Added ImageLoad_stb

include/gul/ImageLoad_stb.h

@@ -0,0 +1,65 @@
+#ifndef GUL_STB_IMAGE_LOAD_H
+#define GUL_STB_IMAGE_LOAD_H
+
+#include <stb_image.h>
+#include <gul/Image.h>
+#include <cstring>
+
+// C++17 includes the <filesystem> library, but
+// unfortunately gcc7 does not have a finalized version of it
+// it is in the <experimental/filesystem lib
+// this section includes the proper header
+// depending on whether the header exists and
+// includes that. It also sets the
+// nfcbn::nf namespace
+#if __has_include(<filesystem>)
+
+    #include <filesystem>
+    namespace gul
+    {
+        namespace fs = std::filesystem;
+    }
+
+#elif __has_include(<experimental/filesystem>)
+
+    #include <experimental/filesystem>
+    namespace gul
+    {
+        namespace fs = std::experimental::filesystem;
+    }
+
+#else
+    #error There is no <filesystem> or <experimental/filesystem>
+#endif
+
+namespace gul
+{
+inline gul::Image loadImage(fs::path const & p, int desiredChannels=4)
+{
+    int x,y,n;
+    unsigned char *data = stbi_load(p.c_str(), &x, &y, &n, desiredChannels);
+
+    gul::Image I( static_cast<uint32_t>(x), static_cast<uint32_t>(y), static_cast<uint32_t>(desiredChannels) );
+    std::memcpy(I.data(), data, I.byteSize());
+
+    stbi_image_free(data);
+    return I;
+}
+
+inline gul::Image loadImage(void const* data, int len, int desiredChannels=4)
+{
+    int x,y,channels;
+
+    auto imgData = stbi_load_from_memory( static_cast<stbi_uc const*>(data), len, &x, &y, &channels, desiredChannels);
+
+    gul::Image I( static_cast<uint32_t>(x), static_cast<uint32_t>(y), static_cast<uint32_t>(desiredChannels) );
+    std::memcpy(I.data(), imgData, I.byteSize());
+
+    stbi_image_free(imgData);
+    return I;
+}
+
+}
+
+
+#endif