[#79] Update documentation of asset loader.

modules/asset_loader/include/vkcv/asset/asset_loader.hpp

@@ -84,20 +84,23 @@ struct Sampler {
 };
 
 /**
- * This struct describes a loaded texture.
- * Note that textures are currently always loaded with 4 channels as RGBA, even
- * if the image has just RGB or is grayscale.
+ * This struct describes a (partially) loaded texture.
+ * The data member is not populated after calling probeScene() but only when
+ * calling loadMesh(), loadScene() or loadTexture(). Note that textures are
+ * currently always loaded with 4 channels as RGBA, even if the image has just
+ * RGB or is grayscale. In the case where the glTF-file does not provide a URI
+ * but references a buffer view for the raw data, the path member will be empty
+ * even though the rest is initialized properly.
  */
 struct Texture {
-	std::filesystem::path path; // file path of the encoded texture data
-	int sampler;				// index into the sampler array of the Scene
+	std::filesystem::path path;	// URI to the encoded texture data
+	int sampler;			// index into the sampler array of the Scene
 	
 	union { int width; int w; };
 	union { int height; int h; };
 	int channels;
 	
-	// binary data of the decoded texture
-	std::vector<char*> data;
+	std::vector<char*> data;	// binary data of the decoded texture
 };
 
 /**

modules/asset_loader/src/vkcv/asset/asset_loader.cpp

@@ -453,7 +453,10 @@ namespace vkcv::asset {
 	}
 
 	/**
-	 * TODO document
+	 * Returns an integer with specific bits set corresponding to the
+	 * textures that appear in the given material. This mask is used in the
+	 * vkcv::asset::Material struct and can be tested via the hasTexture
+	 * method.
 	 */
 	static uint16_t generateTextureMask(fx::gltf::Material &material) {
 		uint16_t textureMask = 0;
@@ -621,6 +624,12 @@ namespace vkcv::asset {
 		return ASSET_SUCCESS;
 	}
 	
+	/**
+	 * Loads and decodes the textures data based on the textures file path.
+	 * The path member is the only one that has to be initialized before
+	 * calling this function, the others (width, height, channels, data)
+	 * are set by this function and the sampler is of no concern here.
+	 */
 	static int loadTextureData(Texture& texture) {
 		if ((texture.width > 0) && (texture.height > 0) && (texture.channels > 0) &&
 			(!texture.data.empty())) {