136 lines
4 KiB
C++
136 lines
4 KiB
C++
#include <cmath>
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#include "FieldOfView.h"
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#include "Tilemap.h"
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#include <SDL2/SDL.h>
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FieldOfView::FieldOfView() {
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}
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FieldOfView::FieldOfView(Tilemap *map) {
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this->map = map;
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seen = std::vector<unsigned int>(map->get_width()*map->get_height(),0);
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}
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void FieldOfView::calc(vec2i pos, float range) {
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counter++;
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seen[map->get_index(pos.x, pos.y)] = counter;
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// Once for each octant
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if (map != nullptr) {
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cast_light(1, 1.0f, 0.0f, 0, -1, -1, 0, pos.x, pos.y, range);
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cast_light(1, 1.0f, 0.0f, -1, 0, 0, -1, pos.x, pos.y, range);
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cast_light(1, 1.0f, 0.0f, 0, 1, -1, 0, pos.x, pos.y, range);
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cast_light(1, 1.0f, 0.0f, 1, 0, 0, -1, pos.x, pos.y, range);
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cast_light(1, 1.0f, 0.0f, 0, -1, 1, 0, pos.x, pos.y, range);
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cast_light(1, 1.0f, 0.0f, -1, 0, 0, 1, pos.x, pos.y, range);
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cast_light(1, 1.0f, 0.0f, 0, 1, 1, 0, pos.x, pos.y, range);
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cast_light(1, 1.0f, 0.0f, 1, 0, 0, 1, pos.x, pos.y, range);
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}
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else {
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SDL_LogError(SDL_LOG_CATEGORY_SYSTEM, "Tried to calc fov with a null tilemap!\n");
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}
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}
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bool FieldOfView::can_see(vec2i pos) {
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return seen[map->get_index(pos.x, pos.y)] >= counter;
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}
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bool FieldOfView::has_seen(vec2i pos) {
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return seen[map->get_index(pos.x, pos.y)] > seen_cutoff;
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}
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void FieldOfView::cast_light(int row, float start, float end, int xx, int xy, int yx, int yy, int startX, int startY,
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float radius) {
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float newStart = 0.0f;
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if (start < end) {
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return;
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}
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bool blocked = false;
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for (int distance = row; distance <= radius && !blocked; distance++) {
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int deltaY = -distance;
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for (int deltaX = -distance; deltaX <= 0; deltaX++) {
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int currentX = startX + deltaX * xx + deltaY * xy;
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int currentY = startY + deltaX * yx + deltaY * yy;
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float leftSlope = (deltaX - 0.5f) / (deltaY + 0.5f);
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float rightSlope = (deltaX + 0.5f) / (deltaY - 0.5f);
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if (!(currentX >= 0 && currentY >= 0 && currentX < map->get_width() && currentY < map->get_height()) || start < rightSlope) {
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continue;
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}
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else if (end > leftSlope) {
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break;
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}
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if (sqrt(deltaX*deltaX + deltaY*deltaY) <= radius) {
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seen[map->get_index(currentX, currentY)] = counter;
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}
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if (blocked) {
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if (map->get_tile(currentX, currentY).opaque) { // TODO: Stop hardcoding tiles
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newStart = rightSlope;
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continue;
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}
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else {
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blocked = false;
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start = newStart;
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}
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}
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else {
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if (map->get_tile(currentX, currentY).opaque && distance < radius) { // TODO: Get rid of hardcoded tiles
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blocked = true;
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cast_light(distance + 1, start, leftSlope, xx, xy, yx, yy, startX, startY, radius);
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newStart = rightSlope;
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}
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}
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}
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}
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}
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bool line_of_sight(Tilemap *map, vec2i start, vec2i end) {
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if (start == end) return true;
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vec2i delta = end - start;
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const char ix = (delta.x > 0) - (delta.x < 0);
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const char iy = (delta.y > 0) - (delta.y < 0);
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delta.x = std::abs(delta.x) << 1;
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delta.y = std::abs(delta.y) << 1;
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if (delta.x >= delta.y)
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{
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// error may go below zero
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int error = delta.y - (delta.x >> 1);
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while (start.x != end.x && map->get_tile(start.x, start.y).opaque)
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{
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// reduce error, while taking into account the corner case of error == 0
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if ((error > 0) || (!error && (ix > 0)))
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{
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error -= delta.x;
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start.y += iy;
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}
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// else do nothing
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error += delta.y;
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start.x += ix;
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}
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}
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else
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{
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// error may go below zero
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int error = delta.x - (delta.y >> 1);
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while (start.y != end.y && !map->get_tile(start.x, start.y).opaque)
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{
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// reduce error, while taking into account the corner case of error == 0
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if ((error > 0) || (!error && (iy > 0)))
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{
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error -= delta.y;
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start.x += ix;
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}
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// else do nothing
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error += delta.x;
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start.y += iy;
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}
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}
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return start == end;
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}
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