math: improve the 2D and 3D box classes.

Box objects (AABB) now have the long awaited extent() and center()
methods. Corners are now called “aa” and “bb” for convenience. The
WorldEntity class uses a box3 for its AABB instead of two vec3s.
This allows us to simplify a lot of verbose code.

doc/samples/meshviewer/meshviewer.cpp

@@ -75,8 +75,8 @@ public:
     //This considers the box usage A to B as top-left to bottom-right
     void AddTarget(box3 new_target)
     {
-        vec3 base_off = .5f * (new_target.B - new_target.A);
-        vec3 base_pos = new_target.A + base_off;
+        vec3 base_off = .5f * new_target.extent();
+        vec3 base_pos = new_target.center();
         int pass = 0;
         while (pass < 3)
         {

doc/tutorial/11_fractal.cpp

@@ -120,8 +120,8 @@ public:
 #endif
 
         m_position = vec3::zero;
-        m_bbox[0] = m_position;
-        m_bbox[1] = vec3((vec2)m_window_size, 0);
+        m_aabb.aa = m_position;
+        m_aabb.bb = vec3((vec2)m_window_size, 0);
         //Input::TrackMouse(this);
 
 #if LOL_FEATURE_THREADS

src/debug/lines.cpp

@@ -212,20 +212,20 @@ void Debug::DrawArrow(vec2 a, vec2 b, vec3 s, vec4 color, float az, float bz)
 }
 
 //-- BOX: 3D -2D - 3D_to_2D ---------------------------------------------------
-void Debug::DrawBox(box3 a)                             { Debug::DrawBox(a.A, a.B, Scene::GetLineColor()); }
-void Debug::DrawBox(box2 a)                             { Debug::DrawBox(a.A, a.B, Scene::GetLineColor()); }
-void Debug::DrawBox(box3 a, vec4 color)                 { Debug::DrawBox(a.A, a.B, color); }
-void Debug::DrawBox(box2 a, vec4 color)                 { Debug::DrawBox(a.A, a.B, color); }
+void Debug::DrawBox(box3 a)                             { Debug::DrawBox(a.aa, a.bb, Scene::GetLineColor()); }
+void Debug::DrawBox(box2 a)                             { Debug::DrawBox(a.aa, a.bb, Scene::GetLineColor()); }
+void Debug::DrawBox(box3 a, vec4 color)                 { Debug::DrawBox(a.aa, a.bb, color); }
+void Debug::DrawBox(box2 a, vec4 color)                 { Debug::DrawBox(a.aa, a.bb, color); }
 void Debug::DrawBox(vec3 a, vec3 b)                     { Debug::DrawBox(a, b, Scene::GetLineColor()); }
 void Debug::DrawBox(vec2 a, vec2 b)                     { Debug::DrawBox(a, b, Scene::GetLineColor()); }
 void Debug::DrawBox(vec2 a, float s)                    { Debug::DrawBox(a, s, Scene::GetLineColor()); }
 void Debug::DrawBox(vec3 a, vec3 b, vec4 color)         { Debug::DrawBox(a, b, mat4::identity, color); }
 void Debug::DrawBox(vec2 a, vec2 b, vec4 color)         { Debug::DrawBox(a, b, mat2::identity, color); }
 void Debug::DrawBox(vec2 a, float s, vec4 color)        { Debug::DrawBox(a, s, mat2::identity, color); }
-void Debug::DrawBox(box3 a, mat4 transform)             { Debug::DrawBox(a.A, a.B, transform, Scene::GetLineColor()); }
-void Debug::DrawBox(box2 a, mat2 transform)             { Debug::DrawBox(a.A, a.B, transform, Scene::GetLineColor()); }
-void Debug::DrawBox(box3 a, mat4 transform, vec4 color) { Debug::DrawBox(a.A, a.B, transform, color); }
-void Debug::DrawBox(box2 a, mat2 transform, vec4 color) { Debug::DrawBox(a.A, a.B, transform, color); }
+void Debug::DrawBox(box3 a, mat4 transform)             { Debug::DrawBox(a.aa, a.bb, transform, Scene::GetLineColor()); }
+void Debug::DrawBox(box2 a, mat2 transform)             { Debug::DrawBox(a.aa, a.bb, transform, Scene::GetLineColor()); }
+void Debug::DrawBox(box3 a, mat4 transform, vec4 color) { Debug::DrawBox(a.aa, a.bb, transform, color); }
+void Debug::DrawBox(box2 a, mat2 transform, vec4 color) { Debug::DrawBox(a.aa, a.bb, transform, color); }
 void Debug::DrawBox(vec3 a, vec3 b, mat4 transform)     { Debug::DrawBox(a, b, transform, Scene::GetLineColor()); }
 void Debug::DrawBox(vec2 a, vec2 b, mat2 transform)     { Debug::DrawBox(a, b, transform, Scene::GetLineColor()); }
 void Debug::DrawBox(vec2 a, float s, mat2 transform)    { Debug::DrawBox(a, s, transform, Scene::GetLineColor()); }

