Add triangle SAT intersection

2024-05-08 09:23:20 -04:00
parent ac4538bba5
commit 4830015060
6 changed files with 284 additions and 2 deletions
--- a/tests/Geometry/TriangleTests.cpp
+++ b/tests/Geometry/TriangleTests.cpp
@@ -0,0 +1,89 @@
+#include <gtest/gtest.h>
+#include <J3ML/Geometry/Triangle.h>
+
+using J3ML::Geometry::Interval;
+using J3ML::Geometry::Triangle;
+
+TEST(TriangleTests, FaceNormal)
+{
+    Triangle t{
+        Vector3{-1, -1, -1},
+        Vector3{0,   1,  0},
+        Vector3{1,  -1,  1}
+    };
+
+    EXPECT_EQ(t.FaceNormal(), (Vector3{4, 0, -4}));
+}
+
+TEST(TriangleTests, IntersectTriangle)
+{
+    Triangle xyTriangle{
+        {0.0f, 0.0f, 0.0f},
+        {1.0f, 1.0f, 0.0f},
+        {2.0f, 0.0f, 0.0f}
+    };
+
+    // Triangle collides with itself
+    EXPECT_EQ(Intersects(xyTriangle, xyTriangle), true);
+    // Translate 1 towards x -- should collide
+    EXPECT_EQ(Intersects(xyTriangle, xyTriangle.Translated(Vector3(1.0f, 0.0f, 0.0f))), true);
+    // Translate 2 towards x -- should collide exactly on V1
+    EXPECT_EQ(Intersects(xyTriangle, xyTriangle.Translated(Vector3(2.0f, 0.0f, 0.0f))), true);
+    // Translate 2 towards negative x -- should collide exactly on V0
+    EXPECT_EQ(Intersects(xyTriangle, xyTriangle.Translated(Vector3(-2.0f, 0.0f, 0.0f))), true);
+    // Translate 3 towards x -- should not collide
+    EXPECT_EQ(Intersects(xyTriangle, xyTriangle.Translated(Vector3(3.0f, 0.0f, 0.0f))), false);
+    // Translate 3 towards negative x -- should not collide
+    EXPECT_EQ(Intersects(xyTriangle, xyTriangle.Translated(Vector3(-3.0f, 0.0f, 0.0f))), false);
+    // Translate 1 towards z -- should not collide
+    EXPECT_EQ(Intersects(xyTriangle, xyTriangle.Translated(Vector3(0.0f, 0.0f, 1.0f))), false);
+    // Triangle collides with contained smaller triangle
+    EXPECT_EQ(Intersects(xyTriangle, xyTriangle.Scaled(Vector3(0.5f, 0.5f, 0.5f)).Translated(Vector3(0.25f, 0.25f, 0.0f))), true);
+
+    Triangle zxTriangle {
+        {0.0f, 0.0f, 0.0f},
+        {1.0f, 0.0f, 1.0f},
+        {0.0f, 0.0f, 2.0f}
+    };
+
+    // Should collide exactly on V0
+    EXPECT_EQ(Intersects(xyTriangle, zxTriangle), true);
+    // Should collide across xyTriangle's edge and  zxTriangle's face
+    EXPECT_EQ(Intersects(xyTriangle, zxTriangle.Translated(Vector3(0.0f, 0.0f, -1.0))), true);
+    // Should collide exactly on V1
+    EXPECT_EQ(Intersects(xyTriangle, zxTriangle.Translated(Vector3(0.0f, 0.0f, -2.0))), true);
+    // xyTriangle's face should be poked by zxTriangle's V0
+    EXPECT_EQ(Intersects(xyTriangle, zxTriangle.Translated(Vector3(1.0f, 1.0f, 0.0f))), true);
+    // xyTriangle's face should be cut by zxTriangle
+    EXPECT_EQ(Intersects(xyTriangle, zxTriangle.Translated(Vector3(1.0f, 1.0f, -0.5f))), true);
+    // Should not collide
+    EXPECT_EQ(Intersects(xyTriangle, zxTriangle.Translated(Vector3(1.0f, 1.0f, 1.0f))), false);
+    // Should not collide
+    EXPECT_EQ(Intersects(xyTriangle, zxTriangle.Translated(Vector3(0.0f, 0.0f, -3.0f))), false);
+
+    Triangle yxTriangle{
+        {0.0f, 0.0f, 0.0f},
+        {1.0f, 1.0f, 0.0f},
+        {0.0f, 2.0f, 0.0f}
+    };
+
+    // Should collide on V0-V1 edge
+    EXPECT_EQ(Intersects(yxTriangle, yxTriangle), true);
+    // Should not collide
+    EXPECT_EQ(Intersects(xyTriangle, yxTriangle.Translated(Vector3(0.0f, 1.0f, 0.0f))), false);
+    // Should not collide
+    EXPECT_EQ(Intersects(yxTriangle, yxTriangle.Translated(Vector3(0.0f, 0.0f, 1.0f))), false);
+
+    Triangle zyInvertedTriangle{
+        {0.0f, 1.0f, -1.0f},
+        {0.0f, 0.0f, 0.0f},
+        {0.0f, 1.0f, 1.0f}
+    };
+    // Should collide exactly on V1
+    EXPECT_EQ(Intersects(xyTriangle, zyInvertedTriangle), true);
+    // Should not collide
+    EXPECT_EQ(Intersects(xyTriangle, zyInvertedTriangle.Translated(Vector3(0.0f, 1.0f, 0.0f))), false);
+    // Should not collide
+    EXPECT_EQ(Intersects(xyTriangle, zyInvertedTriangle.Translated(Vector3(0.25f, 0.75f, 0.0f))), false);
+}
+