/*
 * GDI region objects
 *
 * Copyright 1993, 1994, 1995 Alexandre Julliard
 *
 */

#include <stdlib.h>
#include <stdio.h>

#include "region.h"
#include "stddebug.h"
/* #define DEBUG_REGION */
#include "debug.h"


/***********************************************************************
 *           REGION_DeleteObject
 */
BOOL REGION_DeleteObject( HRGN hrgn, RGNOBJ * obj )
{
    dprintf_region(stddeb, "DeleteRegion: %x\n", hrgn );
    if (obj->xrgn) XDestroyRegion( obj->xrgn );
    return GDI_FreeObject( hrgn );
}


/***********************************************************************
 *           OffsetRgn    (GDI.101)
 */
int OffsetRgn( HRGN hrgn, short x, short y )
{
    RGNOBJ * obj = (RGNOBJ *) GDI_GetObjPtr( hrgn, REGION_MAGIC );
    if (!obj) return ERROR;
    dprintf_region(stddeb, "OffsetRgn: %d %d,%d\n", hrgn, x, y );
    if (!obj->xrgn) return NULLREGION;
    XOffsetRegion( obj->xrgn, x, y );
    return COMPLEXREGION;
}


/***********************************************************************
 *           GetRgnBox    (GDI.134)
 */
int GetRgnBox( HRGN hrgn, LPRECT rect )
{
    RGNOBJ * obj = (RGNOBJ *) GDI_GetObjPtr( hrgn, REGION_MAGIC );
    if (!obj) return ERROR;
    dprintf_region(stddeb, "GetRgnBox: %d\n", hrgn );
    if (!obj->xrgn)
    {
        SetRectEmpty( rect );
        return NULLREGION;
    }
    else
    {
        XRectangle xrect;
        XClipBox( obj->xrgn, &xrect );
        SetRect( rect, xrect.x, xrect.y,
                 xrect.x + xrect.width, xrect.y + xrect.height);
        return COMPLEXREGION;
    }
}


/***********************************************************************
 *           CreateRectRgn    (GDI.64)
 */
HRGN CreateRectRgn( short left, short top, short right, short bottom )
{
    HRGN hrgn;
    RGNOBJ *obj;

    if (!(hrgn = GDI_AllocObject( sizeof(RGNOBJ), REGION_MAGIC ))) return 0;
    obj = (RGNOBJ *) GDI_HEAP_ADDR( hrgn );
    if ((right > left) && (bottom > top))
    {
	XRectangle rect = { left, top, right - left, bottom - top };
	if (!(obj->xrgn = XCreateRegion()))
        {
            GDI_FreeObject( hrgn );
            return 0;
        }
        XUnionRectWithRegion( &rect, obj->xrgn, obj->xrgn );
    }
    else obj->xrgn = 0;
    dprintf_region( stddeb, "CreateRectRgn(%d,%d-%d,%d): returning %x\n",
                    left, top, right, bottom, hrgn );
    return hrgn;
}


/***********************************************************************
 *           CreateRectRgnIndirect    (GDI.65)
 */
HRGN CreateRectRgnIndirect( LPRECT rect )
{
    return CreateRectRgn( rect->left, rect->top, rect->right, rect->bottom );
}


/***********************************************************************
 *           SetRectRgn    (GDI.172)
 */
void SetRectRgn( HRGN hrgn, short left, short top, short right, short bottom )
{
    RGNOBJ * obj;

    dprintf_region(stddeb, "SetRectRgn: %x %d,%d-%d,%d\n", 
		   hrgn, left, top, right, bottom );
    
    if (!(obj = (RGNOBJ *) GDI_GetObjPtr( hrgn, REGION_MAGIC ))) return;
    if (obj->xrgn) XDestroyRegion( obj->xrgn );
    if ((right > left) && (bottom > top))
    {
	XRectangle rect = { left, top, right - left, bottom - top };
	if ((obj->xrgn = XCreateRegion()) != 0)
            XUnionRectWithRegion( &rect, obj->xrgn, obj->xrgn );
    }
    else obj->xrgn = 0;
}


/***********************************************************************
 *           CreateRoundRectRgn    (GDI.444)
 */
HRGN CreateRoundRectRgn( short left, short top, short right, short bottom,
			 short ellipse_width, short ellipse_height )
{
    RGNOBJ * obj;
    HRGN hrgn;
    XRectangle rect;
    int asq, bsq, d, xd, yd;

      /* Check if we can do a normal rectangle instead */

    if ((right <= left) || (bottom <= top) ||
        (ellipse_width <= 0) || (ellipse_height <= 0))
        return CreateRectRgn( left, top, right, bottom );

      /* Create region */

    if (!(hrgn = GDI_AllocObject( sizeof(RGNOBJ), REGION_MAGIC ))) return 0;
    obj = (RGNOBJ *) GDI_HEAP_ADDR( hrgn );
    obj->xrgn = XCreateRegion();
    dprintf_region(stddeb,"CreateRoundRectRgn(%d,%d-%d,%d %dx%d): return=%x\n",
               left, top, right, bottom, ellipse_width, ellipse_height, hrgn );

