scummvm/engines/sci/engine/kpathing.cpp
Colin Snover 8c555200d9 SCI32: Change storage type of int16 arrays to hold reg_ts instead
Memory references and integers in SSCI are both 16-bit numbers,
so game scripts frequently (incorrectly) use an IntArray instead
of an IDArray for holding references. Since references in ScummVM
are 32-bit reg_ts, IntArray entries must be large enough to hold
reg_ts in order to be compatible with game scripts that store
references in integer arrays.

The alternative solution is to find and patch all incorrect use of
IntArray across all games. This is possible, but a bit risky from
a save game stability perspective, since incorrect IntArray usage
is sometimes not apparent until well after the array is
instantiated (like GK1's global interview array).

This change invalidates existing SCI32 save games.
2016-10-09 11:21:13 -05:00

2443 lines
69 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 "sci/sci.h"
#include "sci/engine/state.h"
#include "sci/engine/selector.h"
#include "sci/engine/kernel.h"
#include "sci/graphics/paint16.h"
#include "sci/graphics/palette.h"
#include "sci/graphics/screen.h"
#include "common/debug-channels.h"
#include "common/list.h"
#include "common/system.h"
#include "common/math.h"
//#define DEBUG_MERGEPOLY
namespace Sci {
// TODO: Code cleanup
#define AVOIDPATH_DYNMEM_STRING "AvoidPath polyline"
#define POLY_LAST_POINT 0x7777
#define POLY_POINT_SIZE 4
// SCI-defined polygon types
enum {
POLY_TOTAL_ACCESS = 0,
POLY_NEAREST_ACCESS = 1,
POLY_BARRED_ACCESS = 2,
POLY_CONTAINED_ACCESS = 3
};
// Polygon containment types
enum {
CONT_OUTSIDE = 0,
CONT_ON_EDGE = 1,
CONT_INSIDE = 2
};
#define HUGE_DISTANCE 0xFFFFFFFF
#define VERTEX_HAS_EDGES(V) ((V) != CLIST_NEXT(V))
// Error codes
enum {
PF_OK = 0,
PF_ERROR = -1,
PF_FATAL = -2
};
// Floating point struct
struct FloatPoint {
FloatPoint() : x(0), y(0) {}
FloatPoint(float x_, float y_) : x(x_), y(y_) {}
FloatPoint(Common::Point p) : x(p.x), y(p.y) {}
Common::Point toPoint() {
return Common::Point((int16)(x + 0.5), (int16)(y + 0.5));
}
float operator*(const FloatPoint &p) const {
return x*p.x + y*p.y;
}
FloatPoint operator*(float l) const {
return FloatPoint(l*x, l*y);
}
FloatPoint operator-(const FloatPoint &p) const {
return FloatPoint(x-p.x, y-p.y);
}
float norm() const {
return x*x+y*y;
}
float x, y;
};
struct Vertex {
// Location
Common::Point v;
// Vertex circular list entry
Vertex *_next; // next element
Vertex *_prev; // previous element
// A* cost variables
uint32 costF;
uint32 costG;
// Previous vertex in shortest path
Vertex *path_prev;
public:
Vertex(const Common::Point &p) : v(p) {
costG = HUGE_DISTANCE;
path_prev = NULL;
}
};
class VertexList: public Common::List<Vertex *> {
public:
bool contains(Vertex *v) {
for (iterator it = begin(); it != end(); ++it) {
if (v == *it)
return true;
}
return false;
}
};
/* Circular list definitions. */
#define CLIST_FOREACH(var, head) \
for ((var) = (head)->first(); \
(var); \
(var) = ((var)->_next == (head)->first() ? \
NULL : (var)->_next))
/* Circular list access methods. */
#define CLIST_NEXT(elm) ((elm)->_next)
#define CLIST_PREV(elm) ((elm)->_prev)
class CircularVertexList {
public:
Vertex *_head;
public:
CircularVertexList() : _head(0) {}
Vertex *first() const {
return _head;
}
void insertAtEnd(Vertex *elm) {
if (_head == NULL) {
elm->_next = elm->_prev = elm;
_head = elm;
} else {
elm->_next = _head;
elm->_prev = _head->_prev;
_head->_prev = elm;
elm->_prev->_next = elm;
}
}
void insertHead(Vertex *elm) {
insertAtEnd(elm);
_head = elm;
}
static void insertAfter(Vertex *listelm, Vertex *elm) {
elm->_prev = listelm;
elm->_next = listelm->_next;
listelm->_next->_prev = elm;
listelm->_next = elm;
}
void remove(Vertex *elm) {
if (elm->_next == elm) {
_head = NULL;
} else {
if (_head == elm)
_head = elm->_next;
elm->_prev->_next = elm->_next;
elm->_next->_prev = elm->_prev;
}
}
bool empty() const {
return _head == NULL;
}
uint size() const {
int n = 0;
Vertex *v;
CLIST_FOREACH(v, this)
++n;
return n;
}
/**
* Reverse the order of the elements in this circular list.
*/
void reverse() {
if (!_head)
return;
Vertex *elm = _head;
do {
SWAP(elm->_prev, elm->_next);
elm = elm->_next;
} while (elm != _head);
}
};
struct Polygon {
// SCI polygon type
int type;
// Circular list of vertices
CircularVertexList vertices;
public:
Polygon(int t) : type(t) {
}
~Polygon() {
while (!vertices.empty()) {
Vertex *vertex = vertices.first();
vertices.remove(vertex);
delete vertex;
}
}
};
typedef Common::List<Polygon *> PolygonList;
// Pathfinding state
struct PathfindingState {
// List of all polygons
PolygonList polygons;
// Start and end points for pathfinding
Vertex *vertex_start, *vertex_end;
// Array of all vertices, used for sorting
Vertex **vertex_index;
// Total number of vertices
int vertices;
// Point to prepend and append to final path
Common::Point *_prependPoint;
Common::Point *_appendPoint;
// Screen size
int _width, _height;
PathfindingState(int width, int height) : _width(width), _height(height) {
vertex_start = NULL;
vertex_end = NULL;
vertex_index = NULL;
_prependPoint = NULL;
_appendPoint = NULL;
vertices = 0;
}
~PathfindingState() {
free(vertex_index);
delete _prependPoint;
delete _appendPoint;
for (PolygonList::iterator it = polygons.begin(); it != polygons.end(); ++it) {
delete *it;
}
}
bool pointOnScreenBorder(const Common::Point &p);
bool edgeOnScreenBorder(const Common::Point &p, const Common::Point &q);
int findNearPoint(const Common::Point &p, Polygon *polygon, Common::Point *ret);
};
static Common::Point readPoint(SegmentRef list_r, int offset) {
Common::Point point;
if (list_r.isRaw) { // dynmem blocks are raw
point.x = (int16)READ_SCIENDIAN_UINT16(list_r.raw + offset * POLY_POINT_SIZE);
point.y = (int16)READ_SCIENDIAN_UINT16(list_r.raw + offset * POLY_POINT_SIZE + 2);
} else {
point.x = list_r.reg[offset * 2].toUint16();
point.y = list_r.reg[offset * 2 + 1].toUint16();
}
return point;
}
static void writePoint(SegmentRef ref, int offset, const Common::Point &point) {
if (ref.isRaw) { // dynmem blocks are raw
WRITE_SCIENDIAN_UINT16(ref.raw + offset * POLY_POINT_SIZE, point.x);
WRITE_SCIENDIAN_UINT16(ref.raw + offset * POLY_POINT_SIZE + 2, point.y);
} else {
ref.reg[offset * 2] = make_reg(0, point.x);
ref.reg[offset * 2 + 1] = make_reg(0, point.y);
}
}
static void draw_line(EngineState *s, Common::Point p1, Common::Point p2, int type, int width, int height) {
// Colors for polygon debugging.
