added mipmaps for the hw renderer, improvementsHEADmain

This commit add mipmaps, but for now, mipmaps are generated on the gpu
at runtime. We should generate them in advance.

- added mipmaps for the hardware renderer
- renamed stb_image.c to stb_image.cpp
- add compiler flag to stb_image.cpp to prevent warning
- added pipe notation for various objects to have all clipping functions
  be left to right. We need this for the time being because dot notation
  would considerably complicate the current implementation
- small improvements

1 files changed, 23 insertions, 0 deletions

diff --git a/src/math/utils.hpp b/src/math/utils.hpp
index 5c8c62d..ac19ddc 100644
--- a/src/math/utils.hpp
+++ b/src/math/utils.hpp
@@ -3,6 +3,7 @@
 
 #include <array>
 #include <utility>
+#include <concepts>
 #include "math/vector.hpp"
 
 namespace engine::math {
@@ -35,6 +36,28 @@ constexpr float map(float x, float from1, float from2, float to1, float to2) {
     return to1 + (x - from1) * (to2 - to1) / (from2 - from1);
 }
 
+template<typename UInt>
+constexpr UInt log2_floored(UInt n) noexcept
+requires std::same_as<UInt, unsigned> || std::same_as<UInt, unsigned long> || std::same_as<UInt, unsigned long long>
+{
+#ifdef __GNUG__
+    if constexpr (std::is_same_v<UInt, unsigned>) {
+        return static_cast<UInt>(sizeof(UInt) * 8 - 1) - __builtin_clz(n);
+    } else if constexpr (std::is_same_v<UInt, unsigned long>) {
+        return static_cast<UInt>(sizeof(UInt) * 8 - 1) - __builtin_clzl(n);
+    } else { // unsigned long long
+        return static_cast<UInt>(sizeof(UInt) * 8 - 1) - __builtin_clzll(n);
+    }
+#else
+    UInt ret = 0;
+    while (n & 1) {
+        n >>= 1;
+        ret++;
+    }
+    return ret;
+#endif
+}
+
 }
 
 #endif // MATH_UTILS_HPP