src/gpu/renderer.cpp

@@ -235,12 +235,12 @@ void Renderer::SetViewport(ibox2 viewport)
         return;
 
 #if defined USE_D3D9 || defined _XBOX
-    D3DVIEWPORT9 vp = { viewport.A.x, viewport.A.y,
-                        viewport.B.x, viewport.B.y,
+    D3DVIEWPORT9 vp = { viewport.aa.x, viewport.aa.y,
+                        viewport.bb.x, viewport.bb.y,
                         0.0f, 1.0f };
     m_data->m_d3d_dev->SetViewport(&vp);
 #else
-    glViewport(viewport.A.x, viewport.A.y, viewport.B.x, viewport.B.y);
+    glViewport(viewport.aa.x, viewport.aa.y, viewport.bb.x, viewport.bb.y);
 #endif
 
     m_data->m_viewport = viewport;
@@ -253,17 +253,13 @@ ibox2 Renderer::GetViewport() const
 
 float Renderer::GetXYRatio() const
 {
-    ibox2 a = GetViewport();
-    ibox2 b(a.A, a.B);
-    ivec2 s = b.B - b.A;
+    ivec2 s = GetViewport().extent();
     return (float)s.x / s.y;
 }
 
 float Renderer::GetYXRatio() const
 {
-    ibox2 a = GetViewport();
-    ibox2 b(a.A, a.B);
-    ivec2 s = b.B - b.A;
+    ivec2 s = GetViewport().extent();
     return (float)s.y / s.x;
 }
 

src/gradient.cpp

@@ -38,8 +38,8 @@ Gradient::Gradient(vec3 aa, vec3 bb)
 {
     /* FIXME: this should not be hardcoded */
     m_position = aa;
-    m_bbox[0] = aa;
-    m_bbox[1] = bb;
+    m_aabb.aa = aa;
+    m_aabb.bb = bb;
 
     data->shader = nullptr;
 }
@@ -53,12 +53,12 @@ void Gradient::TickDraw(float seconds, Scene &scene)
 {
     Entity::TickDraw(seconds, scene);
 
-    float const vertex[] = { m_bbox[0].x, m_bbox[0].y, 0.0f,
-                             m_bbox[1].x, m_bbox[0].y, 0.0f,
-                             m_bbox[0].x, m_bbox[1].y, 0.0f,
-                             m_bbox[1].x, m_bbox[1].y, 0.0f,
-                             m_bbox[0].x, m_bbox[1].y, 0.0f,
-                             m_bbox[1].x, m_bbox[0].y, 0.0f, };
+    float const vertex[] = { m_aabb.aa.x, m_aabb.aa.y, 0.0f,
+                             m_aabb.bb.x, m_aabb.aa.y, 0.0f,
+                             m_aabb.aa.x, m_aabb.bb.y, 0.0f,
+                             m_aabb.bb.x, m_aabb.bb.y, 0.0f,
+                             m_aabb.aa.x, m_aabb.bb.y, 0.0f,
+                             m_aabb.bb.x, m_aabb.aa.y, 0.0f, };
 
     float const color[] = { 0.73f, 0.85f, 0.85f, 1.0f,
                             0.73f, 0.85f, 0.85f, 1.0f,

src/image/crop.cpp

@@ -22,7 +22,7 @@ namespace lol
 Image Image::Crop(ibox2 box) const
 {
     ivec2 const srcsize = GetSize();
-    ivec2 const dstsize = box.B - box.A;
+    ivec2 const dstsize = box.extent();
 
