GEEKING

App/v8world/WeldJoint.cpp

@@ -0,0 +1,88 @@
+ /* Copyright 2003-2005 ROBLOX Corporation, All Rights Reserved */
+#include "stdafx.h"
+
+#include "V8World/WeldJoint.h"
+#include "V8World/Primitive.h"
+#include "V8World/Contact.h"
+
+namespace RBX {
+
+const float kTerrainBreakOverlap = -0.2f;
+
+bool WeldJoint::compatibleSurfaces(
+	Primitive* p0, 
+	Primitive* p1, 
+	NormalId nId0, 
+	NormalId nId1)
+{
+	SurfaceType t0 = p0->getSurfaceType(nId0);
+	SurfaceType t1 = p1->getSurfaceType(nId1);
+
+	// weld beats glue - either one is a weld surface, or male/female snap for now
+	return ((t0 == WELD) ||	(t1 == WELD));
+}
+
+WeldJoint* WeldJoint::canBuildJoint(
+	Primitive* p0, 
+	Primitive* p1, 
+	NormalId nId0, 
+	NormalId nId1)
+{
+	if (	WeldJoint::compatibleSurfaces(p0, p1, nId0, nId1) 
+		&&	Joint::canBuildJointTight(p0, p1, nId0, nId1)) {
+
+		CoordinateFrame c0, c1;
+		
+		RigidJoint::faceIdToCoords(p0, p1, nId0, nId1, c0, c1);
+
+        return new WeldJoint(p0, p1, c0, c1);
+	}
+	else {
+		return NULL;
+	}
+}
+
+// Due to legacy reasons, cell index has to be encoded in surface0 and surface1 with a special encoding
+// Cells within the legacy terrain bounds have to have surface0 equal to a linear index within 511x63x511 array (yes, really)
+// and surface1 equal to -1.
+// We extend that encoding to maintain legacy data.
+Vector3int16 ManualWeldJoint::getCell() const
+{
+    short x, y, z;
+
+    if ((int)surface1 == -1)
+    {
+        // legacy encoding
+        x = surface0 % 511 - 256;
+        y = (surface0 / (511 * 511)) % 63;
+        z = (surface0 / 511) % 511 - 256;
+    }
+    else
+    {
+        // new encoding; y was split into two 8-bit vectors, reassemble them
+        x = surface0 & 0xffff;
+        y = ((surface0 >> 16) & 0xff) | (((surface1 >> 16) & 0xff) << 8);
+        z = surface1 & 0xffff;
+    }
+
+    return Vector3int16(x, y, z);
+}
+
+void ManualWeldJoint::setCell(const Vector3int16& pos)
+{
+    // use new encoding: split y into two 8-bit vectors
+    surface0 = (pos.x & 0xffff) | ((pos.y & 0xff) << 16);
+    surface1 = (pos.z & 0xffff) | ((pos.y & 0xff00) << 8);
+}
+
+bool ManualWeldJoint::isTouchingTerrain(Primitive* terrain, Primitive* prim)
+{
+	for (int i = 0; i < prim->getNumContacts(); ++i)
+		if (prim->getContactOther(i) == terrain)
+			if (prim->getContact(i)->computeIsCollidingUi(kTerrainBreakOverlap))
+				return true;
+
+	return false;
+}
+
+} // namespace