dungeon/src/FieldOfView.cpp

135 lines
3.9 KiB
C++

//
// Created by Adrian on 2017-09-21.
//
#include <cmath>
#include "FieldOfView.h"
#include "Tilemap.h"
FieldOfView::FieldOfView(Tilemap *map) {
this->map = map;
seen = new Tilemap(map->GetWidth(), map->GetHeight());
counter = 0;
}
FieldOfView::~FieldOfView() {
delete seen;
}
void FieldOfView::calc(vec2i pos, float range) {
counter++;
seen->set_tile(pos.x, pos.y, counter);
// Once for each octant
cast_light(1, 1.0f, 0.0f, 0, -1, -1, 0, pos.x, pos.y, range);
cast_light(1, 1.0f, 0.0f, -1, 0, 0, -1, pos.x, pos.y, range);
cast_light(1, 1.0f, 0.0f, 0, 1, -1, 0, pos.x, pos.y, range);
cast_light(1, 1.0f, 0.0f, 1, 0, 0, -1, pos.x, pos.y, range);
cast_light(1, 1.0f, 0.0f, 0, -1, 1, 0, pos.x, pos.y, range);
cast_light(1, 1.0f, 0.0f, -1, 0, 0, 1, pos.x, pos.y, range);
cast_light(1, 1.0f, 0.0f, 0, 1, 1, 0, pos.x, pos.y, range);
cast_light(1, 1.0f, 0.0f, 1, 0, 0, 1, pos.x, pos.y, range);
}
bool FieldOfView::can_see(vec2i pos) {
return seen->GetTile(pos.x, pos.y) >= counter;
}
bool FieldOfView::has_seen(vec2i pos) {
return seen->GetTile(pos.x, pos.y) > 0;
}
void FieldOfView::cast_light(int row, float start, float end, int xx, int xy, int yx, int yy, int startX, int startY,
float radius) {
float newStart = 0.0f;
if (start < end) {
return;
}
bool blocked = false;
for (int distance = row; distance <= radius && !blocked; distance++) {
int deltaY = -distance;
for (int deltaX = -distance; deltaX <= 0; deltaX++) {
int currentX = startX + deltaX * xx + deltaY * xy;
int currentY = startY + deltaX * yx + deltaY * yy;
float leftSlope = (deltaX - 0.5f) / (deltaY + 0.5f);
float rightSlope = (deltaX + 0.5f) / (deltaY - 0.5f);
if (!(currentX >= 0 && currentY >= 0 && currentX < map->GetWidth() && currentY < map->GetHeight()) || start < rightSlope) {
continue;
}
else if (end > leftSlope) {
break;
}
if (sqrt(deltaX*deltaX + deltaY*deltaY) <= radius) {
seen->set_tile(currentX, currentY, counter);
}
if (blocked) {
if (map->GetTile(currentX, currentY) == '#') { // TODO: Stop hardcoding tiles
newStart = rightSlope;
continue;
}
else {
blocked = false;
start = newStart;
}
}
else {
if (map->GetTile(currentX, currentY) == '#' && distance < radius) { // TODO: Get rid of hardcoded tiles
blocked = true;
cast_light(distance + 1, start, leftSlope, xx, xy, yx, yy, startX, startY, radius);
newStart = rightSlope;
}
}
}
}
}
bool line_of_sight(Tilemap *map, vec2i start, vec2i end) {
if (start == end) return true;
vec2i delta = end - start;
const char ix = (delta.x > 0) - (delta.x < 0);
const char iy = (delta.y > 0) - (delta.y < 0);
delta.x = std::abs(delta.x) << 1;
delta.y = std::abs(delta.y) << 1;
if (delta.x >= delta.y)
{
// error may go below zero
int error(delta.y - (delta.x >> 1));
while (start.x != end.x && map->GetTile(start.x, start.y) != '#') // TODO: Hardcoded tiles
{
// reduce error, while taking into account the corner case of error == 0
if ((error > 0) || (!error && (ix > 0)))
{
error -= delta.x;
start.y += iy;
}
// else do nothing
error += delta.y;
start.x += ix;
}
}
else
{
// error may go below zero
int error(delta.x - (delta.y >> 1));
while (start.y != end.y && map->GetTile(start.x, start.y) != '#') // TODO: Stop hardcoding tiles
{
// reduce error, while taking into account the corner case of error == 0
if ((error > 0) || (!error && (iy > 0)))
{
error -= delta.y;
start.x += ix;
}
// else do nothing
error += delta.x;
start.y += iy;
}
}
return start == end;
}