     Image dst(dstsize);
     PixelFormat format = GetFormat();
@@ -36,24 +36,24 @@ Image Image::Crop(ibox2 box) const
 
         int len = dstsize.x;
 
-        if (box.A.x < 0)
+        if (box.aa.x < 0)
         {
-            len += box.A.x;
-            box.A.x = 0;
+            len += box.aa.x;
+            box.aa.x = 0;
         }
 
-        if (box.A.x + len > srcsize.x)
-            len = srcsize.x - box.A.x;
+        if (box.aa.x + len > srcsize.x)
+            len = srcsize.x - box.aa.x;
 
         if (len > 0)
         {
             for (int y = 0; y < dstsize.y; y++)
             {
-                if (y + box.A.y < 0 || y + box.A.y >= srcsize.y)
+                if (y + box.aa.y < 0 || y + box.aa.y >= srcsize.y)
                     continue;
 
                 memcpy(dstp + y * dstsize.x * bpp,
-                       srcp + ((y + box.A.y) * srcsize.x + box.A.x) * bpp,
+                       srcp + ((y + box.aa.y) * srcsize.x + box.aa.x) * bpp,
                        len * bpp);
             }
         }

src/lol/algorithm/aabb_tree.h

@@ -81,8 +81,8 @@ void Draw(Quadtree<TE>* tree, vec4 color)
     //vec3 add = vec3(0.0f, 0.1f, 0.0f);
     while (boxes.Count() > 0)
     {
-        Debug::DrawBox(vec3(boxes[0].m1.A.x, tree->m_debug_y_offset, boxes[0].m1.A.y),
-                       vec3(boxes[0].m1.B.x, tree->m_debug_y_offset, boxes[0].m1.B.y),
+        Debug::DrawBox(vec3(boxes[0].m1.aa.x, tree->m_debug_y_offset, boxes[0].m1.aa.y),
+                       vec3(boxes[0].m1.bb.x, tree->m_debug_y_offset, boxes[0].m1.bb.y),
                        boxes[0].m2);
         boxes.Remove(0);
     }
@@ -90,8 +90,8 @@ void Draw(Quadtree<TE>* tree, vec4 color)
     {
         while (elements[0].m2 > 0)
         {
-            Debug::DrawBox(vec3(elements[0].m1->GetAABB().A.x, tree->m_debug_y_offset, elements[0].m1->GetAABB().A.y) + off * (float)elements[0].m2,
-                           vec3(elements[0].m1->GetAABB().B.x, tree->m_debug_y_offset, elements[0].m1->GetAABB().B.y) + off * (float)elements[0].m2,
+            Debug::DrawBox(vec3(elements[0].m1->GetAABB().aa.x, tree->m_debug_y_offset, elements[0].m1->GetAABB().aa.y) + off * (float)elements[0].m2,
+                           vec3(elements[0].m1->GetAABB().bb.x, tree->m_debug_y_offset, elements[0].m1->GetAABB().bb.y) + off * (float)elements[0].m2,
                            elements[0].m3);
             elements[0].m2--;
         }
@@ -112,9 +112,9 @@ void Draw(Octree<TE>* tree, vec4 color)
     //vec3 add = vec3(0.0f, 0.1f, 0.0f);
     while (boxes.Count() > 0)
     {
-        //float size = boxes[0].m1.B.x - boxes[0].m1.A.x;
-        Debug::DrawBox(vec3(boxes[0].m1.A.x, boxes[0].m1.A.y, boxes[0].m1.A.z) /* + off * (m_size.x / size) */,
-                        vec3(boxes[0].m1.B.x, boxes[0].m1.B.y, boxes[0].m1.B.z) /* + off * (m_size.x / size) */,
+        //float size = boxes[0].m1.bb.x - boxes[0].m1.aa.x;
+        Debug::DrawBox(vec3(boxes[0].m1.aa.x, boxes[0].m1.aa.y, boxes[0].m1.aa.z) /* + off * (m_size.x / size) */,
+                        vec3(boxes[0].m1.bb.x, boxes[0].m1.bb.y, boxes[0].m1.bb.z) /* + off * (m_size.x / size) */,
                         boxes[0].m2);
         //off += add;
         boxes.Remove(0);
@@ -123,8 +123,8 @@ void Draw(Octree<TE>* tree, vec4 color)
     {
         while (elements[0].m2 > 0)
         {
-            Debug::DrawBox(vec3(elements[0].m1->GetAABB().A.x, elements[0].m1->GetAABB().A.y, elements[0].m1->GetAABB().A.z) + off * (float)elements[0].m2,
-                            vec3(elements[0].m1->GetAABB().B.x, elements[0].m1->GetAABB().B.y, elements[0].m1->GetAABB().B.z) + off * (float)elements[0].m2,
+            Debug::DrawBox(vec3(elements[0].m1->GetAABB().aa.x, elements[0].m1->GetAABB().aa.y, elements[0].m1->GetAABB().aa.z) + off * (float)elements[0].m2,
+                            vec3(elements[0].m1->GetAABB().bb.x, elements[0].m1->GetAABB().bb.y, elements[0].m1->GetAABB().bb.z) + off * (float)elements[0].m2,
                             elements[0].m3);
             elements[0].m2--;
         }
@@ -341,9 +341,9 @@ public:
     virtual TB          GetSubAABB(const TB& bbox, int sub)
     {
         TV v(GetSubOffset(sub));
-        TV half_vec = (bbox.B - bbox.A) * .5f;
-        return TB(bbox.A + half_vec * v,
-                  bbox.A + half_vec * (v + TV(1.f)));
+        TV half_vec = bbox.extent() * .5f;
+        return TB(bbox.aa + half_vec * v,
+                  bbox.aa + half_vec * (v + TV(1.f)));
     }
 
