/* -*- Mode: C; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 2 -*-
 *
 * The contents of this file are subject to the Netscape Public License
 * Version 1.0 (the "NPL"); you may not use this file except in
 * compliance with the NPL.  You may obtain a copy of the NPL at
 * http://www.mozilla.org/NPL/
 *
 * Software distributed under the NPL is distributed on an "AS IS" basis,
 * WITHOUT WARRANTY OF ANY KIND, either express or implied. See the NPL
 * for the specific language governing rights and limitations under the
 * NPL.
 *
 * The Initial Developer of this code under the NPL is Netscape
 * Communications Corporation.  Portions created by Netscape are
 * Copyright (C) 1998 Netscape Communications Corporation.  All Rights
 * Reserved.
 */
/* 
 *   region.c --- FE specific region operations
 */


#include "mozilla.h"
#include "xfe.h"
#include "fe_rgn.h"
#include "region.h"  /* Internal X region structures.  We need these to      */
                     /* iterate over rect lists in FE_ForEachRectInRegion(). */

/* Creates an empty region. Returns NULL if region can't be created */
FE_Region
FE_CreateRegion()
{
  return (FE_Region)XCreateRegion();
}

/* Creates a region from a rectangle. Returns NULL if region can't be created */
FE_Region
FE_CreateRectRegion(XP_Rect *rect)
{
  XPoint points[4];

  points[0].x = points[3].x = (short)rect->left;  /* points[] corresponds to */
  points[0].y = points[1].y = (short)rect->top;   /* top-left, top-right,    */
  points[1].x = points[2].x = (short)rect->right; /* bot-left and bot-right  */
  points[3].y = points[2].y = (short)rect->bottom;/* respectively.           */

  return (FE_Region)XPolygonRegion(points, 4, EvenOddRule);
                                /* Fill rule is irrelevant since there */
                                /* should be no self overlap.          */
}

/* Set an existing region to a rectangle.                                  */
/* The purpose of this routine is to avoid the overhead of destroying and  */
/* recreating a region on the Windows platform.  Unfortunately, it doesn't */
/* do much for X.                                                          */
FE_Region 
FE_SetRectRegion(FE_Region region, XP_Rect *rect)
{
  XRectangle rectangle;

  XP_ASSERT(region);

  if (!XEmptyRegion((Region)region))    /* If region is not empty.      */
    XSubtractRegion((Region)region, (Region)region, (Region)region);
                                        /* Subtract region from itself. */
  XP_ASSERT(XEmptyRegion((Region)region));

  rectangle.x = (short)rect->left;
  rectangle.y = (short)rect->top;
  rectangle.width = (unsigned short)(rect->right - rect->left);
  rectangle.height = (unsigned short)(rect->bottom - rect->top);

  return (FE_Region)XUnionRectWithRegion(&rectangle, (Region)region,
                                         (Region)region);
}

/* Destroys region */
void
FE_DestroyRegion(FE_Region region)
{
  XP_ASSERT(region);
  XDestroyRegion((Region)region);
}

/* Make a copy of a region */
FE_Region
FE_CopyRegion(FE_Region src, FE_Region dst)
{
  Region copyRegion;

  XP_ASSERT(src);

  if (dst != NULL) {
    copyRegion = (Region)dst;
  }
  else {
	/* Create an empty region */
	copyRegion = XCreateRegion();
	
	if (copyRegion == NULL)
	  return NULL;
  }

  /* Copy the region */
  XUnionRegion((Region)src, (Region)src, (Region)copyRegion);

  return (FE_Region)copyRegion;
}

/* dst = src1 intersect sr2       */
/* dst can be one of src1 or src2 */
void
FE_IntersectRegion(FE_Region src1, FE_Region src2, FE_Region dst)
{
  XP_ASSERT(src1);
  XP_ASSERT(src2);
  XP_ASSERT(dst);

  XIntersectRegion((Region)src1, (Region)src2, (Region)dst);
}

/* dst = src1 union src2          */
/* dst can be one of src1 or src2 */
void
FE_UnionRegion(FE_Region src1, FE_Region src2, FE_Region dst)
{
  XP_ASSERT(src1);
  XP_ASSERT(src2);
  XP_ASSERT(dst);

  XUnionRegion((Region)src1, (Region)src2, (Region)dst);
}

/* dst = src1 - src2              */
/* dst can be one of src1 or src2 */
void
FE_SubtractRegion(FE_Region src1, FE_Region src2, FE_Region dst)
{
  XP_ASSERT(src1);
  XP_ASSERT(src2);
  XP_ASSERT(dst);