// Green: Total access
// Blue: Near-point access
// Red : Barred access
// Yellow: Contained access
int poly_colors[4] = {
g_sci->_gfxPalette16->kernelFindColor(0, 255, 0), // green
g_sci->_gfxPalette16->kernelFindColor(0, 0, 255), // blue
g_sci->_gfxPalette16->kernelFindColor(255, 0, 0), // red
g_sci->_gfxPalette16->kernelFindColor(255, 255, 0) // yellow
};
// Clip
// FIXME: Do proper line clipping
p1.x = CLIP<int16>(p1.x, 0, width - 1);
p1.y = CLIP<int16>(p1.y, 0, height - 1);
p2.x = CLIP<int16>(p2.x, 0, width - 1);
p2.y = CLIP<int16>(p2.y, 0, height - 1);
assert(type >= 0 && type <= 3);
g_sci->_gfxPaint16->kernelGraphDrawLine(p1, p2, poly_colors[type], 255, 255);
}
static void draw_point(EngineState *s, Common::Point p, int start, int width, int height) {
// Colors for starting and end point
// Green: End point
// Blue: Starting point
int point_colors[2] = {
g_sci->_gfxPalette16->kernelFindColor(0, 255, 0), // green
g_sci->_gfxPalette16->kernelFindColor(0, 0, 255) // blue
};
Common::Rect rect = Common::Rect(p.x - 1, p.y - 1, p.x - 1 + 3, p.y - 1 + 3);
// Clip
rect.top = CLIP<int16>(rect.top, 0, height - 1);
rect.bottom = CLIP<int16>(rect.bottom, 0, height - 1);
rect.left = CLIP<int16>(rect.left, 0, width - 1);
rect.right = CLIP<int16>(rect.right, 0, width - 1);
assert(start >= 0 && start <= 1);
if (g_sci->_gfxPaint16)
g_sci->_gfxPaint16->kernelGraphFrameBox(rect, point_colors[start]);
}
static void draw_polygon(EngineState *s, reg_t polygon, int width, int height) {
SegManager *segMan = s->_segMan;
reg_t points = readSelector(segMan, polygon, SELECTOR(points));
#ifdef ENABLE_SCI32
if (segMan->isHeapObject(points))
points = readSelector(segMan, points, SELECTOR(data));
#endif
int size = readSelectorValue(segMan, polygon, SELECTOR(size));
int type = readSelectorValue(segMan, polygon, SELECTOR(type));
Common::Point first, prev;
int i;
SegmentRef pointList = segMan->dereference(points);
if (!pointList.isValid() || pointList.skipByte) {
warning("draw_polygon: Polygon data pointer is invalid, skipping polygon");
return;
}
prev = first = readPoint(pointList, 0);
for (i = 1; i < size; i++) {
Common::Point point = readPoint(pointList, i);
draw_line(s, prev, point, type, width, height);
prev = point;
}
draw_line(s, prev, first, type % 3, width, height);
}
static void draw_input(EngineState *s, reg_t poly_list, Common::Point start, Common::Point end, int opt, int width, int height) {
List *list;
Node *node;
draw_point(s, start, 1, width, height);
draw_point(s, end, 0, width, height);
if (!poly_list.getSegment())
return;
list = s->_segMan->lookupList(poly_list);
if (!list) {
warning("[avoidpath] Could not obtain polygon list");
return;
}
node = s->_segMan->lookupNode(list->first);
while (node) {
draw_polygon(s, node->value, width, height);
node = s->_segMan->lookupNode(node->succ);
}
}
static void print_polygon(SegManager *segMan, reg_t polygon) {
reg_t points = readSelector(segMan, polygon, SELECTOR(points));
#ifdef ENABLE_SCI32
if (segMan->isHeapObject(points))
points = readSelector(segMan, points, SELECTOR(data));
#endif
int size = readSelectorValue(segMan, polygon, SELECTOR(size));
int type = readSelectorValue(segMan, polygon, SELECTOR(type));
int i;
Common::Point point;
debugN(-1, "%i:", type);
SegmentRef pointList = segMan->dereference(points);
if (!pointList.isValid() || pointList.skipByte) {
warning("print_polygon: Polygon data pointer is invalid, skipping polygon");
return;
}
for (i = 0; i < size; i++) {
point = readPoint(pointList, i);
debugN(-1, " (%i, %i)", point.x, point.y);
}
point = readPoint(pointList, 0);
debug(" (%i, %i);", point.x, point.y);
}
static void print_input(EngineState *s, reg_t poly_list, Common::Point start, Common::Point end, int opt) {
List *list;
Node *node;
debug("Start point: (%i, %i)", start.x, start.y);
debug("End point: (%i, %i)", end.x, end.y);
debug("Optimization level: %i", opt);
if (!poly_list.getSegment())
return;
list = s->_segMan->lookupList(poly_list);
if (!list) {
warning("[avoidpath] Could not obtain polygon list");
return;
}
debug("Polygons:");
node = s->_segMan->lookupNode(list->first);
while (node) {
print_polygon(s->_segMan, node->value);
node = s->_segMan->lookupNode(node->succ);
}
}
/**
* Computes the area of a triangle
* Parameters: (const Common::Point &) a, b, c: The points of the triangle
* Returns : (int) The area multiplied by two
*/
static int area(const Common::Point &a, const Common::Point &b, const Common::Point &c) {
return (b.x - a.x) * (a.y - c.y) - (c.x - a.x) * (a.y - b.y);
}
/**
* Determines whether or not a point is to the left of a directed line
* Parameters: (const Common::Point &) a, b: The directed line (a, b)
* (const Common::Point &) c: The query point
* Returns : (int) true if c is to the left of (a, b), false otherwise
*/
static bool left(const Common::Point &a, const Common::Point &b, const Common::Point &c) {
return area(a, b, c) > 0;
}
/**
* Determines whether or not three points are collinear
* Parameters: (const Common::Point &) a, b, c: The three points
* Returns : (int) true if a, b, and c are collinear, false otherwise
*/
static bool collinear(const Common::Point &a, const Common::Point &b, const Common::Point &c) {
return area(a, b, c) == 0;
}
/**
* Determines whether or not a point lies on a line segment
* Parameters: (const Common::Point &) a, b: The line segment (a, b)
* (const Common::Point &) c: The query point
* Returns : (int) true if c lies on (a, b), false otherwise
*/
static bool between(const Common::Point &a, const Common::Point &b, const Common::Point &c) {
if (!collinear(a, b, c))
return false;
// Assumes a != b.
if (a.x != b.x)
return ((a.x <= c.x) && (c.x <= b.x)) || ((a.x >= c.x) && (c.x >= b.x));
else
return ((a.y <= c.y) && (c.y <= b.y)) || ((a.y >= c.y) && (c.y >= b.y));
}
/**
* Determines whether or not two line segments properly intersect
* Parameters: (const Common::Point &) a, b: The line segment (a, b)
* (const Common::Point &) c, d: The line segment (c, d)
* Returns : (int) true if (a, b) properly intersects (c, d), false otherwise
*/
static bool intersect_proper(const Common::Point &a, const Common::Point &b, const Common::Point &c, const Common::Point &d) {
int ab = (left(a, b, c) && left(b, a, d)) || (left(a, b, d) && left(b, a, c));
int cd = (left(c, d, a) && left(d, c, b)) || (left(c, d, b) && left(d, c, a));
return ab && cd;
}
/**
* Polygon containment test
* Parameters: (const Common::Point &) p: The point
* (Polygon *) polygon: The polygon
* Returns : (int) CONT_INSIDE if p is strictly contained in polygon,
* CONT_ON_EDGE if p lies on an edge of polygon,
* CONT_OUTSIDE otherwise
* Number of ray crossing left and right
*/
static int contained(const Common::Point &p, Polygon *polygon) {
int lcross = 0, rcross = 0;
Vertex *vertex;
// Iterate over edges
CLIST_FOREACH(vertex, &polygon->vertices) {
const Common::Point &v1 = vertex->v;
const Common::Point &v2 = CLIST_NEXT(vertex)->v;
// Flags for ray straddling left and right
int rstrad, lstrad;
// Check if p is a vertex
if (p == v1)
return CONT_ON_EDGE;
// Check if edge straddles the ray
rstrad = (v1.y < p.y) != (v2.y < p.y);
lstrad = (v1.y > p.y) != (v2.y > p.y);
if (lstrad || rstrad) {
// Compute intersection point x / xq
int x = v2.x * v1.y - v1.x * v2.y + (v1.x - v2.x) * p.y;
int xq = v1.y - v2.y;
// Multiply by -1 if xq is negative (for comparison that follows)
if (xq < 0) {
x = -x;
xq = -xq;
}
// Avoid floats by multiplying instead of dividing
if (rstrad && (x > xq * p.x))
rcross++;
else if (lstrad && (x < xq * p.x))
lcross++;
}
}
// If we counted an odd number of total crossings the point is on an edge
if ((lcross + rcross) % 2 == 1)
return CONT_ON_EDGE;
// If there are an odd number of crossings to one side the point is contained in the polygon
if (rcross % 2 == 1) {
// Invert result for contained access polygons.
if (polygon->type == POLY_CONTAINED_ACCESS)
return CONT_OUTSIDE;
return CONT_INSIDE;
}
// Point is outside polygon. Invert result for contained access polygons
if (polygon->type == POLY_CONTAINED_ACCESS)
return CONT_INSIDE;
return CONT_OUTSIDE;
}
/**
* Computes polygon area
* Parameters: (Polygon *) polygon: The polygon
* Returns : (int) The area multiplied by two
*/
static int polygon_area(Polygon *polygon) {
Vertex *first = polygon->vertices.first();
Vertex *v;
int size = 0;
v = CLIST_NEXT(first);
while (CLIST_NEXT(v) != first) {
size += area(first->v, v->v, CLIST_NEXT(v)->v);
v = CLIST_NEXT(v);
}
return size;
}
/**
* Fixes the vertex order of a polygon if incorrect. Contained access
* polygons should have their vertices ordered clockwise, all other types
* anti-clockwise
* Parameters: (Polygon *) polygon: The polygon
*/
static void fix_vertex_order(Polygon *polygon) {
int area = polygon_area(polygon);
// When the polygon area is positive the vertices are ordered
// anti-clockwise. When the area is negative the vertices are ordered
// clockwise
if (((area > 0) && (polygon->type == POLY_CONTAINED_ACCESS))
|| ((area < 0) && (polygon->type != POLY_CONTAINED_ACCESS))) {
polygon->vertices.reverse();
}
}
/**
* Determines whether or not a line from a point to a vertex intersects the
* interior of the polygon, locally at that vertex
* Parameters: (Common::Point) p: The point
* (Vertex *) vertex: The vertex
* Returns : (int) 1 if the line (p, vertex->v) intersects the interior of
* the polygon, locally at the vertex. 0 otherwise
*/
static int inside(const Common::Point &p, Vertex *vertex) {
// Check that it's not a single-vertex polygon
if (VERTEX_HAS_EDGES(vertex)) {
const Common::Point &prev = CLIST_PREV(vertex)->v;
const Common::Point &next = CLIST_NEXT(vertex)->v;
const Common::Point &cur = vertex->v;
if (left(prev, cur, next)) {
// Convex vertex, line (p, cur) intersects the inside
// if p is located left of both edges
if (left(cur, next, p) && left(prev, cur, p))
return 1;
} else {
// Non-convex vertex, line (p, cur) intersects the
// inside if p is located left of either edge
if (left(cur, next, p) || left(prev, cur, p))
return 1;
}
}
return 0;
}
/**
* Returns a list of all vertices that are visible from a particular vertex.