      /* Check parameters */

    if (ellipse_width > right-left) ellipse_width = right-left;
    if (ellipse_height > bottom-top) ellipse_height = bottom-top;

      /* Ellipse algorithm, based on an article by K. Porter */
      /* in DDJ Graphics Programming Column, 8/89 */

    asq = ellipse_width * ellipse_width / 4;        /* a^2 */
    bsq = ellipse_height * ellipse_height / 4;      /* b^2 */
    d = bsq - asq * ellipse_height / 2 + asq / 4;   /* b^2 - a^2b + a^2/4 */
    xd = 0;
    yd = asq * ellipse_height;                      /* 2a^2b */

    rect.x      = left + ellipse_width / 2;
    rect.width  = right - left - ellipse_width;
    rect.height = 1;

      /* Loop to draw first half of quadrant */

    while (xd < yd)
    {
        if (d > 0)  /* if nearest pixel is toward the center */
        {
              /* move toward center */
            rect.y = top++;
            XUnionRectWithRegion( &rect, obj->xrgn, obj->xrgn );
            rect.y = --bottom;
            XUnionRectWithRegion( &rect, obj->xrgn, obj->xrgn );
            yd -= 2*asq;
            d  -= yd;
        }
        rect.x--;        /* next horiz point */
        rect.width += 2;
        xd += 2*bsq;
        d  += bsq + xd;
    }

      /* Loop to draw second half of quadrant */

    d += (3 * (asq-bsq) / 2 - (xd+yd)) / 2;
    while (yd >= 0)
    {
          /* next vertical point */
        rect.y = top++;
        XUnionRectWithRegion( &rect, obj->xrgn, obj->xrgn );
        rect.y = --bottom;
        XUnionRectWithRegion( &rect, obj->xrgn, obj->xrgn );
        if (d < 0)   /* if nearest pixel is outside ellipse */
        {
            rect.x--;     /* move away from center */
            rect.width += 2;
            xd += 2*bsq;
            d  += xd;
        }
        yd -= 2*asq;
        d  += asq - yd;
    }

      /* Add the inside rectangle */

    if (top <= bottom)
    {
        rect.y = top;
        rect.height = bottom - top + 1;
        XUnionRectWithRegion( &rect, obj->xrgn, obj->xrgn );
    }
    return hrgn;
}


/***********************************************************************
 *           CreateEllipticRgn    (GDI.54)
 */
HRGN CreateEllipticRgn( short left, short top, short right, short bottom )
{
    return CreateRoundRectRgn( left, top, right, bottom,
                               right-left, bottom-top );
}


/***********************************************************************
 *           CreateEllipticRgnIndirect    (GDI.55)
 */
HRGN CreateEllipticRgnIndirect( LPRECT rect )
{
    return CreateRoundRectRgn(rect->left, rect->top, rect->right, rect->bottom,
                              rect->right-rect->left, rect->bottom-rect->top );
}


/***********************************************************************
 *           CreatePolygonRgn    (GDI.63)
 */
HRGN CreatePolygonRgn( POINT * points, short count, short mode )
{
    return CreatePolyPolygonRgn( points, &count, 1, mode );
}


/***********************************************************************
 *           CreatePolyPolygonRgn    (GDI.451)
 */
HRGN CreatePolyPolygonRgn( POINT * points, short * count,
			   short nbpolygons, short mode )
{
    RGNOBJ * obj;
    HRGN hrgn;
    int i, j, maxPoints;
    XPoint *xpoints, *pt;
    Region xrgn;

      /* Allocate points array */

    if (!nbpolygons) return 0;
    for (i = maxPoints = 0; i < nbpolygons; i++)
	if (maxPoints < count[i]) maxPoints = count[i];
    if (!maxPoints) return 0;
    if (!(xpoints = (XPoint *) malloc( sizeof(XPoint) * maxPoints )))
	return 0;

      /* Allocate region */

    if (!(hrgn = GDI_AllocObject( sizeof(RGNOBJ), REGION_MAGIC )))
    {
	free( xpoints );
	return 0;
    }
    obj = (RGNOBJ *) GDI_HEAP_ADDR( hrgn );
    obj->xrgn = 0;
    dprintf_region(stddeb, "CreatePolyPolygonRgn: %d polygons, returning %x\n",
                   nbpolygons, hrgn );

      /* Create X region */

    for (i = 0; i < nbpolygons; i++, count++)
    {
	for (j = *count, pt = xpoints; j > 0; j--, points++, pt++)
	{
	    pt->x = points->x;
	    pt->y = points->y;
	}
	xrgn = XPolygonRegion( xpoints, *count,
			       (mode == WINDING) ? WindingRule : EvenOddRule );
	if (!xrgn)
        {
            if (obj->xrgn) XDestroyRegion( obj->xrgn );
            free( xpoints );
            GDI_FreeObject( hrgn );
            return 0;
        }
	if (i > 0)
	{
	    Region tmprgn = XCreateRegion();
	    if (mode == WINDING) XUnionRegion( xrgn, obj->xrgn, tmprgn );
	    else XXorRegion( xrgn, obj->xrgn, tmprgn );
	    XDestroyRegion( obj->xrgn );
	    obj->xrgn = tmprgn;
	}
	else obj->xrgn = xrgn;
    }

    free( xpoints );
    return hrgn;
}


/***********************************************************************
 *           PtInRegion    (GDI.161)
 */
BOOL PtInRegion( HRGN hrgn, short x, short y )
{
    RGNOBJ * obj;
    
    if (!(obj = (RGNOBJ *) GDI_GetObjPtr( hrgn, REGION_MAGIC ))) return FALSE;
    if (!obj->xrgn) return FALSE;
    return XPointInRegion( obj->xrgn, x, y );
}


