Graphics Programming in 3D - Essentials of Interactive Computer Graphics - page 435

class UWBD3D _ PrimitiveMeshArrow : public UWB _ Primitive {

public :
.
protected :
// draws with no internal representation

A: void DrawPrimitive( ... );

.

void UWBD3D _ PrimitiveMeshArrow::DrawPrimitive( ... ) {
.
// refernce to a cylinder mesh

B:

pCylinderMesh = graphics.GetMeshResource( L"cylinder.x" );
// reference to a cone mesh
pConeMesh = graphics.GetMeshResource( L"cone.x" );

.
// init matrix stack for xform

draw _ helper.PushModelTransform();
.
cylinder _ xform.SetScale( ... ); // set up xform for the cylinder
. // to represent the arrow body
cylinder _ xform.SetUpModelStack( ... ); // load the xform into WORLD matrix
pCylinderMesh->DrawMesh(... );

C:

// Draw the cylinder

draw _ helper.PopModelTransform();
.
// init matrix stack for xform

draw _ helper.PushModelTransform();
.
cone _ xform.SetScale( ... );

D:

// set up xform for the cone

.

// to represent the arrow head

cone _ xform.SetUpModelStack( ... ); // load the xform into WORLD matrix

pConeMesh->DrawMesh( ... ); // Draw the cone

draw _ helper.PopModelTransform();
.

Listing 16.5. 3D arrow primitive.