* @param s the pathfinding state
* @param vertex_cur the vertex
* @return list of vertices that are visible from vert
*/
static VertexList *visible_vertices(PathfindingState *s, Vertex *vertex_cur) {
VertexList *visVerts = new VertexList();
for (int i = 0; i < s->vertices; i++) {
Vertex *vertex = s->vertex_index[i];
// Make sure we don't intersect a polygon locally at the vertices
if ((vertex == vertex_cur) || (inside(vertex->v, vertex_cur)) || (inside(vertex_cur->v, vertex)))
continue;
// Check for intersecting edges
int j;
for (j = 0; j < s->vertices; j++) {
Vertex *edge = s->vertex_index[j];
if (VERTEX_HAS_EDGES(edge)) {
if (between(vertex_cur->v, vertex->v, edge->v)) {
// If we hit a vertex, make sure we can pass through it without intersecting its polygon
if ((inside(vertex_cur->v, edge)) || (inside(vertex->v, edge)))
break;
// This edge won't properly intersect, so we continue
continue;
}
if (intersect_proper(vertex_cur->v, vertex->v, edge->v, CLIST_NEXT(edge)->v))
break;
}
}
if (j == s->vertices)
visVerts->push_front(vertex);
}
return visVerts;
}
/**
* Determines if a point lies on the screen border
* Parameters: (const Common::Point &) p: The point
* Returns : (int) true if p lies on the screen border, false otherwise
*/
bool PathfindingState::pointOnScreenBorder(const Common::Point &p) {
return (p.x == 0) || (p.x == _width - 1) || (p.y == 0) || (p.y == _height - 1);
}
/**
* Determines if an edge lies on the screen border
* Parameters: (const Common::Point &) p, q: The edge (p, q)
* Returns : (int) true if (p, q) lies on the screen border, false otherwise
*/
bool PathfindingState::edgeOnScreenBorder(const Common::Point &p, const Common::Point &q) {
return ((p.x == 0 && q.x == 0) || (p.y == 0 && q.y == 0)
|| ((p.x == _width - 1) && (q.x == _width - 1))
|| ((p.y == _height - 1) && (q.y == _height - 1)));
}
/**
* Searches for a nearby point that is not contained in a polygon
* Parameters: (FloatPoint) f: The pointf to search nearby
* (Polygon *) polygon: The polygon
* Returns : (int) PF_OK on success, PF_FATAL otherwise
* (Common::Point) *ret: The non-contained point on success
*/
static int find_free_point(FloatPoint f, Polygon *polygon, Common::Point *ret) {
Common::Point p;
// Try nearest point first
p = Common::Point((int)floor(f.x + 0.5), (int)floor(f.y + 0.5));
if (contained(p, polygon) != CONT_INSIDE) {
*ret = p;
return PF_OK;
}
p = Common::Point((int)floor(f.x), (int)floor(f.y));
// Try (x, y), (x + 1, y), (x , y + 1) and (x + 1, y + 1)
if (contained(p, polygon) == CONT_INSIDE) {
p.x++;
if (contained(p, polygon) == CONT_INSIDE) {
p.y++;
if (contained(p, polygon) == CONT_INSIDE) {
p.x--;
if (contained(p, polygon) == CONT_INSIDE)
return PF_FATAL;
}
}
}
*ret = p;
return PF_OK;
}
/**
* Computes the near point of a point contained in a polygon
* Parameters: (const Common::Point &) p: The point
* (Polygon *) polygon: The polygon
* Returns : (int) PF_OK on success, PF_FATAL otherwise
* (Common::Point) *ret: The near point of p in polygon on success
*/
int PathfindingState::findNearPoint(const Common::Point &p, Polygon *polygon, Common::Point *ret) {
Vertex *vertex;
FloatPoint near_p;
uint32 dist = HUGE_DISTANCE;
CLIST_FOREACH(vertex, &polygon->vertices) {
const Common::Point &p1 = vertex->v;
const Common::Point &p2 = CLIST_NEXT(vertex)->v;
float u;
FloatPoint new_point;
uint32 new_dist;
// Ignore edges on the screen border, except for contained access polygons
if ((polygon->type != POLY_CONTAINED_ACCESS) && (edgeOnScreenBorder(p1, p2)))
continue;
// Compute near point
u = ((p.x - p1.x) * (p2.x - p1.x) + (p.y - p1.y) * (p2.y - p1.y)) / (float)p1.sqrDist(p2);
// Clip to edge
if (u < 0.0f)
u = 0.0f;
if (u > 1.0f)
u = 1.0f;
new_point.x = p1.x + u * (p2.x - p1.x);
new_point.y = p1.y + u * (p2.y - p1.y);
new_dist = p.sqrDist(new_point.toPoint());
if (new_dist < dist) {
near_p = new_point;
dist = new_dist;
}
}
// Find point not contained in polygon
return find_free_point(near_p, polygon, ret);
}
/**
* Computes the intersection point of a line segment and an edge (not
* including the vertices themselves)
* Parameters: (const Common::Point &) a, b: The line segment (a, b)
* (Vertex *) vertex: The first vertex of the edge
* Returns : (int) PF_OK on success, PF_ERROR otherwise
* (FloatPoint) *ret: The intersection point
*/
static int intersection(const Common::Point &a, const Common::Point &b, const Vertex *vertex, FloatPoint *ret) {
// Parameters of parametric equations
float s, t;
// Numerator and denominator of equations
float num, denom;
const Common::Point &c = vertex->v;
const Common::Point &d = CLIST_NEXT(vertex)->v;
denom = a.x * (float)(d.y - c.y) + b.x * (float)(c.y - d.y) +
d.x * (float)(b.y - a.y) + c.x * (float)(a.y - b.y);
if (denom == 0.0)
// Segments are parallel, no intersection
return PF_ERROR;
num = a.x * (float)(d.y - c.y) + c.x * (float)(a.y - d.y) + d.x * (float)(c.y - a.y);
s = num / denom;
num = -(a.x * (float)(c.y - b.y) + b.x * (float)(a.y - c.y) + c.x * (float)(b.y - a.y));
t = num / denom;
if ((0.0 <= s) && (s <= 1.0) && (0.0 < t) && (t < 1.0)) {
// Intersection found
ret->x = a.x + s * (b.x - a.x);
ret->y = a.y + s * (b.y - a.y);
return PF_OK;
}
return PF_ERROR;
}
/**
* Computes the nearest intersection point of a line segment and the polygon
* set. Intersection points that are reached from the inside of a polygon
* are ignored as are improper intersections which do not obstruct
* visibility
* Parameters: (PathfindingState *) s: The pathfinding state
* (const Common::Point &) p, q: The line segment (p, q)
* Returns : (int) PF_OK on success, PF_ERROR when no intersections were
* found, PF_FATAL otherwise
* (Common::Point) *ret: On success, the closest intersection point
*/
static int nearest_intersection(PathfindingState *s, const Common::Point &p, const Common::Point &q, Common::Point *ret) {
Polygon *polygon = 0;
FloatPoint isec;
Polygon *ipolygon = 0;
uint32 dist = HUGE_DISTANCE;
for (PolygonList::iterator it = s->polygons.begin(); it != s->polygons.end(); ++it) {
polygon = *it;
Vertex *vertex;
CLIST_FOREACH(vertex, &polygon->vertices) {
uint32 new_dist;
FloatPoint new_isec;
// Check for intersection with vertex
if (between(p, q, vertex->v)) {
// Skip this vertex if we hit it from the
// inside of the polygon
if (inside(q, vertex)) {
new_isec.x = vertex->v.x;
new_isec.y = vertex->v.y;
} else
continue;
} else {
// Check for intersection with edges
// Skip this edge if we hit it from the
// inside of the polygon
if (!left(vertex->v, CLIST_NEXT(vertex)->v, q))
continue;
if (intersection(p, q, vertex, &new_isec) != PF_OK)
continue;
}
new_dist = p.sqrDist(new_isec.toPoint());
if (new_dist < dist) {
ipolygon = polygon;
isec = new_isec;
dist = new_dist;
}
}
}
if (dist == HUGE_DISTANCE)
return PF_ERROR;
// Find point not contained in polygon
return find_free_point(isec, ipolygon, ret);
}
/**
* Checks whether a point is nearby a contained-access polygon (distance 1 pixel)
* @param point the point
* @param polygon the contained-access polygon
* @return true when point is nearby polygon, false otherwise
*/
static bool nearbyPolygon(const Common::Point &point, Polygon *polygon) {
assert(polygon->type == POLY_CONTAINED_ACCESS);
return ((contained(Common::Point(point.x, point.y + 1), polygon) != CONT_INSIDE)
|| (contained(Common::Point(point.x, point.y - 1), polygon) != CONT_INSIDE)
|| (contained(Common::Point(point.x + 1, point.y), polygon) != CONT_INSIDE)
|| (contained(Common::Point(point.x - 1, point.y), polygon) != CONT_INSIDE));
}
/**
* Checks that the start point is in a valid position, and takes appropriate action if it's not.
