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scummvm/scumm/boxes.cpp
Max Horn 051977cd17 cleanup closestPtOnLine 
svn-id: r17876
2005-04-30 22:24:02 +00:00

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/* ScummVM - Scumm Interpreter
* Copyright (C) 2001 Ludvig Strigeus
* Copyright (C) 2001-2005 The ScummVM project
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* as published by the Free Software Foundation; either version 2
* of the License, or (at your option) any later version.
* This program 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 General Public License for more details.
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
*
* $Header$
*
*/
#include "stdafx.h"
#include "scumm/scumm.h"
#include "scumm/actor.h"
#include "scumm/boxes.h"
#include "scumm/util.h"
#include "common/util.h"
namespace Scumm {
#if !defined(__GNUC__)
#pragma START_PACK_STRUCTS
#endif
struct Box { /* Internal walkbox file format */
union {
struct {
byte uy;
byte ly;
byte ulx;
byte urx;
byte llx;
byte lrx;
byte mask;
byte flags;
} GCC_PACK v2;
struct {
int16 ulx, uly;
int16 urx, ury;
int16 lrx, lry;
int16 llx, lly;
byte mask;
byte flags;
uint16 scale;
} GCC_PACK old;
struct {
int32 ulx, uly;
int32 urx, ury;
int32 lrx, lry;
int32 llx, lly;
uint32 mask;
uint32 flags;
uint32 scaleSlot;
uint32 scale;
uint32 unk2;
uint32 unk3;
} GCC_PACK v8;
} GCC_PACK;
} GCC_PACK;
#if !defined(__GNUC__)
#pragma END_PACK_STRUCTS
#endif
#define BOX_MATRIX_SIZE 2000
#define BOX_DEBUG 0
static bool compareSlope(int X1, int Y1, int X2, int Y2, int X3, int Y3);
static Common::Point closestPtOnLine(const Common::Point &start, const Common::Point &end, int x, int y);
byte ScummEngine::getMaskFromBox(int box) {
// Fix for bug #740244 and #755863. This appears to have been a
// long standing bug in the original engine?
if (_version <= 3 && box == 255)
return 1;
Box *ptr = getBoxBaseAddr(box);
if (!ptr)
return 0;
// WORKAROUND for bug #847827: This is a bug in the data files, as it also
// occurs with the original engine. We work around it here anyway.
if (_gameId == GID_INDY4 && _currentRoom == 225 && _roomResource == 94 && box == 8)
return 0;
if (_version == 8)
return (byte) FROM_LE_32(ptr->v8.mask);
else if (_version <= 2)
return ptr->v2.mask;
else
return ptr->old.mask;
}
void ScummEngine::setBoxFlags(int box, int val) {
debug(2, "setBoxFlags(%d, 0x%02x)", box, val);
/* SCUMM7+ stuff */
if (val & 0xC000) {
assert(box >= 0 && box < 65);
_extraBoxFlags[box] = val;
} else {
Box *ptr = getBoxBaseAddr(box);
assert(ptr);
if (_version == 8)
ptr->v8.flags = TO_LE_32(val);
else if (_version <= 2)
ptr->v2.flags = val;
else
ptr->old.flags = val;
}
}
byte ScummEngine::getBoxFlags(int box) {
Box *ptr = getBoxBaseAddr(box);
if (!ptr)
return 0;
if (_version == 8)
return (byte) FROM_LE_32(ptr->v8.flags);
else if (_version <= 2)
return ptr->v2.flags;
else
return ptr->old.flags;
}
void ScummEngine::setBoxScale(int box, int scale) {
Box *ptr = getBoxBaseAddr(box);
assert(ptr);
if (_version == 8)
ptr->v8.scale = TO_LE_32(scale);
else if (_version <= 2)
error("This should not ever be called!");
else
ptr->old.scale = TO_LE_16(scale);
}
void ScummEngine::setBoxScaleSlot(int box, int slot) {
Box *ptr = getBoxBaseAddr(box);
assert(ptr);
ptr->v8.scaleSlot = TO_LE_32(slot);
}
int ScummEngine::getScale(int box, int x, int y) {
if (_features & GF_NO_SCALING)
return 255;
Box *ptr = getBoxBaseAddr(box);
if (!ptr)
return 255;
int slot , scale;
if (_version == 8) {
// COMI has a separate field for the scale slot...
slot = FROM_LE_32(ptr->v8.scaleSlot);
scale = FROM_LE_32(ptr->v8.scale);
} else {
scale = READ_LE_UINT16(&ptr->old.scale);
if (scale & 0x8000)
slot = (scale & 0x7FFF) + 1;
else
slot = 0;
}
// Was a scale slot specified? If so, we compute the effective scale
// from it, ignoring the box scale.
