scummvm/engines/mads/rails.cpp
2014-04-22 23:00:41 -04:00

285 lines
7.1 KiB
C++

/* ScummVM - Graphic Adventure Engine
*
* ScummVM is the legal property of its developers, whose names
* are too numerous to list here. Please refer to the COPYRIGHT
* file distributed with this source distribution.
*
* 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., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
*
*/
#include "common/scummsys.h"
#include "mads/mads.h"
#include "mads/rails.h"
namespace MADS {
WalkNode::WalkNode() {
_active = false;
Common::fill(&_distances[0], &_distances[MAX_ROUTE_NODES], 0);
}
void WalkNode::load(Common::SeekableReadStream *f) {
_walkPos.x = f->readSint16LE();
_walkPos.y = f->readSint16LE();
for (int i = 0; i < MAX_ROUTE_NODES; ++i)
_distances[i] = f->readUint16LE();
}
/*------------------------------------------------------------------------*/
Rails::Rails() {
_depthSurface = nullptr;
_routeLength = 0;
}
void Rails::load(const WalkNodeList &nodes, DepthSurface *depthSurface, int depthStyle) {
// Store the depth surface and depth style to use
_depthSurface = depthSurface;
_depthStyle = depthStyle;
// Load the passed node list
_nodes.clear();
for (uint i = 0; i < nodes.size(); ++i)
_nodes.push_back(nodes[i]);
// Add two more empty nodes for the start and end points of any walk sequence
_nodes.push_back(WalkNode());
_nodes.push_back(WalkNode());
}
void Rails::setupRoute(bool bitFlag, const Common::Point &srcPos, const Common::Point &destPos) {
// Reset the nodes in as being inactive
for (uint i = 0; i < _nodes.size(); ++i)
_nodes[i]._active = false;
// Set the two extra walk nodes to the start and destination positions
setNodePosition(_nodes.size() - 2, srcPos);
setNodePosition(_nodes.size() - 1, destPos);
// Start constructing route node list
_routeLength = 0x3FFF;
_routeIndexes.clear();
// Recursively form a route from the destination walk node back to the player's position
setupRouteNode(&_tempRoute[0], _nodes.size() - 1, bitFlag ? 0xC000 : 0x8000, 0);
_next = 0;
if (_routeIndexes.size() > 0) {
Common::Point currPos = srcPos;
for (int routeCtr = size() - 1; (routeCtr >= 0) && !_next; --routeCtr) {
int idx = _routeIndexes[routeCtr];
const Common::Point &pt = _nodes[idx]._walkPos;
_next = scanPath(currPos, pt);
currPos = pt;
}
}
}
void Rails::setupRouteNode(int *routeIndexP, int nodeIndex, int flags, int routeLength) {
WalkNode &currentNode = _nodes[nodeIndex];
currentNode._active = true;
*routeIndexP++ = nodeIndex;
// Get the index of the ultimate source position (the player)
int subIndex = _nodes.size() - 2;
int distanceVal = _nodes[nodeIndex]._distances[subIndex];
if (distanceVal & flags) {
routeLength += distanceVal & 0x3FFF;
if (routeLength < _routeLength) {
// Found a new shorter route to destination, so set up the route with the found one
_routeIndexes.clear();
for (int i = 0; routeIndexP != &_tempRoute[i]; ++i)
_routeIndexes.push(_tempRoute[i]);
_routeLength = routeLength;
}
} else {
for (int idx = _nodes.size() - 2; idx > 0; --idx) {
int nodePos = idx - 1;
if (!_nodes[nodePos]._active && ((currentNode._distances[nodePos] & flags) != 0))