* @param s the pathfinding state
* @param start the start point
* @return a valid start point on success, NULL otherwise
*/
static Common::Point *fixup_start_point(PathfindingState *s, const Common::Point &start) {
PolygonList::iterator it = s->polygons.begin();
Common::Point *new_start = new Common::Point(start);
while (it != s->polygons.end()) {
int cont = contained(start, *it);
int type = (*it)->type;
switch (type) {
case POLY_TOTAL_ACCESS:
// Remove totally accessible polygons that contain the start point
if (cont != CONT_OUTSIDE) {
delete *it;
it = s->polygons.erase(it);
continue;
}
break;
case POLY_CONTAINED_ACCESS:
// Remove contained access polygons that do not contain
// the start point (containment test is inverted here).
// SSCI appears to be using a small margin of error here,
// so we do the same.
if ((cont == CONT_INSIDE) && !nearbyPolygon(start, *it)) {
delete *it;
it = s->polygons.erase(it);
continue;
}
// Fall through
case POLY_BARRED_ACCESS:
case POLY_NEAREST_ACCESS:
if (cont != CONT_OUTSIDE) {
if (s->_prependPoint != NULL) {
// We shouldn't get here twice.
// We need to break in this case, otherwise we'll end in an infinite
// loop.
warning("AvoidPath: start point is contained in multiple polygons");
break;
}
if (s->findNearPoint(start, (*it), new_start) != PF_OK) {
delete new_start;
return NULL;
}
if ((type == POLY_BARRED_ACCESS) || (type == POLY_CONTAINED_ACCESS))
debugC(kDebugLevelAvoidPath, "AvoidPath: start position at unreachable location");
// The original start position is in an invalid location, so we
// use the moved point and add the original one to the final path
// later on.
if (start != *new_start)
s->_prependPoint = new Common::Point(start);
}
}
++it;
}
return new_start;
}
/**
* Checks that the end point is in a valid position, and takes appropriate action if it's not.
* @param s the pathfinding state
* @param end the end point
* @return a valid end point on success, NULL otherwise
*/
static Common::Point *fixup_end_point(PathfindingState *s, const Common::Point &end) {
PolygonList::iterator it = s->polygons.begin();
Common::Point *new_end = new Common::Point(end);
while (it != s->polygons.end()) {
int cont = contained(end, *it);
int type = (*it)->type;
switch (type) {
case POLY_TOTAL_ACCESS:
// Remove totally accessible polygons that contain the end point
if (cont != CONT_OUTSIDE) {
delete *it;
it = s->polygons.erase(it);
continue;
}
break;
case POLY_CONTAINED_ACCESS:
case POLY_BARRED_ACCESS:
case POLY_NEAREST_ACCESS:
if (cont != CONT_OUTSIDE) {
if (s->_appendPoint != NULL) {
// We shouldn't get here twice.
// Happens in LB2CD, inside the speakeasy when walking from the
// speakeasy (room 310) into the bathroom (room 320), after having
// consulted the notebook (bug #3036299).
// We need to break in this case, otherwise we'll end in an infinite
// loop.
warning("AvoidPath: end point is contained in multiple polygons");
break;
}
// The original end position is in an invalid location, so we move the point
if (s->findNearPoint(end, (*it), new_end) != PF_OK) {
delete new_end;
return NULL;
}
// For near-point access polygons we need to add the original end point
// to the path after pathfinding.
if ((type == POLY_NEAREST_ACCESS) && (end != *new_end))
s->_appendPoint = new Common::Point(end);
}
}
++it;
}
return new_end;
}
/**
* Merges a point into the polygon set. A new vertex is allocated for this
* point, unless a matching vertex already exists. If the point is on an
* already existing edge that edge is split up into two edges connected by
* the new vertex
* Parameters: (PathfindingState *) s: The pathfinding state
* (const Common::Point &) v: The point to merge
* Returns : (Vertex *) The vertex corresponding to v
*/
static Vertex *merge_point(PathfindingState *s, const Common::Point &v) {
Vertex *vertex;
Vertex *v_new;
Polygon *polygon;
// Check for already existing vertex
for (PolygonList::iterator it = s->polygons.begin(); it != s->polygons.end(); ++it) {
polygon = *it;
CLIST_FOREACH(vertex, &polygon->vertices) {
if (vertex->v == v)
return vertex;
}
}
v_new = new Vertex(v);
// Check for point being on an edge
for (PolygonList::iterator it = s->polygons.begin(); it != s->polygons.end(); ++it) {
polygon = *it;
// Skip single-vertex polygons
if (VERTEX_HAS_EDGES(polygon->vertices.first())) {
CLIST_FOREACH(vertex, &polygon->vertices) {
Vertex *next = CLIST_NEXT(vertex);
if (between(vertex->v, next->v, v)) {
// Split edge by adding vertex
polygon->vertices.insertAfter(vertex, v_new);
return v_new;
}
}
}
}
// Add point as single-vertex polygon
polygon = new Polygon(POLY_BARRED_ACCESS);
polygon->vertices.insertHead(v_new);
s->polygons.push_front(polygon);
return v_new;
}
/**
* Converts an SCI polygon into a Polygon
* Parameters: (EngineState *) s: The game state
* (reg_t) polygon: The SCI polygon to convert
* Returns : (Polygon *) The converted polygon, or NULL on error
*/
static Polygon *convert_polygon(EngineState *s, reg_t polygon) {
SegManager *segMan = s->_segMan;
int i;
reg_t points = readSelector(segMan, polygon, SELECTOR(points));
int size = readSelectorValue(segMan, polygon, SELECTOR(size));
#ifdef ENABLE_SCI32
// SCI32 stores the actual points in the data property of points (in a new array)
if (segMan->isHeapObject(points))
points = readSelector(segMan, points, SELECTOR(data));
#endif
if (size == 0) {
// If the polygon has no vertices, we skip it
return NULL;
}
SegmentRef pointList = segMan->dereference(points);
// Check if the target polygon is still valid. It may have been released
// in the meantime (e.g. in LSL6, room 700, when using the elevator).
// Refer to bug #3034501.
if (!pointList.isValid() || pointList.skipByte) {
warning("convert_polygon: Polygon data pointer is invalid, skipping polygon");
return NULL;
}
// Make sure that we have enough points
if (pointList.maxSize < size * POLY_POINT_SIZE) {
warning("convert_polygon: Not enough memory allocated for polygon points. "
"Expected %d, got %d. Skipping polygon",
size * POLY_POINT_SIZE, pointList.maxSize);
return NULL;
}
int skip = 0;
// WORKAROUND: broken polygon in lsl1sci, room 350, after opening elevator
// Polygon has 17 points but size is set to 19
if ((size == 19) && g_sci->getGameId() == GID_LSL1) {
if ((s->currentRoomNumber() == 350)
&& (readPoint(pointList, 18) == Common::Point(108, 137))) {
debug(1, "Applying fix for broken polygon in lsl1sci, room 350");
size = 17;
}
}
Polygon *poly = new Polygon(readSelectorValue(segMan, polygon, SELECTOR(type)));
for (i = skip; i < size; i++) {
Vertex *vertex = new Vertex(readPoint(pointList, i));
poly->vertices.insertHead(vertex);
}
fix_vertex_order(poly);
return poly;
}
/**
* Changes the polygon list for optimization level 0 (used for keyboard
* support). Totally accessible polygons are removed and near-point
* accessible polygons are changed into totally accessible polygons.
* Parameters: (PathfindingState *) s: The pathfinding state
*/
static void change_polygons_opt_0(PathfindingState *s) {
PolygonList::iterator it = s->polygons.begin();
while (it != s->polygons.end()) {
Polygon *polygon = *it;
assert(polygon);
if (polygon->type == POLY_TOTAL_ACCESS) {
delete polygon;
it = s->polygons.erase(it);
} else {
if (polygon->type == POLY_NEAREST_ACCESS)
polygon->type = POLY_TOTAL_ACCESS;
++it;
}
}
}
/**
* Converts the SCI input data for pathfinding
* Parameters: (EngineState *) s: The game state
* (reg_t) poly_list: Polygon list
* (Common::Point) start: The start point
* (Common::Point) end: The end point
* (int) opt: Optimization level (0, 1 or 2)
* Returns : (PathfindingState *) On success a newly allocated pathfinding state,
* NULL otherwise
*/
static PathfindingState *convert_polygon_set(EngineState *s, reg_t poly_list, Common::Point start, Common::Point end, int width, int height, int opt) {
SegManager *segMan = s->_segMan;
Polygon *polygon;
int count = 0;
PathfindingState *pf_s = new PathfindingState(width, height);
// Convert all polygons
if (poly_list.getSegment()) {
List *list = s->_segMan->lookupList(poly_list);
Node *node = s->_segMan->lookupNode(list->first);
while (node) {
// The node value might be null, in which case there's no polygon to parse.
// Happens in LB2 floppy - refer to bug #3041232
polygon = !node->value.isNull() ? convert_polygon(s, node->value) : NULL;
if (polygon) {
pf_s->polygons.push_back(polygon);
count += readSelectorValue(segMan, node->value, SELECTOR(size));
}
node = s->_segMan->lookupNode(node->succ);
}
}
if (opt == 0)
change_polygons_opt_0(pf_s);
Common::Point *new_start = fixup_start_point(pf_s, start);
if (!new_start) {
warning("AvoidPath: Couldn't fixup start position for pathfinding");
delete pf_s;
return NULL;
}
Common::Point *new_end = fixup_end_point(pf_s, end);
if (!new_end) {
warning("AvoidPath: Couldn't fixup end position for pathfinding");
delete new_start;
delete pf_s;
return NULL;
}
if (opt == 0) {
// Keyboard support. Only the first edge of the path we compute
// here matches the path returned by SSCI. This is assumed to be
// sufficient as all known use cases only use the first two
// vertices of the returned path.