if (slot)
scale = getScaleFromSlot(slot, x, y);
return scale;
}
int ScummEngine::getScaleFromSlot(int slot, int x, int y) {
assert(1 <= slot && slot <= ARRAYSIZE(_scaleSlots));
int scale;
int scaleX = 0, scaleY = 0;
ScaleSlot &s = _scaleSlots[slot-1];
if (s.y1 == s.y2 && s.x1 == s.x2)
error("Invalid scale slot %d", slot);
if (s.y1 != s.y2) {
if (y < 0)
y = 0;
scaleY = (s.scale2 - s.scale1) * (y - s.y1) / (s.y2 - s.y1) + s.scale1;
}
if (s.x1 == s.x2) {
scale = scaleY;
} else {
scaleX = (s.scale2 - s.scale1) * (x - s.x1) / (s.x2 - s.x1) + s.scale1;
if (s.y1 == s.y2) {
scale = scaleX;
} else {
scale = (scaleX + scaleY) / 2;
}
}
// Clip the scale to range 1-255
if (scale < 1)
scale = 1;
else if (scale > 255)
scale = 255;
return scale;
}
int ScummEngine::getBoxScale(int box) {
if (_features & GF_NO_SCALING)
return 255;
Box *ptr = getBoxBaseAddr(box);
if (!ptr)
return 255;
if (_version == 8)
return FROM_LE_32(ptr->v8.scale);
else
return READ_LE_UINT16(&ptr->old.scale);
}
/**
* Convert a rtScaleTable resource to a corresponding scale slot entry.
*
* At some point, we discovered that the old scale items (stored in rtScaleTable
* resources) are in fact the same as (or rather, a predecessor of) the
* scale slots used in COMI. While not being precomputed (and thus slightly
* slower), scale slots are more flexible, and most importantly, can cope with
* rooms higher than 200 pixels. That's an essential feature for DIG and FT
* and in fact the lack of it caused various bugs in the past.
*
* Hence, we decided to switch all games to use the more powerful scale slots.
* To accomodate old savegames, we attempt here to convert rtScaleTable
* resources to scale slots.
*/
void ScummEngine::convertScaleTableToScaleSlot(int slot) {
assert(1 <= slot && slot <= ARRAYSIZE(_scaleSlots));
byte *resptr = getResourceAddress(rtScaleTable, slot);
int lowerIdx, upperIdx;
float m, oldM;
// Do nothing if the given scale table doesn't exist
if (resptr == 0)
return;
if (resptr[0] == resptr[199]) {
// The scale is constant. This usually means we encountered one of the
// "broken" cases. We set pseudo scale item values which lead to a
// constant scale of 255.
setScaleSlot(slot, 0, 0, 255, 0, 199, 255);
return;
}
/*
* Essentially, what we are doing here is some kind of "line fitting"
* algorithm. The data in the scale table represents a linear graph. What
* we want to find is the slope and (vertical) offset of this line. Things
* are complicated by the fact that the line is cut of vertically at 1 and
* 255. We have to be careful in handling this and some border cases.
*
* Some typical graphs look like these:
* --- --- ---
* / --- \
* ___/ --- \___
*
* The method used here is to compute the slope of secants fixed at the
* left and right end. For most cases this detects the cut-over points
* quite accurately.
*/
// Search for the bend on the left side
m = (resptr[199] - resptr[0]) / 199.0;
for (lowerIdx = 0; lowerIdx < 199 && (resptr[lowerIdx] == 1 || resptr[lowerIdx] == 255); lowerIdx++) {
oldM = m;
m = (resptr[199] - resptr[lowerIdx+1]) / (float)(199 - (lowerIdx+1));
if (m > 0) {
if (m <= oldM)
break;
} else {
if (m >= oldM)
break;
}
}
// Search for the bend on the right side
m = (resptr[199] - resptr[0]) / 199.0;
for (upperIdx = 199; upperIdx > 1 && (resptr[upperIdx] == 1 || resptr[upperIdx] == 255); upperIdx--) {
oldM = m;
m = (resptr[upperIdx-1] - resptr[0]) / (float)(upperIdx-1);
if (m > 0) {
if (m <= oldM)
break;
} else {
if (m >= oldM)
break;
}
}
// If lowerIdx and upperIdx are equal, we assume that there
// was no bend at all, and go for the maximum range.
if (lowerIdx == upperIdx) {
lowerIdx = 0;
upperIdx = 199;
}
// The values of y1 and y2, as well as the scale, can now easily be computed
setScaleSlot(slot, 0, lowerIdx, resptr[lowerIdx], 0, upperIdx, resptr[upperIdx]);
// Compute the variance, for debugging. It shouldn't exceed 1
ScaleSlot &s = _scaleSlots[slot-1];
int y;
int sum = 0;
int scale;
float variance;
for (y = 0; y < 200; y++) {
scale = (s.scale2 - s.scale1) * (y - s.y1) / (s.y2 - s.y1) + s.scale1;
if (scale < 1)
scale = 1;
else if (scale > 255)
scale = 255;
sum += (resptr[y] - scale) * (resptr[y] - scale);
}
variance = sum / (200.0 - 1.0);
if (variance > 1)
debug(1, "scale item %d, variance %f exceeds 1 (room %d)", slot, variance, _currentRoom);
}
void ScummEngine::setScaleSlot(int slot, int x1, int y1, int scale1, int x2, int y2, int scale2) {
assert(1 <= slot && slot <= ARRAYSIZE(_scaleSlots));
ScaleSlot &s = _scaleSlots[slot-1];
s.x2 = x2;
s.y2 = y2;
s.scale2 = scale2;
s.x1 = x1;
s.y1 = y1;
s.scale1 = scale1;
}
byte ScummEngine::getNumBoxes() {
byte *ptr = getResourceAddress(rtMatrix, 2);
if (!ptr)
return 0;
if (_version == 8)
return (byte) READ_LE_UINT32(ptr);
else
return ptr[0];
}
Box *ScummEngine::getBoxBaseAddr(int box) {
byte *ptr = getResourceAddress(rtMatrix, 2);
if (!ptr || box == 255)
return NULL;
// FIXME: In "pass to adventure", the loom demo, when bobbin enters
// the tent to the elders, box = 2, but ptr[0] = 2 -> errors out.
