Merge branch 'dev', version 2.0.2

Translation could have caused errors getting the three normals for the
sides of a box. The internal normals-fetching function was therefore
made more robust.

CMakeLists.txt

@@ -6,7 +6,7 @@ set(SC_3D_CollisionDetectionHelpers_HEADERS "${CMAKE_CURRENT_SOURCE_DIR}/src/sc_
 
 add_library(SC_3D_CollisionDetectionHelpers ${SC_3D_CollisionDetectionHelpers_SOURCES})
 
-set_target_properties(SC_3D_CollisionDetectionHelpers PROPERTIES VERSION 2.0.1 SOVERSION 2)
+set_target_properties(SC_3D_CollisionDetectionHelpers PROPERTIES VERSION 2.0.2 SOVERSION 2)
 
 if(NOT DEFINED CMAKE_BUILD_TYPE OR "${CMAKE_BUILD_TYPE}" STREQUAL "")
     message("Defaulting to \"Debug\" build type.")

Changelog.md

@@ -1,5 +1,12 @@
 # Changelog
 
+## Version 2.0.2
+
+Fix SC_SACD_Translate_Mat4(...). It was missing a "1" in the first element of
+the Mat4.
+
+Made internal function getting normals of a box more robust.
+
 ## Version 2.0.1
 
 Added check in SC_SACD_Sphere_Box_Collision(...) to see if sphere and box has

src/sc_sacd.cpp

@@ -63,34 +63,84 @@ SC_SACD_Vec3 operator*(const SC_SACD_Mat4 &mat, const SC_SACD_Vec3 &vec) {
 std::vector<SC_SACD_Vec3> SC_SACD_Get_Box_Normals(
     const SC_SACD_Generic_Box *box) {
   std::vector<SC_SACD_Vec3> normals;
+  SC_SACD_Vec3 a, b, c;
 
-  normals.emplace_back(SC_SACD_Vec3{1.0F, 0.0F, 0.0F});
+  // Facing positive x-axis.
-  normals.back() = box->transform * normals.back();
+  a.x = 0.0F;
+  a.y = 0.0F;
+  a.z = 0.0F;
 
-  normals.emplace_back(SC_SACD_Vec3{0.0F, 1.0F, 0.0F});
+  b.x = 0.0F;
-  normals.back() = box->transform * normals.back();
+  b.y = 1.0F;
+  b.z = 0.0F;
 
-  normals.emplace_back(SC_SACD_Vec3{0.0F, 0.0F, 1.0F});
+  c.x = 0.0F;
-  normals.back() = box->transform * normals.back();
+  c.y = 0.0F;
+  c.z = 1.0F;
+
+  a = box->transform * a;
+  b = box->transform * b;
+  c = box->transform * c;
+
+  b = b - a;
+  c = c - a;
+
+  normals.push_back(SC_SACD_Cross_Product(b, c));
+
+  // Facing positive y-axis.
+  a.x = 0.0F;
+  a.y = 0.0F;
+  a.z = 0.0F;
+
+  b.x = 1.0F;
+  b.y = 0.0F;
+  b.z = 0.0F;
+
+  c.x = 0.0F;
+  c.y = 0.0F;
+  c.z = -1.0F;
+
+  a = box->transform * a;
+  b = box->transform * b;
+  c = box->transform * c;
+
+  b = b - a;
+  c = c - a;
+
+  normals.push_back(SC_SACD_Cross_Product(b, c));
+
+  // Facing positive z-axis.
+  a.x = 0.0F;
+  a.y = 0.0F;
+  a.z = 0.0F;
+
+  b.x = 0.0F;
+  b.y = 1.0F;
+  b.z = 0.0F;
+
+  c.x = -1.0F;
+  c.y = 0.0F;
+  c.z = 0.0F;
+
+  a = box->transform * a;
+  b = box->transform * b;
+  c = box->transform * c;
+
+  b = b - a;
+  c = c - a;
+
+  normals.push_back(SC_SACD_Cross_Product(b, c));
 
   return normals;
 }
 
 std::vector<SC_SACD_Vec3> SC_SACD_Get_Box_Normals_Normalized(
     const SC_SACD_Generic_Box *box) {
-  std::vector<SC_SACD_Vec3> normals;
+  std::vector<SC_SACD_Vec3> normals = SC_SACD_Get_Box_Normals(box);
 
-  normals.emplace_back(SC_SACD_Vec3{1.0F, 0.0F, 0.0F});
+  for (auto &normal : normals) {
-  normals.back() = box->transform * normals.back();
+    normal = normal / std::sqrt(SC_SACD_Dot_Product(normal, normal));
-  normals.back() = normals.back() / SC_SACD_Vec3_Length(normals.back());
+  }
-
-  normals.emplace_back(SC_SACD_Vec3{0.0F, 1.0F, 0.0F});
-  normals.back() = box->transform * normals.back();
-  normals.back() = normals.back() / SC_SACD_Vec3_Length(normals.back());
-
-  normals.emplace_back(SC_SACD_Vec3{0.0F, 0.0F, 1.0F});
-  normals.back() = box->transform * normals.back();
-  normals.back() = normals.back() / SC_SACD_Vec3_Length(normals.back());
 
   return normals;
 }
@@ -488,7 +538,7 @@ SC_SACD_Mat4 SC_SACD_Rotation_Mat4_ZAxis(float z_radians) {
 }
 
 SC_SACD_Mat4 SC_SACD_Translate_Mat4(float x, float y, float z) {
-  return SC_SACD_Mat4{0.0F, 0.0F, 0.0F, x, 0.0F, 1.0F, 0.0F, y,
+  return SC_SACD_Mat4{1.0F, 0.0F, 0.0F, x, 0.0F, 1.0F, 0.0F, y,
                       0.0F, 0.0F, 1.0F, z, 0.0F, 0.0F, 0.0F, 1.0F};
 }
 

src/test.cpp

@@ -568,6 +568,29 @@ int main() {
       CHECK_FLOAT(result.y, std::sqrt(2.0F));
     }
   }
+
+  // Box collision with transform that has translation.
+  {
+    SC_SACD_Generic_Box a = SC_SACD_Generic_Box_Default();
+    SC_SACD_Generic_Box b = SC_SACD_Generic_Box_Default();
+
+    a.width = 1.1F;
+    a.height = 1.1F;
+    b.width = 1.1F;
+    b.height = 1.1F;
+    a.transform = SC_SACD_Translate_Mat4(-1.0F, 0.0F, 0.0F);
+    b.transform = SC_SACD_Translate_Mat4(0.0F, -1.0F, 0.0F);
+
+    CHECK_TRUE(SC_SACD_Generic_Box_Collision(&a, &b));
+
+    a.width = 0.9F;
+    a.height = 0.9F;
+    b.width = 0.9F;
+    b.height = 0.9F;
+
+    CHECK_FALSE(SC_SACD_Generic_Box_Collision(&a, &b));
+  }
+
   std::cout << "Checks checked: " << checks_checked << '\n'
             << "Checks passed:  " << checks_passed << '\n';