diff options
| -rw-r--r-- | crawl-ref/source/ray.cc | 40 |
1 files changed, 25 insertions, 15 deletions
diff --git a/crawl-ref/source/ray.cc b/crawl-ref/source/ray.cc index fbcc655c39..b773b4b526 100644 --- a/crawl-ref/source/ray.cc +++ b/crawl-ref/source/ray.cc @@ -147,27 +147,32 @@ void ray_def::bounce(const reflect_grid &rg) // Move to the diamond edge to determine the side. coord_def side; - rtrans.to_grid(diamonds, false); + bool corner = rtrans.to_grid(diamonds, false); double d1 = diamonds.ls1.index(rtrans.start); if (double_is_integral(d1)) - side = (iround(d1) ? coord_def(1,1) : coord_def(-1,-1)); - else + side += iround(d1) ? coord_def(1,1) : coord_def(-1,-1); + double d2 = diamonds.ls2.index(rtrans.start); + if (double_is_integral(d2)) + side += iround(d2) ? coord_def(1,-1) : coord_def(-1,1); + ASSERT(corner == (side.x == 0 || side.y == 0)); + + // In the corner case, we have side == (+-2, 0) or (0, +-2); reduce: + if (corner) { - double d2 = diamonds.ls2.index(rtrans.start); - ASSERT(double_is_integral(d2)); - side = (iround(d2) ? coord_def(1,-1) : coord_def(-1,1)); + side.x = side.x / 2; + side.y = side.y / 2; } - // TODO: for rays in cardinal directions, this is arbitrary - // and can lead to bad behaviour. // Mirror rtrans to have it leave through the positive side. geom::ray rmirr = _mirror(rtrans, side); + // TODO: on a corner, reflect back unless we're on a diagonal. + // Determine which of the three relevant cells are bouncy. const coord_def dx = coord_def(side.x, 0); const coord_def dy = coord_def(0, side.y); - bool rx = rg(rg_o + dx); - bool ry = rg(rg_o + dy); + bool rx = (side.x != 0) && rg(rg_o + dx); + bool ry = (side.y != 0) && rg(rg_o + dy); bool rxy = rg(rg_o + dx + dy); // One of the three neighbours on this side must be bouncy. ASSERT(rx || ry || rxy); @@ -216,15 +221,20 @@ void ray_def::bounce(const reflect_grid &rg) } else if (rx) { - // y = x - 0.5 - l.f = geom::form(1, -1); - l.val = 0.5; + // Flattened corners: y = x - 0.5 + // l.f = geom::form(1, -1); + // l.val = 0.5; + // Instead like rxy && rx: x = 1 + l.f = geom::form(1, 0); + l.val = 1; } else // ry { // y = x + 0.5 - l.f = geom::form(1, -1); - l.val = -0.5; + // l.f = geom::form(1, -1); + // l.val = -0.5; + l.f = geom::form(0, 1); + l.val = 1; } double t = intersect(rmirr, l); ASSERT(double_is_zero(t) || t >= 0); |