better lighting

src/core/pxl8_queue.h

@@ -0,0 +1,53 @@
+#pragma once
+
+#include <stdatomic.h>
+
+#include "pxl8_types.h"
+
+#define PXL8_QUEUE_CAPACITY 256
+
+typedef struct pxl8_queue {
+    void* items[PXL8_QUEUE_CAPACITY];
+    atomic_uint write_idx;
+    atomic_uint read_idx;
+} pxl8_queue;
+
+static inline void pxl8_queue_init(pxl8_queue* q) {
+    atomic_store(&q->write_idx, 0);
+    atomic_store(&q->read_idx, 0);
+    for (u32 i = 0; i < PXL8_QUEUE_CAPACITY; i++) {
+        q->items[i] = NULL;
+    }
+}
+
+static inline bool pxl8_queue_push(pxl8_queue* q, void* item) {
+    u32 w = atomic_load_explicit(&q->write_idx, memory_order_relaxed);
+    u32 next = (w + 1) % PXL8_QUEUE_CAPACITY;
+    if (next == atomic_load_explicit(&q->read_idx, memory_order_acquire)) {
+        return false;
+    }
+    q->items[w] = item;
+    atomic_store_explicit(&q->write_idx, next, memory_order_release);
+    return true;
+}
+
+static inline void* pxl8_queue_pop(pxl8_queue* q) {
+    u32 r = atomic_load_explicit(&q->read_idx, memory_order_relaxed);
+    if (r == atomic_load_explicit(&q->write_idx, memory_order_acquire)) {
+        return NULL;
+    }
+    void* item = q->items[r];
+    atomic_store_explicit(&q->read_idx, (r + 1) % PXL8_QUEUE_CAPACITY, memory_order_release);
+    return item;
+}
+
+static inline bool pxl8_queue_empty(const pxl8_queue* q) {
+    return atomic_load_explicit(&((pxl8_queue*)q)->read_idx, memory_order_acquire) ==
+           atomic_load_explicit(&((pxl8_queue*)q)->write_idx, memory_order_acquire);
+}
+
+static inline u32 pxl8_queue_count(const pxl8_queue* q) {
+    u32 w = atomic_load_explicit(&((pxl8_queue*)q)->write_idx, memory_order_acquire);
+    u32 r = atomic_load_explicit(&((pxl8_queue*)q)->read_idx, memory_order_acquire);
+    return (w >= r) ? (w - r) : (PXL8_QUEUE_CAPACITY - r + w);
+}