// Hence we disable the check for now. Maybe in PASS (and other old games)
// we shouldn't subtract 1 from ptr[0] when performing the check?
// this also seems to be incorrect for atari st demo of zak
// and assumingly other v2 games
// The same happens in Indy3EGA (see bug #770351)
// Also happens in ZakEGA (see bug #771803).
//
// This *might* mean that we have a bug in our box implementation
// OTOH, the original engine, unlike ScummVM, performed no bound
// checking at all. All the problems so far have been cases where
// the value was exactly one more than what we consider the maximum.
// So it's very well possible that all of these are script errors.
if (_version <= 4 && ptr[0] == box)
box--;
checkRange(ptr[0] - 1, 0, box, "Illegal box %d");
if (_version <= 2)
return (Box *)(ptr + box * SIZEOF_BOX_V2 + 1);
else if (_version == 3)
return (Box *)(ptr + box * SIZEOF_BOX_V3 + 1);
else if (_features & GF_SMALL_HEADER)
return (Box *)(ptr + box * SIZEOF_BOX + 1);
else if (_version == 8)
return (Box *)(ptr + box * SIZEOF_BOX_V8 + 4);
else
return (Box *)(ptr + box * SIZEOF_BOX + 2);
}
int ScummEngine::getSpecialBox(int x, int y) {
int i;
int numOfBoxes;
byte flag;
numOfBoxes = getNumBoxes() - 1;
for (i = numOfBoxes; i >= 0; i--) {
flag = getBoxFlags(i);
if (!(flag & kBoxInvisible) && (flag & kBoxPlayerOnly))
return (-1);
if (checkXYInBoxBounds(i, x, y))
return (i);
}
return (-1);
}
bool ScummEngine::checkXYInBoxBounds(int b, int x, int y) {
BoxCoords box;
if (b < 0 || b == Actor::kInvalidBox)
return false;
getBoxCoordinates(b, &box);
if (x < box.ul.x && x < box.ur.x && x < box.lr.x && x < box.ll.x)
return false;
if (x > box.ul.x && x > box.ur.x && x > box.lr.x && x > box.ll.x)
return false;
if (y < box.ul.y && y < box.ur.y && y < box.lr.y && y < box.ll.y)
return false;
if (y > box.ul.y && y > box.ur.y && y > box.lr.y && y > box.ll.y)
return false;
if (box.ul.x == box.ur.x && box.ul.y == box.ur.y && box.lr.x == box.ll.x && box.lr.y == box.ll.y ||
box.ul.x == box.ll.x && box.ul.y == box.ll.y && box.ur.x == box.lr.x && box.ur.y == box.lr.y) {
Common::Point pt;
pt = closestPtOnLine(box.ul, box.lr, x, y);
if (distanceFromPt(x, y, pt.x, pt.y) <= 4)
return true;
}
if (!compareSlope(box.ul.x, box.ul.y, box.ur.x, box.ur.y, x, y))
return false;
if (!compareSlope(box.ur.x, box.ur.y, box.lr.x, box.lr.y, x, y))
return false;
if (!compareSlope(box.ll.x, box.ll.y, x, y, box.lr.x, box.lr.y))
return false;
if (!compareSlope(box.ul.x, box.ul.y, x, y, box.ll.x, box.ll.y))
return false;
return true;
}
void ScummEngine::getBoxCoordinates(int boxnum, BoxCoords *box) {
Box *bp = getBoxBaseAddr(boxnum);
assert(bp);
if (_version == 8) {
box->ul.x = (short)FROM_LE_32(bp->v8.ulx);
box->ul.y = (short)FROM_LE_32(bp->v8.uly);
box->ur.x = (short)FROM_LE_32(bp->v8.urx);
box->ur.y = (short)FROM_LE_32(bp->v8.ury);
box->ll.x = (short)FROM_LE_32(bp->v8.llx);
box->ll.y = (short)FROM_LE_32(bp->v8.lly);
box->lr.x = (short)FROM_LE_32(bp->v8.lrx);
box->lr.y = (short)FROM_LE_32(bp->v8.lry);
// FIXME: Some walkboxes in CMI appear to have been flipped,
// in the sense that for instance the lower boundary is above
// the upper one. Can that really be the case, or is there
// some more sinister problem afoot?
