Added conversion functions from disk/cylinder to AABB.

examples/29-debugdraw/debugdraw.cpp

@@ -206,6 +206,32 @@ class DebugDrawApp : public entry::AppI
 				}
 			ddPop();
 
+			ddPush();
+
+				float mtx[16];
+				bx::mtxSRT(mtx
+					, 1.0f, 1.0f, 1.0f
+					, 0.0f, time, time*0.53f
+					, -10.0f, 1.0f, 10.0f
+					);
+
+				Cylinder cylinder =
+				{
+					{ -10.0f, 1.0f, 10.0f },
+					{ 0.0f, 0.0f, 0.0f },
+					1.0f
+				};
+
+				float up[3] = { 0.0f, 4.0f, 0.0f };
+				bx::vec3MulMtx(cylinder.m_end, up, mtx);
+				ddDraw(cylinder);
+
+				toAabb(aabb, cylinder);
+				ddSetColor(0xff0000ff);
+				ddDraw(aabb);
+
+			ddPop();
+
 			ddDrawOrb(-11.0f, 0.0f, 0.0f, 1.0f);
 			ddEnd();
 

examples/common/bounds.cpp

@@ -19,13 +19,73 @@ void aabbToObb(Obb& _obb, const Aabb& _aabb)
 	_obb.m_mtx[15] = 1.0f;
 }
 
-void sphereToAabb(Aabb& _aabb, const Sphere& _sphere)
+void toAabb(Aabb& _aabb, const Sphere& _sphere)
 {
 	float radius = _sphere.m_radius;
 	bx::vec3Sub(_aabb.m_min, _sphere.m_center, radius);
 	bx::vec3Add(_aabb.m_max, _sphere.m_center, radius);
 }
 
+void toAabb(Aabb& _aabb, const Disk& _disk)
+{
+	// Reference: http://iquilezles.org/www/articles/diskbbox/diskbbox.htm
+	float nsq[3];
+	bx::vec3Mul(nsq, _disk.m_normal, _disk.m_normal);
+
+	float one[3] = { 1.0f, 1.0f, 1.0f };
+	float tmp[3];
+	bx::vec3Sub(tmp, one, nsq);
+
+	const float inv = 1.0f / (tmp[0]*tmp[1]*tmp[2]);
+
+	float extent[3];
+	extent[0] = _disk.m_radius * tmp[0] * bx::fsqrt( (nsq[0] + nsq[1] * nsq[2]) * inv);
+	extent[1] = _disk.m_radius * tmp[1] * bx::fsqrt( (nsq[1] + nsq[2] * nsq[0]) * inv);
+	extent[2] = _disk.m_radius * tmp[2] * bx::fsqrt( (nsq[2] + nsq[0] * nsq[1]) * inv);
+
+	bx::vec3Sub(_aabb.m_min, _disk.m_center, extent);
+	bx::vec3Add(_aabb.m_max, _disk.m_center, extent);
+}
+
+void toAabb(Aabb& _aabb, const Cylinder& _cylinder)
+{
+	// Reference: http://iquilezles.org/www/articles/diskbbox/diskbbox.htm
+	float axis[3];
+	bx::vec3Sub(axis, _cylinder.m_end, _cylinder.m_pos);
+
+	float asq[3];
+	bx::vec3Mul(asq, axis, axis);
+
+	float nsq[3];
+	bx::vec3Mul(nsq, asq, 1.0f/bx::vec3Dot(axis, axis) );
+
+	float one[3] = { 1.0f, 1.0f, 1.0f };
+	float tmp[3];
+	bx::vec3Sub(tmp, one, nsq);
+
+	const float inv = 1.0f / (tmp[0]*tmp[1]*tmp[2]);
+
+	float extent[3];
+	extent[0] = _cylinder.m_radius * tmp[0] * bx::fsqrt( (nsq[0] + nsq[1] * nsq[2]) * inv);
+	extent[1] = _cylinder.m_radius * tmp[1] * bx::fsqrt( (nsq[1] + nsq[2] * nsq[0]) * inv);
+	extent[2] = _cylinder.m_radius * tmp[2] * bx::fsqrt( (nsq[2] + nsq[0] * nsq[1]) * inv);
+
+	float minP[3];
+	bx::vec3Sub(minP, _cylinder.m_pos, extent);
+
+	float minE[3];
+	bx::vec3Sub(minE, _cylinder.m_end, extent);
+
+	float maxP[3];
+	bx::vec3Add(maxP, _cylinder.m_pos, extent);
+
+	float maxE[3];
+	bx::vec3Add(maxE, _cylinder.m_end, extent);
+
+	bx::vec3Min(_aabb.m_min, minP, minE);
+	bx::vec3Max(_aabb.m_max, maxP, maxE);
+}
+
 void aabbTransformToObb(Obb& _obb, const Aabb& _aabb, const float* _mtx)
 {
 	aabbToObb(_obb, _aabb);

examples/common/bounds.h

@@ -67,7 +67,13 @@ struct Intersection
 void aabbToObb(Obb& _obb, const Aabb& _aabb);
 
 /// Convert sphere to axis aligned bounding box.
-void sphereToAabb(Aabb& _aabb, const Sphere& _sphere);
+void toAabb(Aabb& _aabb, const Sphere& _sphere);
+
+/// Convert disk to axis aligned bounding box.
+void toAabb(Aabb& _aabb, const Disk& _disk);
+
+/// Convert cylinder to axis aligned bounding box.
+void toAabb(Aabb& _aabb, const Cylinder& _cylinder);
 
 /// Calculate surface area of axis aligned bounding box.
 float calcAabbArea(Aabb& _aabb);

examples/common/debugdraw/debugdraw.cpp

@@ -967,7 +967,7 @@ struct DebugDraw
 
 	void draw(const Disk& _disk)
 	{
-		BX_UNUSED(_disk);
+		drawCircle(_disk.m_normal, _disk.m_center, _disk.m_radius, 0.0f);
 	}
 
 	void draw(const Obb& _obb)