     //--

src/lol/math/geometry.h

@@ -87,23 +87,23 @@ LOL_BOX_TYPEDEFS(Box3, box3)
 template <typename T> struct Box2
 {
     inline Box2()
-      : A(T(0)),
-        B(T(0))
+      : aa(T(0)),
+        bb(T(0))
     {}
 
     inline Box2(vec_t<T,2> const &a, vec_t<T,2> const &b)
-      : A(a),
-        B(b)
+      : aa(a),
+        bb(b)
     {}
 
     inline Box2(T const &ax, T const &ay, T const &bx, T const &by)
-      : A(ax, ay),
-        B(bx, by)
+      : aa(ax, ay),
+        bb(bx, by)
     {}
 
     Box2<T> operator +(vec_t<T,2> const &v) const
     {
-        return Box2<T>(A + v, B + v);
+        return Box2<T>(aa + v, bb + v);
     }
 
     Box2<T> &operator +=(vec_t<T,2> const &v)
@@ -113,7 +113,7 @@ template <typename T> struct Box2
 
     Box2<T> operator -(vec_t<T,2> const &v) const
     {
-        return Box2<T>(A - v, B - v);
+        return Box2<T>(aa - v, bb - v);
     }
 
     Box2<T> &operator -=(vec_t<T,2> const &v)
@@ -123,7 +123,7 @@ template <typename T> struct Box2
 
     Box2<T> operator *(vec_t<T,2> const &v) const
     {
-        return Box2<T>(A * v, B * v);
+        return Box2<T>(aa * v, bb * v);
     }
 
     Box2<T> &operator *=(vec_t<T,2> const &v)
@@ -131,17 +131,31 @@ template <typename T> struct Box2
         return *this = *this * v;
     }
 
-    bool operator ==(Box2<T> const &box)
+    Box2<T> operator *(T const &s) const
     {
-        return A == box.A && B == box.B;
+        return Box2<T>(aa * s, bb * s);
     }
 
-    bool operator !=(Box2<T> const &box)
+    Box2<T> &operator *=(T const &s)
     {
-        return A != box.A || B != box.B;
+        return *this = *this * s;
     }
 
