qbsp: add BoundBrush (from q3map)

include/qbsp/brush.hh

@@ -48,6 +48,7 @@ int FindPlane(const vec3_t normal, const vec_t dist, int *side);
 bool PlaneEqual(const qbsp_plane_t *p1, const qbsp_plane_t *p2);
 bool PlaneInvEqual(const qbsp_plane_t *p1, const qbsp_plane_t *p2);
 
+bool BoundBrush (brush_t *brush);
 vec_t BrushVolume (const brush_t *brush);
 int BrushMostlyOnSide (const brush_t *brush, const plane_t *plane);
 

include/qbsp/qbsp.hh

@@ -152,8 +152,14 @@
 #define T_EPSILON               0.0002
 #define CONTINUOUS_EPSILON      0.0005
 
+// FIXME: replace with MAX_WORLD_COORD/MIN_WORLD_COORD/WORLD_SIZE
 #define BOGUS_RANGE     65536
 
+// from q3map
+#define MAX_WORLD_COORD		( 128*1024 )
+#define MIN_WORLD_COORD		( -128*1024 )
+#define WORLD_SIZE			( MAX_WORLD_COORD - MIN_WORLD_COORD )
+
 // the exact bounding box of the brushes is expanded some for the headnode
 // volume.  is this still needed?
 #define SIDESPACE       24

qbsp/brush.cc

@@ -1214,6 +1214,38 @@ Brush_LoadEntity(mapentity_t *dst, const mapentity_t *src, const int hullnum)
     }
 }
 
+//============================================================
+
+/*
+==================
+BoundBrush
+
+Sets the mins/maxs based on the windings
+returns false if the brush doesn't enclose a valid volume
+
+from q3map
+==================
+*/
+bool BoundBrush (brush_t *brush)
+{
+    ClearBounds (brush->mins, brush->maxs);
+    
+    for (face_t *face = brush->faces; face; face = face->next) {
+        const winding_t *w = &face->w;
+        for (int j=0 ; j<w->numpoints ; j++)
+            AddPointToBounds (w->points[j], brush->mins, brush->maxs);
+    }
+    
+    for (int i=0 ; i<3 ; i++) {
+        if (brush->mins[i] < MIN_WORLD_COORD || brush->maxs[i] > MAX_WORLD_COORD
+            || brush->mins[i] >= brush->maxs[i] ) {
+            return false;
+        }
+    }
+    
+    return true;
+}
+
 /*
 ==================
 BrushVolume

qbsp/test_qbsp.cc

@@ -177,6 +177,24 @@ TEST(qbsp, BrushMostlyOnSide2) {
     FreeMem(brush, BRUSH, 1);
 }
 
+TEST(qbsp, BoundBrush) {
+    brush_t *brush = load128x128x32Brush();
+    
+    ClearBounds(brush->mins, brush->maxs);
+    
+    EXPECT_EQ(true, BoundBrush(brush));
+    
+    EXPECT_FLOAT_EQ(-64, brush->mins[0]);
+    EXPECT_FLOAT_EQ(-64, brush->mins[1]);
+    EXPECT_FLOAT_EQ(-16, brush->mins[2]);
+    
+    EXPECT_FLOAT_EQ(64, brush->maxs[0]);
+    EXPECT_FLOAT_EQ(64, brush->maxs[1]);
+    EXPECT_FLOAT_EQ(16, brush->maxs[2]);
+    
+    FreeMem(brush, BRUSH, 1);
+}
+
 TEST(mathlib, WindingArea) {
     winding_t w;
     w.numpoints = 5;