From 8a8fab0c68d867d1e1e870252819d15e2b6d0c6f Mon Sep 17 00:00:00 2001
From: Clyne Sullivan <clyne@bitgloo.com>
Date: Tue, 14 May 2024 16:32:10 -0400
Subject: initial commit

---
 renderer.h | 76 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 76 insertions(+)
 create mode 100644 renderer.h

(limited to 'renderer.h')

diff --git a/renderer.h b/renderer.h
new file mode 100644
index 0000000..ec7b170
--- /dev/null
+++ b/renderer.h
@@ -0,0 +1,76 @@
+#include <algorithm>
+#include <atomic>
+#include <memory>
+#include <ranges>
+#include <semaphore>
+#include <thread>
+
+template<int Threads>
+class Renderer
+{
+    std::counting_semaphore<Threads> Workers;
+    std::atomic_uint processed;
+    unsigned total;
+    std::atomic_bool Stop;
+    std::unique_ptr<std::thread> primary;
+
+public:
+    Renderer(auto func, unsigned Width, unsigned Height, auto pbuf):
+        Workers(Threads), processed(0), total(Threads * 8)
+    {
+        Stop.store(false);
+
+        auto threads = std::views::transform(
+            std::views::chunk(
+                std::views::cartesian_product(
+                    std::views::iota(0u, Width),
+                    std::views::iota(0u, Height),
+                    std::views::single(pbuf)),
+                Width * Height / total),
+            [=, this](auto chunk) { return std::thread([=, this] { worker(func, chunk); }); });
+
+        primary.reset(new std::thread([=, this] {
+            for (auto th : threads) {
+                Workers.acquire();
+                th.detach();
+            }
+            for (auto i : std::views::iota(0, Threads))
+                Workers.acquire();
+            for (auto i : std::views::iota(0, Threads))
+                Workers.release();
+            Stop.store(true);
+        }));
+    }
+
+    ~Renderer() {
+        stop();
+    }
+
+    operator bool() const {
+        return !Stop.load();
+    }
+
+    unsigned progress() const {
+        return processed.load() * 100 / total;
+    }
+
+    void stop() {
+        Stop.store(true);
+        if (primary->joinable())
+            primary->join();
+    }
+
+private:
+    void worker(auto func, auto chunk) {
+        for (auto xyb : chunk) {
+            if (Stop.load())
+                break;
+            std::apply(func, xyb);
+        }
+
+        processed++;
+        Workers.release();
+    }
+};
+
+
-- 
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