// Pharkas uses this mode for a secondary polygon set containing
// rectangular polygons used to block an actor's path.
// If we have a prepended point, we do nothing here as the
// actor is in barred territory and should be moved outside of
// it ASAP. This matches the behavior of SSCI.
if (!pf_s->_prependPoint) {
// Actor position is OK, find nearest obstacle.
int err = nearest_intersection(pf_s, start, *new_end, new_start);
if (err == PF_FATAL) {
warning("AvoidPath: error finding nearest intersection");
delete new_start;
delete new_end;
delete pf_s;
return NULL;
}
if (err == PF_OK)
pf_s->_prependPoint = new Common::Point(start);
}
} else {
// WORKAROUND LSL5 room 660. Priority glitch due to us choosing a different path
// than SSCI. Happens when Patti walks to the control room.
if (g_sci->getGameId() == GID_LSL5 && (s->currentRoomNumber() == 660) && (Common::Point(67, 131) == *new_start) && (Common::Point(229, 101) == *new_end)) {
debug(1, "[avoidpath] Applying fix for priority problem in LSL5, room 660");
pf_s->_prependPoint = new_start;
new_start = new Common::Point(77, 107);
}
}
// Merge start and end points into polygon set
pf_s->vertex_start = merge_point(pf_s, *new_start);
pf_s->vertex_end = merge_point(pf_s, *new_end);
delete new_start;
delete new_end;
// Allocate and build vertex index
pf_s->vertex_index = (Vertex**)malloc(sizeof(Vertex *) * (count + 2));
count = 0;
for (PolygonList::iterator it = pf_s->polygons.begin(); it != pf_s->polygons.end(); ++it) {
polygon = *it;
Vertex *vertex;
CLIST_FOREACH(vertex, &polygon->vertices) {
pf_s->vertex_index[count++] = vertex;
}
}
pf_s->vertices = count;
return pf_s;
}
/**
* Computes a shortest path from vertex_start to vertex_end. The caller can
* construct the resulting path by following the path_prev links from
* vertex_end back to vertex_start. If no path exists vertex_end->path_prev
* will be NULL
* Parameters: (PathfindingState *) s: The pathfinding state
*/
static void AStar(PathfindingState *s) {
// Vertices of which the shortest path is known
VertexList closedSet;
// The remaining vertices
VertexList openSet;
openSet.push_front(s->vertex_start);
s->vertex_start->costG = 0;
s->vertex_start->costF = (uint32)sqrt((float)s->vertex_start->v.sqrDist(s->vertex_end->v));
while (!openSet.empty()) {
// Find vertex in open set with lowest F cost
VertexList::iterator vertex_min_it = openSet.end();
Vertex *vertex_min = 0;
uint32 min = HUGE_DISTANCE;
for (VertexList::iterator it = openSet.begin(); it != openSet.end(); ++it) {
Vertex *vertex = *it;
if (vertex->costF < min) {
vertex_min_it = it;
vertex_min = *vertex_min_it;
min = vertex->costF;
}
}
assert(vertex_min != 0); // the vertex cost should never be bigger than HUGE_DISTANCE
// Check if we are done
if (vertex_min == s->vertex_end)
break;
// Move vertex from set open to set closed
closedSet.push_front(vertex_min);
openSet.erase(vertex_min_it);
VertexList *visVerts = visible_vertices(s, vertex_min);
for (VertexList::iterator it = visVerts->begin(); it != visVerts->end(); ++it) {
uint32 new_dist;
Vertex *vertex = *it;
if (closedSet.contains(vertex))
continue;
if (!openSet.contains(vertex))
openSet.push_front(vertex);
new_dist = vertex_min->costG + (uint32)sqrt((float)vertex_min->v.sqrDist(vertex->v));
// When travelling to a vertex on the screen edge, we
// add a penalty score to make this path less appealing.
// NOTE: If an obstacle has only one vertex on a screen edge,
// later SSCI pathfinders will treat that vertex like any
// other, while we apply a penalty to paths traversing it.
// This difference might lead to problems, but none are
// known at the time of writing.
// WORKAROUND: This check fails in QFG1VGA, room 81 (bug report #3568452).
// However, it is needed in other SCI1.1 games, such as LB2. Therefore, we
// add this workaround for that scene in QFG1VGA, until our algorithm matches
// better what SSCI is doing. With this workaround, QFG1VGA no longer freezes
// in that scene.
bool qfg1VgaWorkaround = (g_sci->getGameId() == GID_QFG1VGA &&
g_sci->getEngineState()->currentRoomNumber() == 81);
if (s->pointOnScreenBorder(vertex->v) && !qfg1VgaWorkaround)
new_dist += 10000;
if (new_dist < vertex->costG) {
vertex->costG = new_dist;
vertex->costF = vertex->costG + (uint32)sqrt((float)vertex->v.sqrDist(s->vertex_end->v));
vertex->path_prev = vertex_min;
}
}
delete visVerts;
}
if (openSet.empty())
debugC(kDebugLevelAvoidPath, "AvoidPath: End point (%i, %i) is unreachable", s->vertex_end->v.x, s->vertex_end->v.y);
}
static reg_t allocateOutputArray(SegManager *segMan, int size) {
reg_t addr;
#ifdef ENABLE_SCI32
if (getSciVersion() >= SCI_VERSION_2) {
SciArray *array = segMan->allocateArray(kArrayTypeInt16, size * 2, &addr);
assert(array);
return addr;
}
#endif
segMan->allocDynmem(POLY_POINT_SIZE * size, AVOIDPATH_DYNMEM_STRING, &addr);
return addr;
}
/**
* Stores the final path in newly allocated dynmem
* Parameters: (PathfindingState *) p: The pathfinding state
* (EngineState *) s: The game state
* Returns : (reg_t) Pointer to dynmem containing path
*/
static reg_t output_path(PathfindingState *p, EngineState *s) {
int path_len = 0;
reg_t output;
Vertex *vertex = p->vertex_end;
int unreachable = vertex->path_prev == NULL;
if (!unreachable) {
while (vertex) {
// Compute path length
path_len++;
vertex = vertex->path_prev;
}
}
// Allocate memory for path, plus 3 extra for appended point, prepended point and sentinel
output = allocateOutputArray(s->_segMan, path_len + 3);
SegmentRef arrayRef = s->_segMan->dereference(output);
assert(arrayRef.isValid() && !arrayRef.skipByte);
if (unreachable) {
// If pathfinding failed we only return the path up to vertex_start
if (p->_prependPoint)
writePoint(arrayRef, 0, *p->_prependPoint);
else
writePoint(arrayRef, 0, p->vertex_start->v);
writePoint(arrayRef, 1, p->vertex_start->v);
writePoint(arrayRef, 2, Common::Point(POLY_LAST_POINT, POLY_LAST_POINT));
return output;
}
int offset = 0;
if (p->_prependPoint)
writePoint(arrayRef, offset++, *p->_prependPoint);
vertex = p->vertex_end;
for (int i = path_len - 1; i >= 0; i--) {
writePoint(arrayRef, offset + i, vertex->v);
vertex = vertex->path_prev;
}
offset += path_len;
if (p->_appendPoint)
writePoint(arrayRef, offset++, *p->_appendPoint);
// Sentinel
writePoint(arrayRef, offset, Common::Point(POLY_LAST_POINT, POLY_LAST_POINT));
if (DebugMan.isDebugChannelEnabled(kDebugLevelAvoidPath)) {
debug("\nReturning path:");
SegmentRef outputList = s->_segMan->dereference(output);
if (!outputList.isValid() || outputList.skipByte) {
warning("output_path: Polygon data pointer is invalid, skipping polygon");
return output;
}
for (int i = 0; i < offset; i++) {
Common::Point pt = readPoint(outputList, i);
debugN(-1, " (%i, %i)", pt.x, pt.y);
}
debug(";\n");
}
return output;
}
reg_t kAvoidPath(EngineState *s, int argc, reg_t *argv) {
Common::Point start = Common::Point(argv[0].toSint16(), argv[1].toSint16());
switch (argc) {
case 3 : {
reg_t retval;
Polygon *polygon = convert_polygon(s, argv[2]);
if (!polygon)
return NULL_REG;
// Override polygon type to prevent inverted result for contained access polygons
polygon->type = POLY_BARRED_ACCESS;
retval = make_reg(0, contained(start, polygon) != CONT_OUTSIDE);
delete polygon;
return retval;
}
case 6 :
case 7 :
case 8 : {
Common::Point end = Common::Point(argv[2].toSint16(), argv[3].toSint16());
reg_t poly_list, output;
int width, height, opt = 1;
if (getSciVersion() >= SCI_VERSION_2) {
if (argc < 7)
error("[avoidpath] Not enough arguments");
poly_list = (!argv[4].isNull() ? readSelector(s->_segMan, argv[4], SELECTOR(elements)) : NULL_REG);
width = argv[5].toUint16();
height = argv[6].toUint16();
if (argc > 7)
opt = argv[7].toUint16();
} else {
// SCI1.1 and older games always ran with an internal resolution of 320x200
poly_list = argv[4];
width = 320;
height = 190;
if (argc > 6)
opt = argv[6].toUint16();
}
if (DebugMan.isDebugChannelEnabled(kDebugLevelAvoidPath)) {
debug("[avoidpath] Pathfinding input:");
draw_point(s, start, 1, width, height);
draw_point(s, end, 0, width, height);
if (poly_list.getSegment()) {
print_input(s, poly_list, start, end, opt);
draw_input(s, poly_list, start, end, opt, width, height);
}
// Update the whole screen
g_sci->_gfxScreen->copyToScreen();
g_system->updateScreen();
if (!g_sci->_gfxPaint16)
g_system->delayMillis(2500);
}
PathfindingState *p = convert_polygon_set(s, poly_list, start, end, width, height, opt);
if (!p) {
warning("[avoidpath] Error: pathfinding failed for following input:\n");
print_input(s, poly_list, start, end, opt);
warning("[avoidpath] Returning direct path from start point to end point\n");
output = allocateOutputArray(s->_segMan, 3);
SegmentRef arrayRef = s->_segMan->dereference(output);
assert(arrayRef.isValid() && !arrayRef.skipByte);
writePoint(arrayRef, 0, start);
writePoint(arrayRef, 1, end);
writePoint(arrayRef, 2, Common::Point(POLY_LAST_POINT, POLY_LAST_POINT));
return output;
}
// Apply Dijkstra
AStar(p);
output = output_path(p, s);
delete p;
// Memory is freed by explicit calls to Memory
return output;
}
default:
warning("Unknown AvoidPath subfunction %d", argc);
return NULL_REG;
}
}
static bool PointInRect(const Common::Point &point, int16 rectX1, int16 rectY1, int16 rectX2, int16 rectY2) {
int16 top = MIN<int16>(rectY1, rectY2);
int16 left = MIN<int16>(rectX1, rectX2);
int16 bottom = MAX<int16>(rectY1, rectY2) + 1;
int16 right = MAX<int16>(rectX1, rectX2) + 1;
Common::Rect rect = Common::Rect(left, top, right, bottom);
// Add a one pixel margin of error
rect.grow(1);
return rect.contains(point);
}
reg_t kIntersections(EngineState *s, int argc, reg_t *argv) {
// This function computes intersection points for the "freeway pathing" in MUMG CD.