-    vec_t<T,2> A, B;
+    bool operator ==(Box2<T> const &box) const
+    {
+        return aa == box.aa && bb == box.bb;
+    }
+
+    bool operator !=(Box2<T> const &box) const
+    {
+        return aa != box.aa || bb != box.bb;
+    }
+
+    inline vec_t<T,2> center() const { return (bb + aa) / 2; }
+
+    inline vec_t<T,2> extent() const { return bb - aa; }
+
+    vec_t<T,2> aa, bb;
 };
 
 /*
@@ -151,24 +165,24 @@ template <typename T> struct Box2
 template <typename T> struct Box3
 {
     inline Box3()
-      : A(T(0)),
-        B(T(0))
+      : aa(T(0)),
+        bb(T(0))
     {}
 
     inline Box3(vec_t<T,3> const &a, vec_t<T,3> const &b)
-      : A(a),
-        B(b)
+      : aa(a),
+        bb(b)
     {}
 
     inline Box3(T const &ax, T const &ay, T const &az,
                 T const &bx, T const &by, T const &bz)
-      : A(ax, ay, az),
-        B(bx, by, bz)
+      : aa(ax, ay, az),
+        bb(bx, by, bz)
     {}
 
     Box3<T> operator +(vec_t<T,3> const &v) const
     {
-        return Box3<T>(A + v, B + v);
+        return Box3<T>(aa + v, bb + v);
     }
 
     Box3<T> &operator +=(vec_t<T,3> const &v)
@@ -178,7 +192,7 @@ template <typename T> struct Box3
 
     Box3<T> operator -(vec_t<T,3> const &v) const
     {
-        return Box3<T>(A - v, B - v);
+        return Box3<T>(aa - v, bb - v);
     }
 
     Box3<T> &operator -=(vec_t<T,3> const &v)
@@ -188,7 +202,7 @@ template <typename T> struct Box3
 
     Box3<T> operator *(vec_t<T,3> const &v) const
     {
-        return Box3<T>(A * v, B * v);
+        return Box3<T>(aa * v, bb * v);
     }
 
     Box3<T> &operator *=(vec_t<T,3> const &v)
@@ -196,17 +210,31 @@ template <typename T> struct Box3
         return *this = *this * v;
     }
 
-    bool operator ==(Box3<T> const &box)
+    Box3<T> operator *(T const &s) const
     {
-        return A == box.A && B == box.B;
+        return Box3<T>(aa * s, bb * s);
     }
 
-    bool operator !=(Box3<T> const &box)
+    Box3<T> &operator *=(T const &s)
     {
-        return A != box.A || B != box.B;
+        return *this = *this * s;
     }
 
-    vec_t<T,3> A, B;
+    bool operator ==(Box3<T> const &box) const
+    {
+        return aa == box.aa && bb == box.bb;
+    }
+
+    bool operator !=(Box3<T> const &box) const
+    {
+        return aa != box.aa || bb != box.bb;
+    }
+
+    inline vec_t<T,3> center() const { return (bb + aa) / 2; }
+
+    inline vec_t<T,3> extent() const { return bb - aa; }
+
+    vec_t<T,3> aa, bb;
 };
 
 /*
@@ -243,9 +271,9 @@ bool operator>=(float value, const TestEpsilon& epsilon);
 //--
 static inline bool TestAABBVsAABB(box2 const &b1, box2 const &b2)
 {
-    vec2 c  = 0.5f * ((b1.A + b1.B) - (b2.A + b2.B));
-    vec2 e1 = 0.5f *  (b1.B - b1.A);
-    vec2 e2 = 0.5f *  (b2.B - b2.A);
+    vec2 c = b1.center() - b2.center();
+    vec2 e1 = 0.5f * b1.extent();
+    vec2 e2 = 0.5f * b2.extent();
 
     return abs(c.x) <= e1.x + e2.x
         && abs(c.y) <= e1.y + e2.y;
@@ -257,9 +285,9 @@ static inline bool TestAABBVsPoint(box2 const &b1, vec2 const &p)
 
