WIP raycasting

1 files changed, 63 insertions, 0 deletions

diff --git a/render.c b/render.c
index d36d528..8e74082 100644
--- a/render.c
+++ b/render.c
@@ -1,3 +1,4 @@
+#include "map.h"
 #include "maths.h"
 #include "plat.h"
 #include "render.h"
@@ -686,3 +687,65 @@ void ren_mesh(
 	}
 }
 
+void ren_map(
+	Renderer* r,
+	const struct Map* map,
+	const int* pos,
+	const int* dir,
+	const int* left
+) {
+	int x, w, h, hh;
+	const int* data = (const int*)&map[1];
+	w = r->vp[0] << fbits;
+	h = r->vp[1] << fbits;
+	hh = h / 2;
+	for (x = r->clip[0]; x < r->clip[2]; x++) {
+		Line l;
+		int ray = ((2 * x) << (fbits * 2)) / w - f1;
+		int d[2], plane[2];
+		d[0] = ((left[0] * ray) >> fbits);
+		d[1] = ((left[1] * ray) >> fbits);
+		plane[0] = pos[0] - d[0];
+		plane[1] = pos[1] - d[1];
+		d[0] = dir[0] - d[0];
+		d[1] = dir[1] - d[1];
+		d[0] = (pos[0] + d[0] * 4);
+		d[1] = (pos[1] + d[1] * 4);
+		init_line(&l, pos, d);
+		while (1) {
+			int mp[2], tile;
+			mp[0] = l.x >> fbits;
+			mp[1] = l.y >> fbits;
+			if (
+				mp[0] < 0 ||
+				mp[1] < 0 ||
+				mp[0] >= map->w ||
+				mp[1] >= map->h
+			) break;
+			tile = data[mp[0] + mp[1] * map->w];
+			if (tile) {
+				int lp[2], sy, ey, d, y;
+				lp[0] = l.x;
+				lp[1] = l.y;
+				d = vec_dist(lp, lp, plane, 2);
+				sy = (r->vp[1] / 2) - (((hh << fbits) / d) >> fbits);
+				ey = (r->vp[1] / 2) + (((hh << fbits) / d) >> fbits);
+				sy = maxi(sy, r->clip[1]);
+				ey = mini(ey, r->clip[3]);
+				for (y = sy; y < ey; y++) {
+					int coord = x + y * r->vp[0];
+					Colour c = { 0, 0, 0, 255 };
+					c.r = (((16 << fbits ) - d) / 16);
+					if (d < r->d[coord]) {
+						r->d[coord] = d;
+						r->t[coord] = c;
+					}
+				}
+				break;
+			}
+			step_line(&l);
+		}
+	}
+}
+
+