int32 qSourceX = argv[0].toSint16();
int32 qSourceY = argv[1].toSint16();
int32 qDestX = argv[2].toSint16();
int32 qDestY = argv[3].toSint16();
uint16 startIndex = argv[5].toUint16();
uint16 endIndex = argv[6].toUint16();
uint16 stepSize = argv[7].toUint16();
bool backtrack = argv[9].toUint16();
const int32 kVertical = 0x7fffffff;
uint16 curIndex = startIndex;
reg_t *inpBuf = s->_segMan->derefRegPtr(argv[4], endIndex + 2);
if (!inpBuf) {
warning("Intersections: input buffer invalid");
return NULL_REG;
}
reg_t *outBuf = s->_segMan->derefRegPtr(argv[8], (endIndex - startIndex + 2) / stepSize * 3);
if (!outBuf) {
warning("Intersections: output buffer invalid");
return NULL_REG;
}
// Slope and y-intercept of the query line in centipixels
int32 qIntercept;
int32 qSlope;
if (qSourceX != qDestX) {
// Compute slope of the line and round to nearest centipixel
qSlope = (1000 * (qSourceY - qDestY)) / (qSourceX - qDestX);
if (qSlope >= 0)
qSlope += 5;
else
qSlope -= 5;
qSlope /= 10;
// Compute y-intercept in centipixels
qIntercept = (100 * qDestY) - (qSlope * qDestX);
if (backtrack) {
// If backtrack is set we extend the line from dest to source
// until we hit a screen edge and place the source point there
// First we try to place the source point on the left or right
// screen edge
if (qSourceX >= qDestX)
qSourceX = 319;
else
qSourceX = 0;
// Compute the y-coordinate
qSourceY = ((qSlope * qSourceX) + qIntercept) / 100;
// If the y-coordinate is off-screen, the point we want is on the
// top or bottom edge of the screen instead
if (qSourceY < 0 || qSourceY > 189) {
if (qSourceY < 0)
qSourceY = 0;
else if (qSourceY > 189)
qSourceY = 189;
// Compute the x-coordinate
qSourceX = (((((qSourceY * 100) - qIntercept) * 10) / qSlope) + 5) / 10;
}
}
} else {
// The query line is vertical
qIntercept = qSlope = kVertical;
if (backtrack) {
// If backtrack is set, extend to screen edge
if (qSourceY >= qDestY)
qSourceY = 189;
else
qSourceY = 0;
}
}
int32 pSourceX = inpBuf[curIndex].toSint16();
int32 pSourceY = inpBuf[curIndex + 1].toSint16();
// If it's a polygon, we include the first point again at the end
int16 doneIndex;
if (pSourceX & (1 << 13))
doneIndex = startIndex;
else
doneIndex = endIndex;
pSourceX &= 0x1ff;
debugCN(kDebugLevelAvoidPath, "%s: (%i, %i)[%i]",
(doneIndex == startIndex ? "Polygon" : "Polyline"), pSourceX, pSourceY, curIndex);
curIndex += stepSize;
uint16 outCount = 0;
while (1) {
int32 pDestX = inpBuf[curIndex].toSint16() & 0x1ff;
int32 pDestY = inpBuf[curIndex + 1].toSint16();
if (DebugMan.isDebugChannelEnabled(kDebugLevelAvoidPath)) {
draw_line(s, Common::Point(pSourceX, pSourceY),
Common::Point(pDestX, pDestY), 2, 320, 190);
debugN(-1, " (%i, %i)[%i]", pDestX, pDestY, curIndex);
}
// Slope and y-intercept of the polygon edge in centipixels
int32 pIntercept;
int32 pSlope;
if (pSourceX != pDestX) {
// Compute slope and y-intercept (as above)
pSlope = ((pDestY - pSourceY) * 1000) / (pDestX - pSourceX);
if (pSlope >= 0)
pSlope += 5;
else
pSlope -= 5;
pSlope /= 10;
pIntercept = (pDestY * 100) - (pSlope * pDestX);
} else {
// Polygon edge is vertical
pSlope = pIntercept = kVertical;
}
bool foundIntersection = true;
int32 intersectionX = 0;
int32 intersectionY = 0;
if (qSlope == pSlope) {
// If the lines overlap, we test the source and destination points
// against the poly segment
if ((pIntercept == qIntercept) && (PointInRect(Common::Point(pSourceX, pSourceY), qSourceX, qSourceY, qDestX, qDestY))) {
intersectionX = pSourceX * 100;
intersectionY = pSourceY * 100;
} else if ((pIntercept == qIntercept) && PointInRect(Common::Point(qDestX, qDestY), pSourceX, pSourceY, pDestX, pDestY)) {
intersectionX = qDestX * 100;
intersectionY = qDestY * 100;
} else {
// Lines are parallel or segments don't overlap, no intersection
foundIntersection = false;
}
} else {
// Lines are not parallel
if (qSlope == kVertical) {
// Query segment is vertical, polygon segment is not vertical
intersectionX = qSourceX * 100;
intersectionY = pSlope * qSourceX + pIntercept;
} else if (pSlope == kVertical) {
// Polygon segment is vertical, query segment is not vertical
intersectionX = pDestX * 100;
intersectionY = qSlope * pDestX + qIntercept;
} else {
// Neither line is vertical
intersectionX = ((pIntercept - qIntercept) * 100) / (qSlope - pSlope);
intersectionY = ((intersectionX * pSlope) + (pIntercept * 100)) / 100;
}
}
if (foundIntersection) {
// Round back to pixels
intersectionX = (intersectionX + 50) / 100;
intersectionY = (intersectionY + 50) / 100;
// If intersection point lies on both the query line segment and the poly
// line segment, add it to the output
if (((PointInRect(Common::Point(intersectionX, intersectionY), pSourceX, pSourceY, pDestX, pDestY))
&& PointInRect(Common::Point(intersectionX, intersectionY), qSourceX, qSourceY, qDestX, qDestY))) {
outBuf[outCount * 3] = make_reg(0, intersectionX);
outBuf[outCount * 3 + 1] = make_reg(0, intersectionY);
outBuf[outCount * 3 + 2] = make_reg(0, curIndex);
outCount++;
}
}
if (curIndex == doneIndex) {
// End of polyline/polygon reached
if (DebugMan.isDebugChannelEnabled(kDebugLevelAvoidPath)) {
debug(";");
debugN(-1, "Found %i intersections", outCount);
if (outCount) {
debugN(-1, ":");
for (int i = 0; i < outCount; i++) {
Common::Point p = Common::Point(outBuf[i * 3].toSint16(), outBuf[i * 3 + 1].toSint16());
draw_point(s, p, 0, 320, 190);
debugN(-1, " (%i, %i)[%i]", p.x, p.y, outBuf[i * 3 + 2].toSint16());
}
}
debug(";");
g_sci->_gfxScreen->copyToScreen();
g_system->updateScreen();
}
return make_reg(0, outCount);
}
if (curIndex != endIndex) {
// Go to next point in polyline/polygon
curIndex += stepSize;
} else {
// Wrap-around for polygon case
curIndex = startIndex;
}
// Current destination point is source for the next line segment
pSourceX = pDestX;
pSourceY = pDestY;
}
}
// ==========================================================================
// kMergePoly utility functions
// Compute square of the distance of p to the segment a-b.
static float pointSegDistance(const Common::Point &a, const Common::Point &b,
const Common::Point &p) {
FloatPoint ba(b-a);
FloatPoint pa(p-a);
FloatPoint bp(b-p);
// Check if the projection of p on the line a-b lies between a and b
if (ba*pa >= 0.0f && ba*bp >= 0.0f) {
// If yes, return the (squared) distance of p to the line a-b:
// translate a to origin, project p and subtract
float linedist = (ba*((ba*pa)/(ba*ba)) - pa).norm();
return linedist;
} else {
// If no, return the (squared) distance to either a or b, whichever
// is closest.