//
// Is this fix sufficient, or will we need something more
// elaborate?
if (box->ul.y > box->ll.y && box->ur.y > box->lr.y) {
SWAP(box->ul, box->ll);
SWAP(box->ur, box->lr);
}
if (box->ul.x > box->ur.x && box->ll.x > box->lr.x) {
SWAP(box->ul, box->ur);
SWAP(box->ll, box->lr);
}
} else if (_version <= 2) {
box->ul.x = bp->v2.ulx * 8;
box->ul.y = bp->v2.uy * 2;
box->ur.x = bp->v2.urx * 8;
box->ur.y = bp->v2.uy * 2;
box->ll.x = bp->v2.llx * 8;
box->ll.y = bp->v2.ly * 2;
box->lr.x = bp->v2.lrx * 8;
box->lr.y = bp->v2.ly * 2;
} else {
box->ul.x = (int16)READ_LE_UINT16(&bp->old.ulx);
box->ul.y = (int16)READ_LE_UINT16(&bp->old.uly);
box->ur.x = (int16)READ_LE_UINT16(&bp->old.urx);
box->ur.y = (int16)READ_LE_UINT16(&bp->old.ury);
box->ll.x = (int16)READ_LE_UINT16(&bp->old.llx);
box->ll.y = (int16)READ_LE_UINT16(&bp->old.lly);
box->lr.x = (int16)READ_LE_UINT16(&bp->old.lrx);
box->lr.y = (int16)READ_LE_UINT16(&bp->old.lry);
}
}
uint ScummEngine::distanceFromPt(int x, int y, int ptx, int pty) {
int diffx, diffy;
diffx = ABS(ptx - x);
if (diffx >= 0x1000)
return 0xFFFFFF;
diffy = ABS(pty - y);
if (diffy >= 0x1000)
return 0xFFFFFF;
diffx *= diffx;
diffy *= diffy;
return diffx + diffy;
}
bool compareSlope(int X1, int Y1, int X2, int Y2, int X3, int Y3) {
return (Y2 - Y1) * (X3 - X1) <= (Y3 - Y1) * (X2 - X1);
}
/**
* Find the point on a line segment which is closest to a given point.
*
* @param start the start of the line segment
* @param end the end of the line segment
* @param x the x coordinate of the point which we want to 'project' on the line segment
* @param y the y coordinate of the point which we want to 'project' on the line segment
* @return the point on the line segmen closes to the given point
*/
Common::Point closestPtOnLine(const Common::Point &start, const Common::Point &end, int x, int y) {
Common::Point pt;
const int lxdiff = end.x - start.x;
const int lydiff = end.y - start.y;
if (end.x == start.x) { // Vertical line?
pt.x = start.x;
pt.y = y;
} else if (end.y == start.y) { // Horizontal line?
pt.x = x;
pt.y = start.y;
} else {
const int dist = lxdiff * lxdiff + lydiff * lydiff;
int a, b, c;
if (ABS(lxdiff) > ABS(lydiff)) {
a = start.x * lydiff / lxdiff;
b = x * lxdiff / lydiff;
c = (a + b - start.y + y) * lydiff * lxdiff / dist;
pt.x = c;
pt.y = c * lydiff / lxdiff - a + start.y;
} else {
a = start.y * lxdiff / lydiff;
b = y * lydiff / lxdiff;
c = (a + b - start.x + x) * lydiff * lxdiff / dist;
pt.y = c;
pt.x = c * lxdiff / lydiff - a + start.x;
}
}
if (ABS(lydiff) < ABS(lxdiff)) {
if (lxdiff > 0) {
if (pt.x < start.x)
pt = start;
else if (pt.x > end.x)
pt = end;
} else {
if (pt.x > start.x)
pt = start;
else if (pt.x < end.x)
pt = end;
}
} else {
if (lydiff > 0) {
if (pt.y < start.y)
pt = start;
else if (pt.y > end.y)
pt = end;
} else {
if (pt.y > start.y)
pt = start;
else if (pt.y < end.y)
pt = end;
}
}
return pt;
}
bool ScummEngine::inBoxQuickReject(int b, int x, int y, int threshold) {
int t;
BoxCoords box;
getBoxCoordinates(b, &box);
t = x - threshold;
if (t > box.ul.x && t > box.ur.x && t > box.lr.x && t > box.ll.x)
return true;
t = x + threshold;
if (t < box.ul.x && t < box.ur.x && t < box.lr.x && t < box.ll.x)
return true;
t = y - threshold;
if (t > box.ul.y && t > box.ur.y && t > box.lr.y && t > box.ll.y)
return true;
t = y + threshold;
if (t < box.ul.y && t < box.ur.y && t < box.lr.y && t < box.ll.y)
return true;
return false;
}
int ScummEngine::getClosestPtOnBox(int b, int x, int y, int16& outX, int16& outY) {
Common::Point pt;
uint dist;
uint bestdist = 0xFFFFFF;
BoxCoords box;
getBoxCoordinates(b, &box);
pt = closestPtOnLine(box.ul, box.ur, x, y);
dist = distanceFromPt(x, y, pt.x, pt.y);
if (dist < bestdist) {
bestdist = dist;
outX = pt.x;
outY = pt.y;
}
pt = closestPtOnLine(box.ur, box.lr, x, y);
dist = distanceFromPt(x, y, pt.x, pt.y);
if (dist < bestdist) {
bestdist = dist;
outX = pt.x;
outY = pt.y;
}
pt = closestPtOnLine(box.lr, box.ll, x, y);
dist = distanceFromPt(x, y, pt.x, pt.y);
if (dist < bestdist) {
bestdist = dist;
outX = pt.x;
outY = pt.y;
}
pt = closestPtOnLine(box.ll, box.ul, x, y);
dist = distanceFromPt(x, y, pt.x, pt.y);
if (dist < bestdist) {
bestdist = dist;
outX = pt.x;
outY = pt.y;
}
return bestdist;
}
byte *ScummEngine::getBoxMatrixBaseAddr() {
byte *ptr = getResourceAddress(rtMatrix, 1);
assert(ptr);
if (*ptr == 0xFF)
ptr++;
return ptr;
}
/*
* Compute if there is a way that connects box 'from' with box 'to'.
