slight simplification of cull test

[blank.git] / src / geometry / geometry.cpp

diff --git a/src/geometry/geometry.cpp b/src/geometry/geometry.cpp
index 090f78730474f38f0a1c8888cc0f724ad6988128..7798d33e949362ede44727f75402832e87a286ae 100644 (file)
--- a/src/geometry/geometry.cpp
+++ b/src/geometry/geometry.cpp
@@ -134,15 +134,15 @@ bool Intersection(
                glm::vec3(b_m[0]),
                glm::vec3(b_m[1]),
                glm::vec3(b_m[2]),
-               cross(glm::vec3(a_m[0]), glm::vec3(b_m[0])),
-               cross(glm::vec3(a_m[0]), glm::vec3(b_m[1])),
-               cross(glm::vec3(a_m[0]), glm::vec3(b_m[2])),
-               cross(glm::vec3(a_m[1]), glm::vec3(b_m[0])),
-               cross(glm::vec3(a_m[1]), glm::vec3(b_m[1])),
-               cross(glm::vec3(a_m[1]), glm::vec3(b_m[2])),
-               cross(glm::vec3(a_m[2]), glm::vec3(b_m[0])),
-               cross(glm::vec3(a_m[2]), glm::vec3(b_m[1])),
-               cross(glm::vec3(a_m[2]), glm::vec3(b_m[2])),
+               normalize(cross(glm::vec3(a_m[0]), glm::vec3(b_m[0]))),
+               normalize(cross(glm::vec3(a_m[0]), glm::vec3(b_m[1]))),
+               normalize(cross(glm::vec3(a_m[0]), glm::vec3(b_m[2]))),
+               normalize(cross(glm::vec3(a_m[1]), glm::vec3(b_m[0]))),
+               normalize(cross(glm::vec3(a_m[1]), glm::vec3(b_m[1]))),
+               normalize(cross(glm::vec3(a_m[1]), glm::vec3(b_m[2]))),
+               normalize(cross(glm::vec3(a_m[2]), glm::vec3(b_m[0]))),
+               normalize(cross(glm::vec3(a_m[2]), glm::vec3(b_m[1]))),
+               normalize(cross(glm::vec3(a_m[2]), glm::vec3(b_m[2]))),
        };
 
        depth = std::numeric_limits<float>::infinity();
@@ -150,8 +150,9 @@ bool Intersection(
 
        int cur_axis = 0;
        for (const glm::vec3 &axis : axes) {
-               if (iszero(axis)) {
+               if (any(isnan(axis))) {
                        // can result from the cross products if A and B have parallel axes
+                       ++cur_axis;
                        continue;
                }
                float a_min = std::numeric_limits<float>::infinity();
@@ -198,21 +199,19 @@ bool CullTest(const AABB &box, const glm::mat4 &MVP) noexcept {
                { box.max.x, box.max.y, box.min.z, 1.0f },
                { box.max.x, box.max.y, box.max.z, 1.0f },
        };
+
+       // check how many corners lie outside
+       int hits[6] = { 0, 0, 0, 0, 0, 0 };
        for (glm::vec4 &corner : corners) {
                corner = MVP * corner;
+               // replacing this with *= 1/w is effectively more expensive
                corner /= corner.w;
-       }
-
-       int hits[6] = { 0, 0, 0, 0, 0, 0 };
-
-       // check how many corners lie outside
-       for (const glm::vec4 &corner : corners) {
-               if (corner.x >  1.0f) ++hits[0];
-               if (corner.x < -1.0f) ++hits[1];
-               if (corner.y >  1.0f) ++hits[2];
-               if (corner.y < -1.0f) ++hits[3];
-               if (corner.z >  1.0f) ++hits[4];
-               if (corner.z < -1.0f) ++hits[5];
+               hits[0] += (corner.x >  1.0f);
+               hits[1] += (corner.x < -1.0f);
+               hits[2] += (corner.y >  1.0f);
+               hits[3] += (corner.y < -1.0f);
+               hits[4] += (corner.z >  1.0f);
+               hits[5] += (corner.z < -1.0f);
        }
 
        // if all corners are outside any given clip plane, the test is true