 static inline bool TestAABBVsAABB(box3 const &b1, box3 const &b2)
 {
-    vec3 c =  0.5f * ((b1.A + b1.B) - (b2.A + b2.B));
-    vec3 e1 = 0.5f *  (b1.B - b1.A);
-    vec3 e2 = 0.5f *  (b2.B - b2.A);
+    vec3 c = b1.center() - b2.center();
+    vec3 e1 = 0.5f * b1.extent();
+    vec3 e2 = 0.5f * b2.extent();
 
     return abs(c.x) <= e1.x + e2.x
         && abs(c.y) <= e1.y + e2.y

src/tileset.cpp

@@ -137,8 +137,8 @@ char const *TileSet::GetName()
 ptrdiff_t TileSet::AddTile(ibox2 rect)
 {
     m_tileset_data->m_tiles.Push(rect,
-             box2((vec2)rect.A / (vec2)m_data->m_texture_size,
-                  (vec2)rect.B / (vec2)m_data->m_texture_size));
+             box2((vec2)rect.aa / (vec2)m_data->m_texture_size,
+                  (vec2)rect.bb / (vec2)m_data->m_texture_size));
     return m_tileset_data->m_tiles.Count() - 1;
 }
 
@@ -161,8 +161,7 @@ ptrdiff_t TileSet::GetTileCount() const
 
 ivec2 TileSet::GetTileSize(ptrdiff_t tileid) const
 {
-    ibox2 const &box = m_tileset_data->m_tiles[tileid].m1;
-    return box.B - box.A;
+    return m_tileset_data->m_tiles[tileid].m1.extent();
 }
 
 //Palette ---------------------------------------------------------------------
@@ -186,14 +185,14 @@ void TileSet::BlitTile(uint32_t id, vec3 pos, int o, vec2 scale, float angle,
 {
     ibox2 pixels = m_tileset_data->m_tiles[id].m1;
     box2 texels = m_tileset_data->m_tiles[id].m2;
-    float dtx = texels.B.x - texels.A.x;
-    float dty = texels.B.y - texels.A.y;
-    float tx = texels.A.x;
-    float ty = texels.A.y;
-
-    int dx =         (int)((float)(pixels.B.x - pixels.A.x) * scale.x);
-    int dy = o ? 0 : (int)((float)(pixels.B.y - pixels.A.y) * scale.y);
-    int dz = o ?     (int)((float)(pixels.B.y - pixels.A.y) * scale.y) : 0;
+    float dtx = texels.extent().x;
+    float dty = texels.extent().y;
+    float tx = texels.aa.x;
+    float ty = texels.aa.y;
+
+    int dx =         (int)(pixels.extent().x * scale.x);
+    int dy = o ? 0 : (int)(pixels.extent().y * scale.y);
+    int dz = o ?     (int)(pixels.extent().y * scale.y) : 0;
 
     /* If scaling is negative, switch triangle winding */
     if (scale.x * scale.y < 0.0f)

src/video.cpp

@@ -132,9 +132,7 @@ void Video::Capture(uint32_t *buffer)
 
 ivec2 Video::GetSize()
 {
-    ibox2 viewport = g_renderer->GetViewport();
-
-    return viewport.B - viewport.A;
+    return g_renderer->GetViewport().extent();
 }
 
 } /* namespace lol */

src/worldentity.cpp

@@ -20,8 +20,12 @@ namespace lol
  */
 
 WorldEntity::WorldEntity()
+  : m_aabb(vec3(0.f), vec3(0.f)),
+    m_position(0.f),
+    m_velocity(0.f),
+    m_rotation(1.f),
+    m_rotation_velocity(0.f)
 {
-    m_bbox[0] = m_bbox[1] = vec3::zero;
 }
 
 WorldEntity::~WorldEntity()

src/worldentity.h

@@ -28,11 +28,11 @@ public:
     virtual char const *GetName();
 
 public:
+    box3 m_aabb;
     vec3 m_position = vec3::zero;
     vec3 m_velocity = vec3::zero;
     quat m_rotation = quat(1);
     vec3 m_rotation_velocity = vec3::zero;
-    vec3 m_bbox[2];
 
 protected:
     WorldEntity();