add input validation for utilLoadImage()

src/mesh.cpp

@@ -1,5 +1,4 @@
 #include <cassert>
-#include <string>
 
 #include <assimp/cimport.h>
 #include <assimp/scene.h>
@@ -158,12 +157,10 @@ copyMeshInfo(const char* data_dir, const aiScene* scene, aiMesh* mesh)
 	if (has_tex && mat->GetTextureCount(aiTextureType_DIFFUSE) > 0) {
 		aiString file_name;
 		if (AI_SUCCESS != mat->GetTexture(aiTextureType_DIFFUSE, 0, &file_name, NULL, NULL, NULL, NULL, NULL)) {
-			LOG(ERROR) << "Some Assimp-type-error\n";
+			LOG(ERROR) << "No diffuse texture from assimp\n";
 		} else {
-			std::string file_path;
-			file_path.append(data_dir).append("/").append(file_name.C_Str());
 			LOG(INFO) << "Loading texture file: " << file_name.C_Str() << "\n";
-			mi->diffuse_texture = utilLoadImage(file_path.c_str());
+			mi->diffuse_texture = utilLoadImage(data_dir, file_name.C_Str());
 			mi->use_texture = true;
 		}
 	}

src/util.cpp

@@ -13,6 +13,18 @@
 const uint MAX_FILESIZE = 2 * 1024 * 1024; // 2MB
 const uint MAX_STRING_LENGTH = 1024;
 
+
+const char*
+utilBaseName(const char* path_str)
+{
+	assert(std::strlen(path_str) < MAX_STRING_LENGTH);
+	const char* output = std::strrchr(path_str, '/');
+	if (output)
+		return output;
+	else
+		return path_str;
+}
+
 // TODO: don't use ftell() to get filesize
 // 	https://wiki.sei.cmu.edu/confluence/display/c/FIO19-C.+Do+not+use+fseek%28%29+and+ftell%28%29+to+compute+the+size+of+a+regular+file
 char *
@@ -64,15 +76,21 @@ void utilSafeFree(const void* mem)
 }
 
 util_image
-utilLoadImage(const char* filename)
+utilLoadImage(const char* base_dir, const char* filename)
 {
-	LOG(INFO) << "Loading Image: " << filename << "\n";
+	const uint max_path = 256; // NOTE: util_image.file_path is char[256]
-	assert(std::strlen(filename) < 256);
+	const char* base_name = utilBaseName(filename);
+	uint l = std::strlen(base_dir) + std::strlen(base_name) + 1; // NOTE: +1 for '/' char
+	assert(l < max_path);
+	char full_path[l];
+	std::memcpy(full_path, base_dir, std::strlen(base_dir) + 1);
+	std::strcat(std::strcat(full_path, "/"), base_name);
+	LOG(INFO) << "Loading Image: " << full_path << "\n";
 
 	util_image image;
-	std::memcpy(image.file_path, filename, std::strlen(filename) + 1);
+	std::memcpy(image.file_path, full_path, std::strlen(full_path) + 1);
 	stbi_set_flip_vertically_on_load(1);
-	image.pixels = stbi_load(filename, &image.w, &image.h, &image.num_channels, 0);
+	image.pixels = stbi_load(full_path, &image.w, &image.h, &image.num_channels, 0);
 	image.data_len = image.w * image.h * image.num_channels; // NOTE: assumes 8 bits per channel
 
 	if (image.pixels == 0) {

src/util.h

@@ -86,13 +86,15 @@ utilConvertColor(GLfloat buf[3], uint32 color)
 	buf[2] = (GLfloat) ((color >> 8) & 0xFF) / (GLfloat) 255;
 }
 
+const char* utilBaseName(const char* path_str);
+
 // NOTE: Wrapper for calloc that will send error message on out of memory
 #define UTIL_ALLOC(len, type) (type *) utilLogAlloc((len), sizeof(type), __FILE__, __LINE__)
 void* utilLogAlloc(uint item_count, uint type_size, const char* file_name, const int line);
 
 char* utilDumpTextFile(const char* filename);
 
-util_image utilLoadImage(const char* filename);
+util_image utilLoadImage(const char* base_dir, const char* filename);
 
 void utilFreeImage(util_image image);