* Returns the number of a box adjactant to 'from' that is the next on the
* way to 'to' (this can be 'to' itself or a third box).
* If there is no connection -1 is return.
*/
int ScummEngine::getPathToDestBox(byte from, byte to) {
const byte *boxm;
byte i;
const int numOfBoxes = getNumBoxes();
int dest = -1;
if (from == to)
return to;
if (to == Actor::kInvalidBox)
return -1;
if (from == Actor::kInvalidBox)
return to;
assert(from < numOfBoxes);
assert(to < numOfBoxes);
boxm = getBoxMatrixBaseAddr();
if (_version <= 2) {
// The v2 box matrix is a real matrix with numOfBoxes rows and columns.
// The first numOfBoxes bytes contain indices to the start of the corresponding
// row (although that seems unnecessary to me - the value is easily computable.
boxm += numOfBoxes + boxm[from];
return (int8)boxm[to];
}
// WORKAROUND #1: It seems that in some cases, the box matrix is corrupt
// (more precisely, is too short) in the datafiles already. In
// particular this seems to be the case in room 46 of Indy3 EGA (see
// also bug #770690). This didn't cause problems in the original
// engine, because there, the memory layout is different. After the
// walkbox would follow the rest of the room file, thus the program
// always behaved the same (and by chance, correct). Not so for us,
// since random data may follow after the resource in ScummVM.
//
// As a workaround, we add a check for the end of the box matrix
// resource, and abort the search once we reach the end.
const byte *end = boxm + getResourceSize(rtMatrix, 1);
// WORKAROUND #2: In addition to the above, we have to add this special
// case to fix the scene in Indy3 where Indy meets Hitler in Berlin.
// See bug #770690 and also bug #774783.
if ((_gameId == GID_INDY3) && _roomResource == 46 && from == 1 && to == 0)
return 0;
// Skip up to the matrix data for box 'from'
for (i = 0; i < from && boxm < end; i++) {
while (boxm < end && *boxm != 0xFF)
boxm += 3;
boxm++;
}
// Now search for the entry for box 'to'
while (boxm < end && boxm[0] != 0xFF) {
if (boxm[0] <= to && to <= boxm[1])
dest = (int8)boxm[2];
boxm += 3;
}
if (boxm >= end)
warning("The box matrix apparently is truncated (room %d)", _roomResource);
return dest;
}
/*
* Computes the next point actor a has to walk towards in a straight
* line in order to get from box1 to box3 via box2.
*/
bool Actor::findPathTowards(byte box1nr, byte box2nr, byte box3nr, Common::Point &foundPath) {
BoxCoords box1;
BoxCoords box2;
Common::Point tmp;
int i, j;
int flag;
int q, pos;
_vm->getBoxCoordinates(box1nr, &box1);
_vm->getBoxCoordinates(box2nr, &box2);
for (i = 0; i < 4; i++) {
for (j = 0; j < 4; j++) {
if (box1.ul.x == box1.ur.x && box1.ul.x == box2.ul.x && box1.ul.x == box2.ur.x) {
flag = 0;
if (box1.ul.y > box1.ur.y) {
SWAP(box1.ul.y, box1.ur.y);
flag |= 1;
}
if (box2.ul.y > box2.ur.y) {
SWAP(box2.ul.y, box2.ur.y);
flag |= 2;
}
if (box1.ul.y > box2.ur.y || box2.ul.y > box1.ur.y ||
(box1.ur.y == box2.ul.y || box2.ur.y == box1.ul.y) &&
box1.ul.y != box1.ur.y && box2.ul.y != box2.ur.y) {
if (flag & 1)
SWAP(box1.ul.y, box1.ur.y);
if (flag & 2)
SWAP(box2.ul.y, box2.ur.y);
} else {
pos = _pos.y;
if (box2nr == box3nr) {
int diffX = _walkdata.dest.x - _pos.x;
int diffY = _walkdata.dest.y - _pos.y;
int boxDiffX = box1.ul.x - _pos.x;
if (diffX != 0) {
int t;
diffY *= boxDiffX;
t = diffY / diffX;
if (t == 0 && (diffY <= 0 || diffX <= 0)
&& (diffY >= 0 || diffX >= 0))
t = -1;
pos = _pos.y + t;
}
}
q = pos;
if (q < box2.ul.y)
q = box2.ul.y;
if (q > box2.ur.y)
q = box2.ur.y;
if (q < box1.ul.y)
q = box1.ul.y;
if (q > box1.ur.y)
q = box1.ur.y;
if (q == pos && box2nr == box3nr)
return true;
foundPath.y = q;
foundPath.x = box1.ul.x;
return false;
}
}
if (box1.ul.y == box1.ur.y && box1.ul.y == box2.ul.y && box1.ul.y == box2.ur.y) {
