OutputRect, &ClipRect))
                    {
                        InputToCombinedRect.top = InputRect.top + (CombinedRect.top - OutputRect.top) * SrcHeight / DstHeight;
                        InputToCombinedRect.bottom = InputRect.top + (CombinedRect.bottom - OutputRect.top) * SrcHeight / DstHeight;
                        InputToCombinedRect.left = InputRect.left + (CombinedRect.left - OutputRect.left) * SrcWidth / DstWidth;
                        InputToCombinedRect.right = InputRect.left + (CombinedRect.right - OutputRect.left) * SrcWidth / DstWidth;

                        Ret = DibFunctionsForBitmapFormat[psoDest->iBitmapFormat].DIB_TransparentBlt(
                                  OutputObj, InputObj, &CombinedRect, &InputToCombinedRect, ColorTranslation, iTransColor);
                        if (!Ret)
                        {
                            break;
                        }
                    }
                }
            }
            while (EnumMore && Ret);
            break;
        }
        default:
        {
            Ret = FALSE;
            break;
        }
    }

    IntEngLeave(&EnterLeaveDest);
    IntEngLeave(&EnterLeaveSource);

    return Ret;
}

BOOL
FASTCALL
IntEngTransparentBlt(
    SURFOBJ *psoDest,
    SURFOBJ *psoSource,
    CLIPOBJ *Clip,
    XLATEOBJ *ColorTranslation,
    PRECTL DestRect,
    PRECTL SourceRect,
    ULONG iTransColor,
    ULONG Reserved)
{
    BOOL Ret;
    RECTL OutputRect, InputClippedRect;
    SURFACE *psurfDest;
    SURFACE *psurfSource;
    RECTL InputRect;
    LONG InputClWidth, InputClHeight, InputWidth, InputHeight;

    ASSERT(psoDest);
    ASSERT(psoSource);
    ASSERT(DestRect);

    psurfDest = CONTAINING_RECORD(psoDest, SURFACE, SurfObj);
    psurfSource = CONTAINING_RECORD(psoSource, SURFACE, SurfObj);

    ASSERT(psurfDest);
    ASSERT(psurfSource);

    /* If no clip object is given, use trivial one */
    if (!Clip) Clip = (CLIPOBJ *)&gxcoTrivial;

    InputClippedRect = *DestRect;
    if (InputClippedRect.right < InputClippedRect.left)
    {
        InputClippedRect.left = DestRect->right;
        InputClippedRect.right = DestRect->left;
    }
    if (InputClippedRect.bottom < InputClippedRect.top)
    {
        InputClippedRect.top = DestRect->bottom;
        InputClippedRect.bottom = DestRect->top;
    }

    InputRect = *SourceRect;
    /* Clip against the bounds of the clipping region so we won't try to write
     * outside the surface */
    if (Clip->iDComplexity != DC_TRIVIAL)
    {
        if (!RECTL_bIntersectRect(&OutputRect, &InputClippedRect, &Clip->rclBounds))
        {
            return TRUE;
        }
        /* Update source rect */
        InputClWidth = InputClippedRect.right - InputClippedRect.left;
        InputClHeight = InputClippedRect.bottom - InputClippedRect.top;
        InputWidth = InputRect.right - InputRect.left;
        InputHeight = InputRect.bottom - InputRect.top;

        InputRect.left += (InputWidth * (OutputRect.left - InputClippedRect.left)) / InputClWidth;
        InputRect.right -= (InputWidth * (InputClippedRect.right - OutputRect.right)) / InputClWidth;
        InputRect.top += (InputHeight * (OutputRect.top - InputClippedRect.top)) / InputClHeight;
        InputRect.bottom -= (InputHeight * (InputClippedRect.bottom - OutputRect.bottom)) / InputClHeight;
    }
    else
    {
        OutputRect = InputClippedRect;
    }

    if (psurfDest->flags & HOOK_TRANSPARENTBLT)
    {
        Ret = GDIDEVFUNCS(psoDest).TransparentBlt(psoDest,
                                                  psoSource,
                                                  Clip,
                                                  ColorTranslation,
                                                  &OutputRect,
                                                  &InputRect,
                                                  iTransColor,
                                                  Reserved);
    }
    else
        Ret = FALSE;

    if (!Ret)
    {
        Ret = EngTransparentBlt(psoDest,
                                psoSource,
                                Clip,
                                ColorTranslation,
                                &OutputRect,
                                &InputRect,
                                iTransColor,
                                Reserved);
    }

    return Ret;
}

/* EOF */