setupRouteNode(routeIndexP, nodePos, 0x8000, routeLength + (distanceVal & 0x3fff));
}
}
currentNode._active = false;
}
int Rails::scanPath(const Common::Point &srcPos, const Common::Point &destPos) {
// For compressed depth surfaces, always return 0
if (_depthStyle == 2)
return 0;
int yDiff = destPos.y - srcPos.y;
int yAmount = MADS_SCREEN_WIDTH;
if (yDiff < 0) {
yDiff = -yDiff;
yAmount = -yAmount;
}
int xDiff = destPos.x - srcPos.x;
int xDirection = 1;
int xAmount = 0;
if (xDiff < 0) {
xDiff = -xDiff;
xDirection = -xDirection;
xAmount = MIN(yDiff, xDiff);
}
++xDiff;
++yDiff;
const byte *srcP = _depthSurface->getBasePtr(srcPos.x, srcPos.y);
int index = xAmount;
// Outer loop
for (int xCtr = 0; xCtr < xDiff; ++xCtr, srcP += xDirection) {
index += yDiff;
int v = (*srcP & 0x7F) >> 4;
if (v)
return v;
// Inner loop for handling vertical movement
while (index >= xDiff) {
index -= xDiff;
v = (*srcP & 0x7F) >> 4;
if (v)
return v;
srcP += yAmount;
}
}
return 0;
}
void Rails::resetRoute() {
_routeIndexes.clear();
_next = 0;
}
const WalkNode &Rails::popNode() {
assert(!_routeIndexes.empty());
return _nodes[_routeIndexes.pop()];
}
void Rails::setNodePosition(int nodeIndex, const Common::Point &pt) {
int flags, hypotenuse;
_nodes[nodeIndex]._walkPos = pt;
// Recalculate inter-node lengths
for (uint idx = 0; idx < _nodes.size(); ++idx) {
int entry;
if (idx == (uint)nodeIndex) {
entry = 0x3FFF;
} else {
// Process the node
flags = getRouteFlags(pt, _nodes[idx]._walkPos);
int xDiff = ABS(_nodes[idx]._walkPos.x - pt.x);
int yDiff = ABS(_nodes[idx]._walkPos.y - pt.y);
hypotenuse = sqrt((double)(xDiff * xDiff + yDiff * yDiff));
if (hypotenuse >= 0x3FFF)
// Shouldn't ever be this large
hypotenuse = 0x3FFF;
entry = hypotenuse | flags;
}
_nodes[idx]._distances[nodeIndex] = entry;
_nodes[nodeIndex]._distances[idx] = entry;
}
}
int Rails::getRouteFlags(const Common::Point &src, const Common::Point &dest) {
int result = 0x8000;
bool flag = false;
int xDiff = ABS(dest.x - src.x);
int yDiff = ABS(dest.y - src.y);
int xDirection = dest.x >= src.x ? 1 : -1;
int yDirection = dest.y >= src.y ? _depthSurface->w : -_depthSurface->w;
int minorDiff = 0;
if (dest.x < src.x)
minorDiff = MIN(xDiff, yDiff);
++xDiff;
++yDiff;
byte *srcP = _depthSurface->getBasePtr(src.x, src.y);
int totalCtr = minorDiff;
for (int xCtr = 0; xCtr < xDiff; ++xCtr, srcP += xDirection) {
totalCtr += yDiff;
if ((*srcP & 0x80) == 0)
flag = false;
else if (!flag) {
flag = true;
result -= 0x4000;
if (result == 0)
break;
}
while (totalCtr >= xDiff) {
totalCtr -= xDiff;
if ((*srcP & 0x80) == 0)
flag = false;
else if (!flag) {
flag = true;
result -= 0x4000;
if (result == 0)
break;
}
srcP += yDirection;
}
if (result == 0)
break;
}
return result;
}
void Rails::synchronize(Common::Serializer &s) {
s.syncAsSint16LE(_routeLength);
s.syncAsSint16LE(_next);
int count = _routeIndexes.size();
if (s.isSaving()) {
for (int i = 0; i < count; ++i)
s.syncAsUint16LE(_routeIndexes[i]);
} else {
_routeIndexes.clear();
for (int i = 0; i < count; ++i) {
int v = 0;
s.syncAsUint16LE(v);
_routeIndexes.push(v);
}
}
}
} // End of namespace MADS