flag = 0;
if (box1.ul.x > box1.ur.x) {
SWAP(box1.ul.x, box1.ur.x);
flag |= 1;
}
if (box2.ul.x > box2.ur.x) {
SWAP(box2.ul.x, box2.ur.x);
flag |= 2;
}
if (box1.ul.x > box2.ur.x || box2.ul.x > box1.ur.x ||
(box1.ur.x == box2.ul.x || box2.ur.x == box1.ul.x) &&
box1.ul.x != box1.ur.x && box2.ul.x != box2.ur.x) {
if (flag & 1)
SWAP(box1.ul.x, box1.ur.x);
if (flag & 2)
SWAP(box2.ul.x, box2.ur.x);
} else {
if (box2nr == box3nr) {
int diffX = _walkdata.dest.x - _pos.x;
int diffY = _walkdata.dest.y - _pos.y;
int boxDiffY = box1.ul.y - _pos.y;
pos = _pos.x;
if (diffY != 0) {
pos += diffX * boxDiffY / diffY;
}
} else {
pos = _pos.x;
}
q = pos;
if (q < box2.ul.x)
q = box2.ul.x;
if (q > box2.ur.x)
q = box2.ur.x;
if (q < box1.ul.x)
q = box1.ul.x;
if (q > box1.ur.x)
q = box1.ur.x;
if (q == pos && box2nr == box3nr)
return true;
foundPath.x = q;
foundPath.y = box1.ul.y;
return false;
}
}
tmp = box1.ul;
box1.ul = box1.ur;
box1.ur = box1.lr;
box1.lr = box1.ll;
box1.ll = tmp;
}
tmp = box2.ul;
box2.ul = box2.ur;
box2.ur = box2.lr;
box2.lr = box2.ll;
box2.ll = tmp;
}
return false;
}
#if BOX_DEBUG
static void printMatrix(byte *boxm, int num) {
int i;
for (i = 0; i < num; i++) {
printf("%d: ", i);
while (*boxm != 0xFF) {
printf("%d, ", *boxm);
boxm++;
}
boxm++;
printf("\n");
}
}
static void printMatrix2(byte *matrix, int num) {
int i, j;
printf(" ");
for (i = 0; i < num; i++)
printf("%2d ", i);
printf("\n");
for (i = 0; i < num; i++) {
printf("%2d: ", i);
for (j = 0; j < num; j++) {
int val = matrix[i * 64 + j];
if (val == Actor::kInvalidBox)
printf(" ? ");
else
printf("%2d ", val);
}
printf("\n");
}
}
#endif
void ScummEngine::createBoxMatrix() {
int num, i, j, k;
byte *adjacentMatrix, *itineraryMatrix;
// The total number of boxes
num = getNumBoxes();
assert(num <= 64);
// Allocate the adjacent & itinerary matrices
adjacentMatrix = (byte *)malloc(64 * 64);
itineraryMatrix = (byte *)malloc(64 * 64);
// Initialise the adjacent matrix: each box has distance 0 to itself,
// and distance 1 to its direct neighbors. Initially, it has distance
// 255 (= infinity) to all other boxes.
for (i = 0; i < num; i++) {
for (j = 0; j < num; j++) {
if (i == j) {
adjacentMatrix[i * 64 + j] = 0;
itineraryMatrix[i * 64 + j] = j;
} else if (areBoxesNeighbours(i, j)) {
adjacentMatrix[i * 64 + j] = 1;
itineraryMatrix[i * 64 + j] = j;
} else {
adjacentMatrix[i * 64 + j] = 255;
itineraryMatrix[i * 64 + j] = Actor::kInvalidBox;
}
}
}
// Compute the shortest routes between boxes via Kleene's algorithm.
// The original code used some kind of mangled Dijkstra's algorithm;
// while that might in theory be slightly faster, it was
// a) extremly obfuscated
// b) incorrect: it didn't always find the shortest paths
// c) not any faster in reality for our sparse & small adjacent matrices
for (k = 0; k < num; k++) {
for (i = 0; i < num; i++) {
for (j = 0; j < num; j++) {
if (i == j)
continue;
byte distIK = adjacentMatrix[64 * i + k];
byte distKJ = adjacentMatrix[64 * k + j];
if (adjacentMatrix[64 * i + j] > distIK + distKJ) {
adjacentMatrix[64 * i + j] = distIK + distKJ;
itineraryMatrix[64 * i + j] = itineraryMatrix[64 * i + k];
}
}
}
}
// "Compress" the distance matrix into the box matrix format used
// by the engine. The format is like this:
// For each box (from 0 to num) there is first a byte with value 0xFF,
// followed by an arbitrary number of byte triples; the end is marked
// again by the lead 0xFF for the next "row". The meaning of the
// byte triples is as follows: the first two bytes define a range
// of box numbers (e.g. 7-11), while the third byte defines an
// itineray box. Assuming we are in the 5th "row" and encounter
// the triplet 7,11,15: this means to get from box 5 to any of
// the boxes 7,8,9,10,11 the shortest way is to go via box 15.