  XSubtractRegion((Region)src1, (Region)src2, (Region)dst);
}

/* Returns TRUE if the region contains no pixels */
XP_Bool
FE_IsEmptyRegion(FE_Region region)
{
  XP_ASSERT(region);

  return (XP_Bool)XEmptyRegion((Region)region);
}

/* Returns the bounding rectangle of the region */
void
FE_GetRegionBoundingBox(FE_Region region, XP_Rect *bbox)
{
  XRectangle rect;

  XP_ASSERT(region);
  XP_ASSERT(bbox);

  XClipBox((Region)region, &rect);

  bbox->left = (int32)rect.x;
  bbox->top = (int32)rect.y;
  bbox->right = (int32)(rect.x + rect.width);
  bbox->bottom = (int32)(rect.y + rect.height);
}

/* TRUE if rgn1 == rgn2 */
XP_Bool
FE_IsEqualRegion(FE_Region rgn1, FE_Region rgn2)
{
  XP_ASSERT(rgn1);
  XP_ASSERT(rgn2);

  return (XP_Bool)XEqualRegion((Region)rgn1, (Region)rgn2);
}

/* Moves a region by the specified offsets */
void
FE_OffsetRegion(FE_Region region, int32 x_offset, int32 y_offset)
{
  XOffsetRegion((Region)region, x_offset, y_offset);
}

/* Returns TRUE if any part of the rectangle is in the specified region */
XP_Bool
FE_RectInRegion(FE_Region region, XP_Rect *rect)
{
  int result;
  XRectangle box;

  XP_ASSERT(region);
  XP_ASSERT(rect);

  box.x = (short)rect->left;
  box.y = (short)rect->top;
  box.width = (unsigned short)(rect->right - rect->left);
  box.height = (unsigned short)(rect->bottom - rect->top);

  result = XRectInRegion((Region)region, box.x, box.y, box.width, box.height);

  if (result == RectangleOut)
    return FALSE;
  else                /* result == RectangleIn || result == RectanglePart */
    return TRUE;
}


/* Calls the specified function for each rectangle that makes up the region */
void
FE_ForEachRectInRegion(FE_Region region, FE_RectInRegionFunc func,
                       void *closure)
{
    Region pRegion;
    register int nbox;
    register BOX *pbox;
    XP_Rect rect;

    XP_ASSERT(region);
    XP_ASSERT(func);

    pRegion = (Region)region;
    pbox = pRegion->rects;
    nbox = pRegion->numRects;

    while(nbox--)
        {
            rect.left = pbox->x1;
            rect.right = pbox->x2;
            rect.top = pbox->y1;
            rect.bottom = pbox->y2;
            (*func)(closure, &rect);
            pbox++;
        }
}

#ifdef DEBUG
#include "X11/X.h"
#include <sys/time.h>

static void
wait_usec(long usec)
{
    struct timeval timeout;

    timeout.tv_sec = 0;
    timeout.tv_usec = usec;
    select(0, NULL, NULL, NULL, &timeout);
}

static void
fe_InvertRect(MWContext *context, XP_Rect *rect)
{
    Widget wid;
    Display *dpy;
    Window win;
    Screen *screen;
    XGCValues gcv;
    GC gc;

    uint32 x, y, w, h;
    
    x = rect->left;
    y = rect->top;
    w = rect->right  - rect->left;
    h = rect->bottom - rect->top;
    
    wid = CONTEXT_DATA (context)->drawing_area;
    if (wid == NULL) return;
    XtVaGetValues (wid, XmNscreen, &screen, 0);

    dpy = XtDisplay (wid);
    win = XtWindow (wid);

    gcv.function = GXxor;
    gcv.foreground = 0xFFFFFF;

    gc = XCreateGC (dpy, win, GCForeground | GCFunction, &gcv);
    XFillRectangle (dpy, win, gc, x, y, w, h);
    XFreeGC (dpy, gc);
}

void
FE_HighlightRect(void *c, XP_Rect *rect, int how_much)
{
    MWContext *context = (MWContext*)c;
    while (how_much--) {
        fe_InvertRect(context, rect);
        wait_usec(1000 * how_much);
        fe_InvertRect(context, rect);
    }
}

void
fe_HighlightRegion(MWContext *context, FE_Region region)
{
    FE_ForEachRectInRegion(region, 
                           (FE_RectInRegionFunc)fe_InvertRect,
                           (void *)context);
}

void
FE_HighlightRegion(void *c, FE_Region region, int how_much)
{
    Widget wid;
    Display *dpy;
    MWContext *context = (MWContext*)c;
    
    wid = CONTEXT_DATA (context)->drawing_area;
    if (wid == NULL) return;
    dpy = XtDisplay (wid);

    fe_HighlightRegion(context, region);
    XSync(dpy, 0);
    wait_usec(1000 * how_much);
    fe_HighlightRegion(context, region);
    XSync(dpy, 0);
}
    
#endif /* DEBUG */