/**
* See the derivations of ΔA in SonntagUpdate.h
*
* @see SonntagUpdate.h
*/
float SonntagUpdate::calculateDeltaActivity() {
const float A = currentState->activity;
const float V = calculateV();
const float thetaC = parameters[DECAY_COMPETITION];
const float thetaL = parameters[DECAY_LOSS];
const float thetaA = parameters[ACTIVATION_DAMPENING];
// allow for manual input (CSV, GUI, etc)
float I;
if (currentState->manual_input > 0) {
I = currentState->manual_input;
} else {
I = calculateInput();
}
// equation 4.6, pg79
const float deltaA = (pow(A, thetaA) + I * (1 - A)) * (1 - A) * V - ((pow(A, thetaL) + A * pow((1 - A),
thetaC))) * (1 - V);
// wolfram input, x=A, y=I (no V term):
// (x + y*(1-x)) * (1-x) - (x^5 + x * (1-x)^9) from x = 0 to x = 1, y= 0 to y = 1
#ifdef DEBUG_UPDATES
printf("current A: %f\n", A);
printf("current I: %f\n", I);
printf("V term: %f\n", V);
printf("deltaA: %f\n", deltaA);
#endif
return deltaA;
}
//*****************************************
// SDL Functions
//*****************************************
void init() {
//Initialise SDL.
if(SDL_Init(SDL_INIT_VIDEO) < 0) exit(1);
//Use double buffering (24-bit).
SDL_GL_SetAttribute(SDL_GL_DOUBLEBUFFER, 1);
SDL_GL_SetAttribute(SDL_GL_DEPTH_SIZE, 24);
//Set vertical sync.
//SDL_GL_SetSwapInterval(1);
//Create window.
if (SDL_SetVideoMode(800, 800, 32, SDL_OPENGL) == 0) exit(1);
SDL_WM_SetCaption("Primitives", "Primitives");
//Set up orthographic camera.
glMatrixMode(GL_PROJECTION);
glLoadIdentity();
glOrtho(-2, 2, -2, 2, 2, -2);
glMatrixMode(GL_MODELVIEW);
//Set the clear color.
glClearColor(0, 0, 0, 1);
//Use the z-buffer.
glEnable(GL_DEPTH_TEST);
//Use vertex and colour arrays.
glEnableClientState(GL_VERTEX_ARRAY);
glEnableClientState(GL_COLOR_ARRAY);
//Calculate the vertex and colour data.
calculateV();
calculateC();
}
STImage *FieldMorph(STImage *image,
const std::vector<Feature> &sourceFeatures,
const std::vector<Feature> &targetFeatures,
float t, float a, float b, float p)
{
int width = image->GetWidth();
int height = image->GetHeight();
STImage *result = new STImage(width, height, STColor4ub(255,255,255,255));
std::vector<Feature> interpolatedFeatures = interpolateFeatures(sourceFeatures, targetFeatures, t);
for (int x = 0; x < width; x++) {
for (int y = 0; y < height; y++) {
STVector2 dispSum = STVector2(0, 0);
float weightsum = 0;
STPoint2 X = STPoint2(x, y);
int numFeatures = sourceFeatures.size();
for (int i = 0; i < numFeatures; i++) {
STPoint2 Pp = sourceFeatures[i].P;
STPoint2 Qp = sourceFeatures[i].Q;
STPoint2 P = interpolatedFeatures[i].P;
STPoint2 Q = interpolatedFeatures[i].Q;
float u = calculateU(X, P, Q);
float v = calculateV(X, P, Q);
STPoint2 Xp = calculateXp(Pp, Qp, u, v);
STVector2 displacement = STVector2(Xp) - STVector2(X);
float dist = calculateDistance(X, P, Q, u, v);
float weight = calculateWeight(Q, P, a, b, p, dist);
dispSum += displacement * weight;
weightsum += weight;
}
STPoint2 Xprime = X + dispSum/weightsum;
result->SetPixel(x, y, interpolatedColor(Xprime, image));
}
}
return result;
}
