int is_route_possible(int fromx, int fromy, int tox, int toy, Bitmap *wss)
{
wallscreen = wss;
suggestx = -1;
// ensure it's a memory bitmap, so we can use direct access to line[] array
if ((wss == NULL) || (!wss->IsMemoryBitmap()) || (wss->GetColorDepth() != 8))
quit("is_route_possible: invalid walkable areas bitmap supplied");
if (wallscreen->GetPixel(fromx, fromy) < 1)
return 0;
Bitmap *tempw = BitmapHelper::CreateBitmapCopy(wallscreen, 8);
if (tempw == NULL)
quit("no memory for route calculation");
if (!tempw->IsMemoryBitmap())
quit("tempw is not memory bitmap");
int dd, ff;
// initialize array for finding widths of walkable areas
int thisar, inarow = 0, lastarea = 0;
int walk_area_times[MAX_WALK_AREAS + 1];
for (dd = 0; dd <= MAX_WALK_AREAS; dd++) {
walk_area_times[dd] = 0;
walk_area_granularity[dd] = 0;
}
for (ff = 0; ff < tempw->GetHeight(); ff++) {
const uint8_t *tempw_scanline = tempw->GetScanLine(ff);
for (dd = 0; dd < tempw->GetWidth(); dd++) {
thisar = tempw_scanline[dd];
// count how high the area is at this point
if ((thisar == lastarea) && (thisar > 0))
inarow++;
else if (lastarea > MAX_WALK_AREAS)
quit("!Calculate_Route: invalid colours in walkable area mask");
else if (lastarea != 0) {
walk_area_granularity[lastarea] += inarow;
walk_area_times[lastarea]++;
inarow = 0;
}
lastarea = thisar;
}
}
for (dd = 0; dd < tempw->GetWidth(); dd++) {
for (ff = 0; ff < tempw->GetHeight(); ff++) {
uint8_t *tempw_scanline = tempw->GetScanLineForWriting(ff);
thisar = tempw_scanline[dd];
if (thisar > 0)
tempw_scanline[dd] = 1;
// count how high the area is at this point
if ((thisar == lastarea) && (thisar > 0))
inarow++;
else if (lastarea != 0) {
walk_area_granularity[lastarea] += inarow;
walk_area_times[lastarea]++;
inarow = 0;
}
lastarea = thisar;
}
}
// find the average "width" of a path in this walkable area
for (dd = 1; dd <= MAX_WALK_AREAS; dd++) {
if (walk_area_times[dd] == 0) {
walk_area_granularity[dd] = MAX_GRANULARITY;
continue;
}
walk_area_granularity[dd] /= walk_area_times[dd];
if (walk_area_granularity[dd] <= 4)
walk_area_granularity[dd] = 2;
else if (walk_area_granularity[dd] <= 15)
walk_area_granularity[dd] = 3;
else
walk_area_granularity[dd] = MAX_GRANULARITY;
/*char toprnt[200];
sprintf(toprnt,"area %d: Gran %d", dd, walk_area_granularity[dd]);
winalert(toprnt); */
}
walk_area_granularity[0] = MAX_GRANULARITY;
tempw->FloodFill(fromx, fromy, 232);
if (tempw->GetPixel(tox, toy) != 232)
{
// Destination pixel is not walkable
// Try the 100x100 square around the target first at 3-pixel granularity
int tryFirstX = tox - 50, tryToX = tox + 50;
int tryFirstY = toy - 50, tryToY = toy + 50;
if (!find_nearest_walkable_area(tempw, tryFirstX, tryFirstY, tryToX, tryToY, tox, toy, 3))
{
// Nothing found, sweep the whole room at 5 pixel granularity
find_nearest_walkable_area(tempw, 0, 0, tempw->GetWidth(), tempw->GetHeight(), tox, toy, 5);
}
delete tempw;
return 0;
}
delete tempw;
return 1;
}
