feat(gx): add TextureCalcMipCount

src/gx/Texture.cpp

@@ -856,6 +856,26 @@ void TextureCacheNewTexture(CTexture* texture, const CImVector& color) {
     // TODO
 }
 
+uint32_t TextureCalcMipCount(uint32_t width, uint32_t height) {
+    uint32_t count = 1;
+
+    while (width > 1 || height > 1) {
+        width /= 2;
+        if (width == 0) {
+            width = 1;
+        }
+
+        height /= 2;
+        if (height == 0) {
+            height = 1;
+        }
+
+        count++;
+    }
+
+    return count;
+}
+
 HTEXTURE TextureCreate(const char* fileName, CGxTexFlags texFlags, CStatus* status, int32_t createFlags) {
     STORM_ASSERT(fileName);
     STORM_ASSERT(*fileName);

src/gx/Texture.hpp

@@ -55,6 +55,8 @@ void TextureCacheNewTexture(CTexture*, CGxTexFlags);
 
 void TextureCacheNewTexture(CTexture*, const CImVector&);
 
+uint32_t TextureCalcMipCount(uint32_t width, uint32_t height);
+
 HTEXTURE TextureCreate(const char*, CGxTexFlags, CStatus*, int32_t);
 
 HTEXTURE TextureCreate(uint32_t, uint32_t, EGxTexFormat, EGxTexFormat, CGxTexFlags, void*, void (*)(EGxTexCommand, uint32_t, uint32_t, uint32_t, uint32_t, void*, uint32_t&, const void*&), const char*, int32_t);