// See also getPathToDestBox.
byte *matrixStart = res.createResource(rtMatrix, 1, BOX_MATRIX_SIZE);
const byte *matrixEnd = matrixStart + BOX_MATRIX_SIZE;
#define addToMatrix(b) do { *matrixStart++ = (b); assert(matrixStart < matrixEnd); } while (0)
for (i = 0; i < num; i++) {
addToMatrix(0xFF);
for (j = 0; j < num; j++) {
byte itinerary = itineraryMatrix[64 * i + j];
if (itinerary != Actor::kInvalidBox) {
addToMatrix(j);
while (j < num - 1 && itinerary == itineraryMatrix[64 * i + (j + 1)])
j++;
addToMatrix(j);
addToMatrix(itinerary);
}
}
}
addToMatrix(0xFF);
#if BOX_DEBUG
printf("Itinerary matrix:\n");
printMatrix2(itineraryMatrix, num);
printf("compressed matrix:\n");
printMatrix(getBoxMatrixBaseAddr(), num);
#endif
free(adjacentMatrix);
free(itineraryMatrix);
}
/** Check if two boxes are neighbours. */
bool ScummEngine::areBoxesNeighbours(int box1nr, int box2nr) {
Common::Point tmp;
BoxCoords box;
BoxCoords box2;
if (getBoxFlags(box1nr) & kBoxInvisible || getBoxFlags(box2nr) & kBoxInvisible)
return false;
getBoxCoordinates(box1nr, &box2);
getBoxCoordinates(box2nr, &box);
// Roughly, the idea of this algorithm is to check if we can find
// two sides of the two given boxes which touch.
// In order to keep te code simple, we only match the upper sides;
// then, we "rotate" the box coordinates four times each, for a total
// of 16 comparisions (four sides compared with four sides each).
for (int j = 0; j < 4; j++) {
for (int k = 0; k < 4; k++) {
// Are the "upper" sides of the boxes on a single vertical line
// (i.e. all share one x value) ?
if (box2.ur.x == box2.ul.x && box.ul.x == box2.ul.x && box.ur.x == box2.ul.x) {
bool swappedBox2 = false, swappedBox1 = false;
if (box2.ur.y < box2.ul.y) {
swappedBox2 = 1;
SWAP(box2.ur.y, box2.ul.y);
}
if (box.ur.y < box.ul.y) {
swappedBox1 = 1;
SWAP(box.ur.y, box.ul.y);
}
if (box.ur.y < box2.ul.y ||
box.ul.y > box2.ur.y ||
(box.ul.y == box2.ur.y ||
box.ur.y == box2.ul.y) && box2.ur.y != box2.ul.y && box.ul.y != box.ur.y) {
} else {
return true;
}
// Swap back if necessary
if (swappedBox2) {
SWAP(box2.ur.y, box2.ul.y);
}
if (swappedBox1) {
SWAP(box.ur.y, box.ul.y);
}
}
// Are the "upper" sides of the boxes on a single horizontal line
// (i.e. all share one y value) ?
if (box2.ur.y == box2.ul.y && box.ul.y == box2.ul.y && box.ur.y == box2.ul.y) {
bool swappedBox2 = false, swappedBox1 = false;
if (box2.ur.x < box2.ul.x) {
swappedBox2 = 1;
SWAP(box2.ur.x, box2.ul.x);
}
if (box.ur.x < box.ul.x) {
swappedBox1 = 1;
SWAP(box.ur.x, box.ul.x);
}
if (box.ur.x < box2.ul.x ||
box.ul.x > box2.ur.x ||
(box.ul.x == box2.ur.x ||
box.ur.x == box2.ul.x) && box2.ur.x != box2.ul.x && box.ul.x != box.ur.x) {
} else {
return true;
}
// Swap back if necessary
if (swappedBox2) {
SWAP(box2.ur.x, box2.ul.x);
}
if (swappedBox1) {
SWAP(box.ur.x, box.ul.x);
}
}
// "Rotate" the box coordinates
tmp = box2.ul;
box2.ul = box2.ur;
box2.ur = box2.lr;
box2.lr = box2.ll;
box2.ll = tmp;
}
// "Rotate" the box coordinates
tmp = box.ul;
box.ul = box.ur;
box.ur = box.lr;
box.lr = box.ll;
box.ll = tmp;
}
return false;
}
void Actor::findPathTowardsOld(byte box1, byte box2, byte finalBox, Common::Point &p2, Common::Point &p3) {
Common::Point pt;
Common::Point gateA[2];
Common::Point gateB[2];
_vm->getGates(box1, box2, gateA, gateB);
p2.x = 32000;
p3.x = 32000;
// next box (box2) = final box?
