implement custom texture preload

src/common/texture.cpp

@@ -0,0 +1,22 @@
+#include <vector>
+#include "common/assert.h"
+#include "common/common_types.h"
+
+namespace Common {
+void FlipRGBA8Texture(std::vector<u8>& tex, u64 width, u64 height) {
+    ASSERT(tex.size() == width * height * 4);
+    const u64 line_size = width * 4;
+    u8* temp_row = new u8[line_size];
+    u32 offset_1;
+    u32 offset_2;
+    for (u64 line = 0; line < height / 2; line++) {
+        offset_1 = line * line_size;
+        offset_2 = (height - line - 1) * line_size;
+        // Swap lines
+        std::memcpy(temp_row, &tex[offset_1], line_size);
+        std::memcpy(&tex[offset_1], &tex[offset_2], line_size);
+        std::memcpy(&tex[offset_2], temp_row, line_size);
+    }
+    delete[] temp_row;
+}
+} // namespace Common