/***********************************************************************
 *           RectInRegion    (GDI.181)
 */
BOOL RectInRegion( HRGN hrgn, LPRECT rect )
{
    RGNOBJ * obj;
    
    if (!(obj = (RGNOBJ *) GDI_GetObjPtr( hrgn, REGION_MAGIC ))) return FALSE;
    if (!obj->xrgn) return FALSE;
    return (XRectInRegion( obj->xrgn, rect->left, rect->top,
                           rect->right-rect->left,
                           rect->bottom-rect->top ) != RectangleOut);
}


/***********************************************************************
 *           EqualRgn    (GDI.72)
 */
BOOL EqualRgn( HRGN rgn1, HRGN rgn2 )
{
    RGNOBJ *obj1, *obj2;
    if (!(obj1 = (RGNOBJ *) GDI_GetObjPtr( rgn1, REGION_MAGIC ))) return FALSE;
    if (!(obj2 = (RGNOBJ *) GDI_GetObjPtr( rgn2, REGION_MAGIC ))) return FALSE;
    if (!obj1->xrgn || !obj2->xrgn) return (!obj1->xrgn && !obj2->xrgn);
    return XEqualRegion( obj1->xrgn, obj2->xrgn );
}


/***********************************************************************
 *           REGION_CopyRegion
 *
 * Copy region src into dest.
 */
static int REGION_CopyRegion( RGNOBJ *src, RGNOBJ *dest )
{
    if (src->xrgn)
    {
        Region tmprgn = XCreateRegion();
        if (!dest->xrgn) dest->xrgn = XCreateRegion();
        XUnionRegion( tmprgn, src->xrgn, dest->xrgn );
        XDestroyRegion( tmprgn );
        return COMPLEXREGION;
    }
    else
    {
        if (dest->xrgn) XDestroyRegion( dest->xrgn );
        dest->xrgn = 0;
        return NULLREGION;
    }
}


/***********************************************************************
 *           CombineRgn    (GDI.451)
 */
int CombineRgn( HRGN hDest, HRGN hSrc1, HRGN hSrc2, short mode )
{
    RGNOBJ *destObj, *src1Obj, *src2Obj;
    
    dprintf_region(stddeb, "CombineRgn: %x,%x -> %x mode=%x\n", 
		   hSrc1, hSrc2, hDest, mode );
    
    if (!(destObj = (RGNOBJ *) GDI_GetObjPtr( hDest, REGION_MAGIC )))
	return ERROR;
    if (!(src1Obj = (RGNOBJ *) GDI_GetObjPtr( hSrc1, REGION_MAGIC )))
	return ERROR;
    if (mode == RGN_COPY) return REGION_CopyRegion( src1Obj, destObj );

    if (!(src2Obj = (RGNOBJ *) GDI_GetObjPtr( hSrc2, REGION_MAGIC )))
        return ERROR;

      /* Some optimizations for null regions */

    if (!src1Obj->xrgn || !src2Obj->xrgn)
    {
        switch(mode)
        {
        case RGN_DIFF:
            if (src1Obj->xrgn)
                return REGION_CopyRegion( src1Obj, destObj );
            /* else fall through */
        case RGN_AND:
            if (destObj->xrgn) XDestroyRegion( destObj->xrgn );
	    destObj->xrgn = 0;
	    return NULLREGION;
        case RGN_OR:
        case RGN_XOR:
            if (src1Obj->xrgn)
                return REGION_CopyRegion( src1Obj, destObj );
            else
                return REGION_CopyRegion( src2Obj, destObj );
	default:
	    return ERROR;
        }
    }

      /* Perform the operation with the two X regions */

    if (!destObj->xrgn) destObj->xrgn = XCreateRegion();
    switch(mode)
    {
    case RGN_AND:
        XIntersectRegion( src1Obj->xrgn, src2Obj->xrgn, destObj->xrgn );
        break;
    case RGN_OR:
        XUnionRegion( src1Obj->xrgn, src2Obj->xrgn, destObj->xrgn );
        break;
    case RGN_XOR:
        XXorRegion( src1Obj->xrgn, src2Obj->xrgn, destObj->xrgn );
        break;
    case RGN_DIFF:
        XSubtractRegion( src1Obj->xrgn, src2Obj->xrgn, destObj->xrgn );
        break;
    default:
        return ERROR;
    }
    if (XEmptyRegion(destObj->xrgn))
    {
        XDestroyRegion( destObj->xrgn );
        destObj->xrgn = 0;
        return NULLREGION;
    }
    else return COMPLEXREGION;
}