// distance to a:
float adist = pa.norm();
// distance to b:
float bdist = FloatPoint(p-b).norm();
return MIN(adist, bdist);
}
}
// find intersection between edges of two polygons.
// endpoints count, except v2->_next
static bool segSegIntersect(const Vertex *v1, const Vertex *v2, Common::Point &intp) {
const Common::Point &a = v1->v;
const Common::Point &b = v1->_next->v;
const Common::Point &c = v2->v;
const Common::Point &d = v2->_next->v;
// First handle the endpoint cases manually
if (collinear(a, b, c) && collinear(a, b, d))
return false;
if (collinear(a, b, c)) {
// a, b, c collinear
// return true/c if c is between a and b
intp = c;
if (a.x != b.x) {
if ((a.x <= c.x && c.x <= b.x) || (b.x <= c.x && c.x <= a.x))
return true;
} else {
if ((a.y <= c.y && c.y <= b.y) || (b.y <= c.y && c.y <= a.y))
return true;
}
}
if (collinear(a, b, d)) {
intp = d;
// a, b, d collinear
// return false/d if d is between a and b
if (a.x != b.x) {
if ((a.x <= d.x && d.x <= b.x) || (b.x <= d.x && d.x <= a.x))
return false;
} else {
if ((a.y <= d.y && d.y <= b.y) || (b.y <= d.y && d.y <= a.y))
return false;
}
}
int len_dc = c.sqrDist(d);
if (!len_dc) error("zero length edge in polygon");
if (pointSegDistance(c, d, a) <= 2.0f) {
intp = a;
return true;
}
if (pointSegDistance(c, d, b) <= 2.0f) {
intp = b;
return true;
}
// If not an endpoint, call the generic intersection function
FloatPoint p;
if (intersection(a, b, v2, &p) == PF_OK) {
intp = p.toPoint();
return true;
} else {
return false;
}
}
// For intersecting polygon segments, determine if
// * the v2 edge enters polygon 1 at this intersection: positive return value
// * the v2 edge and the v1 edges are parallel: zero return value
// * the v2 edge exits polygon 1 at this intersection: negative return value
static int intersectDir(const Vertex *v1, const Vertex *v2) {
Common::Point p1 = v1->_next->v - v1->v;
Common::Point p2 = v2->_next->v - v2->v;
return (p1.x*p2.y - p2.x*p1.y);
}
// Direction of edge in degrees from pos. x-axis, between -180 and 180
static int edgeDir(const Vertex *v) {
Common::Point p = v->_next->v - v->v;
int deg = (int)Common::rad2deg((float)atan2((double)p.y, (double)p.x));
if (deg < -180) deg += 360;
if (deg > 180) deg -= 360;
return deg;
}
// For points p1, p2 on the polygon segment v, determine if
// * p1 lies before p2: negative return value
// * p1 and p2 are the same: zero return value
// * p1 lies after p2: positive return value
static int liesBefore(const Vertex *v, const Common::Point &p1, const Common::Point &p2) {
return v->v.sqrDist(p1) - v->v.sqrDist(p2);
}
// Structure describing an "extension" to the work polygon following edges
// of the polygon being merged.
// The patch begins on the point intersection1, being the intersection
// of the edges starting at indexw1/vertexw1 on the work polygon, and at
// indexp1/vertexp1 on the polygon being merged.
// It ends with the point intersection2, being the analogous intersection.
struct Patch {
uint32 indexw1;
uint32 indexp1;
const Vertex *vertexw1;
const Vertex *vertexp1;
Common::Point intersection1;
uint32 indexw2;
uint32 indexp2;
const Vertex *vertexw2;
const Vertex *vertexp2;
Common::Point intersection2;
bool disabled; // If true, this Patch was made superfluous by another Patch
};
// Check if the given vertex on the work polygon is bypassed by this patch.
static bool isVertexCovered(const Patch &p, uint32 wi) {
// / v (outside)
// ---w1--1----p----w2--2----
// ^ \ (inside)
if (wi > p.indexw1 && wi <= p.indexw2)
return true;
// v / (outside)
// ---w2--2----p----w1--1----
// \ ^ (inside)
if (p.indexw1 > p.indexw2 && (wi <= p.indexw2 || wi > p.indexw1))
return true;
// v / (outside)
// ---w1--2--1-------p-----
// w2 \ ^ (inside)
if (p.indexw1 == p.indexw2 && liesBefore(p.vertexw1, p.intersection1, p.intersection2) > 0)
return true; // This patch actually covers _all_ vertices on work
return false;
}
// Check if patch p1 makes patch p2 superfluous.
static bool isPatchCovered(const Patch &p1, const Patch &p2) {
// Same exit and entry points
if (p1.intersection1 == p2.intersection1 && p1.intersection2 == p2.intersection2)
return true;
// / * v (outside)
// ---p1w1--1----p2w1-1---p1w2--2----
// ^ * \ (inside)
if (p1.indexw1 < p2.indexw1 && p2.indexw1 < p1.indexw2)
return true;
if (p1.indexw1 > p1.indexw2 && (p2.indexw1 > p1.indexw1 || p2.indexw1 < p1.indexw2))
return true;
// / * v (outside)
// ---p1w1--11----p2w2-2---p1w2--12----
// ^ * \ (inside)
if (p1.indexw1 < p2.indexw2 && p2.indexw2 < p1.indexw2)
return true;
if (p1.indexw1 > p1.indexw2 && (p2.indexw2 > p1.indexw1 || p2.indexw2 < p1.indexw2))
return true;
// Opposite of two above situations
if (p2.indexw1 < p1.indexw1 && p1.indexw1 < p2.indexw2)
return false;
if (p2.indexw1 > p2.indexw2 && (p1.indexw1 > p2.indexw1 || p1.indexw1 < p2.indexw2))
return false;
if (p2.indexw1 < p1.indexw2 && p1.indexw2 < p2.indexw2)
return false;
if (p2.indexw1 > p2.indexw2 && (p1.indexw2 > p2.indexw1 || p1.indexw2 < p2.indexw2))
return false;
// The above checks covered the cases where one patch covers the other and
// the intersections of the patches are on different edges.
// So, if we passed the above checks, we have to check the order of
// intersections on edges.
if (p1.indexw1 != p1.indexw2) {
// / * v (outside)
// ---p1w1--11---21--------p1w2--2----
// p2w1 ^ * \ (inside)
if (p1.indexw1 == p2.indexw1)
return (liesBefore(p1.vertexw1, p1.intersection1, p2.intersection1) < 0);
// / * v (outside)
// ---p1w1--11---------p1w2--21---12----
// ^ p2w1 * \ (inside)
if (p1.indexw2 == p2.indexw1)
return (liesBefore(p1.vertexw2, p1.intersection2, p2.intersection1) > 0);
// If neither of the above, then the intervals of the polygon
// covered by patch1 and patch2 are disjoint
return false;
}
// p1w1 == p1w2
// Also, p1w1/p1w2 isn't strictly between p2
// v / * (outside)
// ---p1w1--12--11-------p2w1-21----
// p1w2 \ ^ * (inside)
// v / / (outside)
// ---p1w1--12--21--11---------
// p1w2 \ ^ ^ (inside)
// p2w1
if (liesBefore(p1.vertexw1, p1.intersection1, p1.intersection2) > 0)
return (p1.indexw1 != p2.indexw1);
// CHECKME: This is meaningless if p2w1 != p2w2 ??
if (liesBefore(p2.vertexw1, p2.intersection1, p2.intersection2) > 0)
return false;
// CHECKME: This is meaningless if p1w1 != p2w1 ??
if (liesBefore(p2.vertexw1, p2.intersection1, p1.intersection1) <= 0)
return false;
// CHECKME: This is meaningless if p1w2 != p2w1 ??
if (liesBefore(p2.vertexw1, p2.intersection1, p1.intersection2) >= 0)
return false;
return true;
}
// Merge a single polygon into the work polygon.
// If there is an intersection between work and polygon, this function
// returns true, and replaces the vertex list of work by an extended version,
// that covers polygon.
//
// NOTE: The strategy used matches qfg1new closely, and is a bit error-prone.
// A more robust strategy would be inserting all intersection points directly
// into both vertex lists as a first pass. This would make finding the merged
// polygon a much more straightforward edge-walk, and avoid cases where SSCI's
// algorithm mixes up the order of multiple intersections on a single edge.
bool mergeSinglePolygon(Polygon &work, const Polygon &polygon) {
#ifdef DEBUG_MERGEPOLY
const Vertex *vertex;
debugN("work:");
CLIST_FOREACH(vertex, &(work.vertices)) {
debugN(" (%d,%d) ", vertex->v.x, vertex->v.y);
}
debugN("\n");
debugN("poly:");
CLIST_FOREACH(vertex, &(polygon.vertices)) {
debugN(" (%d,%d) ", vertex->v.x, vertex->v.y);
}
debugN("\n");
#endif
uint workSize = work.vertices.size();
uint polygonSize = polygon.vertices.size();
int patchCount = 0;
Patch patchList[8];
const Vertex *workv = work.vertices._head;
const Vertex *polyv = polygon.vertices._head;
for (uint wi = 0; wi < workSize; ++wi, workv = workv->_next) {
for (uint pi = 0; pi < polygonSize; ++pi, polyv = polyv->_next) {
Common::Point intersection1;
Common::Point intersection2;
bool intersects = segSegIntersect(workv, polyv, intersection1);
if (!intersects)
continue;
#ifdef DEBUG_MERGEPOLY
debug("mergePoly: intersection at work %d, poly %d", wi, pi);
#endif
if (intersectDir(workv, polyv) >= 0)
continue;
#ifdef DEBUG_MERGEPOLY
debug("mergePoly: intersection in right direction");
#endif
int angle = 0;
int baseAngle = edgeDir(workv);
// We now found the point where an edge of 'polygon' left 'work'.
