add camera example

tools/camera/viewer.cpp

@@ -0,0 +1,51 @@
+#include <rw.h>
+#include <skeleton.h>
+
+rw::Camera*
+ViewerCreate(rw::World *world)
+{
+	rw::Camera *camera = sk::CameraCreate(sk::globals.width, sk::globals.height, 1);
+	assert(camera);
+	camera->setNearPlane(0.1f);
+	camera->setFarPlane(500.0f);
+	world->addCamera(camera);
+	return camera;
+}
+
+void
+ViewerDestroy(rw::Camera *camera, rw::World *world)
+{
+	if(camera && world){
+		world->removeCamera(camera);
+		sk::CameraDestroy(camera);
+	}
+}
+
+void
+ViewerMove(rw::Camera *camera, rw::V3d *offset)
+{
+	sk::CameraMove(camera, offset);
+}
+
+void
+ViewerRotate(rw::Camera *camera, float deltaX, float deltaY)
+{
+	sk::CameraTilt(camera, nil, deltaY);
+	sk::CameraPan(camera, nil, deltaX);
+}
+
+void
+ViewerTranslate(rw::Camera *camera, float deltaX, float deltaY)
+{
+	rw::V3d offset;
+	offset.x = deltaX;
+	offset.y = deltaY;
+	offset.z = 0.0f;
+	sk::CameraMove(camera, &offset);
+}
+
+void
+ViewerSetPosition(rw::Camera *camera, rw::V3d *position)
+{
+	camera->getFrame()->translate(position, rw::COMBINEREPLACE);
+}