void
RandomKnot::assignColors(void)
{
// Initialize the color indices; -1 indicates an as-yet-unknown color.
int color = mPrefs.technicolor() ? -1 : 0;
for (int y = 0; y < mVSections; ++y) {
for (int x = 0; x < mHSections; ++x) {
mpSectionColors[BOT][y * mHSections + x] = color;
mpSectionColors[TOP][y * mHSections + x] = color;
}
}
++color;
// Assign colors to the sections by tracing all the 'strands' in the knot.
for (int y = 0; y < mVSections; ++y) {
for (int x = 0; x < mHSections; ++x) {
if (mpSectionColors[TOP][y * mHSections + x] < 0) {
// Assign a color to the top strand.
if (traceColor(color, TOP, x, y, 0, 0)) {
++color;
}
}
if (mpSectionColors[BOT][y * mHSections + x] < 0) {
// Assign a color to the bottom strand.
switch (mpSectionTypes[y * mHSections + x]) {
case D:
case H:
if (traceColor(color, BOT, x, y, 0, 1)) {
++color;
}
break;
case V:
if (traceColor(color, BOT, x, y, 1, 0)) {
++color;
}
break;
case N:
break;
}
}
}
}
// Generate the random colors.
mpColors = new RandomColor[color];
int hue = randomInteger(360);
const int gamut = 90 + randomInteger(270);
const int shift = gamut / color;
for (int i = 0; i < color; ++i) {
mpColors[i] = RandomColor(0.4, 0.9, 0.6, 1.0, 1.0, 1.0, hue);
hue = (hue + shift) % 360;
}
}
//trace the ray and find out the color at its intersection point with the scene
Vector4 Renderer::traceColor(Ray ray, Scene* scene, unsigned int recDepth) {
Vector4 color(0,0,0);
ray.min_t = ray.min_t + ray.epsilon_t;
IntersectionData* iData = scene->intersect(ray);
if (iData && (recDepth < m_recursionDepth)) { // sucessful intersection test
//=== EXERCISE 2.2.3 ===
Vector3 N = (iData->normal).normalize();
Vector3 R = ((N.operator*(2)).operator*(N.dot(-ray.direction))+ray.direction).normalize(); // calculate R
Ray newRay(iData->position, R);
newRay.min_t = newRay.min_t + ray.epsilon_t;
color = traceColor(newRay, scene, recDepth+1).operator*(iData->reflectionPercentage) + ( m_shader->shade(iData, scene).operator*(1 - iData->reflectionPercentage)) ; // recursion
}
else {
color = m_shader->shade(iData, scene);
//color = scene->getBackground(); // background color
}
// clean
if (iData!=NULL){
delete(iData);
}
return color.clamp01();
}
//main renderloop that raytraces the given scene
void Renderer::render(Scene* scene){
if (scene) {
// Initialize Sampler
Point p = scene->getCamera()->getResolution();
m_sampler->init(p.x, p.y);
// Initialize fields
Ray ray;
std::vector<Ray> shadowRays;
IntersectionData* iData = 0;
Sample* sample = new Sample(0,0);
//reset film in camera
sample->setSize( (p.x > p.y? p.x : p.y) );
scene->setSample(*sample);
scene->getCamera()->initFilm();
// Renderloop
while (m_sampler->getNextSample(sample)) {
// generate camera ray and intersect it with the scene
ray = scene->getCamera()->generateRay(*sample);
sample->setColor(traceColor(ray, scene,0));
// write back the sample color
scene->setSample(*sample);
// observer update
if (m_sampler->cycleComplete())
notifyObservers();
}
//cleanup
delete sample;
}
}