if (box2 == finalBox) {
// In Indy3, the masks (= z-level) have to match, too -- needed for the
// 'maze' in the zeppeling (see bug #1032964).
if (_vm->_gameId != GID_INDY3 || _vm->getMaskFromBox(box1) == _vm->getMaskFromBox(box2)) {
// Is the actor (x,y) between both gates?
if (compareSlope(_pos.x, _pos.y, _walkdata.dest.x, _walkdata.dest.y, gateA[0].x, gateA[0].y) !=
compareSlope(_pos.x, _pos.y, _walkdata.dest.x, _walkdata.dest.y, gateB[0].x, gateB[0].y) &&
compareSlope(_pos.x, _pos.y, _walkdata.dest.x, _walkdata.dest.y, gateA[1].x, gateA[1].y) !=
compareSlope(_pos.x, _pos.y, _walkdata.dest.x, _walkdata.dest.y, gateB[1].x, gateB[1].y)) {
return;
}
}
}
p3 = pt = closestPtOnLine(gateA[1], gateB[1], _pos.x, _pos.y);
if (compareSlope(_pos.x, _pos.y, p3.x, p3.y, gateA[0].x, gateA[0].y) ==
compareSlope(_pos.x, _pos.y, p3.x, p3.y, gateB[0].x, gateB[0].y)) {
closestPtOnLine(gateA[0], gateB[0], _pos.x, _pos.y);
p2 = pt; // if point 2 between gates, ignore!
}
}
/**
* Compute the "gate" between two boxes. The gate is a pair of two lines which
* both start on box 'box1' and end on 'box2'. For both lines, one of its
* end points is the corner point of one of the two boxes. The other end point
* is a point on the other point closest to first end point.
* This way the lines bound a 'corridor' between the two boxes, through which
* the actor has to walk to get from box1 to box2.
*/
void ScummEngine::getGates(int box1, int box2, Common::Point gateA[2], Common::Point gateB[2]) {
int i, j;
int dist[8];
int minDist[3];
int closest[3];
int box[3];
BoxCoords coords;
Common::Point closestPoint[8];
Common::Point boxCorner[8];
int line1, line2;
// For all corner coordinates of the first box, compute the point closest
// to them on the second box (and also compute the distance of these points).
getBoxCoordinates(box1, &coords);
boxCorner[0] = coords.ul;
boxCorner[1] = coords.ur;
boxCorner[2] = coords.lr;
boxCorner[3] = coords.ll;
for (i = 0; i < 4; i++) {
dist[i] = getClosestPtOnBox(box2, boxCorner[i].x, boxCorner[i].y, closestPoint[i].x, closestPoint[i].y);
}
// Now do the same but with the roles of the first and second box swapped.
getBoxCoordinates(box2, &coords);
boxCorner[4] = coords.ul;
boxCorner[5] = coords.ur;
boxCorner[6] = coords.lr;
boxCorner[7] = coords.ll;
for (i = 4; i < 8; i++) {
dist[i] = getClosestPtOnBox(box1, boxCorner[i].x, boxCorner[i].y, closestPoint[i].x, closestPoint[i].y);
}
// Find the three closest "close" points between the two boxes.
for (j = 0; j < 3; j++) {
minDist[j] = 0xFFFF;
for (i = 0; i < 8; i++) {
if (dist[i] < minDist[j]) {
minDist[j] = dist[i];
closest[j] = i;
}
}
dist[closest[j]] = 0xFFFF;
minDist[j] = (int)sqrt((double)minDist[j]);
box[j] = (closest[j] > 3); // Is the point on the first or on the second box?
}
// Finally, compute the actual "gate".
if (box[0] == box[1] && ABS(minDist[0] - minDist[1]) < 4) {
line1 = closest[0];
line2 = closest[1];
} else if (box[0] == box[1] && minDist[0] == minDist[1]) { // parallel
line1 = closest[0];
line2 = closest[1];
} else if (box[0] == box[2] && minDist[0] == minDist[2]) { // parallel
line1 = closest[0];
line2 = closest[2];
} else if (box[1] == box[2] && minDist[1] == minDist[2]) { // parallel
line1 = closest[1];
line2 = closest[2];
} else if (box[0] == box[2] && ABS(minDist[0] - minDist[2]) < 4) {
line1 = closest[0];
line2 = closest[2];
} else if (ABS(minDist[0] - minDist[2]) < 4) {
line1 = closest[1];
line2 = closest[2];
} else if (ABS(minDist[0] - minDist[1]) < 4) {
line1 = closest[0];
line2 = closest[1];
} else {
line1 = closest[0];
line2 = closest[0];
}
// Set the gate
if (line1 < 4) {
gateA[0] = boxCorner[line1];
gateA[1] = closestPoint[line1];
} else {
gateA[1] = boxCorner[line1];
gateA[0] = closestPoint[line1];
}
if (line2 < 4) {
gateB[0] = boxCorner[line2];
gateB[1] = closestPoint[line2];
} else {
gateB[1] = boxCorner[line2];
gateB[0] = closestPoint[line2];
}
}
} // End of namespace Scumm
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