/** * Simple octree color quantization: Similar to http://rosettacode.org/wiki/Color_quantization#C */ void octreeColorQuantize(const RGBAImage& image, size_t max_colors, std::vector<RGBAPixel>& colors, Octree** octree) { assert(max_colors > 0); // have an octree with the colors as leaves Octree* internal_octree = new Octree(); // and a priority queue of leaves to be processed // the order of leaves is very important, see NodeComparator std::priority_queue<Octree*, std::vector<Octree*>, NodeComparator> queue; // insert the colors into the octree for (int x = 0; x < image.getWidth(); x++) { for (int y = 0; y < image.getHeight(); y++) { RGBAPixel color = image.pixel(x, y); Octree* node = Octree::findOrCreateNode(internal_octree, color); node->setColor(color); // add the leaf only once to the queue if (node->getCount() == 1) queue.push(node); } } // now: reduce the leaves until we have less colors than maximum while (queue.size() > max_colors) { Octree* node = queue.top(); assert(node->isLeaf()); queue.pop(); // add the color value of the leaf to the parent node->reduceToParent(); Octree* parent = node->getParent(); // delete the leaf (leaf is automatically removed from parent in reduceToParent()) delete node; // add parent to queue if it is a leaf now if (parent->isLeaf()) queue.push(parent); } // gather the quantized colors while (queue.size()) { Octree* node = queue.top(); assert(node->isLeaf()); node->setColorID(colors.size()); colors.push_back(node->getColor()); queue.pop(); } if (octree != nullptr) *octree = internal_octree; else delete internal_octree; }
void testOctreeWithImage(const RGBAImage& image) { std::set<RGBAPixel> colors; int r = 0, g = 0, b = 0, count = 0; Octree octree; // insert all pixels into an octree for (int x = 0; x < image.getWidth(); x++) { for (int y = 0; y < image.getHeight(); y++) { RGBAPixel color = image.getPixel(x, y); colors.insert(color); r += rgba_red(color); g += rgba_green(color); b += rgba_blue(color); count++; Octree::findOrCreateNode(&octree, color)->setColor(color); } } // make sure that all colors are inserted correctly BOOST_CHECK(octree.isRoot() && !octree.isLeaf()); BOOST_CHECK(!octree.hasColor()); // reduce all colors up to the root of the tree // the color should be the overall average color traverseReduceOctree(&octree); BOOST_CHECK(octree.hasColor()); RGBAPixel average1 = octree.getColor(); RGBAPixel average2 = rgba(r / count, g / count, b / count, 255); BOOST_CHECK_EQUAL(average1, average2); BOOST_TEST_MESSAGE("Overall colors: " << colors.size()); BOOST_TEST_MESSAGE("Pixels per color: " << (double) (image.getWidth() * image.getHeight()) / colors.size()); BOOST_TEST_MESSAGE("Average color: " << (int) rgba_red(average1) << "," << (int) rgba_green(average1) << "," << (int) rgba_blue(average1)); }
MeshComponent* OctreeSpatialPartitions::RayCast(Ray ray, float* outDistance) { ScopedLock _lock(octree.elementsLock); if (filterDuplicates) lastRaycastBucket = nullptr; Octree* currentLeaf = &octree; float dist = 0; Vector<3> point = ray.origin; MeshComponent* result = nullptr; float distance = 0; while (true) { if (currentLeaf == nullptr) break; point = ray.origin + ray.direction * dist; while (!currentLeaf->isLeaf()) { currentLeaf = currentLeaf->child(point[0] > currentLeaf->centerX(), point[1] > currentLeaf->centerY(), point[2] > currentLeaf->centerZ()); } float xDist = (ray.direction[0] < 0 ? currentLeaf->minX() : currentLeaf->maxX()) - point[0]; float yDist = (ray.direction[1] < 0 ? currentLeaf->minY() : currentLeaf->maxY()) - point[1]; float zDist = (ray.direction[2] < 0 ? currentLeaf->minZ() : currentLeaf->maxZ()) - point[2]; float xNext = dist + xDist / ray.direction[0]; float yNext = dist + yDist / ray.direction[1]; float zNext = dist + zDist / ray.direction[2]; float currentDistance; MeshComponent* currentResult = RayCastPartition(currentLeaf, ray, ¤tDistance); if (currentResult != nullptr) { if (aggressiveShortCircuit) { result = currentResult; distance = currentDistance; break; } else { if (result == nullptr || currentDistance < distance) { result = currentResult; distance = currentDistance; } } } if (!aggressiveShortCircuit && result != nullptr && distance < xNext && distance < yNext && distance < zNext) { break; } if (xNext < yNext) { if (xNext < zNext) { dist = xNext; currentLeaf = currentLeaf->neighborX(ray.direction[0] > 0); continue; } } else if (yNext < zNext) { dist = yNext; currentLeaf = currentLeaf->neighborY(ray.direction[1] > 0); continue; } dist = zNext; currentLeaf = currentLeaf->neighborZ(ray.direction[2] > 0); } if (result != nullptr) *outDistance = distance; return result; }