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Aryadev Chavali
2025-11-17 01:20:57 +00:00
parent 8a2214f2fb
commit 15b3f9fb12
2 changed files with 21 additions and 2 deletions
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19
README.org
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@@ -1,6 +1,7 @@
#+title: Calkin-Wilf trees #+title: Calkin-Wilf trees
#+author: Aryadev Chavali #+author: Aryadev Chavali
#+date: 2024-07-27 #+date: 2024-07-27
#+filetags: cpp cw_tree
A graphical visualisation of A graphical visualisation of
[[https://en.wikipedia.org/wiki/Calkin%E2%80%93Wilf_tree][Calkin-Wilf [[https://en.wikipedia.org/wiki/Calkin%E2%80%93Wilf_tree][Calkin-Wilf
@@ -19,12 +20,30 @@ This was done just for fun really, but it's quite fun to see it
generate a dense number line over many iterations. generate a dense number line over many iterations.
* TODOs * TODOs
** TODO Multithreading ** TODO Multithreading
SCHEDULED: <2025-11-18 Tue>
Currently single threaded. A multithreaded implementation could have Currently single threaded. A multithreaded implementation could have
multiple nodes generated at once, which would speed up the multiple nodes generated at once, which would speed up the
implementation. implementation.
Might need to study my current implementation to see if it could be Might need to study my current implementation to see if it could be
done better. done better.
2025-11-17: Notes:
- Mutex on the queue [[file:src/main.cpp::std::queue<word_t>
iteration_queue;][the queue]] and the allocator will be necessary.
- Perhaps we could do two mutexes, one per structure?
- We'd need to lock for [[file:src/numerics.cpp::std::tuple<Fraction,
Fraction, Fraction> iterate(std::queue<word_t> &queue,][iterate]]
- Locking scheme could be:
- Lock queue when popping a value as root, then unlock.
- Leave queue and allocator unlocked while getting root/left/right
values (readonly) and computing (but not setting/allocating) the
left and right node values
- Allocator Lock when allocating the left/right values, setting the
root's left and right, then unlock.
- Queue lock when pushing the left and right fractions for further
processing, then unlock
- Unlock all when returning relevant values
** TODO Prettify code base ** TODO Prettify code base
It's a big blob of code currently in the graphics portion. Not very It's a big blob of code currently in the graphics portion. Not very
pretty but it gets the job done. Try modularisation. pretty but it gets the job done. Try modularisation.

4
src/main.cpp
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@@ -33,7 +33,7 @@
#define LINE_TOP (7 * HEIGHT / 16) #define LINE_TOP (7 * HEIGHT / 16)
#define LINE_BOTTOM (9 * HEIGHT / 16) #define LINE_BOTTOM (9 * HEIGHT / 16)
std::pair<std::string, int> get_fraction_drawable(Fraction f) std::pair<std::string, int> fraction_to_string(Fraction f)
{ {
std::string s{to_string(f)}; std::string s{to_string(f)};
int width = MeasureText(s.c_str(), FONT_SIZE); int width = MeasureText(s.c_str(), FONT_SIZE);
@@ -44,7 +44,7 @@ void draw_fraction(Fraction f, word_t x, word_t y)
{ {
std::string s; std::string s;
int width; int width;
std::tie(s, width) = get_fraction_drawable(f); std::tie(s, width) = fraction_to_string(f);
// Centered at (x, y) // Centered at (x, y)
DrawText(s.c_str(), x - width / 2, y - FONT_SIZE, FONT_SIZE, WHITE); DrawText(s.c_str(), x - width / 2, y - FONT_SIZE, FONT_SIZE, WHITE);
} }