// Now find the re-entry point.
// NOTE: The order in which this searches does not always work
// properly if the correct patch would only use a single partial
// edge of poly. Because it starts at polyv->_next, it will skip
// the correct re-entry and proceed to the next.
const Vertex *workv2;
const Vertex *polyv2 = polyv->_next;
intersects = false;
uint pi2, wi2;
for (pi2 = 0; pi2 < polygonSize; ++pi2, polyv2 = polyv2->_next) {
int newAngle = edgeDir(polyv2);
int relAngle = newAngle - baseAngle;
if (relAngle > 180) relAngle -= 360;
if (relAngle < -180) relAngle += 360;
angle += relAngle;
baseAngle = newAngle;
workv2 = workv;
for (wi2 = 0; wi2 < workSize; ++wi2, workv2 = workv2->_next) {
intersects = segSegIntersect(workv2, polyv2, intersection2);
if (!intersects)
continue;
#ifdef DEBUG_MERGEPOLY
debug("mergePoly: re-entry intersection at work %d, poly %d", (wi + wi2) % workSize, (pi + 1 + pi2) % polygonSize);
#endif
if (intersectDir(workv2, polyv2) > 0) {
#ifdef DEBUG_MERGEPOLY
debug("mergePoly: re-entry intersection in right direction, angle = %d", angle);
#endif
break; // found re-entry point
}
}
if (intersects)
break;
}
if (!intersects || angle < 0)
continue;
if (patchCount >= 8)
error("kMergePoly: Too many patches");
// convert relative to absolute vertex indices
pi2 = (pi + 1 + pi2) % polygonSize;
wi2 = (wi + wi2) % workSize;
Patch &newPatch = patchList[patchCount];
newPatch.indexw1 = wi;
newPatch.vertexw1 = workv;
newPatch.indexp1 = pi;
newPatch.vertexp1 = polyv;
newPatch.intersection1 = intersection1;
newPatch.indexw2 = wi2;
newPatch.vertexw2 = workv2;
newPatch.indexp2 = pi2;
newPatch.vertexp2 = polyv2;
newPatch.intersection2 = intersection2;
newPatch.disabled = false;
#ifdef DEBUG_MERGEPOLY
debug("mergePoly: adding patch at work %d, poly %d", wi, pi);
#endif
if (patchCount == 0) {
patchCount++;
continue;
}
bool necessary = true;
for (int i = 0; i < patchCount; ++i) {
if (isPatchCovered(patchList[i], newPatch)) {
necessary = false;
break;
}
}
if (!necessary)
continue;
patchCount++;
if (patchCount > 1) {
// check if this patch makes other patches superfluous
for (int i = 0; i < patchCount-1; ++i)
if (isPatchCovered(newPatch, patchList[i]))
patchList[i].disabled = true;
}
}
}
if (patchCount == 0)
return false; // nothing changed
// Determine merged work by doing a walk over the edges
// of work, crossing over to polygon when encountering a patch.
Polygon output(0);
workv = work.vertices._head;
for (uint wi = 0; wi < workSize; ++wi, workv = workv->_next) {
bool covered = false;
for (int p = 0; p < patchCount; ++p) {
if (patchList[p].disabled) continue;
if (isVertexCovered(patchList[p], wi)) {
covered = true;
break;
}
}
if (!covered) {
// Add vertex to output
output.vertices.insertAtEnd(new Vertex(workv->v));
}
// CHECKME: Why is this the correct order in which to process
// the patches? (What if two of them start on this line segment
// in the opposite order?)
for (int p = 0; p < patchCount; ++p) {
const Patch &patch = patchList[p];
if (patch.disabled) continue;
if (patch.indexw1 != wi) continue;
if (patch.intersection1 != workv->v) {
// Add intersection point to output
output.vertices.insertAtEnd(new Vertex(patch.intersection1));
}
// Add vertices from polygon between vertexp1 (excl) and vertexp2 (incl)
for (polyv = patch.vertexp1->_next; polyv != patch.vertexp2; polyv = polyv->_next)
output.vertices.insertAtEnd(new Vertex(polyv->v));
output.vertices.insertAtEnd(new Vertex(patch.vertexp2->v));
if (patch.intersection2 != patch.vertexp2->v) {
// Add intersection point to output
output.vertices.insertAtEnd(new Vertex(patch.intersection2));
}
// TODO: We could continue after the re-entry point here?
}
}
// Remove last vertex if it's the same as the first vertex
if (output.vertices._head->v == output.vertices._head->_prev->v)
output.vertices.remove(output.vertices._head->_prev);
// Slight hack: swap vertex lists of output and work polygons.
SWAP(output.vertices._head, work.vertices._head);
return true;
}
/**
* This is a quite rare kernel function. An example of when it's called
* is in QFG1VGA, after killing any monster.
*
* It takes a polygon, and extends it to also cover any polygons from the
* input list with which it intersects. Any of those polygons so covered
* from the input list are marked by adding 0x10 to their type field.
*/
reg_t kMergePoly(EngineState *s, int argc, reg_t *argv) {
// 3 parameters: raw polygon data, polygon list, list size
reg_t polygonData = argv[0];
List *list = s->_segMan->lookupList(argv[1]);
// The size of the "work" point list SSCI uses. We use a dynamic one instead
//reg_t listSize = argv[2];
SegmentRef pointList = s->_segMan->dereference(polygonData);
if (!pointList.isValid() || pointList.skipByte) {
warning("kMergePoly: Polygon data pointer is invalid");
return make_reg(0, 0);
}
Node *node;
#ifdef DEBUG_MERGEPOLY
node = s->_segMan->lookupNode(list->first);
while (node) {
draw_polygon(s, node->value, 320, 190);
node = s->_segMan->lookupNode(node->succ);
}
Common::Point prev, first;
prev = first = readPoint(pointList, 0);
for (int i = 1; readPoint(pointList, i).x != 0x7777; i++) {
Common::Point point = readPoint(pointList, i);
draw_line(s, prev, point, 1, 320, 190);
prev = point;
}
draw_line(s, prev, first, 1, 320, 190);
// Update the whole screen
g_sci->_gfxScreen->copyToScreen();
g_system->updateScreen();
g_system->delayMillis(1000);
#endif
// The work polygon which we're going to merge with the polygons in list
Polygon work(0);
for (int i = 0; true; ++i) {
Common::Point p = readPoint(pointList, i);
if (p.x == POLY_LAST_POINT)
break;
Vertex *vertex = new Vertex(p);
work.vertices.insertAtEnd(vertex);
}
// TODO: Check behaviour for single-vertex polygons
node = s->_segMan->lookupNode(list->first);
while (node) {
Polygon *polygon = convert_polygon(s, node->value);
if (polygon) {
// CHECKME: Confirm vertex order that convert_polygon and
// fix_vertex_order output. For now, we re-reverse the order since
// convert_polygon reads the vertices reversed, and fix up head.
polygon->vertices.reverse();
polygon->vertices._head = polygon->vertices._head->_next;
// Merge this polygon into the work polygon if there is an
// intersection.
bool intersected = mergeSinglePolygon(work, *polygon);
// If so, flag it
if (intersected) {
writeSelectorValue(s->_segMan, node->value,
SELECTOR(type), polygon->type + 0x10);
#ifdef DEBUG_MERGEPOLY
debugN("Merged polygon: ");
// Iterate over edges
Vertex *vertex;
CLIST_FOREACH(vertex, &(work.vertices)) {
debugN(" (%d,%d) ", vertex->v.x, vertex->v.y);
}
debugN("\n");
#endif
}
delete polygon;
}
node = s->_segMan->lookupNode(node->succ);
}
// Allocate output array
reg_t output = allocateOutputArray(s->_segMan, work.vertices.size()+1);
SegmentRef arrayRef = s->_segMan->dereference(output);
// Copy work.vertices into arrayRef
Vertex *vertex;
uint32 n = 0;
CLIST_FOREACH(vertex, &work.vertices) {
if (vertex == work.vertices._head || vertex->v != vertex->_prev->v)
writePoint(arrayRef, n++, vertex->v);
}
writePoint(arrayRef, n, Common::Point(POLY_LAST_POINT, POLY_LAST_POINT));
#ifdef DEBUG_MERGEPOLY
prev = first = readPoint(arrayRef, 0);
for (int i = 1; readPoint(arrayRef, i).x != 0x7777; i++) {
Common::Point point = readPoint(arrayRef, i);
draw_line(s, prev, point, 3, 320, 190);
prev = point;
}
draw_line(s, prev, first, 3, 320, 190);
// Update the whole screen
g_sci->_gfxScreen->copyToScreen();
g_system->updateScreen();
if (!g_sci->_gfxPaint16)
g_system->delayMillis(1000);
debug("kMergePoly done");
#endif
return output;
}
#ifdef ENABLE_SCI32
reg_t kInPolygon(EngineState *s, int argc, reg_t *argv) {
// kAvoidPath already implements this
return kAvoidPath(s, argc, argv);
}
#endif
} // End of namespace Sci