Camera::Camera(EngineParams& params) : KernelObject(params)
{
fprintf(stderr, "Initializing <Camera>.\n");
fprintf(stderr, "Loading '*/camera.xml'.\n");
std::fstream stream;
pugi::xml_document doc;
GetData("camera.xml", stream);
fprintf(stderr, "Parsing camera parameters...");
ParseXML(doc, stream);
fprintf(stderr, " done.\n");
pugi::xml_node node = doc.child("camera");
Vector cameraPos = parseVector(node.child("position"));
Vector cameraTarget = parseVector(node.child("target"));
Vector dir = normalize(cameraTarget - cameraPos);
node = node.child("misc");
float FOV = (PI / 180.0f) * node.attribute("fov").as_float();
node = node.parent();
node = node.child("focal"); /* Depth-of-field params. */
float focalSpread = node.attribute("spread").as_float();
float focalLength = node.attribute("length").as_float();
fprintf(stderr, "Camera position = (%.2f, %.2f, %.2f).\n", cameraPos.x,
cameraPos.y,
cameraPos.z);
fprintf(stderr, "Camera target = (%.2f, %.2f, %.2f).\n", cameraTarget.x,
cameraTarget.y,
cameraTarget.z);
fprintf(stderr, "Field of view = %.2f radians.\n", FOV);
fprintf(stderr, "Focal length = %.2f.\n", focalLength);
fprintf(stderr, "Focal spread = %.2f.\n", focalSpread);
Vector normal, tangent;
Basis(dir, &normal, &tangent);
Vector focalPlane[4];
float z = 1.0f / tan(FOV * 0.5f);
focalPlane[0] = normalize(Vector(-1.0f, +1.0f, z));
focalPlane[1] = normalize(Vector(+1.0f, +1.0f, z));
focalPlane[2] = normalize(Vector(+1.0f, -1.0f, z));
focalPlane[3] = normalize(Vector(-1.0f, -1.0f, z));
for (size_t t = 0; t < 4; ++t)
{
/* Transform the focal plane to camera space (= "rotate" it) */
focalPlane[t] = Transform(focalPlane[t], tangent, normal, dir);
focalPlane[t] = focalPlane[t] * focalLength + cameraPos;
}
this->buffer = CreateBuffer(params.context, CL_MEM_READ_ONLY,
sizeof(cl_data), nullptr);
cl_data data;
for (size_t t = 0; t < 4; ++t) focalPlane[t].CL(&data.p[t]);
cameraPos.CL(&data.pos);
normal.CL(&data.up);
tangent.CL(&data.left);
data.spread = focalSpread;
WriteToBuffer(params.queue, this->buffer, CL_TRUE,
0, sizeof(cl_data), &data);
fprintf(stderr, "Initialization complete.\n\n");
stream.close();
}
