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First draft of the revised octree generation code

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MitchellHansen
2017-06-30 01:47:19 -07:00
parent 1fab4943bf
commit b82d543479
1 changed files with 39 additions and 22 deletions
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59
src/map/Octree.cpp
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@@ -271,7 +271,6 @@ std::tuple<uint64_t, uint64_t> Octree::GenerationRecursion(char* data, sf::Vecto
// We are working bottom up so we need to subtract from the stack position
// the amount of elements we want to use
int worst_case_insertion_size = descriptor_position_array.size() * 2;
// check to see if we exceeded this page header, if so set the header and move the global position
@@ -288,38 +287,56 @@ std::tuple<uint64_t, uint64_t> Octree::GenerationRecursion(char* data, sf::Vecto
}
unsigned int far_pointer_count = 0;
uint64_t far_pointer_block_position = descriptor_buffer_position;
// Count the far pointers we need to allocate
for (int i = descriptor_position_array.size() - 1; i >= 0; i--) {
// this is not the actual relative distance write, so we pessimistically guess that we will have
// the worst relative distance via the insertion size
uint64_t relative_distance = std::get<1>(descriptor_position_array.at(i)) - (descriptor_buffer_position - worst_case_insertion_size);
// check to see if we tripped the far pointer
if (relative_distance > 0x8000) {
// This is writing the ABSOLUTE POSITION for far pointers, is this what I want?
memcpy(&descriptor_buffer[descriptor_buffer_position], &std::get<1>(descriptor_position_array.at(i)), sizeof(uint64_t));
descriptor_buffer_position--;
far_pointer_count++;
}
}
// We gotta go backwards as memcpy of a vector can be emulated by starting from the rear
for (int i = descriptor_position_array.size() - 1; i >= 0; i--) {
// just gonna redo the far pointer check loosing a couple of cycles but oh well
uint64_t relative_distance = std::get<1>(descriptor_position_array.at(i)) - descriptor_buffer_position;
uint64_t descriptor = std::get<0>(descriptor_position_array.at(i));
// check to see if the
if (relative_distance > 0x8000) {
memcpy(&descriptor_buffer[descriptor_buffer_position], &std::get<1>(descriptor_position_array.at(i)), sizeof(uint64_t));
descriptor_buffer_position--;
descriptor |= far_bit_mask;
descriptor |= far_pointer_block_position;
far_pointer_block_position--;
} else {
descriptor |= relative_distance;
}
memcpy(&descriptor_buffer[descriptor_buffer_position], descriptor_position_array.at(i), descriptor_array.size() * sizeof(uint64_t));
// We have finished building the CD so we push it onto the buffer
memcpy(&descriptor_buffer[descriptor_buffer_position], &descriptor, sizeof(uint64_t));
descriptor_buffer_position--;
}
if (stack_pos - descriptor_position_array.size() > stack_pos) {
global_pos -= stack_pos;
stack_pos = 0x8000;
}
else {
stack_pos -= descriptor_position_array.size();
}
memcpy(&descriptor_buffer[stack_pos + global_pos], descriptor_array.data(), descriptor_array.size() * sizeof(uint64_t));
std::get<1>(descriptor_and_position) = descriptor_buffer_position + 1;
// Return the node up the stack
return descriptor_and_position;