A decent amount of progress on voxel traversal. Converted most of it to C code to make the CL version easier

include/Map.h

@@ -79,18 +79,41 @@ public:
 		
 	}
 
+	// (X, Y, Z) mask for the idx
+	uint8_t idx_set_x_mask = 0x1;
+	uint8_t idx_set_y_mask = 0x2;
+	uint8_t idx_set_z_mask = 0x4;
+
+	uint8_t mask_8[8] = {
+		0x0, 0x1, 0x2, 0x3,
+		0x4, 0x5, 0x6, 0x7
+	};
+
+	uint8_t count_mask_8[8]{
+		0x1,  0x3,  0x7,  0xF,
+		0x1F, 0x3F, 0x7F, 0xFF
+	};
 
+	// With a position and the head of the stack. Traverse down the voxel hierarchy to find
+	// the IDX and stack position of the highest resolution (maybe set resolution?) oct
 	bool get_voxel(sf::Vector3i position) {
 
 		// Init the parent stack and push the head node
-		std::queue<uint64_t> parent_stack;
+		//std::queue<uint64_t> parent_stack;
+
+		int parent_stack_position = 0;
+		uint64_t parent_stack[32] = {0};
 		
 		uint64_t head = block_stack.front()[stack_pos];
-		parent_stack.push(head);
+		parent_stack[parent_stack_position] = head;
+		
 
 		// Get the index of the first child of the head node
 		uint64_t index = head & child_pointer_mask;
 
+		uint8_t scale = 0;
+		uint8_t idx_stack[32] = {0};
+
 		// Init the idx stack
 		std::vector<std::bitset<3>> scale_stack(log2(OCT_DIM));
 
@@ -100,31 +123,83 @@ public:
 
 		while (dimension > 1) {
 			
-			// Do the logic steps to find which sub oct we step down into
+			// So we can be a little bit tricky here and increment our
+			// array index that holds our masks as we build the idx. 
+			// Adding 1 for X, 2 for Y, and 4 for Z
+			int mask_index = 0;
+
 
+			// Do the logic steps to find which sub oct we step down into
 			if (position.x >= (dimension / 2) + quad_position.x) {
+
+				// Set our voxel position to the (0,0) of the correct oct
 				quad_position.x += (dimension / 2);
+
+				// increment the mask index and mentioned above
+				mask_index += 1;
+
+				// Set the idx to represent the move
+				idx_stack[scale] |= idx_set_x_mask;
+
+				// Debug
 				scale_stack.at(log2(OCT_DIM) - log2(dimension)).set(0);
+				
 			}
 			if (position.y >= (dimension / 2) + quad_position.y) {
-				quad_position.y += (dimension / 2);
+
+				quad_position.y |= (dimension / 2);
+
+				mask_index += 2;
+
+				idx_stack[scale] ^= idx_set_y_mask;
 				scale_stack.at(log2(OCT_DIM) - log2(dimension)).set(1);
 			}
 			if (position.z >= (dimension / 2) + quad_position.z) {
+
 				quad_position.z += (dimension / 2);
-				scale_stack.at(log2(OCT_DIM) - log2(dimension)).set(2);
-			}
 
-			// Set the new dimension
-			dimension /= 2;
+				mask_index += 4;
 
+				idx_stack[scale] |= idx_set_z_mask;
+				scale_stack.at(log2(OCT_DIM) - log2(dimension)).set(2);
+			}
 
+			// Check to see if we are on a valid oct
+			if ((head >> 16) & mask_8[mask_index]) {
+				
+				// Check to see if it is a leaf
+				if ((head >> 24) & mask_8[mask_index]) {
+
+					// If it is, then we cannot traverse further as CP's won't have been generated
+					break;
+				}
+
+				// If all went well and we found a valid non-leaf oct then we will traverse further down the hierarchy
+				scale++;
+				dimension /= 2;
+
+				// We also need to traverse to the correct child pointer
+				
+				// Count the number of non-leaf octs that come before and add it to the current parent stack position
+				int count = count_bits((uint8_t)(head >> 24) ^ count_mask_8[mask_index]);
+				int index = (parent_stack[parent_stack_position] & child_pointer_mask) + count;
+				
+				// Increment the parent stack position and put the new oct node as the parent
+				parent_stack_position++;
+				parent_stack[parent_stack_position] = block_stack.front()[index];
+			
+			} else {
+				// If the oct was not valid, then no CP's exists any further
 
