Initial Commit

source/utils.cpp

@@ -0,0 +1,92 @@
+#include <amethyst/utils.hpp>
+#include <fstream>
+
+namespace amy {
+namespace utils {
+ui fastHash(cstr& s) {
+  ui hash = 5381;
+  for (auto& it : s) {
+    hash = (hash * 33) + static_cast<uc>(it);
+  }
+  return hash;
+}
+
+vec<uc> loadFile2Mem(cstr& path) {
+  std::ifstream iff(path, std::ios::binary);
+  if (!iff) {
+    return vec<uc>();
+  }
+  iff.seekg(0, std::ios::end);
+  size_t szs = iff.tellg();
+  iff.seekg(0, std::ios::beg);
+  vec<uc> res(szs, 0);
+  iff.read(reinterpret_cast<char*>(res.data()), res.size());
+  iff.close();
+  return res;
+}
+
+ui hashMemory(cvec<uc>& data) {
+  ui hash = 4477;
+  for (auto& it : data) {
+    hash = (hash * 33) + it;
+  }
+  return hash;
+}
+
+ui nextPow2(ui v) {
+  v--;
+  v |= v >> 1;
+  v |= v >> 2;
+  v |= v >> 4;
+  v |= v >> 8;
+  v |= v >> 16;
+  v++;
+  return (v >= 64 ? v : 64);
+}
+
+bool isSingleBitNum(ui v) { return v && !(v & (v - 1)); }
+
+namespace image {
+void reverseBuf(vec<uc>& buf, int w, int h, int c) {
+  vec<uc> cpy = buf;
+  for (int x = 0; x < w; x++) {
+    for (int y = 0; y < h; y++) {
+      int pos = (y * w + x) * c;
+      for (size_t i = 0; i < c; i++) {
+        buf[pos + c - 1 - i] = cpy[pos + i];
+      }
+    }
+  }
+}
+
+void removeAlphaChannel(vec<uc>& buf, int w, int h) {
+  vec<uc> cpy = buf;
+  buf.resize(w * h * 3);
+  for (int y = 0; y < h; y++) {
+    for (int x = 0; x < w; x++) {
+      int src = (y * w + x) * 4;
+      int dst = (y * w + x) * 3;
+      buf[dst + 0] = cpy[src + 0];
+      buf[dst + 1] = cpy[src + 1];
+      buf[dst + 2] = cpy[src + 2];
+    }
+  }
+}
+
+void addAlphaChannel(vec<uc>& buf, int w, int h) {
+  vec<uc> cpy = buf;
+  buf.resize(w * h * 4);
+  for (int y = 0; y < h; y++) {
+    for (int x = 0; x < w; x++) {
+      int src = (y * w + x) * 3;
+      int dst = (y * w + x) * 4;
+      buf[dst + 0] = cpy[src + 0];
+      buf[dst + 1] = cpy[src + 1];
+      buf[dst + 2] = cpy[src + 2];
+      buf[dst + 3] = 255;
+    }
+  }
+}
+}  // namespace image
+}  // namespace utils
+}  // namespace amy