 
+				// It appears that the traversal is now working but I need
+				// to focus on how to now take care of the end condition.
+				// Currently it adds the last parent on the second to lowest
+				// oct CP. Not sure if thats correct
+				break;
+			}
 		}
 
-		uint64_t child1 = block_stack.front()[index];
-        uint64_t child2 = block_stack.front()[index+1];
 
         std::bitset<64> t(index);
         auto val = t.count();

include/util.hpp

@@ -272,3 +272,25 @@ inline std::vector<float> sfml_get_float_input(sf::RenderWindow *window) {
 
 }
 
+inline int count_bits(int32_t v) {
+	
+	v = v - ((v >> 1) & 0x55555555);                       // reuse input as temporary
+	v = (v & 0x33333333) + ((v >> 2) & 0x33333333);        // temp
+	return (((v + (v >> 4)) & 0xF0F0F0F) * 0x1010101) >> 24; // count
+}
+
+inline int count_bits(int64_t v) {
+
+	int32_t left = (int32_t)(v);
+	int32_t right = (int32_t)(v >> 32);
+
+	left = left - ((left >> 1) & 0x55555555);                    // reuse input as temporary
+	left = (left & 0x33333333) + ((left >> 2) & 0x33333333);     // temp
+	left = ((left + (left >> 4) & 0xF0F0F0F) * 0x1010101) >> 24; // count
+
+	right = right - ((right >> 1) & 0x55555555);                    // reuse input as temporary
+	right = (right & 0x33333333) + ((right >> 2) & 0x33333333);     // temp
+	right = ((right + (right >> 4) & 0xF0F0F0F) * 0x1010101) >> 24; // count
+
+	return left + right;
+}

src/Map.cpp

@@ -86,13 +86,13 @@ uint64_t Map::generate_children(sf::Vector3i pos, int dim) {
 	// The 8 subvoxel coords starting from the 1th direction, the direction of the origin of the 3d grid
 	// XY, Z++, XY
 	std::vector<sf::Vector3i> v = { 
-		sf::Vector3i(pos.x, pos.y, pos.z),
-		sf::Vector3i(pos.x + dim, pos.y, pos.z),
-		sf::Vector3i(pos.x, pos.y + dim, pos.z),
+		sf::Vector3i(pos.x      , pos.y      , pos.z),
+		sf::Vector3i(pos.x + dim, pos.y      , pos.z),
+		sf::Vector3i(pos.x      , pos.y + dim, pos.z),
 		sf::Vector3i(pos.x + dim, pos.y + dim, pos.z),
-		sf::Vector3i(pos.x, pos.y, pos.z + dim),
-		sf::Vector3i(pos.x + dim, pos.y, pos.z + dim),
-		sf::Vector3i(pos.x, pos.y + dim, pos.z + dim),
+		sf::Vector3i(pos.x      , pos.y      , pos.z + dim),
+		sf::Vector3i(pos.x + dim, pos.y      , pos.z + dim),
+		sf::Vector3i(pos.x      , pos.y + dim, pos.z + dim),
 		sf::Vector3i(pos.x + dim, pos.y + dim, pos.z + dim) 
 	};
 

src/main.cpp

@@ -68,7 +68,11 @@ sf::Texture window_texture;
 // Y: 1.57 is straight down
 
 
-
+// TODO: 
+// - Texture axis sign flipping issue
+// - Diffuse fog hard cut off
+// - Infinite light distance, no inverse square
+// - Inconsistent lighting constants. GUI manipulation
 
 int main() {
 
@@ -92,7 +96,7 @@ int main() {
 	_map.a.get_voxel(sf::Vector3i(5, 5, 0));
 	// =============================
 
-
+	return 0;
 
     sf::RenderWindow window(sf::VideoMode(WINDOW_X, WINDOW_Y), "SFML");
     window.setMouseCursorVisible(false);